The Italian Society for Clinical Neurophysiology

Clinical Neurophysiology 112 (2001) 2333–2355 www.elsevier.com/locate/clinph Society Proceedings The Italian Society for Clinical Neurophysiology Secretary: Professor L. Santoro 1 Influence of motor and cognitive functions on postural stability in Parkinson’s disease – G. Abbruzzese, R. Marchese, C. Giusti, B. Aiachini, M. Bove (Department of Neurological and Visual Sciences, University of Genova, Genova, Italy) Postural instability represents an invalidating, little responsive to the treatment and of dubious physiopathology symptom of the advanced stage of Parkinson’s disease (PD). Static posturography is considered the appropriate instrument to analyze all the factors influencing postural stability. Using a conventional static platform (QFP – Systemes) we carried out a quantitative analysis on postural oscillations in 24 patients with PD (age: 52–81, Hoehn-Yahr stage: 2–3) and in 12 check-ups of the same age. We measured area and length of projections’ route (‘ball’) on the ground of the centre of gravity, both with open eyes (OE) and with closed eyes (CE) during the keeping of erect position in the following conditions: rest, arithmetic calculus, sequential movement of thumb’s opposition to the other fingers of the dominant hand. In resting conditions the deprivation of visual input (CE to OE) produced a significant increase of oscillatory activity in both groups. Repeated variance analysis showed a significant increase of instability in Parkinson’s disease patients during the execution of motor and cognitive functions, which was more evident in patients having clinical signs of instability (score $1 at item 30 of UPDRS/III). These modifications did not occur in check-up subjects. Results suggest that in PD patients contemporary execution of a function compromises not only motor control, but also postural stability. Quantitative analysis of oscillations during an additional function is better related to clinical evaluation of postural instability and can give useful indications on the prediction of falling risk. M-NET: neural network for surface electromyographic screening – N. Accornero a, E. Galiè a, G. Romaniello a, G.C. Filligoi b ( aDepartment of Neurological Sciences; bDepartment INFOCOM – University of Rome “La Sapienza”, Italy) Electrode needle traditional electromyographic examination (EMG), though widely used, shows some problems due to invasive methodology and considerable dependence on examiner’s experience, that often makes comparison with diagnostic results difficult. Surface electromyography (SEMG), though not invasive, is not used because of the still greater complexity of the signal, showing chaotic-deterministic aspects. According to these considerations we planned a connection system in order to carry out a screening between normality and pathology using simultaneously surface electrical and vibratory signal (AMG) of the examined muscle. Neural network receives both signals sampled at 1 Hz for 20 s and compressed in spectrographic form, and works out a numeric index of normality and pathology. Network has been trained previously with 150 (normal and pathologic) pattern-cases, the test carried out on 20 new cases produced promising results, reaching the 85% of correct classification. After a further training on larger scale we expect that the system can reach a more reliable and detailed diagnosis of pathology. 3 Neurophysiologic study on the effect of genic therapy on motor system in experimental metachromatic leucodystrophia – S. Amadio a, A. Trojani b, G. Galardi a, A. Quattrini a, D. Dolcetta b, C. Bordignon b, G. Comi a ( aDepartment of Neurosciences; b TIGET-IRCCS San Raffaele, Milan, Italy) Aim: To evaluate, through neurophysiologic tests, the effect on motor system of the transfer of the gene coding for Arilsulfatasi A (ASA) enzyme in staminal hematopoietic cells of mouse affected by experimental metachromatic leucodystrophia (MLD). Methods: We have studied two groups of mice, the former knocked out by ASA (ASA2/2) gene, the latter where, after a previous lethal irradiation, we transplanted ASA2/2 staminal medullar cells transduced with a retroviral vector containing ASA’s cDNA. In both groups a study has been carried out on both motor evoked potentials (MEP) produced by electric transcranial bipolar stimulation of motor cortex, and of motor conduction rate (MCR) of ischial nerve. Results: Average latency of cortical MEPs proved significantly smaller in the group of transplanted mice than in the ASA2/2 ones. (4.9 vs. 6.5 ms; P , 0:05). Average MCR of ischial nerve in the group of transplanted mice proved smaller than in ASA2/2 group, but the difference wasn’t statistically significant. Conclusions: Neurophysiologic methodologies, together with the histoand biochemical ones, show that transplantation of staminal medullar cells transduced by ASA gene exerts a protective effect on the function of motor system in mouse affected by MLD. As we didn’t detect any significant difference of MCR in ischial nerve compared to ASA2/2 group, neurophysiologic data suggest that such an effect is developed mainly on corticospinal tracts. 2 4 Creutzfeld-Jacob disease: serial clinical and EEG study of a case – A. Ammendola a, B. Lettieri b, M.R. Tata b ( aDepartment of Neurophysiopatology and Intensive Care; b2nd University of Naples, Italy) Objective: To point out particular clinical and EEG findings of Creutzfeld-Jacob disease (CJD) with short duration of illness. Methods: A woman affected by CJD, 50 years old, underwent clinical, EEG and polygraphic follow up from the prodromal stage up to exitus. The first recording was performed during the prodromal stage, when the diagnosis was not still considered. The diagnosis was autoptically verified. Results: The prominent clinical aspects were the early age of the patient at onset of CJD (50 years), the very short disease duration (only 2 months), the prodromal stage characterized by ataxia and cerebellar troubles and the full stage mainly dominated by localized or diffuse myoclonus. The most consistent EEG findings were generalized, bilateral, short interval, periodic sharp wave complexes (PSWC) on both hemispheres, more evident in the anterior regions. No constant correlation was found between EEG activity and EMG-detected myoclonus. PSWC appeared during the prodromal stage and were present during all the course of the disease. Conclusion: Emphasis is placed on: (1) the very short course of disease; (2) the early presence of PSWC during prodromal stage; (3) the presence of PSWC, even if with different morphological expression, during the different stages of the disease up to exitus. 1388-2457/01/$ - see front matter q 2001 Elsevier Science Ireland Ltd. All rights reserved. PII: S 1388-245 7(01)00635-6 CLINPH 2001648 2334 The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 5 Changes in motor cortex excitability in patients with cerebellar lesions – S. Bagnato, A. Quartarone, V. Rizzo, F. Battaglia, L. Morgante, C. Messina, P. Girlanda (Department of Neuroscience, Psychiatric and Anaesthesiological Science University of Messina, Italy) Objective: In experimental animals it has been reported that either lesions or stimulation of the cerebellum can produce excitability changes of the motor cortex. Transcranical magnetic stimulation (TMS) was used to study intracortical inhibitory and excitatory phenomena in patients with cerebella stroke. Methods: Nine patients with cerebellar unilateral lesions, due to stroke in the territory of posterior-inferior cerebellar artery, and 10 age matched healthy subjects were enrolled. Resting (RMT) and active (AMT) motor threshold paired pulse inhibition (ICI) and facilitation (ICF) at short intervals, cortical and peripheral silent period and evaluation of motor imagery evaluation using TMS were tested bilaterally. Results: The RMT was found to be increased contralateral to the affected cerebellar hemisphere while the cortical silent period was prolonged according to the data reported in literature. Moreover the amount of ICI was reduced bilaterally. The ICF was within normal ranges. The amount of MEP facilitation after motor imagery was reduced in the cortex contralateral to the affected cerebellar hemisphere. Conclusion: These data confirm that cerebellar lesions may determine alterations in motor cortex excitability The bilateral alteration of ICI could be due to compensatory mechanisms. 6 Normative neurophysiologic study for a mapping of sensory nerves in lower limb – R. Bassi, E. De Vincenzi, R. Del Colle, R. Niego, P. Secchi (Service of Neurophysiology Legnago ASL 21 of Veneto, Italy) To evaluate dysto-proximal compromising level in neuropathies concerning sensitive somatic system, a useful thing to do is to consider reference data including the combined values of sensory nerves of the lower limb’s 3 sections (foot, leg, thigh). The collection of these data can also determine the reliability level of the tests. Aiming to collect normative data, we carried out a neurophysiologic study on medial plantar, sural and medial femoral cutaneous sensory nerves in the same subject on the same side; for a further comparison we also analyzed the nerval potential of medial plantar. We examined a cohort of subjects to be considered normal, spontaneously arrived or invited at the electromyography laboratory of a hospital: the test was carried out by the same operator. Twenty-five subjects, aged 24–75 (mean age 51 years) were recruited. They underwent a monolateral analysis (left lower limb) recording latency (at the beginning of Sap), amplitude (peak-to-peak) and sensory conduction rate in conditions of moderate temperature. We always used subcutaneous monopolar electrodes recording and surface stimulation by orthodromic technique for medial plantar (by means of hallux’ stimulation) and antidromic technique for the sural and medial femoro-cutaneous; stimulation ranges were respectively 19–13–14 cm. Medial plantar nerve’s Nap was obtained by orthodromic technique with a 10 cm range. Latency values of sensory nerves proved respectively of 5.2(^0.55), 2.78(^0.26) and 2.47(^0.29) ms. Micronvolt amplitudes were 2.25(^0.77), 25.91(^12.50) and 7.01(^2.15) ms. VCS in M/s were 37.06(^3.01), 45.53(^2.29) and 53.86(^3.46) ms. Medial Plantar Nap values showed latency at 2.48(^0.41) ms, amplitude 13.44(^7.41) mV and VCS at 40.86 ^ 2.97 M/s. PM and FCM amplitude ratios compared to sural resulted about 1/10 and 1/3; the VCS’s, respectively, 0.8 and 1.2. Age increase was always related to the extremes of values in all the 3 nerves. Data were always distributed homogeneously. In each subject all the SAPs were easily valuable (with PM averaging); the study did not show particular problems as it needed about 20–30 min. Conclusions: though on limited scale, these compared normative data can be useful for the evaluation of sensitive side’s peripheral pathology, especially in length-addicted neuropathies. 7 Evidence for a role of a -Synuclein during long-term synaptic plasticity – F. Battaglia a,c, I. Antonova b, P. Girlanda c, G. Vita c, A. Toscano c, A. Quartarone c, R.D. Hawkins b, O. Arancio a ( aAnatomy and Cell Biology Department SUNY; Brooklyn, NY, USA; bCtr. Neurobiology and Behaviour, Columbia University, NY, USA; cDepartment of Neuroscience, Psychiatric and Anaesthesiological Science, University of Messina, Italy) Objective: a -Synuclein, is involved in neuroitransmitter release and plasticity in the central nervous system. However, the mechanism of this involvement are poorly understood. We have begun to address this question in cultured hippocampal neurons where glutamate produces long-lasting increase of mEPSC frequency, EPSC amplitude and the number of synaptophysinimmunoreactive puncta. Methods: For immunocytochemistry a -Synuclein and Synpapsin-I immunoreactivities were measured 5 min after 200 mM glutamate application. For electrophysiological experiments glutamate-induced increase of spontaneous miniature synaptic currents (mEPSCs) frequency was measured after 4 days treatment with antisense- (AS), sense- (S) and scrambled -(Sc) oligonucleotides. Results: In control conditions, a -Synuclein immunoreactive appeared in puncta along the process and also throughout the cell body. Double staining for a -Synuclein and the presynaptic vesicle associated protein, Synapsin I, showed that approximately 51% of the a -Synuclein immunoreactive puncta colocalized with Synapse 1-immunoreactive puncta. After 1 min glutamate application, the number of a -Synuclein immunoreactive puncta increased significantly (41.8% ^ 9.1, mean ^ SEM, P , 0:01), as well as the number of Synapsin 1-immunoreactive puncta (46.2 ^ 17.1%, P , 0:05),and the number of the sites where a -Synuclein and Synapsin 1- immunoreactive puncta were colocalized (60.8 ^ 23.4, P , 0:05).Down regulation of the expression of a -Synuclein by AS oligonucleotide produces a block of glutamate induce long-lasting increase in mEPSC frequency. Conclusion: Taken together these results indicate a role of a -Synuclein during procedures that can cause a long-lasting enhancement of synaptic transmission. 8 Primary torsion dystonia does not link to known genes (including DYT13) in 3 Italian families – A.R. Bentivoglio a, E.M. Valente b,c, T. Ialongo a, A. Ferraris b, A. Albanese a,d. ( aIstituto di Neurologia, Università Cattolica, Roma; bIstituto CSS Mendel, Roma; cInstitute of Neurology, London; dIstituto Neurologico C. Besta, Milano, Italy) Primary torsion dystonia (PTD) is a clinically and genetically heterogeneous group of movement disorders, including sporadic and familial cases. Familial PTD is inherited in an autosomal dominant fashion. The DYT1 gene on chromosome 9q34 is responsible for most cases of early limb-onset PTD. Three other PTD loci have been mapped to date. DYT6 on chromosome 8 is associated with a mixed phenotype, while DYT7 on chromosome 18p is associated with adult onset cervical dystonia. Recently we identified a new locus on chromosome 1p36 in a large Italian PTD family from Central Italy. Phenotype was characterized by early onset and prominent cranial-cervical and upper limb involvement. Among familial cases of PTD in the database of the Gemelli Hospital we selected 3 Italian families suitable for the genetic screening. Family 2: The proband is a 69-year-old woman affected by generalized PTD, started with cervical dystonia when she was 64; during the following 3 years, dystonia rapidly progressed to involve the face, larynx, trunk, upper and lower limbs. Her twin sister was affected by cranial (oromandibular) dystonia since the age of 65. Adult onset focal dystonia (blepharospasm and writer’s cramp were observed in other relatives). Family 14: The proband is a 63-year-old man affected by blepharospasm since he was 55. This is a very large and branched family (200 living members) which presents a remarkably homogeneity of clinical features: 18 members are reportedly affected by adult-onset blepharospasm; no progression of dystonia to other body districts was reported. Seventy- The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 three subjects have been examined so far: 5 received a diagnosis of definite PTD; in two cases the diagnosis was of probable ITD. All were affected by blepharospasm one subject, who was affected by writer’s cramp. Family 15: Family 15 included 15 subjects. The phenotypic presentation of the affected subjects was adult onset, cervical and upper limb dystonia. In these families there was no linkage to either of the above mentioned loci. These evidences illustrate the phenotypic variability of PTD and indicate the existence of still unmapped genes. 9 Occurrence of gastro-esophageal reflux in patients with obstructive sleep apnea – E. Bonanni a, S. Fanucchi a, M. Maestri a, M. Fabbrini a, G. Guastamacchia c, L. Murri a, M. Anselmino b, M.G. Bellomini b, M. Rossi b ( aDipartimento di Neuroscienze - Clinica Neurologica, Università di Pisa; bU.O Chirurgia Generale IV, Ospedale S. Chiara, Pisa; cDipartimento di Neuroscienze, Università di Torino, Italy) Objective: Purpose of this study was to evaluate gastro-esophageal reflux (GER) features in OSAS patients and in control subjects respectively. Methods: Twelve patients with GER symptoms were included in the study. A simultaneous standard polysomnographic study and a 24 h esophageal PH-metry were performed in each patient. OSAS was observed in 7 cases (3 F, 4 M; mean RDI 61.9); the 5 other patients (5 M; mean RDI 2.7) were considered as controls. The PH-metric parameters evaluated included: mean number of total and nocturnal GER, mean nocturnal GER duration, acid exposure time (AET), De Meester Index (DMI: normal value ,14.72). Results: In OSAS group we observed a mean number of total GER ¼ 51,4 (47.1% nocturnal), a mean nocturnal AET ¼ 3.9%, a mean DMI ¼ 16.4. In control group we observed a mean number of total GER ¼ 62.6 (7.6% nocturnal), a mean nocturnal AET ¼ 1%, a mean DMI ¼ 1.6. Nocturnal GER occurred meanly during arousals or 1–2 NREM sleep, whereas no GER was observed during REM sleep. Conclusions: OSAS patients showed a greater number of nocturnal GER and a worse clinical degree when compared to control subjects. 10 Residual autonomic functions in neurodegenerative diseases – L.G. Bongiovanni, C. Bonato, S. Fusina, G. Gulli, G. Rossato, A. Cevese (Dipartimento di Scienze Neurologiche e della Visione, Verona, Italy) The residual autonomic function was evaluated in 11 patients, 6 with Multiple System Atrophy (MSA) and 5 with pure autonomic failure (PAF), at the appearance of the recurrent syncope. We used spectral analysis of heart rate and arterial pressure time series in resting supine position and after tilting. No qualitative difference was found in the autonomic dysfunction between the two groups. Spectral analysis confirmed a widespread impairment of the autonomic control of the cardiovascular system, showing scanty residual spontaneous oscillatory activity, with very low coherence between heart rate and pressure oscillations. In all cases, sympathetic impairment was concurrent with parasympathetic dysfunction. A progressive sympathetic skin response (SSR) amplitude reduction up to complete suppression was evident at the feet. On the contrary, SSR was always preserved at the hands. The veno–arteriolar reflex, induced by passive limb dependency, showed a progressive attenuation. This seems to indicate that an impairment of post-ganglionic sympathetic fibres could be present not only in the PAF but also in the MSA as effect of trans-synaptic lengthdependent mechanisms. However, differentiation among patients was not possible, because typical trends were not detected in such severe conditions. 11 Vibratory modulation of somatosensory evoked potentials in focal dystonia – A. Buccolieri, R. Marchese, C. Trompetto, L. Marinelli, G. Abbruzzese (Department of Neurological Sciences Vision, University of Genoa, Italy) Sensori-motor integration may be abnormal in focal dystonia. It has been shown that distortion of afferent inputs may be relevant to the pathophysiology of dystonia and that the vibratory stimulation may induce dystoinc phenomena. In addition, muscle vibration may reduce the amplitude of somatosensory evoked potentials (SEPs) through a subcortical gating 2335 mechanism. We analyzed changes of SEPs induced by vibratory stimulation in 10 patients (aged 23–60 years) with focal hand dystonia and 10 agematched (26–68 years) normal controls. Parietal (N20-P25), frontal (P 22-N 30) and Erb’s (P9) potentials were recorded after median nerve stimulation at rest during continuous vibration (80 Hz) on intrinsic hand muscles. No difference of amplitude or latency of SEP components was observed at rest in the 3 groups. Muscle vibration induced a significant amplitude reduction of parietal and frontal SEPs without any latency shift. Such modulation was not difference (ANOVA) in dystoinc patients and controls. The results suggested that the excitability of primary sensory areas at rest is normal in focal dystonia and the associative areas are likely to be involved in sensori-motor integration abnormalities. 12 Nocturnal obstructive apneas syndrome and cardiac risk. Normalization of ECG graph after CPAP application – E. Caggia a, A. Giordano a, M. Latino a, V.G. Lettiga b, M. Rasi b, S. Russo b, F. Iemolo a ( aCentre of Sleep’s Medicine, U.O. Neurology, Vittoria; bU.O. Cardiology, Vittoria, Italy) Nocturnal obstructive apneas (OSAS) syndrome is a frequent, often underestimated disorder that still has a great influence on different apparata. Clinical aspects of the syndrome include intermittent snoring, nocturnal apneas, high cardiac frequency and disorders of neurovegetative system. We pointed in particular at the evaluation of cardiac risk in quite young subjects (range 30/50 years) where evident cardiac alteration during the watch did not occur when they first visited our Centre. Aiming at this purpose we exposed to nocturnal polysomniographic recording by Mesam 4 10 OSAS-suspected patients. The procedure implied the execution of an ECG analysis including cardiological examination before polysomniographic evaluation. In most patients ECG recording executed during the watch showed a quite normal cardiac recovery; on the contrary some patients showed an increase in pressure values. On the other hand nocturnal polysomniographic recording showed a significant variability in cardiac frequency and pressure values related to apneas stages. The application of CPAP fan solved apneas totally and also standardized pressure values and stabilized cardiac frequency. In conclusion, we evidence that, in subjects with particular anthropometrical aspects (obese subjects, etc.), before introducing cardiologic therapy, it is always important to evaluate the possible occurrence of OSAS in order to reduce even cardiac risk, with the application of CPAP fans. 13 Symptoms and neurophysiological picture of carpal tunnel syndrome in pregnancy – I. Aprile a, P. Caliandro a, T. Carboni c, A. Meloni a, A. Massi d, S. Mazza a, M. Mondelli e, A. Morini f, D. Murasecco g, M. Romano h, P. Tonali a, L. Padua a, b ( aInstitute of Neurology, University Cattolica-Rm; bA.Fa.R. Osp Fatebenefratelli-Rm, Oper.; cUnit of Neurology, Osp. Civ. Madonna Soccorso San Benedetto-Ascoli; dInstitute Valdarno, San Giovanni Valdarno-Ar; eEMG Service, ASL 7-Siena; fOper. Unit Neurology Osp. Santa Chiara-Trento; gDepartment of Neuroscience, University of Perugia; hServ. Neurophyisiopath., A.O.Villa Sofia C.T.O, Palermo, Italy) To evaluate the incidence of carpal tunnel syndrome (CTS) in pregnancy through a validated and multiperspective assessment of CTS. During 2000, the Italian CTS study group studied the occurrence of CTS in women during the last period of pregnancy, enrolled in 7 Italian centers. In addition to the physician-centered and neurophysiologic traditional evaluations, we used a validated patient-oriented measurement to obtain more comprehensive and consistent data for severity of symptoms and functional impairment. In our study CTS was clinically diagnosed in more than half of women (62%). Neurophysiological evaluation provided diagnosis of CTS in around half of women (43% were positive in one hand at least). Our study provides evidences, never reported before, of correlation between edema and neurophysiological picture. Similarly, our study provides a correlation between validated patient-oriented measurement and edema. Moreover, a significant correlation between a negative trend (subjectively assessed) and the use of smoke and alcohol was observed. Our observations confirm that the edema of the tissues in the carpal tunnel could induce a mechanical compression of 2336 The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 the nerve. Moreover, our data suggest a negative role in the evolution of the syndrome of smoke and alcohol probably through an impairment of the microcirculation. 14 Persistent unilateral neurogenic calf hypertrophy with complex repetitive discharges and myalgia. Response to botulinum toxin – C. Callegarini a, M. Galeotti b, B. Mercuri a ( aDepartment of Neurology, S. Maria delle Croci Hospital, Ravenna, Italy; b Department of Neurology, Lugo, Ravenna, Italy) We report the case of a 65 year old man with a history of myocardial infarction, high blood pressure, hypercholesterolemia and a constant increase of muscular enzymes. In 2 years this man developed a progressive enlargement of both posterior calf muscles, mainly on the right. He complained pain and cramps when at rest, with an important impairment of right leg movements. These persistent symptoms were emphasized during the load on the right leg and the plantar flexion of the foot. Neurological examination showed a marked hypertrophy of right calf with weakness, painful foot plantar flexion and a reduced right ankle reflex. There were no sensitive deficits. LDH and CPK enzymes were increased (657, 973 U/l, respectively) and an MRI of lumbar spine showed only a lumbar stenosis without focal lesion on S1 root. Nerve conduction velocities were normal while concentric needle examination showed neurogenic potentials in both lumbosacral myotomes especially in right S1. A lot of complex repetitive discharges (CRD) and myokimic discharges were recorded in the soleus muscle. MRI of right leg showed an inhomogeneous signal from fatty or connective tissue replacement within all the posterior right calf muscles (pseudohypertrophy). The CRD recorded within the soleus muscles are due to altered muscle membranes but we found no radiculopathy in our patient. The volitional forceful contraction always increased the CRD activity leading to increased muscle work and, likely, hypertrophy. After the botulinum toxin treatment this activity as well as the painful muscle contractions after voluntary muscle movement decreased. 15 Clinical/neurophysiologic integrated outcome of fatigue symptom in multiple sclerosis – E. Candeloro a, E. Alfonsi b, A. Romani a, R. Bergamaschi a, A. Moglia a, V. Cosi a ( aDepartment of Neurological Sciences of the University of Studies of Pavia; b Laboratory Trunkencephalic and Spinal Reflexes, Neurological Institute “C. Mondino” IRCCS, Pavia, Italy) Aims: Fatigue is a frequent, often disabling and sometimes early stimulus of multiple sclerosis (MS). In this study we have analyzed the ‘fatigue’ phenomenon using an integrated approach considering both the evaluation of experiential datum and neurophysiologic evaluations aiming at the analysis of the relations between experiential and neurophysiologic aspects of fatigue, and the supply of evaluation instruments also useful for the determination of therapeutic behaviour. Method: Forty patients affected by defined MS, at a stationary stage, have undergone the scales of fatigue (Krupp and Fisk), a psychological (Beck, Hamilton, MMPI) neuropsychological (Stroop, Digit-span, Digitsymbol, Trail Making, Verbal Fluidity) and neurophysiologic evaluation. Neurophysiologic evaluation included cortical magnetic stimulation, somatosensitive evoked potentials (SSEP), biomechanical test for the evaluation of central activation during tiring. The 32 fatigued patients have been subjected to two kinds of treatment: fluoxetine 20 mg/die and 4-aminopyridine (4-AP) 24 mg/die. After 4 weeks treated patients have been subjected to scales of fatigue and depression evaluation again. Results: After biomechanical test we found a correlation between amplitude decrease of mechanogram and central activation decrease. The time of central motor conduction was weakly correlated to EDSS and more consistently to ambulation index. We did not detect any association between SSEPs and clinical variables. Both drugs showed a similar clinical efficacy. We have also evinced a significant correlation between the decrease of central activation, basally evaluated, and the response to 4-AP treatment. Conclusions: This study confirms that the evaluation of fatigue symptom in MS is complex. It reports the reliability of biomechanical test in the quantification of central fatigue. At last, it suggests the utility of biomechanical test in the choice of a more suitable treatment to each patient. 16 Influence of local warming on the regulation of cutaneous blood flow – J. Capone, V. Tugnoli, M. Sensi, E. Gastaldo, E. Fallica, R. Quatrale, R. Eleopra (Department of Neurology, S’Anna Hospital & University of Ferrara, Ferrara, Italy) Background: Cutaneous blood flow (CBF) is controlled by both neurogenic and local factors. Sympathetic adrenergic nerves mediate vasoconstriction. The regulation of vasodilatation is more complex and poorly understood. After core temperature rising there is a marked and progressive increase of CBF due both to withdrawal of sympathetic vasoconstriction tone (passive vasodilatation) and active neuromediate vasodilatation. Local warming causes a localized CBF increase but the mechanism is not fully defined. Objective: To evaluate the effect of different degrees of local warming on CBF responses in hairy and glabrous skin. To evaluate the interaction between vasoconstriction and vasodilatation by local warming. Methods: In 20 subjects we assess CBF modifications in fingertip and forearm, by using laser Doppler Flowmetry, after progressive steps of local warming (30–35–40–448C) and the variations of vasoconstrictor response induced by deep breath stimuli at each step. Results: There is a linear correlation between CBF increase and local warming at 30–35–408C, at 448C there is a higher increase of CBF. The vasoconstriction amplitude progressive decrease with the rise of local CBF. Conclusions: Our data confirm that two different mechanisms regulate local warming vasodilatation depending on skin temperature degree, over or above 408C. The effect of deep breathing on CBF differs depending on the local skin temperature, suggesting a dynamic interaction (functional competition) between the vasodilators and vasoconstrictor cutaneous systems. 17 Stance: an unsupervised neural network model – M. Capozza, N. Accornero (Dipartimento di Scienze Neurologiche, Università di Roma “La Sapienza”, Italy) We present an unsupervised neural network that learns to control the stance of a simplified computer model of human body. This simplified human body is made of 5 segments articulated with 4 joints (ankle – knee – hip – neck), moving on a two-dimensional space (sagittal plane). Any segment is subject to gravity and is driven by a couple of muscles: a flexor and an extensor. System physics, while simplified, also takes into account the inertia of segments, rigidity of joints, and elastic forces arising from joint flexion and extension. The muscles are activated by a neural network fed with sensory data from: (1) ‘visual’ channels (position of head in space); (2) ‘proprioceptive’ channels (opening angles of joints, and position of the centre of foot pressure, i.e. the projection of the body mass centre on the floor); and (3) ‘vestibular’ channels (inclination of head in space, and direction and strength of head velocity vector). The learning method is the so-called ‘learning-by-doing’, where the patterns to be learnt are provided by the spontaneous (and even casual) movements of the model. There is no teaching set, as well as no external supervisor. Although a delta rule is used, error computation is performed locally for each neural unit in an entirely feed-forward way, differently from the well known back-propagation algorithm (that features undoubted working effectiveness, but also more questionable biologic plausibility). Learning session takes about 50 thousands movements (a few minutes with a 400 Mhz PC)to reach a good stance performance. Our simulation makes it possible to perturbate the system’s equilibrium by means of thrusts to the body or sudden changes in the inclination of the floor, as well as to exclude some of the sensory channels (visual, proprioceptive, vestibular) in order to study the effects of a simulated neurologic damage. 18 Idiopathic herniation of spinal marrow: case report – R. Caramelli a, L. Tirelli a, G.C. Guizzardi b, M. Cellerini c, M.E. Bastianelli a, A. Amantini a, F. Pinto a ( aDepartment of Neurological Sciences; bU.O. of Neurosurgery; cService of Neuroradiology Hospital Company Careggi, Florence, Italy) Idiopathic herniation of spinal marrow (IHSM) is a rare neurological condition expressed by Brown–Sequard’s disease or, less frequently, by spastical paraparesis; a deficit of thermo-painful sensibility generally The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 reveals itself some years before motor symptomatology. We describe the case of a 54-year-old man come to our observation for sensibility disorders at the left lower limb, arisen about 4 years before and slowly worsening, and hyposthenia at the right lower limb, more recently appeared, without sphincteric disorders. Objective examination showed left thermo-painful hypesthesia with T6 higher level, marked increase of cutaneous nociceptive threshold at CO2 laser stimulus, integrity of proprioceptive and epicritic sensibility, spastic monoparesis at the right lower limb (4-MRC). The study of front-lateral and back cord transmission by means of CO2 PE laser, PEM and PES confirmed clinical reports about incomplete Brown–Sequard’s disease. The images of RMN, cineRMN for the study of cerebrospinal flux, myeloTAC and selective angiography at dorsal rachis level showed a front-lateral transdural herniation of spinal marrow at T8–T9 level, without extrinsic compression, arachnoid cyst or arachnoiditis. The patient has been subjected to T8–T9 laminectomy with the reduction of medullar and dural-plastic hernia. Four months after the operation he showed an improvement in strength (4 1 MRC) with persisting sensory symptomatology. About 25 IHSM cases have been described in literature, but data appear truly underestimated. Usually herniation turns to symptomatic before being diagnosable at RMN; the importance of an early electro-clinical diagnosis follows from that. Despite the prolonged and progressive deficit of neurological functions (sometimes 10-year periods), surgical reduction produces a clinical improvement. Therefore IHSM is a surgically treatable cause of torax Brown–Sequard’s disease, to be suspected also in absence of starting evidence in neuroimaging tests. 19 Abnormalities of trigemino-facial reflex inhibitory response in hemifacial spasm – L. Cattaneo, G. Pavesi, D. Mancia (Istituto di Clinica Neurologica, Parma, Italy) Objective: We recently described in normal subjects inhibitory trigemino-facial reflexes limited to levator labii superioris (LLS), depressor anguli oris and depressor labii inferioris muscle. In the present study we investigated excitatory and inhibitory trigemino-facial reflexes in 14 patients with hemifacial spasm (HFS). Methods: Inhibitory and excitatory reflex responses were recorded bilaterally, at rest and during voluntary contraction after ipsilateral and contralateral mentalis and supraorbital nerves stimulation. Results: Early and late excitatory responses were present in LLS muscle in 11 subjects. Inhibitory late responses in activated LLs muscle were absent in 7 subjects and were present, though with abnormally longer latency and short duration, in the remaining 7 subjects. On the unaffected side inhibitory responses were normally present. Patients with preserved inhibitory responses in LLS muscle had spasms mainly restricted to the upper hemiface. Conclusion: Inhibitory trigemino-facial reflexes are impaired in HFS. This abnormality seems to parallel the extension of the spasm to the lower hemiface. 20 Congenital mirror movements, clinical aspects and prospects for rehabilitation – M. Cincotta a, A. Borgheresi a,G. Zeloni b, L. Balzini b, L. Vannucchi b, A. Ragazzoni a, F. Benvenuti b, G. Zaccara a, U. Ziemann c, G. Arnetoli d ( aU.O di Neurologia, Azienda Sanitaria di Firenze, Italy; bOspedale I.N.R.C.A. “ I Fraticini”, Firenze, Italy; cNeurologische Klinik, J.W. GoetheUniversitaet, Frankfurt, Germany; dDip.to di Scienze Neurologiche e Psichiatriche, Università di Firenze, Italy) Mirror movements (MM) are unintended movements on one side of the body, which are mirror reversals of the contralateral voluntary movements. They mainly involve the distal upper limb muscles. Congenital MM have been reported in association with brain injury and malformations as well as in absence of other neurological abnormalities. Fast-conducting pathways connecting the primary motor cortex (MI) with ipsilateral spinal motoneurons have been demonstrated in subjects with congenital MM. In a 41-yearold man with severe congenital hemiparesis and in two otherwise normal women (15 and 40-years-old, respectively), MM were videotaped during intended unilateral phasic and tonic hand muscle contraction. In the 40year old patient, mirror writing was shown. We summarized neurophysio- 2337 logical data suggesting the presence in our patients of a substantial population of ipsilateral cortico fugal fibers independent from the crossed corticospinal pathways. Steps of a rehabilitation programme aiming to strengthen the independent activation of crossed and ipsilateral corticospinal projections during intended unilateral movements were videotaped. We showed that, in the 15-year-old patient the amplitude of MM during sequential finger movements was significantly reduced following a 7-motnhs training period. 21 Reorganization of the somatosensory input in a patient with congenital hemiparesis – M. Cincotta a, A. Ragazzoni a, A. Borgheresi a, G. Zaccara a, U. Ziemann b ( aU.O di Neurologia, Azienda Sanitaria di Firenze, Italy; bNeurologische Klinik, J.W. Goethe-Universitaet, Frankfurt, Germany) Objective: To investigate the reorganization of the afferent projections to sensory cortex in congenital brain injury. Methods: We recorded somatosensory evoked potential (SEPs) to electrical stimulation of the median nerve in a 41-year-old man with sever right congenital hemiparesis and mild proprioceptive impairment. Brain MRI showed a large poroencephalic cavitation in the left hemisphere mainly involving the frontal and parietal lobes. He showed mirror movements and transcranial magnetic stimulation suggested the presence of fastconducting projections from the undamaged primary motor cortex (MI) to the paretic hand. SEPs were mapped out over the scalp by 25 electrodes referred to the mastoid of the stimulated side. Results: Left median nerve stimulation evoked normal SEPs on the contralateral hemisphere, whereas no cortical response was recorded ipsilaterally. After right median nerve stimulation, no early contralateral cortical component was seen, whereas a longer latency wave (positive– negative–positive, 45–50–55 ms) was observed ipsilaterally, with a central scalp distribution. Conclusion: Our data suggest that upper limb and the primary somatosensory cortex, probably trough either ipsilateral slow pathways or nonprimary sensory areas. In contrast, clinical motor recovery was poor notwithstanding a remarkable reorganization of the cortical motor output. 22 Anomalies of time constant of intensity-duration curve in patients affected with motor neuron disease – C. Cinnante, M. Carpo, A. Pesenti, G. Gherardi, E. Nobile-Orazio, S. Barbieri, G. Scarlato, A. Priori (Department of Neurosciences – University of Milan, IRCCS Greater Hospital of Milan, 20122 Milan, Italy) Time constant (t SD) of intensity-duration curve reflects the intrinsic properties of axonal membrane at nodal level. In 12 nerves of 10 healthy voluntary subjects (44–77 years) and in 14 nerves of 10 patients with motor neuron disease (MND) (43–74 years) we calculated t SD of motor axons of wrist ulnar nerve, max CMAP amplitude, present rheobase (rh) and estimated rheobase (rhs). In hypothenar eminence muscles we evoked a constant CMAP having the value of 50% of maximal CMAP, changing current intensity by determined duration stimula (1, 0.7, 0.5, 0.3, 0.2, 0.1, 0.05, 0.02 ms). Intensity-duration function has been linearly transformed according to Weiss’formula (1901). The intercept of the x-axis of linear regression function is found to be the t SD of intensity-duration curve of motor axons, while the slope represents rhs. As expected maximal CMAP amplitude in MND patients (6.5 ^ 3.2 mV [mean ^ 1 SD]) is significantly reduced (P ¼ 0:002 [Mann–Whitney test]) compared to check-up subjects (11.9 ^ 2.4 mV). rh (patients ¼ 12.6 ^ 7.1 mA, checkups ¼ 9.4 ^ 3.5 mA; P ¼ 0:27) and rhs (patients ¼ 6.1 ^ 4mA, checkups ¼ 5.1 ^ 2.1 mA; P ¼ 0:71) do not change significantly, on the contrary t SD proves significantly increased (P , 0:05) in patients (218 ^ 47 ms) compared to checkups (190.9 ^ 51 ms). t SD reflects intrinsic properties of nodal membrane determined by Na 1 not-voltage-depending conductances. So our results show an increase in such conductances at the level of axonal nodal membrane in MND and suggest that the resulting nodal relative depolarization can contribute to the appearance of cramps and fasciculations typical of this condition. 2338 The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 23 Cortical excitability in obstructive sleep apnea syndrome – P. Naldi, C. Civardi, R. Cantello, R. Mutani (Clinica Neurologica, Università del Piemonte Orientale, Novara, Italy) Objective: To test with transcranial magnetic stimulation (TMS) the excitability of the motor cortex in group of OSAS patients. Methods: We studied 7 obese patients with OSAS (4 male and 3 female, mean age 32.7 years SD ^ 12.7). The stimuli were delivered with a round coil at the vertex; we recorded motor evoked potentials (MEP) from the right FDI muscle. We measured: relax threshold (rT), central silent period (CSP). Then we compared the MEP amplitude of a test stimulus (intensity ¼ 1.6 £ rT) while the patient was awake with those obtained in non-REM sleep in two different situations: during or outside apnoea episodes. Results: The rT was normal, while the CSP was mildly prolonged (229 ms SD ^ 17.2; P , 0:05). During non-REM sleep, there was a decrease (54% of the test-MEP, SD ¼ ^ 8.7%; P , 0:001) of the MEP amplitude respect to the awake state. When apnoea occurred, there was a further strong (15.2% of the test-MEP, SD ¼ ^ 6.3; P , 0:0001) reduction of the MEP amplitude. Conclusions: The dramatic reduction in amplitude of the MEP during the apnoea could be due to a reduction of the cortical excitability. This changes may somehow relate to the intrinsic mechanisms of the OSAS pathophysiology. 24 Changes of the human motor cortical excitability induced by rizatriptan: a transcranial magnetic stimulation study – C. Civardi, L. Bolamperti, C. Boccagni, R. Vicentini, R. Cantello (Clinica Neurologica, Università del Piemonte Orientale, Novara, Italy) Objective: To test with transcranial magnetic stimulation (TMS), if a single therapeutic oral dose of rizatriptan, a novel selective 1B/1D 5-hydroxytriptamine receptor agonist, was able to modulate the excitability of the motor cortex in a group of migraine patients. Methods: We studied 9 patients affected by migraine without aura (3 men and 6 women; mean age 30.2 ^ 4 years); all were in the inter-ictal period. With focal TMS for the right FDI muscle we determined: (a) resting threshold (rT); (b) central silent period (CSP); (c) amount of inhibition on paired TMS at the interstimulus intervals 3 and 4 ms; amount of facilitation at interstimulus intervals 14 and 16 ms. The whole TMS session was performed before and after one (Tmax) and 2 h (T1/2) the intake of a single oral dose of rizatriptan (10 mg). Results: No significant changes were observed for the rT and for the CSP. We observed a decrease of the amount of inhibition [Fð1; 8Þ ¼ 6; 78; P , 0:05] only for the Tmax determination. Conclusions: Our findings are in favour on an action of rizatriptan on the excitability of the primary motor cortex; it appears to act on GABAergic inhibitory interneurones. This could support the idea that 5-hydroxytriptamine transmission is involved in the modulation of motor output. 25 Non-convulsive status epilepticus in intensive care unit: prevalence, clinical and neurophysiological data – P. Costa a, M. Bonzanino a, E. Montalenti b, P. Benna b, G. Faccani a (Department of Neurosurgery, CTO Hospital, Turin; bDepartment of Neuroscience, University of Turin, Italy) Objective: Non-convulsive status epilepticus (NCSE) can occur in comatose patients with no clear clinical sign of seizures: its identification and treatment can contribute to a better outcome. Methods: Retrospective analysis of clinical and electroencephalographic data obtained in 62 consecutive patients admitted in our ICU between January and September 2000: all of them presented various degree of consciousness alteration. The EEG criteria for NCSE consisted of discrete electrographic seizures, continuous spike and wave activity, or rhythmic recurrent epileptiform activity lasting at least 30 min without clear clinical seizure activity. These demonstrated marked improvement with the injection of an IV benzodiazepines. Results: Seven patients (11.3%) showed EEG features of NCSE, in absence of unequivocal clinical signs of seizures. Etiology of NCSE was anoxia (two), traumatic brain injury (3 pts.) subaracnoidal hemorrhage (one) and renal failure plus NCSE (one). Conclusions: NCSE is a frequent, treatable, often unrecognized cause of coma: EEG should be included in the evaluation of comatose patients with even in absence of clinical signs of seizures. 26 Kinematic anomalies of sequential fingers’ movements in patients with Parkinson’s disease – A. Currà, R. Agostino, M. Giovannelli, M. Manfredi, A. Berardelli (Department of Neurological Sciences, University of Rome “La Sapienza” and I.N.M. Neuromed IRCCS, Pozzilli, IS, Italy) A comparison has been made between the execution of thumb-forefinger opposition (single) movements and all fingers-to-thumb contemporary opposition (not single) movements. We examined 10 normal subjects and 11 patients affected by Parkinson’s disease (PD) after suspension of pharmacological treatment (severity of slight-moderate disease). Kinematic analysis was executed with ELITE (BTS) system, recording movements into 3 subsequent blocks, lasting 5 s each, evincing the parameters of: amplitude, rate and pause between opposition stages of flexion-extension. In normal subjects both flexion stage and the following pause resulted, respectively, quicker than extension stage and the following pause, with no difference between thumb-forefinger movements performed by the forefinger alone and those performed together with the other fingers. Compared to normal subjects, in both conditions patients performed a shorter number of even less amplitude oppositions. Bradykinesia proved more intense in flexion stage, and the pause following flexion proved more prolonged than the one following extension. In patients the repetition of opposition movements occurred together with a progressive duration increase in opposition stages and a reduction in their amplitude. At last, ‘fatigue’ resulted more evident during flexion stage of thumb-forefinger movements. The study shows that PD patients present anomalies in the execution of fingers’ opposition movements, find greater difficulties in flexion stage, and get more tired during single opposition movements. Specific anomalies of flexion stage can be related to alterations in the control of agonist and antagonist muscles during repeated movements. The greatest implication of single movements is due to the finer cortical control requested for their execution. 27 Topiramate modulation of R3 nociceptive reflex in multiple sclerosis patients with paroxysmal symptoms – G. D’Aleo, P. Di Bella, E. Sessa, C. Rifici, D.A. Restivo, N. Muscarà, A. Cannata, P. Bramanti (Centro per lo Studio ed il Trattamento dei Neurolesi Lungodegenti, Cattedra di Neurofisiopatologia, Università degli Studi di Messina, Italy) Aim: Topiramate (TPR) is a third generation, well-tolerated antiepileptic drug (AED) found to be effective for refractory intercostal and trigeminal neuralgia. No neurophysiological evaluation of the effects of TPR on paroxysmal symptoms (PS) in multiple sclerosis (MS) patients has been performed. A close relationship has been found between the subjective sensation of pain, the R3 component of the blink reflex and the pain threshold on electrical stimulation of the supraorbitalis nerve. This reflex has also been studied in MS patients and found to be a good tool for evaluating the nociceptive system in this disease with and without AED therapy. The aim of this study was to obtain a neurophysiological evaluation of the effects of TPR on the nociceptive system of MS patients suffering PS. Methods: We studied 13 MS patients, 5 males, 8 females (mean age 37.2 years), suffering PS (4 had trigeminal neuralgia, 5 painful tonic spasms and 4 dysesthetic or paresthetic symptoms). Pain was evaluated by means of the Visual Analogue Scale (VAS). R3 nociceptive reflex (according to Rossi B. technique) was recorded before and after 12 weeks’ TPR treatment. R3 thresholds and latencies were evaluated and a statistical analysis (Student’s t test) was performed. Results: A significant variation was found in VAS and R3 thresholds between the values recorded before and after a 12 week TPR treatment; no significant variation was observed in R3 latencies. Conclusions: From a clinical and neurophysiological point of view, this study suggests that TPR may be an effective therapy in MS patients suffer- The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 ing PS in whom conventional therapies are ineffective or poorly tolerated. Further studies with a greater number of patients are needed to confirm this. 28 An uncommon cause of uniltateral diaphragmatic palsy. An electropshysiological study – P. De Massis a, A. Gabellini a, L. Lazzari Agli b ( aU.O. Di Neurologia – Laboratorio di Neurofisiologia; bU.O di Pneumatologia, Ospedale Maggiore, Bologna, Italy) We describe an uncommon cause of diaphragmatic palsy. A 70-year-old man, previously healthy, underwent laterocervical infiltration for neck pain. Two days later he started complaining of nocturnal dyspnoea and sweating. His chest X-ray demonstrated an elevation of the left hemidiaphragm, confirmed by the months after the symptoms onset. The neurological examination was normal. The electromyographic evaluation of the hemidiaphragms, performed with a standard monopolar needle electrode, showed a normal findings on the right side. On the left side we found denervation potentials at rest and decreased recruitment pattern of voluntary activation with increased size of the motor units. The phrenic nerve conduction time was normal bilaterally. We discuss the diagnostic and prognostic value of the electrodiagnostic study in phrenic nerve injures. 29 Analysis of EEG activity by artificial neural network evaluation in Huntington’s disease (HD) patients and at-risk relatives – M. de Tommaso a, R. Bellotti b,V. Sciruicchio a, G. Libro a, M. Guido a, O. Difruscolo a, N. Specchio a, L.M. Specchio a, F.M. Puca a ( aDipartimento di Scienze Neurologiche e Psichiatriche, b Dipartimento di Fisica, Università di Bari, Italy) Several neurophysiological abnormalities have been described in Huntington’s disease patients. In previous studies, a decreased EEG amplitude correlated with severity of neurological and cognitive impairment was shown, using both a linear discriminant method and an artificial neural network classifier. The aim of this study was to distinguish, between asymptomatic gene carriers and Huntington’s disease patients by means an artificial neural network classifier, in order to evaluate whether EEG abnormality should be a feature of the disease rather than a consequence of chorea. We selected 20 Huntington’s disease patients and 20 at risk subjects were studied. Fifty normal subjects sex- and age-matched were also evaluated. The mutation analysis was performed for the CAG expansion within HD gene trinucleotide repeat (CAG) sequence on short arm of the chromosome 4, using HD 333-HD 447 as oligonucleotide primers. A total of 10 asymptomatic gene carriers were found. Electroencephalographic recordings were performed using 19 electrodes. Ten artefact-free epochs were selected and analyzed by fast Fourier transformation. Training data were presented to a standard ‘3-layered feed forward’ neural network (19 input, two hidden, one output cells). The most important EEG pattern in giving a classification of HD patients was absolute alfa power. At risk relatives EEG was classified by neural network as those of normal subjects. These preliminary results could suggest that EEG abnormalities in HD appear during the development of the disease and confirm the utility of neural networks in classifying EEG data. 30 Botulinum toxin a treatment for primary hemifacial spasm: 10year multicenter study – G. Defazio a, G. Abbruzzese b, P. Girlanda c, L. Vacca d, A. Currà d, R. Marchese b, R. Raineri c, F. Roselli a, P. Livrea a, A Berardelli d ( aDepartment of Neurologic and Psychiatric Sciences, University of Bari; bDepartment of Neurological Sciences and Vision, University of Genova; c Department of Neurosciences, Psychiatric and Anaesthesiological Sciences, University of Messina; dDepartment of Neurological Sciences, (Roma) and Institute NEUROMED (Pozzilli IS), University of Rome “La Sapienza”, Italy) Objective: To assess the long-term effectiveness and safety of botulinum toxin A (BTX) treatment in a series of 65 patients with primary HFS who had received BTX injections regularly for at least 10 years treatment with the same commercial product (Botox, Allergan, Irvine, CA, USA). Methods: Sixty-five patients (19 men and 46 women; mean age at first treatment, 56 ^ 11 years) attending the outpatient clinics at 4 Italian 2339 University centers belonging to the Italian Movement Disorders Study group completed at least 10 years of BTX. Patients’ medical records for the first and tenth years of treatment were reviewed to collect relevant information. Results: Using a mean BTX dose per treatment session (17.5 units, range 7.5–45). similar to that used by others, the effectiveness of BTX in relieving the symptoms of primary HFS, as measured by the % response rate and average duration of improvement, remained unchanged in the first and tenth year. The rate of local side effects diminished significantly in the tenth year despite the mean BTX dose remained unchanged throughout the study. Conclusion: BTX seems to induce substantial, sustained relief of HFS in the long-term (10 years in this study) with only minimal and transient adverse reactions. 31 Cortical mechanisms mediating the inhibitory period after magnetic stimulation of the tongue motor area – P. Di Bella, D.A. Restivo, E. Sessa, G. D’Aleo, C. Rifici, N. Muscarà, A. Cannata, P. Bramanti (Centro per lo Studio ed il Trattamento dei Neurolesi Lungodegenti, Cattedra di Neurofisiopatologia, Università degli studi di Messina, Italy) Aim: To evaluate the mechanisms mediating cortical inhibition of the tongue motor area in humans. Methods: We studied the silent period (SP) that interrupts voluntary EMG activity in tongue muscle following transcranial magnetic stimulation (TMS), in 12 normal subjects and in 4 dysarthric patients (3 with cortical lesions for vascular accidents or tumours and one with lesion at medullar level, evaluated by TC or MR). Cortical SP was induced by TMS performed with a circular coil centred at the vertex as well as with a focal coil positioned over both the controlateral and ipsilateral tongue motor area contemporary recording from right and left hemitongue. Results: SPs showed shorter duration in ipsilateral than in controlateral muscles following focal as well as circular-coil stimulation. Focal magnetic stimulation showed that positioning of the coil was critical and that the optimal scalp sites for evoking the largest potentials and the longest SPs coincided. In patients (3) with hemispheric lesions the stimulation over the affected motor area showed a shortening of the SP in both ipsi and contralateral hemitongues, leaving unaffected the muscles controlled by the other hemisphere. In the patient with medullar lesion SPs were normal. Conclusions: We conclude that the SP induced in tongue muscles by TMS results from the excitation of cortical inhibitory interneurons surrounding the upper motoneurons. The controlateral hemisphere has apparently a stronger influence on motor neuron activation than the controlateral one. 32 Neurophysiological evaluation in patients affected with hereditary spastic paraparesis – M.T. Palmisani, E. Bertini, C. Dionisi Vici, F. Santorelli, M. Di Capua (Department of Neurosciences, Bambino Gesù Children’s Hospital, Rome, Italy) We report on 14 patients affected by hereditary spastic paraparesis (HSP), a group of clinically and genetically different disorders, characterized by a progressive lower extremity spasticity. We studied these patients using tibial nerve somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs), using magnetic transcranial stimulation. MEPs were abnormal in all cases, while SEPs were altered in 7 patients. Four patients were affected by HHH syndrome, an autosomal recessive metabolic disease characterized by increased plasma ornithine concentration, post-prandial hyperammoniemia and homocitrullinuria. Neurological symptoms were variable and included delayed developmental milestones, seizures, muscle hypotonia, mental retardation and spasticity. Our patients clinically presented spastic paraparesis of variable entity; only one case was affected by mental retardation. All HHH patients presented normal SEPs and abnormal MEPs. One case, with abnormal SEPs and MEPs, presented a SPG7 gene alteration, codifying for ‘paraplegin’ protein. One brother, who did not present this gene alteration, had normal SEPs and MEPs. Our results show the importance of evoked potentials as ‘neurophysiological data’ demonstrating the possibility of a more precise diagnosis of involvement of the spinal pathways in hereditary spastic paraparesis. 2340 The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 33 Tridimensional integration of electroencephalographic signal with data of anatomic-functional neuroimaging – M. Ermani a, A. De Zanche a, P. Benetello a, M. Saladini a, G. Zara a, P. Rampazzo a, P. Zucchetta b, P. Amistà c ( aDepartment of Neurological and Psychiatric Sciences, University of Padova; bService of Nuclear Medicine I. Hospital Company Padova; cService of Neuroradiology, Hospital Company Padova, Italy) Aim: We propose a methodology for the integration of electrophysiologic (EEG) and morphofunctional (RMN, SPET, cerebral PET) data, conceived for the study of epileptogenic centres and directed to both bloodless preoperating evaluation of drug-resistant patients destined to surgical operation and to the evolution of such centres in time, as a calculation of therapeutic efficacy. Methods: We planned and executed a stereotactic helmet allowing to calculate tridimensional coordinates of the points where electrodes are positioned on the scalp. Four of these positions at least get marked with paramagnetic reports, opaque at RMN and formed by small plexiglass cylinders, planned and produced on purpose. This fact allows to reconstruct the positions of all the other electrodes on RMN images. Planning aspects of the helmet also allow to reposition electrodes in the same scalp position when the same patient is subjected to subsequent EEG at a control distance. Integration includes the elaboration of EEGraphic data at different levels (projection on the scalp of amplitude maps, calculation of Laplace operator, of cross-correlation function), with projection of the obtained data on RMN and SPET/PET images, whose integration is obtained through a methodology of minimization of entropy. Results: Methodology has been tested on a drug-resistant female patient affected by epilepsy. EEG elaboration pointed out a possible origin of pathologic activity at the right frontal-basal level. Cerebral RMN proved normal. Cerebral SPET, effectuated in intercritical stage, showed an area of right frontal hypo-perfusion. Integration by EEG data projection on RMN and SPET showed suitability in the data obtained by EEG and SPET, localizing the possible centre in the right frontal-basal region. Conclusions: The methodology we propose allows to integrate information enabling to evaluate exactly epileptic phenomena in time but not in space, as in EEG, with those which, on the contrary, give a fine evaluation in space but not in time, as happens about neuroimages. 34 Study of MEPs in a case of post-traumatic syringomyelia – E. Ferraro a, A. Foti a, F. Caputi b, L. Conti a, F. Fiume Garelli a ( aU.O. Neurology; bU.O. Neurosurgery Hospital S. Filippo Neri, Roma, Italy) Little and coll.’s studies (1992) showed how the recording of motor evoked potentials (MEP) through Magnetic transcortical stimulation can usefully support neuroradiologic researches in diagnosis and follow-up of patients affected by syringomyelia, including the forms with post-traumatic origin. We report the case of a 46-year-old woman who, at the age of 16, had suffered a D7 wedge-shaped fracture with kyphoscoliotic vertebral deformity after a car crash. She had led a normal life until 1996, when she showed urinary retention and strength deficit at lower limbs. RM showed the occurrence of a widespread syringomyelic cavity, so she underwent a D4-D9 dorsal laminectomy operation with cicatricial lysis of arachnoidal and duroplastic adhesions. With the passing of the years motor deficit and painful symptomatology at both limbs have increasingly worsened. Once admitted to our hospital the patient showed fair deficit at lower limbs, D7–D8 anesthetic band, left L1–L5 and S1–S3 thermo-painful anesthesia and hypesthesia in the symmetrical right parts. Absence of ROT. A new RM with study of cerebrospinal fluid fluxes, documented the prevailing wide syringomyelic cavity at medullar cone level and flux absence. The study of MEPs in preoperating stage showed a significant bilateral extension of central conduction time (CCT) by recording at upper and lower limbs (low . up); in particular evoked potentials by recording at lower limbs resulted of very low voltage and dismantling. The study of intraoperating MEPs (L5–S1 bilateral DREZ-tomy operation, with syringo-subarachnoidal emptying and derivation of syringomyelic cavity), recorded at front left m.tibial showed a significant increase in motor potential amplitude, after emptying cystic cavity. Soon after the operation we witnessed a distinct improvement in motor deficit. RM documented the collapse of syringomyelic cavity. Just 5 days after the operation, control MEPs showed a moderate bilateral extension of CCT by recording at lower limbs, a normal CCT by recording at upper limbs: so there was a global, significant recovery of electrophysiologic parameters in extremely early times. These data suggest that the amplitude increase of intraoperating MEPs and the improvement in their parameters in post-operating period, can represent a valid predictive index to recover motor functions. 35 Change in somatosensory disinhibition in patients with writer’s cramp after successful treatment with botulinum toxina – E. Frasson a, L. Bertolasi b, M. Tinazzi b, G. Didonè a, A. Priori c ( aDivision of Neurology, Civil Hospital, Cittadella, Padova; b Department of Neurological and Visual Sciences, Neurology Section, Verona; cInstitute of Neurological Clinic, University of Milan, IRCCS Greater Policlinic Hospital, Milan, Italy) To evaluate if botulinum toxina exerts a modificatory action on the excitability of somatosensory system in dystonia we analysed recovery functions of the following somatosensory evoked potentials (SSEP): N13 spinal, P14 trunk-encephalic, N20 parietal, P27 and N30 frontal by means of middle nerve’s double stimulus technique in patients affected with writer’s cramp before, 1 month and 3 months after the treatment with botulinum toxina in the affected muscles. Ten patients affected with writer’s cramp have been analysed and normative values have been obtained by 10 normal subjects. Patients have been treated with local injections of botulinum toxina type A (100–150 UI). The average treatment duration was 15 months. We determined SSEP’s recovery functions (conditioning stimulus: S1; test stimulus: S2) at stimulus’ intervals (ISI) of 20 and 40 ms. Evoked-by-S2 SSEPs have been calculated subtracting S1-response SSEP from double stimulus response SSEP (S1 1 S2) and amplitudes have been compared to those of check-up responses (S1), every ISI considered. In somatosensory system the ratio (S2/S1)*100 determines the functionality of inhibitory circuits. SSEPs have been evaluated before the treatment with botulinum toxina, 1 month and 3 months after the treatment. We did not detect any significant difference in SSEP single stimulus amplitude (S1) between patients affected with writer’s cramp and the normal ones. Before the treatment the ratio (S2/S1)*100 was higher in patients than in normals as concerns N13, N20, P27 and N30 components. One month after the injection of botulinum toxina, SSEP’s amplitude to ISI 20 and 40 ms resulted significantly reduced and was not different from normals. From a clinical point of view all the patients had improved. Three months after the injection SSEPs resulted less inhibited than in normals and in patients after 1 month of treatment. Our data suggest that in writer’s cramp there is an altered inhibition of somatosensory system determining an alteration of motor program and that the botulinum toxina treatment can produce a clinical improvement modulating the action of inhibitory circuits at spinal and cortical level of somatosensory system. 36 Time course of sympathetic skin response and veno-arteriolar reflex in Parkinson’s disease – S. Fusina, L. Bertolasi, L. Gemma, E. Nardelli, G. Rossato, L.G. Bongiovanni (Clinica Neurologica, Università di Verona, Italy) Objective/methods: Recently, amplitude asymmetry of the sympathetic skin response (SSR) has been detected in patients affected with early HemiParkinson’s disease (HPD). To define the neurophysiological basis of such a phenomenon we have studied the veno-arteriolar reflex (VAR), the basal mean blood flux (BMF) and the basal skin temperature (BST) in 25 early HPD patients with demonstrated SSR amplitude asymmetry (group A). To analyze the post-ganglionic adrenergic sympathetic output and the central autonomic network activity, the VAR was evoked by means of either passive leg dependency (VAR1) or a passage from clinostatic to orthostatic posture (VAR2). The time course of SSR and VAR was analysed in a group of patients affected with bilateral Parkinson’s disease (group B) already studied when the motor symptoms were unilateral. Results: In group A, SSR and VAR2 showed a significant impairment corresponding to the motor affected side. In group B only SSR maintained a significant amplitude asymmetry. The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 Conclusions: Such data support the hypothesis that, in HPD, the dysfunction of sympathetic output is due to a pre-ganglionic involvement. Moreover, integration between extrapyramidal motor system and central autonomic network seems to emerge from our results. 37 Laser evoked potentials in patients with trigeminal neuralgia – F. Galeotti, G.D. Iannetti, A. Romaniello, A. Truini, G. Cruccu, M. Manfredi (Department of Neurological Sciences, University “La Sapienza”, Rome, Italy) Introduction: In patients affected by trigeminal neuralgia sensory disorders do not occur clinically. Studies on reflexes and evoked potentials have already produced information on the running of large-caliber (not nociceptive) afferences. In the following study we investigated the running of small-caliber (nociceptive) afferences using laser evoked potentials (LEPs). Methods: We analysed the cerebral potentials evoked by CO2-laser stimulation directed to perioral and supraorbital regions in 67 patients affected by idiopathic or symptomatic trigeminal neuralgia and in 30 normal subjects. Forty-nine out of 67 patients took carbamazepine. Results: All the patients with symptomatic neuralgia and the 51% of those with idiophatic trigeminal neuralgia showed evidently altered LEPs on the affected side. Average latency resulted significantly higher and average amplitude lower on the affected side, compared to the counterlateral one. Nevertheless average latency resulted significantly increased compared to that of the same age check-ups, even on the unaffected side. Latency on the unaffected side resulted significantly related to carbamazepine dosage. Conclusions: Even though carbamazepine can depress these cerebral potentials bilaterally, LEPs show a severe compromission of the afferent nociceptive system on the affected side of patients with both idiopathic and symptomatic trigeminal neuralgia. We assume that a dysfunction of smallcaliber afferents plays a leading role in neuralgic pain physiopathology. 38 Cognitive profile of epileptic treated with topiromate added to carbamazepine – R. Galli, G. Dell’Agnello, C. Pizzanelli, A. Iudice, L.Murri (Dipartimento di Neuroscienze, Universita di Pisa, Italy) Objective: The aim of this prospective open trial was to evaluate the effects on cognition of topiramate to pre-existing carbamazepine monotherapy. Methods: Ten epileptic patients were administered a battery of neuropsychological tests exploring memory, attention and verbal skills. All suffered from partial epilepsy and showed an unsatisfactory control of their seizure frequency. Assessments were performed at baseline, on monotherapy with carbamazepine (1200 mg/day average dose) and 2 months after topiramate 200 mg/day add-on-therapy. Results: Results show that no significant deterioration of cognitive functions is associated with drug combination, as compared with carbamazepine monotherapy, while patients’ seizure frequency achieves a better control. Conclusions: Despite a limited number of ad hoc studies exploring cognitive changes, the new antiepilectic drugs seem to yield a better cognitive profile than older agents. Results of neuropsycological studies with topiramate have so far reported conflicting findings in epileptic patients, where some evidence shows negative effects, but others have emphasized a lower cognitive impact of this agent over the older ones. Our findings show a negligible influence of mild daily dose of topiramate added to carbamazepine on cognitive performances in epileptic patients. Recovery curve of inhibitory masseter reflex by electric and magnetic stimulation in normal subjects – E. Gastaldo, A. Graziani, M. Paiardi, M. Manconi, R. Quatrale, R. Eleopra, V. Tugnoli, E. Granieri (Service of Neurophysiology, Hospital Company, University of Ferrara, Italy) Background: Variations of trigeminal motor neural excitability have been widely documented through the study of recovery cycles of electrically stimulated inhibitory masseter reflex. Aim: To evaluate the possible differences of recovery cycle of inhibitory masseter reflex obtained by electric and magnetic stimulus. 2341 Method: The study of trigeminal motor neuronal excitability in a population of 16 healthy subjects has been carried out through the evaluation of inhibitory masseter reflex by electric stimulus at n.Mental, of inhibitory masseter reflex by magnetic stimulus at mental level, of recovery curves of inhibitory reflex both by magnetic and electric stimulus, at different ISI, from 100 to 800 ms. Results: Comparing the two stimulating methodologies there are no significant differences in the duration of both early and late inhibitory masseter periods. Magnetic stimulation recovery curve shows a complete recovery at inter-stimulus intervals, greater than what is evinced through electric stimulation. Electric and especially magnetic recovery curves show an increase of ISIs in a limited population of patients affected by bruxism compared to normal population. Conclusions: In normal subjects these results are strictly related to a different implication of inhibitory trunkencephalic processes from the involved afferences by the two types of stimulus. 40 Repetitive nerve stimulation during ischemia (RNSisch-Test) and AchR-Ab in the follow-up of myasthenic patients – F. Giannini a, E. Venturini a, G. Bibbò a, R. Cioni a, A. Spreafico a, L. Bracci a, S. Passero a ( aDip. Neuroscienze e Biologia Molecolare, Siena, Italy) Objective: Besides the clinical assessment, the quantitative evaluation of the immunological state (AchR-Ab) and of the neuromuscular junction transmission (RNSisch-test) could be useful in the follow-up of myasthenic patients (Bergmans, 1980; Oosterhuis, 1983; Romi, 2000). The aim of this study is to compare the time-course of these parameters. Methods: After informed consent, 24 patients (13 M/11 F; 18–84 years), all positive for AchR-Ab, were recruited: 5 suffered from the ocular form and 19 from the generalized one. Five patients had previously undergone to thymomectomy and 8 to thymectomy; all were under appropriate pharmacological therapy. Each patient was observed longitudinally every 3 months (on average), by means of Oosterhuis’s clinical score, AchR-Ab titer (125iRadio Assay-DLD) and RNSisch-test (Bergmans, 1973). Therefore, a total of 240 measures was collected. Results: The RNSisch-test decremental pattern ranged from 0 to 85% and AchR-Ab titer from 0 to150 nmol/l; the two values significantly correlated (P , 0:001). The clinical score ranged from 0 to 4 and significantly correlated with RNSisch (P , 0:001), but not with the AchR-Ab titer. Conclusions: The RNSisch-test, easy and quick to perform, is a useful tool in the follow-up of myasthenic patient. 41 Intestinal pseudo-obstruction, ocular myositis and mysthenia gravis associated to thymoma – S. Greco, R. Ravenni, A. Trovato, P. Passadore, D. De Grandis (Department of Neurosciences; U.O. of Neurology, Clinical Neurofisiology; Civil Hospital, Rovigo, Italy) We report the case of a female patient who, after showing acute intestinal obstruction, developed a paresis diplopia of left eye’s abduction and, later, fluctuating ptosis and widespread hyposthenia. After detection of thymoma she has undergone a surgical operation to remove neoplasia and a corticosteroidal therapy associated to a cycle of plasmapheresis. The treatment improved hyposthenic and gastrointestinal symptomatology while abduction deficit remained unchanged. In literature, cases of disorders in intestinal motility associated to thymoma, as expression of the presence of neuronal nicotinic anti-receptor antibodies have already been described. Such a case was not proved in our patient. 39 42 Color visual evoked potentials in multiple sclerosis: correlations with severity and duration of the disease – B. Gregori, S. Rinalduzzi, G. Busonero, N. Accornero (Department of Neurological Sciences, “La Sapienza” University – Rome, Italy) Recent evidences suggest that visual evoked potentials (VEP) elicited by different chromatic stimuli increase specificity and sensibility of the method and can detect even subclinical visual impairment. Our aim is to study the reliability of this method in an elevated number of patients with multiple sclerosis at different stage of the disease. We have studied 140 eyes 2342 The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 of 76 patients with multiple sclerosis at different stage (from subclinical to more advanced cases, all with recognizable VEP). In all patients, we obtained VEP by achromatic pattern-reversal with different contrast values (grey and white), and by chromatic pattern-reversal (blue and red) with similar contrast values. Latencies of P1 component of different VEP were used to obtain chromatic and achromatic ‘contrast’ indices (blue-red/ blue 1 red, and grey-white/grey 1 white, respectively). Preliminar analysis of clinical and neurophysiological data suggest that: (1) absolute achromatic and chromatic P1-latencies are significantly related to disease severity and duration; (2) in the early stage of the disease, VEP elicited by red stimuli appeared significantly more affected. Indeed, the chromatic index allowed to detect visual conduction impairment even in subclinical cases in which absolute P1-latencies were still normal. This study confirmed the high specificity and sensibility of chromatic VEP in multiple sclerosis. Moreover, our data suggest that this method can be useful in the severity assessment and follow-up of the disease. 43 Predictive value of EEG reactivity and somatosensorial evoked potentials in the prognosis of grave post-traumatic coma – A. Grippo a, A. Amantini a, A. Piccioli b, S. Widmann a, C. Cesaretti a, V. Schiavone a, A. Ragazzoni c, C. Cossu a, F. Pinto a ( aDepartment of Neurological Sciences; bU.O. of Anaesthetics and Reanimation, Hospital Company Careggi; cU.O. Neurology, ASL 10, Firenze, Italy) We carried out a retrospective analysis on a group of 50 patients (mean age 27 years, range 16–72) in grave condition of post-traumatic coma according to Glasgow Coma Scale (GCS) #7. After 1 week they showed uncertain prognosis according to clinical evolution (variation in mean GCS score from 4.7 to 4.9). The following parameters have been considered: GCS at 1st and 7th day; EEG reactivity at 3rd and 10th day; stimulus PES of n.Medial at 10th and 12th day. The average duration of coma was 14 days (range 7–56). Clinical outcome was determined after 1 year by Glasgow Outcome Score. Fifty percent of the patients showed favourable outcome (fine recovery or moderate disability), the remaining 50% showed unfavorable outcome (grave disability, vegetative condition, decease). Predictive value for prognostic purposes of GCS, EEG reactivity and PESs was obtained by discriminating analysis (SPSS/PC 1 ). GCS prediction possibility was of 65.6% at the first determination and of 67.5% at the following one; the predictive value of EEG reactivity was, respectively, of 58.2 and 62.4%. PESs allowed to anticipate the prognosis exactly in 87% of the cases. These results underline the high predictive value of PESs. The last, though widely showed in literature, is confirmed also in our case histories, selected according to a criterion of coma seriousness and of high prognostic uncertainty. 44 Effects of carbamazepine and gabapentin on motor cortex excitability in humans: a study with repetitive transcranial magnetic stimulation – M. Inghilleri, A. Conte, F. Gilio, C. Lorenzano, F. Pedace, D. Perinelli, A. Berardelli (Department of Neuroscience, University of Rome “La Sapienza”, Italy) Objective: Repetitive transcranial magnetic stimulation (rTMS) is a technique which allows the stimulation of cortical motor areas at different intensities and frequencies. Trains of stimuli (5 Hz, suprathreshold intensity) progressively increase muscle evoked potential (MEP) size and cortical silent period (CSP) duration in normal subjects. We tested the modifications of motor threshold (Mth), MEP size and CSP duration evoked by rTMS before and 1 week after treatment with carbamazepine and gabapentin in 10 subjects suffering of trigeminal neuralgia. Methods: Trains of 10 stimuli (5 Hz, 120% Mth) were delivered with a Cadwell Magnetic High Speed Stimulator with a figure-8 coil positioned over the FDI muscle area of the left hemisphere. EMG activity was recorded from the FDI muscle contralateral to the side of stimulation. Results: Before treatment rTMS produced a significant increase in MEP size and CSP duration during the train. Carbamazepine and gabapentin did not produce significant changes in Mth and CSP duration; conversely they significantly reduced the facilitatory effect of rTMS on MEP size. Conclusions: Our findings suggest that carbamazepine and gabapentin modify the excitability of facilitatory cortical interneurones probably reducing post-tetanic potentiation already described in previous studies in animals. 45 EEG desynchronization/synchronization correlated to movement in patients with motor neuron disease – L. Leocani a, M. Corbo b, G. Galardi a, M. Cursi a, G. Magnani b, R. Fazio b, G. Comi a,b ( aDepartment of Neurofisiology; bNeurology, Scientific Istitute San Raffaele Hospital, Milano, Italy) The presence of disorders in executive functions has been reported with varying frequency and degree in amyotrophic lateral sclerosis (ALS) (Abe et al., 1997), while it has not been determined in primary lateral sclerosis (PLS). Frontal lobes play an important role in planning and control of voluntary movement. The functionality of cortical circuits deputed to movement programming and execution can be studied through eventrelated desynchronization (ERD) analysis. Event-related desynchronization of EEG senso-motor rhythms, in alfa and beta bands, is considered a cortical activation index during programming and execution of the movement. Beta rhytnms synchronization (ERS), occurring after the movement, is considered a correlate of cortico-spinal inhibition. We have considered ERD/ERS pattern during right hand voluntary movement through EEG at 29 channels in a group of 12 patients affected by ALS and 7 by PLS, with similar age distribution. Data have been compared to a group of 10 normal subjects of about the same age. During the preparation of movement ERD did not show significant differences in the two groups of patients compared to normal subjects at the level of primary counterlateral motor senso-motor area (C3 electrode), while it proved significantly increased in medial frontal areas (Fcz electrode, P , 0:02). At the end of the movement ERS in frontal and senso-motor regions resulted significantly reduced in both groups of patients compared to normal subjects (P , 0:02). Increased frontal ERD during the preparation of movement, facing a normal desynchronization at the level of primary senso-motor areas, is compatible with the compensational role of motor areas supplementary to motor deficit, while ERS reduction at the end of the movement can be the expression of both a reduction in peripheral afferences, correlated to hyposthenia, and an alteration of inhibitory circuits intervening at the end of the movement. 46 X-linked myopathy with excessive autophagy (XMEA): clinical and electrophysiologic study – R. Liguori, M. Villanova, M. Tassinari, P. Montagna (Institute of Neurology, Bologna University, Bologna, Italy) Objective: Clinical and electrophysiologic study of a patient with Xlinked myopathy with excessive autophagy (XMEA). Patient/methods: We studied a 32-year-old man with XMEA; he had had difficulty running since childhood; at age 20, standing up from a squatting position and climbing a ladder were difficult. At age 30 neurologic examination disclosed severe atrophy of the thigh muscles, strength in the thigh muscles was MRC 3/5, in the upper limb girdle muscles 4/5 and in the ankle dorsiflexor muscle 2/5; normal superficial and deep sensitivity, normal deep tendon reflexes and intelligence. Electromyographic (EMG) examination was performed with qualitative and quantitative analysis from different muscles; single fiber EMG and macro MUP analysis in brachial biceps and lateral vastus muscles; motor and sensory nerve conduction and late-responses study; muscle biopsy from right lateral vastus muscle. Results: Needle EMG examination revealed frequent myotonic and high frequency discharges in all muscles; quantitative MUP analysis showed increased occurrence of polyphasic MUPs, increased mean amplitude and normal mean duration; increased jitter and fiber density; normal macroMUP analysis; normal late-responses and sensory and motor nerve conduction velocities. Muscle biopsy showed abundant vacuolation of muscle fibers. Conclusions: XMEA is a rare hereditary myotonic myopathy. Electromyographic examination revealed abundant spontaneous myotonic activity associated with peculiar myopathic findings. The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 47 Somatosensory evoked potentials in prognostic evaluation of coma: a study in 134 patients – F. Logi a, C. Fischer a, F. Sartucci b, L. Murri b, F. Mauguière a ( aFunctional Neurology, Hopital Neurologique, Lyon, France; bDepartment of Neuroscience, University of Pisa, Italy) The aim of this study was to define the patterns of median nerve somatosensory evoked potentials (msSEPs) abnormalities in comatose patients, in relation to the etiology of coma. We examined of 134 patients (mean age: 50, 6 ^ 16.6 years; range 14–85) comatose after cardiac and respiratory failure (n ¼ 50), ischemic or hemorragic stroke syndrome (n ¼ 46), traumatic brain injury (n ¼ 23), complications of neurosurgery (n ¼ 12) and encephalitis (n ¼ 3). Bilateral mnSEPs were recorded according to the technique routinely employed in our laboratory, using an extracephalic reference: the cortical components following the P 14, to the N 30 were analysed. One month after the onset of coma all patients were classified in 3 categories. Awaken, not awaken and dead. In post-anoxic coma bilateral absence of cortical response or N20 , 0.6 mV (56%) proved to be associated to poor prognosis (no awakening) in traumatic coma bilateral absence of N20 (21.7%) did not always imply such a negative event and the outcome was not related to N20 component amplitude. The central conduction time (CCT) did not relate to the outcome in any group. The prognosis of coma is firstly related to its etiology so that for each group of patients we distinguishes different cut-off criteria as regards amplitude of N20, in order to better predict outcome. Indeed, recording primary cortex SEPs may foresee poor evolution after cardiac arrest but it is never sufficient to predict awakening, known to be better evaluated by late EPs. 48 Harlequin syndrome: clinical and neurophysiological study – C. Lombardi a, R. Vetrugno a, P. Cortelli a, F. Provini a, G. Pierangeli a, G. Plazzi a, M. Mascalchi b, R. Liguori a, G. Coccagna a, E. Lugaresi a, P. Montagna a ( aNeurological Institute, Bologna University, Bologna; bCareggi Hospital, Florence, Italy) Objective: Description of a patient with Harlequin syndrome and congenital Horner’s syndrome. Material and methods: We describe a 66-year-old woman with a 2-year history of asymmetry in sweating and flushing. The patient noticed that only the right side of her face flushed and sweated, particularly after exercise or in a hot room. Neurological evaluation showed left ptosis-miosis and enophthalmos, anisocromia and lower limbs hyporeflexia. The patient underwent evoked potentials, blink reflex, polygraphic examination, cardiovascular reflexes, study of sweating and circadian rhythm of rectal temperature. Results: In basal condition the polygraphic evaluation revealed an asymmetry of dilatation of skin vessels (plethysmogram) on the upper limbs (right . left). This finding was accentuated during and after provoking manoeuvres. During a spontaneous crisis, the sweating study disclosed left side anhydrosis of the forehead and asymmetry of upper limb sweating (right , left). Brain and spinal cord MRI showed multiple D1–D3 vertebral angiomas and multiple radicular cysts located at the level of the left C6–D1 root foramen. Angio-MR investigation showed tortuosity of the pre-petrous portion of the left internal carotid artery. Conclusions: Our patient showed anhydrosis of the left face associated with ipsilateral congenital Horner’s syndrome. These symptoms are characteristic of Harlequin syndrome. The enhanced vasomotor response and reduced sudomotor response on the right arm with respect to the left suggest a dissociation of the ‘drive’ along the sudo-vasomotor pathways. 49 Effects of repetitive transcranial magnetic stimulation on human cortical excitability – C. Lorenzano, F. Gilio, A. Conte, L. Fofi, N. Modugno, M. Inghilleri, A. Berardelli (Department of Neurological Sciences, University of Rome, Italy) Objective: At rest repetitive transcranial magnetic stimulation (rTMS) delivered to the motor cortex at 5 Hz frequency with a suprathreshold intensity, produces a progressive increase in the amplitude of motor evoked potential (MEP), due to mechanisms of intracortical facilitation (PascualLeone et al., 1994; Berardelli et al., 1998). We studied the spread of the rTMS-induced excitation in 7 normal subjects at rest. 2343 Methods: Trains of 10 stimuli were delivered at 5, 10 and 20 Hz frequencies (stimulation intensity 120% of the motor threshold) with a Magstim Repetitive Magnetic Stimulator. A figure-of-8 coil was placed over the contralateral first dorsal interosseus (FDI) motor area. The EMG activity was recorded simultaneously from FDI, forearm flexor (FF) and biceps muscles (BCP) contralateral and ipsilateral to the side of stimulation. Results: At rest the first stimulus of the rTMS produced an MEP simultaneously in the FDI and FF muscles which gradually increased in the amplitude over the train at all frequencies studied. In BCP muscle the MEP appeared only after the second/third stimulus and increased significantly over the train. rTMS did not produce a MEP in the FDI ipsilateral to the FDI motor area of stimulation. Conclusions: In conclusion rTMS at 5, 10 and 20 Hz frequencies produced a facilitation of MEP in the ‘target muscle’ (FDI) and the appearance of the EMG responses in near muscles. rTMS produced a progressive recruitment of the excitatory intracortical interneurones. 50 Lormetazepam residual effects in young adult healthy volunteers – M. Maestri, B. Nucciarone, G. Iudice, M. Fabbrini, S. Brotini, E. Bonanni, L. Murri (Department of Neurosciences, Section of Neurology, University of Pisa, Italy) Objective: To evaluate daytime vigilance, psychomotor performance and simulated driving in adult healthy volunteers after subchronic use of lormetazepam. Methods: Twelve subjects (7 women, 5 men, mean age 31 years), received lormetazepam 1 mg tablet and placebo for 3 days at night-time in a randomized, double-blind, double-dummy, cross-over design, with a 1 week interval between medication. On the morning following last drug administration, daytime vigilance was assessed by a 15-min battery of neuropsychological tests aimed at assessing memory and attention, simple and choice visual reaction times, and Epworth Sleepiness Scale. Afterward, an interactive, computer-based driving simulator (STISIM) was used to assess the effect of the study drugs on driving ability, and neurophysiological evaluation of sleepiness was performed using Multiple Sleep Latency Test (MSLT). Results: The findings showed that performance test results and sleep latency were similar when participants were treated with lormetazepam or placebo and did not significantly change as compared with baseline. Conclusion: The data suggest that subchronic use of lormetazepam 1 mg/day does neither influence daytime vigilance nor impairs psychomotor task performance and simulated driving. 51 Botulinum toxina and focal dystonias: a 10-year history – F. Mancini, C. Pacchetti, R. Zangaglia, S. Cristina, G. Nappi (UO Parkinson and Movement Disorders, Neurological Institute IRCCS “C. Mondino”, Pavia, Italy) It is more than 10 years since botulinum toxina (BT) has been considered the first-choice treatment for Focal Dystonias (FD). BT is a symptomatic and reversible therapy, so it needs to be repeated on average every 3 months along a patient’s life. BT short-term efficacy is widely showed by now, but there are still some missing data concerning its long-term effects (5–10 years) on FD course. In this retrospective study, among all the patients treated with BT in our Centre during the last 10 years, there has been the analysis of case sheets belonging to idiopathic patients suffering from Cervical Distonia (CD) and Blepharospasm (B). We examined 56 B and 33 CD patients’personal data (such as: sex, age and profession), referred-todisease data (such as: age at the appearance of FD, symptom susceptibility at stressing events, concurrent pathologies) and pharmacological data (such as: oral therapy, latency between diagnosis and first BT treatment and intervals between the treatments). The aim was to detect similarities and differences among subjects of the examined sample, concerning the course of BT treatments in the years. Moreover we have been looking for eventual correlations inside resulting data, aiming at the detection of prognostic indicators of long-term efficacy of BT therapy. Table 1 shows preliminary results of the study. A retrospective analysis of BT long-term effects on FD allows to detect some predictive factors concerning the prognosis of cronical and disabling pathologies, such as B and CD. 2344 Sex (M/F) Mean age at the appearance Mean interval between the treatments Mean wait between appearance and treatment Mean time from the first treatment Correlation interval/time from the first treatment Correlation interval/age at the appearance The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 Blepharospasm Cervical dystonia 13/42 53 ^ 13 years 11/22 46 ^ 18 years 137 ^ 85 days 197 ^ 221 days 9 ^ 17 years 9 ^ 16 years 4 ^ 2 years 4 ^ 3 years r ¼ 0.56 r ¼ 0.40 r ¼ 0.12 r ¼ 20.41 Description of two cases of POEMS syndrome – F. Manganelli a, R. Bruno a, M. Nolano b, L. Iadicicco a, F. Barbieri a, L. Santoro a ( aDepartment of Neurological Sciences, University of Naples “Federico II”; bMedical Centre “Salvatore Maugeri”, Telese T. (BN), Italy) POEMS syndrome is a rare multisistemic disorder which includes polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes. We describe two patients affected by POEMS syndrome. The first is a 45 year-old woman with a 2 year history of symmetric distal paresthesia and progressive severe muscle weakness and atrophy. The second case is a 41 year-old woman with 1 year history of symmetric distal burning paresthesia, pain and slight weakness prevalently in the lower limbs. Electrophysiological examination showed an axonal and demyelinating polyneuropathy more severe in the first patient. Laboratory investigation disclosed diabetes mellitus and IgG-lambda monoclonal serum protein in the one and thiroiditis and IgA-kappa monoclonal serum protein in the other. Organomegaly and skin hyperpigmentation were present in both. The sural nerve biopsy showed in the first a complete loss of the large myelinated fibres with signs of like-Wallerian degeneration, an epineurial small vessels destructuration and enlargement and a perivascular infiltration of inflammatory cells in one of them. In the second patient there was present a moderate loss of large myelinated fibres with like-Wallerian degeneration and some features suggesting demyelination. In both patients immunohistochemical study of glabrous skin was performed, that showed, in the first one, a marked loss of Meissner corpuscles and myelinated nerve fibers with evident anomalies of blood vessels. The two cases described, confirm that POEMS pathogenesis is still unclear and different mechanisms could be responsible for systemic involvement. 52 Negative myoclonus and modification EEG during treatment with valproate in a subject with epilepsy and a novel mithocondrial DNA mutation – R. Manni a, I. Sartori a, M. Versino a, M. Terzaghi a, C.A. Galimberti a, M. Diegoli b, E. Arbustini c, A. Tartara a ( aEpilepsy Centre, Neurological Institute “C.Mondino” IRCCS, Pavia, Italy; bIstituto Anatomia Patologica, University of Pavia; cLaboratori di Ricerca Area Trapiantologica IRCSS Policlinico S. Matteo, Pavia, Italy) Introduction: We report a case of negative myoclonus during valproateinduced encephalopathy in a subject with mitochondrial dysfunction. Case report: A 58 year old female, affected by focal cryptogenic epilepsy, after 4 months of valproate therapy (1000 mg/die) developed attacks characterized by ataxia, oculogyrus fits, nystagmus, dizziness, with or without headache. She developed also a deterioration of cognitive and behavioural abilities, postural tremor and myoclonus at limbs. The laboratory data were normal except for an increase of basal plasma lactate and pyruvate; a brain MRI was normal. A novel heteroplasmic mutation C8393T in ND5 gene (CCC ! TCC; Pro ! Ser) was identified. Heteroplasmia was assessed on DNA from blood and skeletal muscle. Three unaffected siblings carried the mutation. Valproate was withdrawn with an immediate clinical benefit. Method: These neurophysiological parameters were documented, during and after valproate: EEG, multimodal evoked potentials, recovery cycle for evaluation of cortical excitability, EMG, ENG, cortical magnetic stimulation. Result: EEG and EMG are simultaneously recorded while the patient was holding arms outstretched: it was recorded negative myoclonus, asynchronous between the two sides, prevalent at right. The technique of jerklocked back-averaging demonstrated a sharp transient at central and parietal controlateral lobe, preceding 95 ms the onset of myoclonus. An EEG showed diffuse slowing of the background rhythm and diffuse bouffee of slow wave. After withdrawal of valproate we observe a normalization of EEG and a marked reduction of negative myoclonus. Conclusion: The data suggested the causal role of valproate on negative myoclonus, such as described for other antiepileptic drugs. This possible role has a particular interest in clinical and physiopathogenic terms since it occurs in the context of a facilitation by a mitochondrial disorder. 54 Acquired cronical hepato-cerebral degeneration: video-presentation of two clinical cases and catamnestic study – R. Marchese, A. Primavera, G. Abbruzzese (Department of Neurological and Visual Sciences, University of Genova, Italy) The term ‘acquired cronical hepato-cerebral degeneration’ indicates a heterogeneous disorder mostly appearing with neurological and hepatic alterations, or with both. The spectrum of neurological manifestations includes neuropsychiatric disorders (apathy, somnolence and lethargy) and movement disorders (tremor, ataxy, chorea, Parkinson’s disease symptoms, myoclone, dystonia). We describe the clinical case of two patients who, together with episodic hyperammoniemia and decompensation of hepatic functionality, showed two different neurological description, both characterized by movement disorders. The first case concerns a female cirrhotic patient (HCV 1 ) who, as a consequence of high increase in hematic levels of ammonium, started to show involuntary movements of choreic type, widespread to cranial sector and limbs, rapidly worsening but reversible with a therapy aimed at internistic pathology. The second case concerns a young woman affected by cryptogenic hepatic cirrhosis who, after about 6 months, developed a very serious akinesic-hypertonic syndrome (not levodopa-responsive), started with hypomimy and micrography and developed with the appearance of widespread rigidity, bradykinesia, hypophonic dysarthria, limitation of vertical ocular motility and impossibility of postural changes. Following the two cases described above, we carried out a catamnestic study on 120 hepatophatic patients (considered for transplantation), looking for the possible occurrence of similar neurological disorders. Ten patients (8.3%) showed signs of suffering of extrapyramidal system characterized by kinetic and writing tremor at rest, rigidity at limbs and bradykinesia, not correlated to the presence of acclaimed hepatic encephalopathy. 53 55 Atypical infantile Fischer’s syndrome: clinical and neuropshysiological case report – S. Medaglini, S. Amadio, R. Bonfanti, R. Nemni, S. Bianchi, G. Galardi, G. Comi (Neurologic and Pediatric Department, IRCCS S. Raffaele, Milano, Italy) Fischer’s syndrome (FS) is associated with IgG antibody to GQ1b ganglioside. Several cases of Acute Ophthalmoparesis without ataxia are reported subsequent to infection or immunization. In these cases high IgG anti GQ1b antibody titers were present so to be categorized as an autoimmune disease related to FS and also called ‘atypical FS’. An 11 year old girl developed a 1-day history of fever without diarrhoea. Three weeks later she had sudden onset of double vision followed by mild bilateral eyelid ptosis. On admission to hospital she had bilateral abducens palsy 3 days after she developed impairment of adduction and vertical movements. No limb weakness, ataxia or areflexia were present. She was alert showing a normal mental state. Brain CT and NMR with gadolinium were normal. Blood and CSF examination did not show any abnormality, except for an increase (1:16) of anti Mycoplasma serum IgM. The research of anti Arch receptors antibody was negative. C.J. was isolated from stool speci- The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 men and treated with Claritromicina 400 mg/die for 7 days. High titers of anti-GQ1b IgG antibodies (1:500) were demonstrated. Neurologic signs began to improve after 3 weeks from onset with complete recovery and normalized anti GQ1b antibody titer 2 months later. Neurophysiological study showed normal brainstem auditory evoked response, EEG and EMGENG examinations. Circulating IgG antibodies can induce both pre and post synaptic transmission blockade but in our patient repetitive stimulation and single fiber tests resulted normal. This report shows the importance to research the presence of antibody against ganglioside GQ1b in all patients with ophthalmoplegia of unknown origin. 56 Neurophysiologic evaluation in post-traumatic plexopathies with neurosurgical direction – C. Minardi a, G. Staffa b, F. Rasi a ( aU.O. of Neurology; bDivision of Neurosurgery, “M. Bufalini” Hospital, Cesena, Italy) The aim of the present study is to detect the specific stages in neurophysiologic diagnosis and follow-up of post-traumatic plexopathy cases with possible neurosurgical direction. Plexopathies with possible neurosurgical direction answer to the following criterion: presence of a complete lesion of one element at least (root, trunk, cord, nerve) persisting 4 months after the trauma. The most probably successful forms are those with proximal clinical concerning. We report 6 cases subsequently examined and subjected to neurosurgical operation. Three stages have been detected in clinical and neurophysiologic evaluation: an early stage about 6 weeks after the traumatic event, an intermediate stage after 3 months and a late one after 5 months. Neurophysiologic study was directed, especially in the last stages, by neurosurgical evaluation detecting specific useful information for a correct elaboration of the operating program. The following relevant points have been pointed out: (1) electromyographic evaluation extended to trunk muscles; (2) detection of target muscles and reinnervation monitoring of such muscles; (3) determination of concerning level of specific plexus’ less important components for residual motor functionality to be used in suitable surgical techniques; (4) intraoperating monitoring completed the contribution of neurophysiologic study to neurosurgical management giving further diagnostic directions beyond neuroradiology contribution. To conclude this preliminary analysis we traced a register of neurophysiologic study directed both to a follow-up rationalization and to a more accurate diagnostic definition in collaboration with neurosurgical directions. 57 Neurophysiological follow-up of ulnar neuropathy at the elbow – M. Mondelli a, F. Ginanneschi b, E. Martorelli c, F. Giannini c ( aASL7; bNeurological Sciences Institute; cDepartment of Neurosciences, Siena University, Italy) Objective: To evaluate electrophysiological and clinical follow-up in 32 patients with elbow ulnar neuropathy (EUN). Methods: Twelve males (mean age 54.1 years) were surgically treated with incision of the arcuate ligament. The remaining 20 cases (11 men and 9 women, mean age 51.1) were not operated. EUN was diagnosed according to AAEM-AAN guidelines (Neurology 52 (1999) 688–690). The severity scale proposed by Antoniadis et al. (Neurosurgery 41 (1997) 585–591) and global neurophysiological scale based on 13-step evaluation were used (Giannini et al., J. Periph. Nerv. Syst. 6 (2001) 50). Results: After surgery, 9 out of 10 subjects showed good recovery, one case was unchanged. There was a significant improvement of all neurographic findings and global neurophysiological score (sign test). The follow-up of the non-operated cases, showed an improvement in clinical score in 6, a worsening in 6 and no change in 8 subjects. There was no significant modification of neurographic values and global electrophysiological score. At the diagnosis and at the follow-up both surgically treated and untreated cases showed a significant correlation between clinical and electrophysiological severity scores (Spearman test). Discussion: The normalization of the neurographic parameters was gained only in surgically treated cases with minor preoperative clinical and electrophysiological severity score. In non-surgically treated cases the improvement was noted only in idiopathic EUN. 2345 58 Carpal tunnel syndrome, menopause and hormone substitution therapy – P. Moretti, R. Chionna, G. Molteni, G. Comi, G. Galardi (Department of Neurosciences, Division of Gynaecotokology, Division of Medicine, IRCCS San Raffaele, Milan, Italy) Objective: To confirm the high level of carpal tunnel syndrome (CTS) in menopause and to verify the protective effects of the hormone substitution therapy. Methods: A questionnaire was distributed amongst patients in the menopause clinic to evaluate two aspects of CTS: the seriousness of the symptoms and the functional status (Levine et al., 1993). All patients, one after the other, where then divided into two groups on the basis of those who took hormone substitutions to those who did not. Results: The group of patients with CTS symptoms who were not on the hormone substitution treatment were 58.8% whereas those with the symptoms under treatment were 33.9%. This was the overall results taken out on 93 patients. The difference is statistically significant. Conclusions: These results demonstrate the high level of CTS in menopause and the protection given by hormone substitution therapy against CTS. This confirms how the female hormone profile performs a major rule in the pathogenesis of CTS in menopause. 59 Prevalence study of Parkinson’s disease in the Eolian and in the Elba arcipelago populations: study design – L. Morgante a, U. Bonuccelli b, G. Savettieri c, A. Epifanio a, A. Nuti b, G. Salemi c, P. La Spina a, M. Paino a, C. Di Perri a, R. Musolino a ( aDepartment of Neuroscience, University of Messina; bDepartment of Neuroscience, University of Pisa; cDepartment of Neuroscience, University of Palermo, Italy) Objective: This study is aimed at investigating the point and the age and sex-specific prevalence of Parkinson’s disease in the Eolian and in the Elba arcipelago populations. The secondary objective is to compare these rates with those of other Italian areas and with those obtained with other methodologies. Methods: The study population includes all subjects residing in the Eolian arcipelago (14 095 residents) and in the Elba arcipelago (29 940 residents) for a total of 44 035 residents on the prevalence day (January 1st 2001). We will ascertain cases of parkinsonism through a two phase design. During phase 1, the ascertaiment will be based on an indirect screening through information from clinical records of general practitioners and neurologists and prescription records of chemists. Concerning the cases at the onset of the symptoms, not yet diagnosed, a simple validated questionnaire will be administrated to study population aging over 40 years. In the second phase, those who will be screened positive will be examined clinically by a neurologist using a standardized diagnostic protocol. Diagnoses will be formulated using standardized diagnostic criteria. Conclusions: The number of expected cases will be between 34 and 113. Could the particular genetic and environmental condition of the islands modify the number of the expected cases? Tilting test in syncope – M.G. Natali-Sora a, C. Meloni b, O. Vimercati a, G. Comi a ( aDepartment of Neurosciences; bDepartment of Cardiology, IRCCS San Raffaele, Milan, Italy) Tilting test has come to be one of the most successful instruments for syncope diagnosis. Syncope is a frequent event; it represents the 3% of P.S. services’ requests and the 1–6% of admission causes. Diagnostic procedure faced by the patient affected by syncope is extremely variable as he does not follow a diagnostic procedure considering etiopathogenesis according to different age and costs. We have analysed the data concerning patients afferent to neurophysiology service from November ’99 to November 2000 with request for tilting test execution. One hundred and sixty patients (66 M and 94 F) aged between 11 and 80 have been exposed to the test (Sutton and Westminster Register). Patients result homogeneously distributed in the different decades. Twenty-five patients were sent to neurologists, 25 to cardiology specialists, and 110 to internists and general practitioners. The percentage of test-positives was not significantly different in the 3 groups. In the group of test-positives 38 subjects showed a mixed (cardioinhibitory and vasodepressive) response, 8 an exclusively 60 2346 The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 cardioinhibitory response, in one subject there was a diagnosis of POTS, in one of hypersensibility at the carotid sinus, in one of conversion syncope and in the remaining of vasodepressive syncope with different therapeutic implications. Tilting test has become popular in recent years as the most successful instrument to diagnose vasovagal syncope for its high clinicaldiagnostic, of outpatient execution and low cost value. 61 Prevalence of carotid stenosis in consecutive outpatients – F. Nobili, M. Delmonte, R. Vitali, C. De Leo, C. Barone, G. Rodriguez (Clinical Neuropshysiology and Clinical Internal Medicine 3 (DIMI), University of Genoa, Italy) Objective: To assess the incidence and severity of atherosclerotic lesions in an outpatient population. Methods: The incidence of carotid atherosclerosis was examined in 650 consecutive outpatients (377 women: 58%, mean age: 67.4 ^ 11.3; 273 men: 42%, mean age: 66.9 ^ 111.4) undergoing Duplex-scanning for the first time. By short clinical interview, proper indications were found in 77% of cases, but it was infrequently reported by the physician requesting the examination. Hypertension, hypercholesterolemia, cigarette smoking, diabetes mellitus, ischemic heart disease, other cardiovascular pathology (including the TIA-stroke syndromes) and asymptotic carotid bruit were the correct indications in this order. In the 23% of patients, no correct indication was found, the reason leading to examination being (in this order): lone vertigo, syncope, acuphenes, migraine and headache, aspecific ocular symptoms, amnestic episodes, non-focal paresthesias, cervical osteoarthrosis. Results: Among patients with correct indication, examination was normal in 5.2% ,30% stenosis of at least one arterial vessel was found in 52% of cases, 30–60% stenosis in 24.3% of cases and stenosis .60% in 6.3% of cases. Corresponding percentages among patients without correct indication were: 17.9%, 15%, 49.7%, 17.9%, 0% (P , 0:0001, chi- square test). Conclusions: These results confirm that proper evaluation of indications is needed to avoid unnecessary expenses. It is noteworthy that no surgical referral was identified among patients without correct indications. 62 Influences of upper limb somatosensory afferences on trigeminal motoneurons in man – E. Ortu a, G.F. Sau a, F. Deriu b, M. Milia b, M.V. Podda b, E. Tolu b, M. Maioli a, M. Porcheddu a, K.S. Paulus a, I. Magnano a, I. Aiello a ( aNeurological Clinic, University of Sassari, Italy; bDepartment of Biomedical Sciences, University of Sassari, Italy) In order to assess whether somatosensory afferences from upper limbs affect, as previously reported in animals, the excitability of trigeminal motoneurons, the duration and the latency of the two components of the masseterine exteroceptive silent period (ESP1, ESP2) were evaluated on 10 healthy volunteers aged from 20 to 35 years. They were instructed to maintain a constant submaximal isometric masseter contraction. EMG activity was simultaneously recorded from both masseter muscles. ESP was evoked by non-painful electrical stimulation of the mental nerve. Median and radial nerves were stimulated at the elbow at different millisecond intervals before mental nerve stimulation. Latency and duration of ESP1 and ESP2 were measured in basal conditions and at different interstimulus intervals after upper limb stimulation. The post-stimulus time histogram were used to measure both ESP1 and ESP2 latency and duration. The results show that median and radial nerves stimulation affect the trigeminal motoneuron excitability. 63 A new sensitive test for diagnosis of minimal conduction block – L. Padua a, I. Aprile a, M. Sabatelli a, P. D’Amico b, P. Caliandro a P. Tonali a ( aInstitute of Neurology, Università Cattolica, Roma; b Fondazione Pro Iuventute Don Gnocchi, Roma, Italy) The concept of motor nerve conduction block has gained more importance with the identification of new disease entities. In fact, the presence of motor conduction block greatly influences the diagnostic and therapeutical approach of neuropathies. In spite of the generally good sensitivity of the conventional nerve conduction evaluation, normal findings are still observed in a number of patients with clinical data strongly suggesting the presence of conduction block. We have developed a simple technique for the detection of conduction block by using SFEMG electrode. This test is based on the concept that from stimulation proximal and distal to a partial conduction block, several registrations from few muscle fibers could show some ‘blocked’ fibers (innervated by ‘blocked’ axons). To evaluate the usefulness, sensitivity and specificity of a new neurophysiological test for partial conduction block we studied 17 patients (17 nerves) with clinical picture strongly suggesting the presence of motor conduction block and 20 healthy subjects (40 nerves). Motor nerve conduction studies were performed with conventional surface technique and with the new technique we developed. Moreover we also evaluated patients with other neurological disease. According to recent AAEM consensus criteria, 5/17 cases presented ‘definite’ partial conduction block and 6 presented ‘probable’ partial conduction block. In contrast, 16/17 cases (94%) presented an evidence of conduction block at SFEMG conduction block test. The 5/6 cases that not filled in the AAEM criteria and that presented abnormal findings at SFEMG nerve conduction test could be considered affected by ‘minimal conduction block’. The sensitivity of this new test was greater than conventional test. The specificity was 100% (no abnormal findings in healthy subjects or patients with other diseases than neuropathy). SFEMG conduction block test is a sensitive, complementary, technique for diagnosis of minimal conduction block in patients with normal findings in standard nerve conduction studies. 64 Pergolide monotherapy efficacy in Parkinson’s disease: 1 year clinical and electrophysiological follow-up – D. Paladini, P. Guidoni, A. Cinti, F. Di Marzio, S. Cocci Grifoni (Clinica Neurologica, Ancona, Italy) The aim of our study was to evaluate pergolide monotherapy efficacy (average dose 3.6 mg/die) in early Parkinson’s disease (PD), particularly considering if this dopamine-agonist is able to control properly parkinsonian symptoms during the first year of treatment. We selected 20 de novo PD patients (stage I–II Hoen & Yahr): we excluded other parkinsonisms (vascular, toxic, pharmacological, etc.) submitting all the subjects to an accurate clinical history, neurological exam and neuroimaging (brain TC or MRI). We monitored PD patients in basal condition, 1 month after they started therapy, 6 months later and finally after 12 months. Each time clinical variations were verified using Unified Parkinson’s Disease Rating Scale (UPDRS). Moreover we submitted PD patients to electrophyisological tests (Long Loop Reflexes, LLRs). According to several studies, LLRs recorded from eminentia thenar are modified in PD patients: these changings are partially reversible after l-DOPA administration. Our results showed that pergolide monotherapy, after 1 month, determined a significant clinical improvement, with an overall UPDRS score decrease of 41%. These results were steady after 6 months (37% UPDRS score decrease) and after 12 months (42% UPDRS score decrease). Also LLRs studies showed a significant changing to the baseline with a progressive LLR1 amplitude decrease followed by LLR2 amplitude increase. According to our data pergolide monotherapy is efficacy to control parkinsonian symptoms in the first year as well as l-DOPA. 65 Neurophysiologic reports of motor implication in sensory, not neoplastic neuropathies – P. Passadore a, R. Ravenni a, M. Dall’Olio b, D. De Grandis a ( aDivision of Neurology, Clinical Neurophysiology; bU.O. Neuroradiology, Civil Hospital, Rovigo, Italy) Among sensory, uninflammatory neuropathies unrelated to the presence of neoplastic pathologies, some cases prove secondary to disorders of connective tissue or other autoimmune type disorders. Among the last it is possible to detect some situations where it is difficult to attribute an exact nosological description and where there is an almost exclusively axonal damage. The aim of this research is to evaluate the implication level of the motor side of peripheral nervous system in patients with no sign or clinical symptom of weakness and muscular atrophy, afferent to our laboratory of Clinical Neurophysiology for a description of cryptogenic sensory peripheral polineuropathy. At present we analysed 8 patients suffering from The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 symmetric sensitive peripheral neuropathy electrophysiologically proved. Muscular strength analysis, evaluated according to MRC scale, proved to be standard. In all the patients, after accurate laboratory screenings, we excluded: HIV infection, Lyme disease, diphtheritis, metabolic disorders, amyloidosis, endocrinologic disorders, dysprothidemies, neoplastic diseases, immunological disorders and vitaminic deficits. Cerebrospinal fluid analysis proved negative in every subject. In each of them we carried out a neurophysiologic study characterized by: (1) sensitive VDC of radial, medial, ulnar, and medial and lateral cutaneous nerves of the forearm bilaterally at upper limbs and superficial sural and peroneal at lower limbs; (2) VCM of medial, ulnar, peroneal and tibial nerves; (3) we calculated amplitude, area and duration of each CMAP and SAP; (4) F waves recorded by all the examined motor nerves calculating minimum latency; (5) further evaluations, such as: transcranial magnetic stimulation, multimodal evoked potentials, quantitative and qualitative needle EMG (T/A analysis) and blink reflex. Sensory responses proved completely absent in all the explored segments, both at lower and upper limbs. R1 component latency of blink reflex proved significantly increased in two patients. Signs of the implication of peripheral nervous system on the motor side were characterized by a significant reduction in amplitude and by an asymmetry in motor responses in 3 patients. In one of the patients there was a selective reduction of conduction rate at short segments level. In two patients there was a significant asymmetry of F waves’ latency at upper limbs. A patient presented an increase in the cramp activity asymmetrically at lower limbs. Selective reduction of motor conductions and the increase of latency values of R1 in blink reflex underline the presence of a multifocal heterogeneous damage with asymmetrical distribution, even in subjects where clinical aspects lead to a pure sensitive form. This datum, associated to a clinical improvement after Aferetic and with immunoglobulines treatment, is supposed to recognize these forms from ganglionopathy descriptions, suggesting, on the contrary, some similarities to multifocal cronical motor-sensory neuropathies. 66 Syntactic (P600) and semantic (N400) ERPs with Italian written words for language comprehension studies – I. Magnano, K.S. Paulus, M.G. Deriu, M. Zedde, I. Delogu, G.F. Sau, T. Pulina, I. Aiello (Institute of Neurological Clinic, University of Sassari, Italy) Over the last past decades the field of cognitive neuroscience has made enormous progress, also with respect to the language-brain relationship. One of the major goals in neurolinguistic research is language comprehension. Non-electrophysiological approach is given by linguistic eventrelated potentials (ERPs), which provide information about a number of specific components that can be linked to distinct aspects of language understanding. In particular, the separation of structure and meaning in language is associated with two main ERP features, P600 and N400, respectively. A recent trend in neurolinguistics is the association between different paradigms eliciting various ERP components with the possible advantage of specificity increase of this electrophysiological method. To standardize a method in Italian written words 20 healthy volunteers were studied using the association between a classic auditory oddball paradigm as preliminary assessment of cognitive status, and two linguistic tasks. The former detected postlexical syntactic integration aspects by a syntactic paradigm with reflexive-antecedent number agreement violations (‘Il bambino maleducato lanciano il gioco sul pavimento’), and the latter semantic memory by means of a word (‘tavolo-sedia’) – non-word (‘televisione-girlemgo’) paradigm. ERPs were recorded by 30 scalp electrodes to elaborate topographical maps. Subjects showed the expected central positive wave (P300) elicited by the auditory target stimuli, a late symmetric positive effect (P600) for syntactically incorrect sentences, and a broad negative deflection (N400) for semantically incongruent words. The association of P300 and linguistic ERPs could be useful to evaluate of subclinical language impairment such as those recognizable in early stage Alzheimer’s disease and selective cortical and subcortical hemispheric lesions. 2347 67 P300 and neuropsychological findings in a case of cerebellar cognitive affective syndrome – K.S. Paulus, I. Magnano, M. D’Onofrio, M. Deidda, P. Galistu, E. Ortu, G.F. Sau, M. Porcheddu, E. Aiello, C. Occhineri, I. Aiello (Institute of Neurological Clinic, University of Sassari, Italy) Recent functional neuroimaging and neuropsychological (NP) studies suggest that the cerebellum is implicated in diverse higher cognitive functions. In a neuroradiological and NP study Schmahmann and Sherman (Brain 121 (1998) 561–579) provide prominent non-motor deficits in 20 patients with diseases confined to the cerebellum and characterized by impairments of executive function, spatial cognition, language and emotional regulation of behaviour. They called this clinical entity ‘cerebellar cognitive affective syndrome’. Less attention has been directed to eventrelated potential (ERP) researches in cerebellar syndrome conditions. Thus, we examine a 68-year-old man referred to our observation with an acute onset of a cerebellar syndrome characterized by poor and transitory motor features, and predominant mental and behavioral disorders, such as disinhibition, perseverance, dysprosodia, disorientation, and loss of attention. The neuroradiological investigation (CT, MRI) revealed an extended ischemic lesion of the cerebellar cortex (vermis and posterior lobe hemispheres).To further investigate the cognitive dysfunction we recorded visual and auditory oddball ERPs, and conducted a NP study to assess executive functions, attention, language, short- and long-term memory. In the auditory ERP task the patient performed acceptable target responses obtaining a multipeaked, amplitude reduced P300 with normal early components (N1, P2). Because of the behavioral symptoms no visual task was correctly performed. The NP assessment revealed deficits in attention, executive function and long-term verbal and visuo-spatial memory. ERP and NP results strengthen the hypothesis of cerebral frontal cortex involvement in cerebellar syndrome patients, which is probably the consequence of cerebello-frontal cortex loop alterations. Especially the ERP features observed in this case are similar to those of patients with frontal lobe lesions and could explain the essential role of cortical frontal dorsolateral circuitry in the P300 genesis. 68 Brain activation during simple hand-fingers movements vs. handwriting: a functional magnetic resonance imaging study. – F. Pauri a, C. Del Gratta b, A. Ferretti b, G.L. Romani b, P.M. Rossini a,c ( aAfaR, Ospedale Fatebenefratelli Isola Tiberina, Roma; bITAB, Università di Chieti; cUniversità Campus Biomedico, Roma, Italy) Hand writing is a highly sophisticated cerebral function which requires a highly integrated brain-hand activity. In this respect few investigations through functional brain imaging methodologies have been shown. The aim of the present study is to analyze in detail within the same subjects the pattern of brain activation via fMRI when the healthy volunteer is performing hand-finger movement task or is writing with a pen Both these tasks have been compared when using the ‘dominant’ and the ‘ non-dominant’ hand. Six healthy volunteers, participated to this study, after their informed consent have been given and the protocol had received the approval of the local Ethics Committee. All of them were right handed according top the Edinburgh Inventory. They were instructed to perform two different motor tasks: a self-paced finger tapping and a writing exercise. The latter consisted in writing with pens several letter ‘ l’ without interruption and without visual feed back. Top detect areas of increased MR signal intensity due to the motor tasks, fMRI was performed during a rest condition and during each of the two motor tasks. Statistical comparison between activation due to finger tapping and writing task has been performed, for each hand separately. The finger movements performed with the right hand induced activation of primary motor (M1) and sensorimotor (S1) area, whereas the mean results for the same task performed with the left hand showed activation only of M1, even if the activated volume is higher. The right hand writing provoked activation of the same areas that the right finger tapping, but the M1 volume was about two times and half larger. The M1 volume activated by left writing was 3 times larger that the finger tapping performed with the same hand, whereas the Talairach coordinates indicated that the localization is the same. Supplementary motor 2348 The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 area (SMA was activated by both right and left hand at the same position: on the left closed to the median line. Inferior parietal regions were activated predominately by left-hand writing. The cerebellum was preferentially activated by tasks performed with the left, probably because more attention is devoted to the task when the non-dominant hand is involved. The mean difference between the two motor task seems to be the significant larger activation of M1 and the involvement of the parietal region during writing. The other major finding is the involvement of the left (dominant) cerebral hemisphere in both tasks, performed with the left hand. 69 Brain activation during hand-fingers movements vs. handwriting in patients with writer’s cramp: a functional magnetic resonance imaging study – F. Pauri a, C. Del Gratta b, A. Ferretti b, E. Cassetta a, G.L. Romani b, P.M. Rossini a,c ( aAfaR, Ospedale Fatebenefratelli Isola Tiberina, Roma; bITAB, Università di Chieti; c Università Campus Biomedico, Roma, Italy) Several disturbance have been found and used to explain to the pathogenesis of writer’s cramp: inability to efficiently control the force output during manipulative activities, wrong setting of the sensitivity of sensory input channels from the hand, combined abnormalities in the central motor command and central processing of sensory input, maladaptive plasticity. In order to better understand the patophysiology of this focal dystoina, fMRI was performed in 3 (two males and one female) patients affected by writer’s cramp during two different motor tasks: a self-paced finger tapping task consisting of the sequential opposition of the thumb to the other fingers at a frequency of about 1 s, and a handwriting exercise consisting in holding a pen and writing consecutively the letter ‘l’ without interruption and without visual feed-back. The examined subject was lying supine on the bed of the MRI scanner inside the magnet bore, with his head firmly held inside the receiver coil. Results were similar in the 3 patients. A smaller activation in the primary motor and sensorimotor areas during writing-in comparison with finger movements was found when the subjects used their right hand. Activation of supplementary motor area was found only during finger tapping. No differences were found when the left hand was performing the two tasks in the activation of primary motor area, but the supplementary motor area was activated only during finger tapping. Results confirmed an abnormal recruitment of cortical area involved in the motor control during the task-induced movement disorder in writer’s cramp dystonia. 70 Blepharospasm contralateral to peripheral facial nerve palsy: a case report – G. Pavesi, L. Cattaneo, D. Mancia (Istituto di Clinica Neurologica, Parma, Italy) Objective: To investigate electrophysiologically and with apomorphine challenge test a case of blepharospasm associated with peripheral facial nerve palsy (FNP). Methods: A 56-years-old woman came to our observation 1 month after the acute onset of FNP associated with a persistent involuntary contraction of the contralateral orbicularis oculis (Ooc) muscle. The patient was able to interrupt the contraction of the right eyelid, by manually lowering the left superior eyelid. Results: Needle EMG showed complete denervation of muscles of the left hemiface and blink reflex showed a compete efferent block on the left side. Blink reflex recovery curves of the right Ooc showed hyperexcitability of the R2 response. An apomorphine challenge test normalized the R2 recovery curve and reduced significantly the closure of the right eyelid. Placebo administration had no effect. Conclusion: The appearance of blepharospasm contralateral to FNP, relieved by lowering of the paretic eyelid has already been described. Facial nucleus excitability is known to increase bilaterally as an adaptive change in FNP. An animal model of blepharospasm has recently been developed by wakening of Ooc muscle, together with partial central dopaminergic depletion, in rat. In our case, hyperxcitabilty of the facial nucleus contralateral to FNP could be modified by the administration of apomorphine, suggesting a possible pathogenic role of dopaminergic depletion. 71 Functional interactions between motor axons and sensory axons in mixed human nerve – A. Pesenti, C. Cinnante, M. Pastori, S. Barbieri, G. Scarlato, A. Priori (Department of Neurosciences, University of Milan, IRCCS Greater Hospital, Milan, Italy) In mixed nerve sensory and motor axons are considered functionally independent. Nevertheless there are evidences of not-synaptic interactions among adjacent neural elements. We have carried out an analysis to see if the activity of sensory fibres can determinate functional modifications of motor axons in mixed human nerve. In 8 nerves of 5 healthy voluntary subjects (24–38 years) we have evaluated max CMAP, present rheobase (rh), estimated rheobase (rhs), time constant (t SD) of intensity-duration curve (IDC), of wrist’s ulnar nerve before and after the stimulation of interdigital cutaneous nerves by ring electrodes on homolateral finger 5 for 20 min at 40 Hz. Cutaneous stimulation (square wave, 0.1 ms) has been carried out at the lowest intensity to obtain the composed orthodromic sensory potential (CSAP) of the greatest amplitude. IDC has been determined for 50% CMAP of maximal CMAP using stimula of 1, 0.3 and 0.02 ms immediately before cutaneous stimulation and at the end of it. t SD and rhs have been determined through a linear transformation of IDC according to Weiss’ formula (1901). rh (before: 10.8 ^ 1.8 mA, after: 12.3 ^ 3.3 mA [mean 1 1 SD]; P ¼ 0:1 [Wilcoxon matched pairs test]) and rhs (before: 5.2 ^ 1.7, after: 5.4 ^ 2.6; P ¼ 0:74) and maximal CMAP amplitude (before: 10.9 ^ 1.8 mV, after: 10.2 ^ 1.7; P ¼ 0:37) do not change at the end of cutaneous stimulation. On the contrary the stimulation of cutaneous fibres produces a significant t SD extension (before: 165.9 ^ 39.2 ms; after: 200.3 ^ 48.9 ms; P ¼ 0:01) in motor axons. In conclusion, prolonged activation of sensitive fibres produces persisting modifications of bioelectric properties of nodal motor axonal membrane. This observation introduces the concept of prespinal not-synaptic sensor-motor functional interactions produced at axonal level in nervous trunk. 72 Occupational risk factors for carpal tunnel syndrome in Sardinian sheep breeders – M. Porcheddu a, G.F. Sau a, M. Maioli a, T. Marras b, A. Baldessaroni c, R. Tartaglia d, E. Ortu a, K.S. Paulus a, I. Magnano a, V. Perria a, I. Aiello a ( aNeurological Clinic, University of Sassari; bUnit of Occupational Health, ASL N1, Sassari; cUnit of Epidemiology, ASL di Firenze; d Ergonomic Research, ASL di Firenze, Italy) Carpal tunnel syndrome (CTS) is one of the most common work-related injuries and a leading cause of work disability, related to bending/twisting of the hands/wrists at work. The prevalence of CTS among manual milkers in Italy is actually unknown. Sardinia is one of the areas in the world with a very high concentration of sheep and sheep breeders that perform manual milking are still numerous, as consequence of several difficulties, both economical and environmental. The study objective was to identify the prevalence and work-related risk factors associated with CTS in sheep breeders in order to perform a prevention program. A random sample of 80 breeders, aged between 18 and 58 years, who practice manual milking was studied. Specific symptoms have been collected by a clinical-anamnestic questionnaire. In all of them, NCS of median and ulnar nerves were performed according to AAEM guidelines. The results obtained showed a very high prevalence rate of CTS in sheep breeders. A good correlation between electrodiagnostic findings and the amount of milkers’ working hours is suggested by statistical analysis. 73 Small fibres neuropathy in sclerodermic patients – V. Provitera a, M. Nolano a, N. Pappone a, C. Di Girolamo a, F. Lullo a, C. Crisci a, L. Santoro b ( a“Salvatore Maugeri” Foundation I.R.C.C.S. Medical Centre of Telese Terme (Bn) Italy; bDepartment of Neurological Sciences, University of Naples “Federico II”, Italy) In order to evaluate the implication of peripheral nervous system in systemic sclerosis, we have studied cutaneous innervation in 10 sclerodermic patients using immunohistochemical and cofocal microscopy. All the patients have been exposed to skin taking through a 3 mm-diameter punch from fibrotic areas and apparently uninjured areas. Nervous and vascular structures have been marked with anti-pgp, anti-coliv and anti-mbp anti- The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 bodies, and also with ulex europaeus agglutinin. All the patients have been exposed to the study of motor and sensory conduction rate, quantitative analysis of thermic and tactile thresholds of the perception of mechanical stimulus pain (pin-prick). Moreover to evaluate autonomic function patients have been exposed to the analysis of sympathetic-cutaneous response and of perspiration induced by pilocarpine through ionography enumerating sweat drops on a silicone mould (sylastic imprint test). In fibrotic skin and, less frequently, in apparently uninjured skin we detected a loss of epidermic nervous fibres, an impoverishment of sub-epidermic nervous plexus and a reduction in the innervation of vascular and glandular structures. Variable alterations of vascular tree were present particularly in fibrotic areas. Nervous and vascular alterations proved more evident in patients with a longer duration of the disease. The study of nervous conduction just showed slight wrist located anomalies in most subjects. We also noticed a widespread increase of thermic and tactile thresholds and a reduction in the perception of mechanical stimulus pain, more evident in distal sites. Sympathetic-cutaneous response proved normal in every subject in spite of a reduction in the density of sweat drops pointed out on the silicone mould. These data show a widespread and progressive damage of peripheral nervous system in sclerodermia with special concerning of small fibres. 74 Effects of thyroid hormones on cortical excitability – A. Quartarone a, S. Benvenga b, F. Battaglia a, V. Rizzo a, L. Bartolone b, C. Messina a, P. Girlanda a (Department of Neurosciences, Psychiatric and Anaesthesiological Science University of Messina, Italy; Department of Endocrinology, University of Messina, Italy) Objective: Given recent evidence that T3 may act as neurally active molecule within regions innerved by the locus coeruleus (LC), we studied the effect of thyroid hormones deficiency on motor cortical excitability in patient with hypothyroidism magnetic stimulation (TMS). Methods: Eleven patients with hypothyroidism and 12 age-matched healthy subjects were enrolled. Motor cortical excitability was evaluated by means of transcaranial magnetic stimulation. Resting (RMT) and active (AMT) motor threshold, MEP amplitude (recruitment curve), intracortical inhibition (ICI) and facilitation (ICF) at short intervals, paired pulse inhibition at long intervals, cortical and peripheal silent period duration(CSP, PSP) were studied. The patients were evaluated before treatment and in euthyroid phase, after 3 months of hormone replacement therapy. Results: At baseline, the CSP duration was prolonged (P , 0:05) while MEP amplitude, as showed by the recruitment curve, was reduced. In euthyroidism both CSP and recruitment curve showed a significant improvement. Conclusion: Patients with hypothyroidism showed a decreased in cortical excitability. These findings provide strong support for earlier proposal that triodothyronine may exert a critical role in cells receiving noradregenic innervation. Loss of pre-central components and strengthening of parietal components through vascular lesion of motor cortex – A. Ragazzoni a, R. Chiaramonti a, L. Ercolini b, M. Cosottini c, C. Navona d ( aU.O. Neurology; bU.O. Vascular Surgery, ASL Florence; c Radiology Chair, University of Pisa; dInformation Elaboration Institute, C.N.R., Pisa, Italy) It is well known that cortical or capsulary focal lesions can selectively alternate the components of short-latency somesthetical evoked potentials (SEP) recorded at frontal or parietal level. Such evidences imply the hypothesis of existing generators, separated according to the different components of SEPs, located in post-central (areas 3b and 1: N20, P24) and pre-central area (area 4: P22). The aim of the present contribution is to show SEP reports in two patients (male, 61 and 69 years old) with unilateral ischemic lesion involving motor cortex selectively. Exposed to carotid endoarteriectomy the two patients, awakening after the operation, showed Dx hemiplegia, without any associated sensory disorder. TC/RNM researches showed an interesting lesion which was, in a case, the lower part of Sn precentral area, and in the other, the almost total part of Sn motor cortex. SEPs (stimulation of wrist’s median nerve, derivation from 19 electrodes on the scalp, from cervical rachis, from Erb point) have been 2349 recorded both during surgical operation and after it, when we found the development of vascular cortical lesion. In both patients pre-central lesion provoked: (1) abolition of P22 and N30 components; (2) persistence of N20 and P24 components, which showed an evident amplitude increase (especially of P24 component, and of the corresponding frontal N24). These data confirm the pre-central origin (area 4?) of P22 component, already supported by numerous contributions in literature, and they also suggest that normally pre-central cortex has an inhibitory influence on primary somatosensitive cortex. Study partly financed by C.N.R. Coordinate Project ‘ARES’. 76 Impaired cortical inhibition in familial hyperekplexia: a transcranial magnetic stimulation study – D.A. Restivo, P. Bramanti, P. Di Bella, G. D’Aleo, E. Sessa, N. Muscarà, R. Ravenni, D. De Grandis (Centro per lo Studio ed il Trattamento dei Neurolesi Lungodegenti, Cattedra di Neurofisiopatologia, Università degli studi di Messina; Dipartimento di Neuroscienze. Ospedale Civile di Rovigo, Italy) Aim: To evaluate motor cortex excitability in familial hyperekplexia in order to test the hypothesis that cortical excitability may be abnormal in this disorder. Methods: Conditioning electrical or tap stimuli were applied to the basis of the nose 4–25 ms before a cortical magnetic stimulation (test stimulus) applied over the sternocleidomastoid muscle motor area, in 7 patients with familial hyperekplexia and 10 controls. The conditioning electrical stimulus was set to an intensity enough to elicit a bilateral R1 response of a blink reflex. Motor evoked potentials (MEPs) were recorded in sternocleidomastoid muscles. Moreover, the duration of the cortical silent period (CSP) and the cortical motor threshold was studied, using single pulse transcranial magnetic stimulation (TMS) in sternocleidomastoid and abductor digiti minimi (ADM) muscles of 7 patients with familial hyperekplexia and 10 normal controls. Results: MT was reduced in one out of 7 patients. However, group comparison of MTs showed no significant differences between patients and controls. CSP durations from sternomastoid muscles were reduced in 3/7 patients, and they were normal in the remaining 4 patients. CSP was normal in ADM in all patients. A significant increase of the conditioned MEP amplitude as compared with the unconditioned one was seen in all normal subjects at interstimulus intervals of 11 and 12 ms. These changes were significantly more remarkable in patients than in controls. Conclusions: It is known that the dysfunction present in hyperekplexia is due to a brainsteam involvement. In this study we were interested in learning whether this brainsteam hyperactivity can influence cortical excitability. Our findings suggest that cortical excitatory and inhibitory outputs are abnormal in hyperekplexia, probably as a consequence of brainsteam hyperexcitability, and that impaired functioning of inhibitory interneuronal circuits may play a role in this disorder. 75 77 Electrophysiologic evaluation of conservative treatment in carpal tunnel syndrome – S. Rinalduzzi, B. Gregori, N. Vanacore, N. Accornero (Dipartimento Scienze Neurologiche, Università di Roma, “La Sapienza”, Roma, Italy) The clinical usefulness of conservative treatment in early carpal tunnel syndrome (CTS) remains a matter of debate. The purpose of this study is to evaluate the short-term usefulness of combinate wrist splint and ketoprofen treatment for mild-moderate CTS. Eighteen hands with idiopathic CTS were identified in 13 patients, following the AAEM electrodiagnostic guidelines. Eleven hands were classified as mild CTS (decreased SNCV and normal DML) and 7 hands as moderate CTS (decreased SNCV and increased DML). Patients were instructed to wear the wrist splint and put local antinflammatory medication (ketoprofen) during the night for a period of 4 weeks. Neurophysiological examination and the Boston Questionnaire were performed by each patient before treatment and 1 month later. At follow-up, SNCV of median nerve showed a significant increase as regards the baseline value (II finger, 44.7 ^ 7.7 vs. 48.6 ^ 5.4, P , 0:05; III finger, 37.9 ^ 12.2 vs. 40.6 ^ 12.8, P , 0:05), while DML decreased (4.3 ^ 0.8 vs. 3.9 ^ 0.6; P , 0:005). The total score of the Boston Questionnaire 2350 The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 improved after treatment (48 ^ 17.1 vs. 38.4 ^ 14.7; P , 0:005). These results suggest an improvement of clinical and neurophysiological data after 4 weeks of combinate ketoprofen and wrist splint treatment in mildmoderate CTS. 78 Transcranial magnetic stimulation as trigger of dystonic attacks in a patient affected by paroxysmal dystonia – V. Rizzo, A. Quartarone, S. Bagnato, G. Gallitto, V. Dattola, A. Scalfari, R. Raineri, P. Girlanda (Department of Neurosciences, Psychiatric and Anaesthesiological Science University of Messina, Italy) We describe a patient of 22 years old with attacks of paroximal dystoina which started with a feeling of stiffness in both hands and forearms followed by abduction of the thumb and by tonic co-contraction of the forearm flexor and extensors muscles resulting in slight wrist flexion. Moreover there was a rotation of the head on the right and a torsional component involving trunk muscles. The attacks were induced by voluntary movements and lasted between 5 and 10 s with 1–5 attacks per day. Dystonic attacks with the same pattern were induced by trans- cranial magnetic stimulation (TMS). The occurrence of reflex epilectic seizures was excluded by means of EEG recording before and after the TMS induced dystonic attacks by using TMS. The main finding was an increase in the amplitudes of the cortical elicited responses in hand muscles. Resting (RMT) and active (AMT) motor threshold, paired pulse and evaluation of sensory-motor integration were tested between attacks. these parametres were normal and can help to differentiate paroximal dystonia from task specific dystonias. spectral power density (SPD) of neurographic signal derivable from subthalamic nucleus (STN). We have analysed the neural signals coming from 10 STN belonging to 5 Parkinson’s disease patients. Neural activity has been obtained by concentrical microelectrodes (Inomed mod.230760, impedance ,1M() and referred to STN stereotaxic coordinates, by means of a special TC-T2MRI (Neuroplan-Radionics) image fusion algorithm. Signals have been recorded on magnetic support, converted into 16 bit digital format, sampled at 22 050 or 44 100 Hz according to the passing band (100–10 000 Hz; 100–20 000 Hz). Spectral power density (SPD) has been calculated out of the line in positions being 1 mm far from each other along the electrode penetration trace from 5 mm cranially to 7 mm caudally to STN. In 5 nuclea it has been possible to characterize biphasic morfology single spikes: [mean ^ SD] rise-time 193.5 ^ 25.2 ms, decay-time 159.1 ^ 34.4 ms, useful band ,2.31 ^ 0.6 KHz. Inter-spikes intervals’ distribution is poissonian, mean interval is 21.33 ^ 33.91 ms (46 Hz) and we noticed an increase of 45% of shooting frequency related to limbs’ movements. In these nuclea with identifiable spikes SPD analysis documented selectively, in correspondence to STN, the typical increase of mean power in a wide band of frequency 0.1–5 KHz. In the remaining 5 STN where spikes could not be identified SPD analysis always showed, in correspondence to STN, the typical increase of mean power in the band, i.e. 0.1–5 KHz. Our results characterize quantitatively biphasic spikes derivable from human STN and for the first time they show that, even in absence of spikes, STN can be electrophysiologically located by intraoperating calculation of spectral power density (SPD). 81 79 Long-term Donepezil administration to Alzheimer’s patients qEEG–MMSE correlations – G. Rodriguez a, P. Vitali a, F. De Carli b, F. Copello c, F. Bollati a, N. Girlter a, C. De Leo a, F. Nobili a ( aClinical Neuropshysiology (DIMI), University; bCNR; cPreventive Medicine S.Martino Hospital, Genoa, Italy) Objective: To evaluate qEEG–MMSE changes and correlation in patients with Alzheimer’s disease (AD) during long-term Donepezil (D) administration. Methods: Twenty-four patients (17 women, mean age: 75.2 ^ 7.1) with mild-to-moderate AD were studied before and during D (5 mg/day) therapy. All patients were scored on MMSE and underwent qEEG with power spectral analysis. The remaining 20 patients (4 excluded due to artefacts) (T group: 14 women; mean age 75.2 ^ 7.1; basal MMSE score: 19.9 ^ 4.5) were followed-up for 12.3 ^ 3.6 months and were re-examined by qEEG and MMSe. Eleven patients (6 women, mean age 73.5 ^ 6, basal MMSE score: 22.3 ^ 4.1) followed-up with qEEG and MMSE for 13.7 ^ 3.95 months without treatment were the controls (C group). The ratio between 6.5 and 12 Hz and 2–6 Hz band power was considered in 4 regions (frontal and temporo-parietal in each hemisphere) by averaging values from couples of leads (F3–F7, P3–T5, F4–F8, P4–T6). Results: MMSE score (group T: 21.7 ^ 1.9; group C: 24.3 ^ 2.2; P , 0:01) and ratio in frontal regions (F4–F8: P ¼ 0:007; F3–F7: P ¼ 0:02) reduced less in group T than in group C, but not ration in temporo-parietal regions (P4–T6: P ¼ 0:05; P3–T5: P ¼ 0:07) (Wilcoxon test). The correlation between ration and MMSE changes was significant the right frontal region (P ¼ 0:007). Conclusion: Cholinergic therapy improves the background activity with respect to slow activities, the latter representing disease worsening in both groups. 80 Electric activity of subthalamic nucleus: spikes’ analysis and characterization of spatial profile of spectral power density – M. Rohr a, A. Pesenti b, M. Egidi b, P. Rampini b, M. Locatelli b, F. Tamma c, E. Caputo c, C. Marcias b, A. Pellati b, M. Corbetta b, V. Bruno b, C. Cinnante b, A. Bianchi a, G. Baselli a, R.M. Villani b, G. Scarlato b, S. Barbieri b, A. Priori b ( aDepartment of Bioengineering, Polytechnic of Milan; bDepartment of Neurosciences, IRCCS Greater Hospital, Milan; cNeurological Clinic, San Paolo Hospital, Milan, Italy) The aim of the present work has been to characterize spikes and calculate Sympathetic skin response evoked by laser skin stimulation – P. Rossi a, A. Truini b, M. Serrao a, A. Martini a, G.D. Iannetti b, G. Cruccu b ( aIstituto di Clinica delle Malattie Nervose e Mentali, Università degli studi di Roma “ La Sapienza”, Rome, Italy; b Dipartimento di Scienze Neurologiche, Università degli studi di Roma “ La Sapienza”, Rome, Italy) Objective: To evoke sympathetic skin response (SSrs) in healthy subjects using laser stimulation and to compare these responses with those induced by conventional electrical stimuli. Methods: Twenty healthy subjects were investigated. The SSr was obtained by using non-painful electrical (eSSR) and laser (lSSR) stimuli delivered to the wrist controlaterally to the recording site (palm of the hand).The symphatetic sudomotor conduction velocity (SSFCV) was measured in 8 subjects by simultaneously recording the SSR from the hand and the axilla. The reproducibility of the eSSR and lSSR latency (L) was studied as well. Results: The lSSR latency was significantly longer than that of eSSr (mean lSSRL ¼ 1.7 ^ 0.145, mean eSSRL ¼ 1.56 ^ 0.14, P , 0:05; median lSSRL ¼ 1.7 ^ 0.146, median eSSRl ¼ 1.57 ^ 0.13, P , 0:05).The lSSR amplitude (A) was lower than eSSR amplitude (mean lSSRA ¼ 1.31 ^ 0.26, mean eSSRA ¼ 2.59 ^ 0.49, P , 0:05). No significant difference, between the lSSR and eSSr, was observed for the SSFCV, and the variability and reproducibility parameters. Conclusion: Our findings have shown that SSRs can be easily induced by laser stimuli and that this method shares the same technical limitations of conventional eSSR in terms of variability and reproducibility. 82 Rapid modifications of the neuronal excitability in the human somatosensory system induced by percutaneous lateral cervical cordotomy: a somatosensory evoked potential study – T. Rosso a, M. Tinazzi a, S. Farina a, G. Zanette a, S. Ischia b, G. Finco b, A. Fiaschi a (Department of Neurological Sciences and Vision, Neurorehabilitation Unit, University of Verona, Italy; bInstitute of Anesthesiology, Pain Therapy Center, University of Verona, Italy) Evidences in animals and humans have shown somatosensory reorganization induced by sensory deprivation, in the primary somatosensory cortex (S1) and subcortical structures. Besides this form of ‘topographical’ plasticity, recent researches in animals suggest that plastic changes can occur across different sub-modalities of the somatosensory system. We recorded spinal (N22), brainstem (P30) and cortical (P37, N50 and P60) somatosen- The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 sory evoked potentials (SEPs) by stimulation of the posterior tibial nerve at the ankle, before and 1 day after lateral percutaneous cervical cordotomy (PCC) (section of the spino-thalamic tract). Patients were affected by chronic drug-resistant malignant monolateral pain: 6 suffered from pain on the left side (4 with Pancoast syndrome, two with thoracic pain); one subject had right dorsal pain. All of them developed deep analgesia after PCC, with a sensory level at C5–C3. Amplitudes of cortical responses, by stimulation of the analgesic side, significantly increased after PCC. Spinal N22 and brainstem P30 were not modified, as well as responses from the healthy side. Our results suggest that spino-thalamic deafferentation may induce in human a rapid modulation of neuronal activity at the level of S1, providing evidence of short-term cortical plasticity across somatosensory sub-modalities. Unmasking of cutaneous-proprioceptive afferents projections, induced by spino-thalamic deafferentation, may be one of the mechanisms underlying cortical SEP enhancement. 83 Negative myoclon induced by intracerebral electric stimulation of motor supplementary area – G. Rubboli a, R. Mai b, L. Tassi b, S. Francione b, G. Lo Russo b, F. Cardinale b, S. Meletti a, F. Rondelli a, C.A. Tassinari a, C. Munari b ( aDepartment of Neurological Sciences, University of Bologna, Hospital Bellaria, Bologna; bCentre of Epilepsy Surgery “C. Munari”, Hospital Niguarda, Milano, Italy) Aim: To test the hypothesis proposing the implication of motor supplementary area (MSA) in the genesis of negative myoclon (NM) (Tassinari et al., 1995). Methods: By means of stereo-electroencephalographic methodology (SEEG) aiming at pre-surgical evaluation, we have studied two patients affected by drug-resistant partial epilepsy. Both patients showed crisis compatible with the participation of frontal structures; etiology was posttraumatic (patient 1) and cryptogenetic (patient 2). Patient 1 has been explored unilaterally, patient 2 bilaterally. SEEG exploration concerned frontal structures: lateral and mesial (including MSA) and parietal (in both patients), and middle-front temporal in patient 1. Low-frequency (1 Hz) intracerebral electric stimulation (IES) was carried out as functional mapping, with the supply of electric stimula (duration: 3 ms; intensity: 0.2– 3 mA) through pairs of adjacent contacts for each SEEG electrode. During the whole procedure EMG activity of both deltoids has been monitored. Results: In both patients, MSA’s IES (at intensities between 1.2 and 3 mA) induced short losses in postural tone, compatible with a NM, at the upper limb counterlateral to the stimulated MSA. The correlated EMG was represented by a short phasic inhibition of EMG activity, preceded by no muscular strengthening. (such as a motor evoked potential, MEP). In patient 1, NM silent period duration increased proportionally to the increase of stimulus’intensity: 35.3 ^ 13 ms at 1.2 mA, and 48.4 ^ 15 ms at 3 mA (P , 0:01); stimulus’latency was about 75 ms. The stimulation of primary motor area (intensity: 0.4 mA) evoked a MEP in counterlateral deltoid with a latency of 15 ^ 3 ms, followed, at a latency of 51.7 ^ 6 ms, by a silent period with duration of 189.8 ^ 30 ms. Conclusions: Our results show that electric stimulation of MSA can induce phasic negative motor phenomena, suggesting that this area can play a role in NM genesis. 84 Reversal of synaptic plasticity impairment in a conditional model of Huntington’s disease – A. Sant’Angelo a,c, F. Battaglia a,c, A. Yamamoto b, A. Quartarone c, G. Vita c, A. Toscano c, R. Hen b, O. Arancio a,c, P. Girlanda c ( aAnatomy and Cellular Biology Department, SUNY Brooklyn, NY 11203, USA; bCenter for Neurobiological and Behaviour, Columbia University, New York, NY 10032, USA; cDepartment of Neuosciences, Psychiatric and Anaesthesiological Science, University of Messina, Italy) Objective: A conditional experimental model of Huntington’s disease has been generated by using the tet-regulatable system. Mice expressing a truncated N_terminal mutated huntingtin showed neuronal inclusions and other characteristics nueropathologic changes together with progressive motor dysfunction, that were reserved by blockade of the gene expression. 2351 We have explored whether the expression of the mutated protein changes hippocampal long-term potentiation (LPT). Methods: We generated input-output curves by plotting the stimulus voltage against the slope of the field EPSP. We elicited paired pulse facilitation by using 4 interstimulus intervals (300, 200, 100, 50 ms).LTP was induced through a theta-burst stimulation applied to the Schaeffer-collateral fibers in hippocampal slices. Field-excitatory postsynaptic responses were recorded from Ca1 neurons. Results: Mutant mice showed a 122% (n ¼ 12 slices) increase compared to baseline values 60 min after the stimulation, whereas wild type animals showed 180% increase (n ¼ 12 slices). Blocking the gene expression reserved the LTP impairment. Conclusions: Thus, expression of a mutated huntingtin causes an impairment of synaptic plasticity that could underlie cognitive changes in disease. We demonstrate that a continuos influx of the mutant protein is required to maintain of LTP in hippocampus, raising the possibility that cognitive deficit in HD may be reversible. 85 Colour PERG abnormalities in ‘de novo’ Parkinson’s disease – F. Sartucci a, C. Lucetti a, U. Bonuccelli a, L. Murri a, C. Orsini b, V. Porciatti b ( aDepartment of Neuroscience, Institute of Neurology, University of Pisa; bInstitute of Neurophysiology, CNR, Pisa, Italy) Dopamine is a neurotransmitter found in the retina and it has been suggested that an altered intraretinal dopaminergic synaptic activity might underlie some visual processing abnormalities in Parkinson’s disease (PD). In a previous work we noted that cortical VEPs to blue-yellow (B-Y) chromatic stimuli were more vulnerable than those to red-green (R-G) and black-white stimuli (Sartucci et al., Invest. Ophthalmol. Visual Sci. 40(4) (1999) S822). This study is focused on the relative involvement at retinal level of pathways to R-G and B-Y equiluminant stimuli compared with those to achromatic luminance yellow-black (Y-Bk) stimuli in PD. Data were obtained from 12 ‘de novo’ PD patients (mean age 60.1 ^ 8.3 years, range 46–74) at early stages of disease, not undergoing treatment with lDOPA, and from 12 age- and sex-matched healthy adults. PERGs were recorded monocularly in response to equiluminant R-G, B-Y and Y-Bk horizontal gratings of 0.3 c/deg and 90% contrast, reversed at 1 Hz, displayed on a TV monitor at a viewing distance of 24 cm (59.2*59 deg field). Mean PERG amplitude was dramatically reduced by about 45% for both chromatic- and luminance stimuli; mean latencies were significantly delayed and the amount of delay was stimulus-dependent (R-G: 4.5 ms; BY: 14.3 ms; Y-Bk: 5.7 ms), suggesting a differential retinal impairment of visual subsystems, at least in the early stages of the disease, in PD patients. In summary, the present data indicate that also chromatic PERGs are altered in PD before l-DOPA therapy. Overall B-Y equiluminant stimuli exhibited the largest changes, confirming that VEPs to B-Y chromatic stimuli are more vulnerable than those to R-G and Y-Bk stimuli. 86 Presentation of a database for patients affected by autoimmune myasthenia gravis – C. Scoppetta a, F. Babiloni a, L. Bianchi b, P. Onorati a, B. Mercuri a, F. Eusebi a ( aDip. Fisiologia umana, Università La Sapienza; bDip. Scienze Neurologiche, Università Tor Vergata, Italy) Objective: Regarding autoimmune myasthenia gravis (MG) many questions are unanswered concerning mechanism inducing both the onset and the relapses of the disease; both therapeutical interventions and the risk/ benefit balance are often empiric and arbitrary. Moreover: what dosages of corticosteroids are needed to arrest the activity of the illness and to prevent the relapses? What dosages and duration of treatment are safe and what are at risk of complications and side-effects? We are trying to respond to these questions by preparing a database for patients affected by MG. Methods/results/conclusions: The relational database was designed and built up to restore graphical and statistical information about the trend of variables in terms of time course. The query program of the relational database runs in a Windows (98, 2000 versions) software installed on a personal computer and it was implemented by using C11 language with a Paradox database engine. This was due to the particular statistical opera- 2352 The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 tions required to the database; these requirements are not met by commercial programmes. A second goal will be to put the database on MG on the Web to allow remote research units to connect with it. different afferents may activate different central neural networks with separate functional significance. 89 87 Neurophysilogical evaluation of spinal and cortical excitability in unaffected upper limbs of patients with spastic paraparesis during continuous intratechal baclofen infusion – M. Sensi, E. Gastaldo, E. Iezzi, J. Capone, R. Quatrale, V. Tugnoli, R. Eleopra (Neuroscience Department, S. Anna Hospital, Ferrara, Italy) Background: In literature there has been studied in details the neurophysological effect on spinal excitability of continuous IntraThecal Baclofen infusion (ITB) while the influence on cortical excitability has not been well characterized. Objective: The aim of this study was to verify the peripheral, spinal and cortical modifications after ITB in the non-affected limbs of patients treated for spastic paraparesis. Methods: We studied 3 patients with lower limbs spasticity due to traumatic spinal cord injury (at dorsal level). Before and during ITB at doses of 100,150, 200, 250 mg/day we examined in the right non-affected upper limb the following electrophysiological parameters: the maximum peak to peak amplitude, the mean area of CMAP, the F wave from ABP elicited by median nerve stimulation, the H reflex and M response recorded from flexor carpi radialis and stimulation of median nerve, cutaneous and mixed nerve silent periods (CSP and MNSP) by stimulation at the tip of index finger and median nerve at the wrist. Evaluation of motor cortical excitability with TMs were: resting and active threshold, MEP amplitude, duration of cortical silent period. The study of intracortical facilitation and inhibition were done with paired pulse technique with interstimulus intervals of 12 and 3 ms, respectively, recording from ABP. Results: In all patients we have observed early changes of CSP and MNSP, H reflex and M response and cortical silent period that were proportional to the dosage of the drug delivered. The modification of cortical facilitation and inhibition were less significant compared with the other parameters examined. Conclusion: ITB determines early and significant neurophysiological modifications not only at spinal level but also on cortical excitability. 88 Cutaneous afferents mediating the cutaneous silent period in the upper limbs: evidences for a role of low threshold sensory fibers – M. Serrao a, L. Parisi a, A. Martini a, F. Pierelli b, P. Rossi a (Istituto di Clinica delle Malattie Nervose e Mentali, II Clinica Neurologica, Università di Roma “La Sapienza”; aIstituto di Clinica delle Malattie Nervose e Mentali, Università degli Studi di Roma “La Sapienza”, Italy; bIRCCS Neuromed, Pozzilli (IS), Italy) Objectives: To evaluate the contribution of the low-threshold afferents to the production of the cutaneous silent period (CSP) in the upper limbs. Methods: The CSP was studied in 10 healthy adults and 4 patients with Friedrieich’s ataxia. The following neurophysiological aspects were studied: (a) relationship between sensory threshold (ST), sensory action potential amplitude (SAP) and CSP parameters; (b) habituation and recovery cycle of the CSP at different stimulus intensities (2 £ ST and 8 £ ST); (c) pattern of responses in distal and proximal muscles at different stimulus intensities (2 £ ST and 8 £ ST). Results: (a) The CSP occurred at low intensities (1 £ ST and 2 £ ST) and increased abruptly between 3.5 £ ST and 4 £ ST (corresponding to the pain threshold). The SAP amplitude was saturated before CSP saturation. In the patients with Freidreich’s ataxia, the CSP appeared only at higher stimulus intensities (6 £ –8 £ ST). (b) The CSP evoked at 2 £ ST showed a fast habituation and slow recovery cycle whereas the opposite behaviour was found at 8 £ ST. (c) Low threshold stimuli induced an inhibitory response restricted to the distal muscles. High intensity stimulation produced an EMG suppression significantly increasing from proximal to distal muscles. Conclusions: Our findings support the notion that low-threshold afferents participate in the production of the CSP in the upper limbs. The Cognitive and attentive variations induced by long-lasting exposition to traffic noise: an MEG study – F. Tecchio a,b, F. Zappasodi a, P. Chiovenda c, F. Moffa c, P. Pasqualetti b,c, F. Tomei d, F. Iecher e, R. Riservato d, M. Iosue d, A. Martini d, G.L. Romani f, P.M. Rossini b,c,g ( aIESS-CNR, Rome, Italy; bIRCCS “S. Giovanni di Dio-Fatebenefratelli”, Brescia, Italy; cAFaRCRCCS, Dip. Neuroscienze, Osp. Fatebenefratelli, Roma, Italy, dDip. Medicina del Lavoro, Univ. La Sapienza, Roma, Italy; eDirezione Servizi Sicurezza del Lavoro, Comune di Roma, Italy; fITAB and Istituto di Fisica Medica, Università “G.d’Annunzio”, Chieti, Italy; gNeurologia, Università Campus Biomedico, Rome, Italy) The aim of the present study was to quantitatively evaluate the effects of long-lasting exposition to environmental noise on cognitive and attentive abilities, as well as on anxiety and mood states in risk-workers categories. In particular, 40 policemen working in the noisiest city areas were taken into account. Results were compared to those found in 40 office-workers. Neurophysiological and neuropsychological evaluations were performed to identify possible cerebral activity alterations during discriminative cognitive tasks, and relate them with individual anxiety level (state- and traitanxiety) alterations. Electroencefalographic (EEG) and magnetoencefalographic (MEG) recordings during electrical odd-ball paradigm were performed using a 28-channels system within a magnetically shielded room. Cerebral activation subtending discrimination tasks (the so-called P300/P300m responses) was studied in relaxation and during audition of traffic noise (recorded in a Roma’s area with very heavy traffic); the same two conditions were considered following the performance of the ‘Stroop’ test (creating a stressing condition). Parallel to neurophysiological examination, neuropsychological evaluation was assessed: general cognitive (Raven progressive matrices(PM38)), attentive abilities (digit span of Weschsler Adult Intelligence Scale; visual search matrices), concentration abilities (arithmetic tests of Weschsler Adult Intelligence Scale) were evaluated in relation to anxiety characteristics of individual personality and those anxiety aspects related to his/her work environmental conditions (STAI-State-Trait Anxiety Inventory) and in relation to different mood states (POMS, Profile of Mood States). Preliminary results showed negative correlation between anxiety, depression, aggressiveness, and tiredness levels as evaluated by POMS test, and amplitude of cerebral responses in the 4 different conditions. Moreover, combined exposition to stress-evoking condition and traffic noise audition induced alterations in the cerebral activation subtending discrimination abilities. 90 Deficits of temporal discrimination in dystonia are not influenced by spatial variables – M. Tinazzi a, A. Fiaschi a, E. Frasso a, T. Rosso a, F. Cortese b, S. Farina a, S.M. Aglioti c ( aDepartment of Neurological Sciences and Vision-Neurorehabilitation Unit, University of Verona, Italy; bMultifunctional Rehabilitation Institute, “Chiarenzi” Hospital, Zevio-Verona, Italy; cDepartment of Psychology, University of Rome “La Sapienza” and IRCCS, “S. Lucia” Foundation, Roma, Italy) Idiopathic dystonia is a still poorly understood neurological syndrome characterized by sustained and involuntary muscle contractions which lead to abnormal postures and repetitive movements. It is largely believed that a dysfunction of cortical- striato- thalamo-cortical motor circuits plays a major role in the pathophysiology of dystonia. Several lines of evidence, however, hint at the involvement of somatosensory systems in dystonia. Ten patients with idiopathic dystonia and twelve healthy controls were tested with pairs of non-noxious electrical stimuli, separated by different time intervals. Stimuli were delivered: (i) to the (distal) pad of the index finger (same-point condition); (ii) to the pad and to the base of the index finger (same-finger condition); and (iii) to the pad of the index and ring fingers (different fingers condition). Subjects reported if they perceived single or double stimuli in the first condition and synchronous or asynchronous stimuli in the other conditions. Somesthetic temporal discrimination The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 thresholds (STDT) were obtained by computing the shortest time interval at which stimuli were perceived as separate in the first condition or asynchronous in the other conditions. STDT were significantly higher in dystonic than controls in all 3 conditions. In both dystonia patients and controls, STDT were maximal in the task whereby stimuli were maximally separated in space. We extend current knowledge on deficits of somesthetic temporal discrimination in dystonia by showing that somesthetic temporal discrimination deficits are not influenced by spatial variables. 91 Modulation of motor evoked potentials and cortical silent period by activation of intracortical inhibitory circuits – C. Trompetto, A. Buccolieri, L. Marinelli, G. Abruzzese (Department of Neurological Sciences & Vision University of Genoa, Italy) Transcranial magnetic stimulation (TMS). During voluntary muscle contraction, evokes motor potentials (MEPs) followed by a pause in the EMG activity (cortical silent period, SP). Different mechanisms are likely to underlie the facilitatory and inhibitory effects of TMS. We investigated in 9 normal subjects the effect of the activation of intracortical inhibitory circuits (by means of paired pulse TMS) on SP duration. During submaximal (70–90%) contraction of the first dorsal interosseus muscle, we compared the duration of the SP following paired pulse TMS was significantly longer that the duration of the SP following a similar size MEP evoked by single pulse TMS of reduced intensity. This finding indicates that subthreshold conditioning stimulation of the motor cortex is more powerful in reducing the MEP size than in cutting down the subsequent EMG silence, suggesting that the neutral circuits underlying MEP and SP are, at least in part, different. 92 Conduction block in absence of myelinic damage in the early stage of polyradicoloneuritis – W. Troni a, C. Bianco a, M. Dotta b ( aU.O.A. of Neurology, ASL 19, Asti; bU.O.A. of Neurology, ASL 18, Alba-Bra, Italy) In 3 patients affected by polyradicoloneuritis characterized by acute, exactly datable beginning, and by appearance of significant sthenic deficit at lower limbs in the space of 12–24 h, a seriate study has been carried out on motor CV along the whole extent of SNP by means of high-voltage electric stimulation of lumbo-sacral roots. We used the already described ‘back-ventral’ technique (Troni et al., 1996), which assures a supramaximal stimulation of roots at their origin. The stimulating cathode was located at D12/L1 interspace level and the anode was in ventral position, right between umbilicus and xyloid apophysis. Muscular responses have been recorded by front tibial and pedal of both sides. The first determination was executed as early as it was possible and, anyway, within 24–36 h since the beginning of symptomatology, together with cerebrospinal fluid research, and repeated after about 1 week and 3–4 months. In all the patients the report in its acute stage was characterized by a marked block of proximal conduction in absence of significant increase in latency values of M responses by radicular stimulation. In all of them conventional parameters of motor conduction, including distal latencies and (rare) F responses, were quite normal. Two out of 3 patients did not show albumin-cytologic dissociation in cerebrospinal fluid. In all the patients, a significant proximal and distal slowdown in conduction rate, associated to temporal dispersion of motor responses, occurred only in a more advanced stage and was followed, in the following months, by a progressive recovery, parallel to functional recovery. Such an evolution of electrophysiologic report, that borrows what was observed in animal during experimental allergic neuritis, shows that also in man motor deficit in acute stage is really supported by a functional block at the level of Ranvier’s knot (due to possible interference of humoral factors with membrane biophysic processes) preceding myelinic damage by cell-mediate hypersensibility. The described results show that radicular stimulation technique, as it can show exactly and simultaneously to clinical deficit the proximal conduction block supporting it, can confirm the diagnosis of polyradicoloneuritis in a very early stage of the disease where both cerebrospinal fluid report and conventional neurophysiologic parameters are generally still normal. 2353 93 Laser evoked potentials by mechanical activation of AMH I nociceptors – A. Truini, A. Romaniello, G.D. Iannetti, F. Galeotti, G. Cruccu (Department of Neurological Sciences, University “La Sapienza”, Rome, Italy) Introduction: Laser stimulus activates selectively A-delta and C mechanothermic nociceptors and evokes cortical evoked potentials (LEPs). LEPs’ more analysed component is the ‘late’ component reflecting the activation of A-delta, type II mechano-thermic nociceptors (AMH II) occurring only on piliferous skin. AMH I nociceptors (occurring on glabrous and piliferous skin) do not take part in LEP’s generation but can be activated by mechanical stimulation thanks to their mechanical threshold, which is lower than AMH II. The aim of this study is to test the capacity of high intensity laser stimula to activate AMH I mechanically and to study the possible evoked potential. Methods: In 10 subjects we have studied LEPs and the mechanographic response induced by low (9 mJ/mm 2) and high intensity (31.5 mJ/mm 2) laser stimulation of hand’s back and palm. In 3 subjects we have also recorded the late components of evoked potential by mechanical stimulus (A-beta afferents) of hand’s palm. Results: Low intensity laser stimula evoked the classic LEPs’ late component (N: 241 ^ 25.9 ms) by stimulation of hand’s back but no potential by palm’s stimulation. At high intensity, both by palm’s and back’s stimulation, it was possible to record an ‘early’ LEP (N: 186.7 ^ 12.4 ms; N: 191.1 ^ 21 ms). High intensity, but not low intensity stimula, have also produced a mechanograghic response both by hand’s back and palm. Mechanical evoked potential’s latency could not be compared to any of the recorded LEPs’components. Conclusions: Our data show that high intensity stimula can activate AMH I nociceptors mechanically and evoke an early evoked potential thanks to the higher conduction rate of AMH I afferents compared to AMH II. 94 Influence of sleeping stages on cutaneous flux variations at cranial and limbs’ level in healthy adult – V. Tugnoli, J. Capone, M. Manconi, M. Sensi, V.C. Monetti, R. Quatrale, R. Eleopra, E. Gastaldo (Operative Unit of Neurology, Hospital Company, University of Ferrara, Italy) Background: The influence of sleeping stages on spontaneous and stimulus-correlated variability of the cholinergic and adrenergic cutaneous sympathetic at segmentary level in adult has been well characterized in literature. In man there are some differences in segmentary cutaneous sympathetic and cranial district regulation, showed even during baby’s sleep. Laser-Doppler fluximetry (LDF) allows to evaluate the modifications of cutaneous hematic flux (CBF), expression of sympathetic vasomotor activity. Aim: To evaluate in healthy adult subjects the spontaneous modifications of CBF and of somato-sympathetic and local thermic reflexes, related to sleeping stages by means of comparison between cranial and segmentary level results. Method: CBF has been monitored through LDF, in 6 adult subjects, at the forehead level and distally at the upper limb (fingertip), in state of wakefulness and during the NREM and REM sleeping stages, calculating: basal flux, ‘vasomotion’, phasic events. CBF quantitative analysis was carried out considering intrahypnic variations and compared to relaxed watch. Results: Vasomotor sympathetic activity changes considerably during the different stages of sleep, and in the two examined districts. Phasic events, in particular, show a frequency reduction in stage 3–4. During REM stage there is a considering activation of the vasomotor sympathetic with a reduction of basal flux, a modification of ‘vasomotion’ and an increase of phasic events. Conclusions: Final data confirm the different hypnic district regulation of cutaneous flux in cranial and segmentary district. LDF allows to analyze the modifications of vasomotor sympathetic activity in different corporeal districts. 2354 The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 95 A novel locus for early-onset parkinsonism (PARK6) maps to chromosome 1 in several European families – E.M. Valente a,b, A.R. Bentivoglio c, A. Ferraris a, F. Brancati a, V. Bonifati d, J. Vaughan b, G. De Michele e, A. Dürr f, T. Gasser g, M. Breteler h, A. Filla e, G. Meco d, B.A. Oostra h, A. Brice f, B. Dallapiccola a, A. Albanese c, N.W. Wood b, and the European Consortium on Genetic Susceptibility in Parkinson’s Disease. ( aIstituto CSS Mendel, Rome; bInstitute of Neurology, London; cIstituto di Neurologia, Università Cattolica, Rome; dDipart. di Scienze Neurologiche, Università La Sapienza, Rome; eDipart. di Scienze Neurologiche, Università Federico II, Naples; f INSERM U289, Hôpital de la Salpêtrière, Paris; gNeurologische Klinik, Klinikum Glob hadern, Ludwig Maximilians Universität, Munich; hErasmus University, Rotterdam) Parkinson’s disease (PD) is a common neurodegenerative disorder. The major features of the disease are tremor, rigidity and bradykinesia. The cause of PD is unknown but genetic factors have been implicated in the aetiology of the disease. Autosomal recessive juvenile parkinsonism (ARJP) is a clinically and genetically distinct entity. The common PD features are associated with early onset, good response to levodopa and early levodopa-induced dyskinesias. So far, only one ARJP gene (Parkin) has been cloned, and several mutations have been detected in AR families and sporadic cases. However, in at least 50% of ARJP patients analysed, no mutations could be found in the Parkin gene. We have studied 4 affected individuals from a large ARJP Sicilian family, with early onset parkinsonism (range: 32–48 years), slow progression and sustained response to levodopa. Linkage of the disease to the Parkin locus was excluded. A genome search by means of homozygosity mapping allowed us to map a novel locus (PARK6) to a 12.5 cM region on chromosome 1 (max lodscore: 4.01). We then analysed 25 European multiplex families with ARJP not linked to the Parkin locus. There were at least two affected sibs in each nuclear family, with unaffected parents. Age of onset was below 50 years in at least one affected sib. We genotyped all affected sibs for markers spanning the PARK6 region, and detected linkage in 7 families, of which 3 from the Netherlands, two from Germany, one from the United Kingdom and one from Central Italy (maximum cumulated lodscore: 3.60). Reconstruction of shared haplotypes between the affected sibs from each family and determination of the smallest region of homozygosity in a consanguineous family allowed us to reduce the candidate interval to 9 cM. These findings confirm the linkage of a subset of Parkin-negative ARJP families to the recently mapped PARK6 locus. No common haplotypes were detected among the linked families, suggesting different independent mutational events. PARK6 appears to be an important locus for ARJP in European patients. 96 Evaluation of the cerebral function after carotid endarterectomy – N. Vanacore a, P. Pulitano a, A. Piacenti a, M.C. Tornambè a, P. Sapienza b, L. Di Marzo b, N. Accornero a, O. Mecarelli a ( aDipartimento di Scienze Neurologiche; bDipartimento di Chirurgia “P. Valdoni”, Università degli Studi “La Sapienza”, Roma, Italy) Carotid endarterectomy (CEA) is effective in reducing risk of ischemic stroke in patients with a high level of carotid stenosis. Several studies have shown that this surgical operation improves intellectual performances and EEG (the power of the alfa band increases). We present the preliminary results, related to 10 patients (6 M, 4 F; age 71.8 ^ 8.2; stenosis level between 60 and 80%), of a perspective study whose purpose is to evaluate the cerebral functionality, before and after CEA, by means of neuropsychological tests and EEG (visual inspection and quantitative analysis). To this purpose, patients underwent a neurological visit, neuropsychological tests (Mini Mental State Examination, Rey Test, Digit Span) and EEG before the operation and 3 months later. From a clinical point of view, no patient has revealed, either before or after the operation, objective signs of neurological lesions. Neuropsychological tests have shown a statistical significative improvement in the 5 trials of the Rey Test (P . 0:01). Visual inspection of EEG has not shown significative variations between recording realized before and after the surgical operation; quantitative EEG analyses do not show significative differences in the absolute and relative power of various frequency bands. These preliminary data suggest an improvement of the mnestic functions in the group of 10 patients after CEA, not correlated with significant EEG changes. 97 Catathrenia-nocturnal groaning: a new type of parasomnia – R. Vetrugno, F. Provini, G. Plazzi, L. Vignatelli, E. Lugaresi, P. Montagna (Institute of Neurology, Bologna University, Bologna, Italy) Objective: To describe 4 patients with expiratory nocturnal groaning, an unusual sleep-related behaviour. Background: Several disorders of sleep have noise among their signs. Groaning during sleep is not widely recognized as an unusual sleep-related pathological condition. Design/methods: Four patients, 3 males and one female, aged between 15 and 25 years presented, from ages 5 to 16 years, a unique exclusively expiratory groaning during sleep. Physical and laboratory examinations and fibroscopy of the upper airways with vocal cord evaluation and polysomnographic studies were performed. Results: Otorhinolaryngology and neurological examinations were all normal. Polysomnographic studies revealed that the groaning arose during REM sleep and NREM sleep stage 2 and was repeated in clusters. Groaning occurred during expiration only, was associated with slightly decreased heart-rate (HR) and arterial pressure (AP) and moderately positive intraoesophageal pressure. Every groaning episode ended with a snort and was followed by rebound in HR and AP, SaO2 remaining normal at 95–98%. Conclusions: Nocturnal groaning does not fit within existing nosological categories of sleep-related noise production and must be recognized as unusual sleep-related behaviour. The origins of groaning remain unexplained. The normal wake laryngoscopic investigations cannot rule out a functional sleep-related obstruction of the upper airways during expiration. The long term prognosis and treatment of nocturnal groaning remain unknown. 98 Morphofunctional neuroimaging in a case of primary progressive aphemia – P. Vitali a, U. Raiteri b, F. Nobili a, P. Calvini c, G. Regesta b, G. Rodriguez a ( aClinical Neurophysiology (DIMI); b Department of Neurology, S. Martino Hosp., Genova, Italy; c Department of Physics (INFM), University) Background: Primary Progressive Aphemia (PPAm) is characterized by dysartria and dysprosodia and then by involvement of other language functions, and is usually associated with atrophy of the left frontal operculus. Methods: A 59-year-old, right-handed woman with typical PPAm presentation (BADA test) underwent both morphological and functional (fMRI) MRI, the latter during phonemic verbal fluency test. Perfusional brain SPECT was performed by high-resolution device (CERASPECT) by 99mm Tc-HMPAO SPECT images were reconstructed with an iterative algorithm (Conjugate Gradients) with an original software that takes into account MRI-T1 images during the reconstructing, a procedure which further improves spatial resolution and reduces the volume effect on SPECT IMAGES. As final result, a high-resolution perfusional image is produced, with superimposition of fMRI-activated areas. Results: In this very unusual case, bilateral but mainly right frontal atrophy was found. However, hypoperfusion extended beyond atrophy, by involving the frontal lobe, the parietal lobule and inferior thalamus in the right hemisphere. The main fMRI activation was found in the right inferior frontal gyrus, at the same time the most involved area high both atrophy and hypoperfusion. Conclusions: The combined use of morphological and functional neuroimaging has led to the full pathophysiological understanding of this case ‘crossed’ PPAm. The Italian Society for Clinical Neurophysiology / Clinical Neurophysiology 112 (2001) 2333–2355 99 Detection of fetal auditory evoked responses by means of magnetoencephalografy – F. Zappasodi a, C. Salustri a, F. Tecchio a, V. Pizzella c, E. Cassetta b,d, G.V. Romano d, P.M. Rossini b,d,e ( aIESS - CNR-Roma; bI.R.C.C.S. “Centro S.Giovanni di Dio”, Brescia, Italy; cITAB and Dipartimento di Scienze Cliniche e di Bioimmagini - Università “G.d’Annunzio”, Chieti; d AFaR- Dip. Neuroscienze, Dip. Ginecologia Osp.Fatebenefratelli, Isola Tiberina, Roma; eNeurologia, Università Campus Biomedico, Roma, Italy) MagnetoEncephaloGraphy (MEG) is proposed as a non-invasive technique to detect the physiological activity of foetal brains, due to its ability to record brain activity without direct contact with the head and the transparency of magnetic signals in passing through extracerebral foetal layers and mother’s abdomen. Twelve healthy women with uncomplicated pregnancies and foetuses in breech presentation were examined; gestational ages at the time of study ranged between 36 and 40 weeks. In order to evaluate foetal well-being, ultrasound and cardiotocographic data were assessed both before and after MEG recording sessions. The participating women were placed in a semi-reclining position in a magnetically shielded room; there the foetus’ presentation and the precise region of mother’s abdomen corresponding to the foetal head were determined by ultrasound in order to place the MEG detecting system as near the foetal brain as possible. MEG recordings were performed by means of a 28channel neuromagnetic system. Every MEG recording session was performed during an acoustic stimulation of the foetuses, in order to detect cerebral events evoked by external stimuli. The auditory stimuli were delivered via a plastic tube placed on mother’s abdomen, near the foetal head, and consisted of a 300 ms 103 dB pure tone at 500 and 1000 Hz, presented at a 0.4 c/s repetition rate. In all cases, both maternal and foetal heart artifacts were quite evident in the recorded magnetoencephalographic traces. Accurate digital subtraction of these artifacts was performed by means of 3 different methods: adaptative noise cancelling (ANC), orthogonal signal projection algorithm (OSPA), and singular value decomposition (SVD). In 6 cases a stimulus-related response seemed to appear peaking at about 250 ms; in 3 cases ANC and OSPA produced a clear dipolar distribution at peak latencies. However this distribution was not confirmed in all cases by SVD. Despite several technical problems requiring solution before a possible routine clinical application, MEG has been found to be suitable for the non-invasive exploration of the foetal brain. 100 2355 Diaschisis-like effect of frontal and parieto-temporal cortical ablations on auditory neurocognitive potentials evocable from apparently intact ipsilateral association areas in humans – R. Zappoli a, F. Zappoli b, C. Uggetti b, R. Chiaramonti a, M.G. Arneodo a, G.D. Zappoli Thyrion c, V. Zerauschek d ( aDepartment of Neurological and Psychiatric Sciences, University of Florence, Italy; bNeuroradiology Unit, Institute of Neurology, University of Pavia, Italy; cDepartment of Clinical Medicine, University of Florence, Italy; dAbel Key s.c.r.l. Software Solution Consulting, Florence, Italy) Objective: To investigate the effects of disruption on the warning auditory S1-elicted ERP and CNV complexes which were recordable on the site and on remote ipsilateral apparently normal anotomo-functionally interconnected brain regions. These effects in some cases showed aspects of a probable diaschisis-like phenomenon, due to resections of extensive frontal association cortex or of primary and secondary sensory parieto-temporal areas damaged by differing pathological processes. Methods: Using a standard CNV paradigm, 21/19 EEG electrodes connected with 3 different references and scalp-topographic bidimensional mapping analysis, the S1 auditory binaural/monaural clicks N1a,b,c, P2,N2,P3 and CNV waves were recorded in 10 normal subjects and 11 patients, 9 of the latter had been submitted to unilateral frontal dorsolateral cortex ablation, one to bihemispheric dorsomedial cortex ablation and one to unilateral ablation of sensory parieto-temporal cortex and underlying white matter, verified through CT/MRI examinations. Results: No true S1ERP/CNV components were recordable over the ablated cortical areas, whereas normal ERP/CNV complexes were observable on the intact hemispheres. In 5 patients, 4 of whom with frontocortical ablations the S1ERP/CNV complexes appeared severely diminished or disrupted, in two cases in a slow, partially reversible manner also in the neuroradiologically normal ipsilateral functionally-connected post-rolandic sensory and association areas. Similar deactivation of some ERP components was observed in reverse on unilateral dorsolateral frontocortical region in the fifth patient with parieto-temporal cortex ablation. Conclusion: Even when they are partially reversible, these ipsilateral remoter ERP changes in apparently intact brain regions, due to ablations of functionally-interconnected cortical formations, probably reflect cortical deactivation or simply dysfacilitation deriving from functional unilateral diaschisis. If these changes are instead irreversible they may probably be interpreted as transneuronal degeneration phenomena, though they are not at present easy to document either neuroradiologically or electroclinically.