Psychiatry

Visuospatial neglect after stroke is often characterized by a disengage deficit on a cued orienting task, in which individuals are disproportionately slower to respond to targets presented on the contralesional side of space following an ispilesional cue as compared to the reverse. The purpose of this study was to investigate the generality of the finding of a disengage deficit on another measure of cued attention, the temporal order judgment (TOJ) task, that does not depend upon speeded manual responses. Individuals with right hemisphere stroke with and without spatial neglect and older healthy controls (OHC) were tested with both a speeded RT cueing task and an unspeeded TOJ-with-cuing task. All stroke patients evidenced a disengage deficit on the speeded RT cueing task, although the size and direction of the bias was not associated with the severity of neglect. In contrast, few neglect patients showed a disengage deficit on the TOJ task. This discrepancy suggests that the disengage deficit may be related to task demands, rather than solely due to impaired attentional mechanisms per se. Further, the results of our study show that the disengage deficit is neither necessary nor sufficient for neglect to manifest.

Background: we aimed to assess whether the performance of stroke outcome models comprising simple clinical variables could be improved by the addition of more complex clinical variables and information from the first computed tomography (CT) scan. Methods: 538 consecutive acute ischaemic and haemorrhagic stroke patients were enrolled in a Stroke Outcome Study between 2001 and 2002. Independent survival (modified Rankin scale ≤2) was assessed at 6 months. Models based on clinical and radiological variables from the first assessment were developed using multivariate logistic regression analysis. Results: three models were developed (I-III). Model I included age, pre-stroke independence, arm power and a stroke severity score (area under a receiver operating characteristic curve, AUC = 0.882) but performed no better than Model II, which comprised age, pre-stroke independence, normal verbal component of the Glasgow coma score, arm power and being able to walk without assistance (AUC 0.876). Model III, including two radiological variables and clinical variables, was not statistically superior to model II (AUC 0.901, P = 0.12). Model II was externally validated in two independent datasets (AUCs of 0.773 and 0.787). Conclusion: this study demonstrates an externally validated stroke outcome prediction model using simple clinical variables. Outcome prediction was not significantly improved with CT-derived radiological variables or more complex clinical variables.

Objectives: Our primary objective was to test the hypothesis that people with stroke can learn to use powered wheelchairs safely and effectively. Our secondary objective was to explore the influence of visuospatial neglect on the ability to learn powered wheelchair skills. Design: Prospective, uncontrolled pilot study using withinparticipant comparisons. Setting: Rehabilitation center. Participants: Inpatients (Nϭ10; 6 with visuospatial neglect), all with a primary diagnosis of stroke. Interventions: Participants received 5 wheelchair skills training sessions of up to 30 minutes each using the Wheelchair Skills Training Program (version 3.2). Main Outcome Measures: Powered wheelchair skills were tested before and after training using the Wheelchair Skills Test, Power Mobility version 3.2 (WST-P). Results: The group's total mean WST-P scores improved from 25.5% of skills passed at baseline to 71.5% posttraining (Pϭ.002). The participants with neglect improved their WST-P scores to the same extent as the participants without neglect, although their pretraining and posttraining scores were lower. The training and testing sessions were well tolerated by the participants, and there were no serious adverse events. Conclusions: Many people with stroke, with or without visuospatial neglect, can learn to use powered wheelchairs safely and effectively with appropriate training.

Objectives: To examine the general phenomenon of fatigue in stroke and other neurologic disorders and to review what is currently known about its occurrence, including its frequency, duration, severity, and associated factors, to develop a strategy for treatment. Data Sources: Computerized databases (eg, PubMed, PsycInfo, Science Citation Index, Ovid EMBASE, Ovid MEDLINE) searched from inception to May 2002. Additional references were identified from bibliographies of pertinent articles and books. Study Selection: Over 1000 articles were identified as relevant to fatigue experienced by patients with neurologic or nonneurologic disorders. Articles on fatigue in stroke and neurologic disorders, mechanisms, and/or treatment were selected for inclusion. Data Extraction: Authors reviewed the articles and assessed the purpose, study design, and conclusions for validity and relevance to the topic of fatigue in stroke. Data Synthesis: Fatigue is a common complaint among patients with neurologic disorders including stroke. Few studies have documented the high frequency of fatigue in poststroke patients and its negative impact on daily functioning and quality of life. Little is known about associated factors or about therapeutic strategies that may be used to alleviate it. Examination of fatigue in other neurologic populations suggests common characteristics and associated factors that may be useful in the development of potential therapeutic strategies. Pharmacologic and nonpharmacologic therapeutic interventions, such as stimulants, amantadine, or sleep and stress-management education, have been used with some success in neurologic and other patient populations (eg, multiple sclerosis, human immunodeficiency virus, acquired immune deficiency syndrome, cancer), but evidence of effectiveness based on randomized clinical trials is rare. Conclusions: Poststroke fatigue is common. Therapeutic strategies have been used to treat fatigue in other patient populations, but it is unclear whether these will be beneficial to poststroke patients. Frequency, severity, duration, impact, predisposing factors, and causes of poststroke fatigue, as well as the development of effective treatment, require further research. Criteria for assessment of fatigue and potential therapeutic interventions are outlined as a first step for stimulating further research.

Background: Aging and physical inactivity are associated with declines in some cognitive domains and cerebrovascular function, as well as an elevated risk of cerebrovascular disease and other morbidities. With the increase in the number of sedentary older Canadians, promoting healthy brain aging is becoming an increasingly important population health issue. Emerging research suggests that higher levels of physical fitness at any age are associated with better cognitive functioning and this may be mediated, at least in part, by improvements in cerebrovascular reserve. We are currently conducting a study to determine: if a structured 6-month aerobic exercise program is associated with improvements or maintenance of both cerebrovascular function and cognitive abilities in older individuals; and, the extent to which any changes seen persist 6 months after the completion of the structured exercise program. Methods/design: Two hundred and fifty men and women aged 55-80 years are being enrolled into an 18-month combined quasi-experimental and prospective cohort study. Participants are eligible for enrollment into the study if they are inactive (i.e., not participating in regular physical activity), non-smokers, have a body mass index <35.0 kg/ m 2 , are free of significant cognitive impairment (defined as a Montreal Cognitive Assessment score of 24 or more), and do not have clinically significant cardiovascular, cerebrovascular disease, or chronic obstructive pulmonary airway disease. Repeated measurements are done during three sequential six-month phases: 1) pre-intervention; 2) aerobic exercise intervention; and 3) post-intervention. These outcomes include: cardiorespiratory fitness, resting cerebral blood flow, cerebrovascular reserve, and cognitive function. Discussion: This is the first study to our knowledge that will examine contemporaneously the effect of an exercise intervention on both cerebrovascular reserve and cognition in an older population. This study will further our understanding of whether cerebrovascular mechanisms might explain how exercise promotes healthy brain aging. In addition our study will address the potential of increasing physical activity to prevent age-associated cognitive decline.

Normal observers demonstrate a bias to process the left sides of faces during perceptual judgments about identity or emotion. This effect suggests a right cerebral hemisphere processing bias. To test the role of the right hemisphere and the involvement of configural processing underlying this effect, young and older control observers and patients with right hemisphere damage completed two chimeric faces tasks (emotion judgment and face identity matching) with both upright and inverted faces. For control observers, the emotion judgment task elicited a strong left-sided perceptual bias that was reduced in young controls and eliminated in older controls by face inversion. Right hemisphere damage reversed the bias, suggesting the right hemisphere was dominant for this task, but that the left hemisphere could be flexibly recruited when right hemisphere mechanisms are not available or dominant. In contrast, face identity judgments were associated most clearly with a vertical bias favouring the uppermost stimuli that was eliminated by face inversion and right hemisphere lesions. The results suggest these tasks involve different neurocognitive mechanisms. The role of the right hemisphere and ventral cortical stream involvement with configural processes in face processing is discussed.

Objective: This study investigated the effectiveness of an ERP-compatible Digit Span Backward (ERP-DB) task to determine working memory abilities in healthy participants. Methods: Participants were administered both the standard digit span backward and ERP-DB tasks. The ERP-DB task was divided into two sections, consisting of 2, 4, 6 and 8 (Group 1) and 3, 5, and 7 (Group 2) set sizes. A set of digits was aurally presented, followed by a second set that either corresponded to the reverse order of the first set (correct condition) or had one digit in the sequence replaced by an incorrect digit (incorrect condition). Results: Two posterior positive components were found to distinguish the two conditions; an earlier positive component (P200/P300) was elicited in the correct condition, whereas a comparatively robust and prolonged positive slow wave (PSW) was elicited in the incorrect condition. Furthermore, the PSW and the difference in PSW amplitude between incorrect and correct conditions (dPSW) dissipated as working memory load increased and were related to working memory capacity. Conclusions: The PSW, dPSW and P200/P300 components were found to be associated with working memory abilities and may have the potential to act as neurophysiological markers for the assessment of working memory capacity. Significance: This research lends support for the utility of the ERP-DB task as a means of assessing working memory abilities, which may have implications for testing patients with expressive communication impairments.

The extent to which letter-by-letter reading results from a specific orthographic deficit, as compared with a nonspecific disturbance in basic visuoperceptual mechanisms, is unclear. The current study directly compared processing of letters and digits in a letter-by-letter reader, G.M., using a rapid serial visual presentation (RSVP) task and a speeded matching task. Comparisons were made to a group of six brain-damaged individuals without reading deficits. In the RSVP task, G.M. had increased difficulty reporting the target identities when they were letters, as compared with digits. Although this general pattern was also evident in the control group, the magnitude of the letter–digit accuracy difference was greater in G.M. Similarly, in the matching task, G.M. was slower to match letters than digits, relative to the control group, although his response times to both item types were increased. These data suggest that letter-by-letter reading, at least in this case, results from a vi...

h i g h l i g h t s Previous work suggests IOR results from sensory/attentional or motor programming processes. We develop a paradigm to isolate and measure potential RT biases in response execution processes. We show for the first time that IOR affecting saccades can result from a late stage execution bias.

Key won& paraventricular nucleus-suprachiasmatic nucleus photoperiod testicular function circadian rhythm pineal gland golden hamster We used horizontal knife cuts near the suprachiasmatic nucleus (SCN) to investigate the route for daylength inl\~rmation transmission from the SCN to the paraventricular nucleus (PVN). Testicular regression w~ blocked in animals with knife cuts dorsal to the SCN that spanned its entire rostrocaudal extent, and in PVN-ablated animals. Misplaced cuts in the ventral preoptic area also prevented gonadal regression. These neural insults did not systematically affect the circadian control of activity rhythms. The pathway from the SCN to the pineal runs from the dorsal border of the SCN and travels through the periventricular area toward the PVN. *Results previously published in abstract form (Soc. Neurosci. Ahstr., 10 (1984) 820).

h i g h l i g h t s Previous work suggests IOR results from sensory/attentional or motor programming processes. We show that motor IOR affecting reaching can arise from response execution processes. Our result confirms that motor IOR can be observed outside of the oculomotor system.

Purpose: To investigate the use of constraint-induced movement therapy (CIMT) in Canadian neurological occupational and physical therapy. Method: An online survey was completed by occupational and physical therapists practising in Canadian adult neurological rehabilitation. We measured participants&#39; practices, perceptions, and opinions in relation to their use of CIMT in clinical practice. Results: A total of 338 surveys were returned for a 13% response rate; 92% of respondents knew of CIMT, and 43% reported using it. The majority (88%) of respondents using CIMT employed a non-traditional protocol. Self-rating of level of CIMT knowledge was found to be a significant predictor of CIMT use (p≤0.001). Commonly identified barriers to use included “patients having cognitive challenges that prohibit use of this treatment” and “lack of knowledge regarding treatment.” Conclusions: Although the majority of respondents knew about CIMT, less than half reported using it. Barriers to CIMT us...

Neurophysiological studies in monkeys show that activity of neurons in primary cortex (M1), pre-motor cortex (PMC), and cerebellum varies systematically with the direction of reaching movements. These neurons exhibit preferred direction tuning, where the level of neural activity is highest when movements are made in the preferred direction (PD), and gets progressively lower as movements are made at increasing degrees of offset from the PD. Using a functional magnetic resonance imaging adaptation (fMRI-A) paradigm, we show that PD coding does exist in regions of the human motor system that are homologous to those observed in non-human primates. Consistent with predictions of the PD model, we show adaptation (i.e., a lower level) of the blood oxygen level dependent (BOLD) time-course signal in M1, PMC, SMA, and cerebellum when consecutive wrist movements were made in the same direction (0u offset) relative to movements offset by 90u or 180u. The BOLD signal in dorsolateral prefrontal cortex adapted equally in all movement offset conditions, mitigating against the possibility that the present results are the consequence of differential task complexity or attention to action in each movement offset condition.

We investigated the role of daytime sleepiness and sleep quality in psychosocial outcomes of patients with obstructive sleep apnea (OSA) treated with continuous positive airway pressure (CPAP). Thirty-seven individuals with moderate to severe OSA and compliant with CPAP treatment for at least 3 months were compared to 27 age- and education-matched healthy controls. The OSA group and the control group were studied with overnight polysomnography (PSG) and compared on measures of daytime sleepiness (Epworth Sleepiness Scale), sleep quality (Pittsburg Sleep Quality Index), mood (Beck Depression Inventory, Profile of Mood States), and functional outcomes (Functional Outcomes of Sleep Questionnaire). After CPAP treatment, the OSA group improved on sleep quality and sleepiness. As a group, they did not differ from controls on sleep architecture after CPAP. The OSA group also showed significant improvements in functional outcomes and was comparable to controls on mood and functional outcome...

Background:Fatigue affects 33-77% of stroke survivors. There is no consensus concerning risk factors for fatigue post-stroke, perhaps reflecting the multifaceted nature of fatigue. We characterized post-stroke fatigue using the Fatigue Impact Scale (FIS), a validated questionnaire capturing physical, cognitive, and psychosocial aspects of fatigue.Methods:The Stroke Outcomes Study (SOS) prospectively enrolled ischemic stroke patients from 2001-2002. Measures collected included basic demographics, pre-morbid function (Oxford Handicap Scale, OHS), stroke severity (Stroke Severity Scale, SSS), stroke subtype (Oxfordshire Community Stroke Project Classification, OCSP), and discharge function (OHS; Barthel Index, BI). An interview was performed at 12 months evaluating function (BI; Modified Rankin Score, mRS), quality of life (Reintegration into Normal living Scale, RNL), depression (Geriatric Depression Scale, GDS), and fatigue (FIS).Results:We enrolled 522 ischemic stroke patients and 2...

BACKGROUND: Evidence suggests that 15-30% of individuals with obstructive sleep apnoea (OSA) have type 2 diabetes mellitus (T2DM), and that OSA is an independent risk factor for T2DM. There is considerable interest in ascertaining whether OSA treatment improves glycaemic control and insulin sensitivity in patients with OSA and T2DM. AIMS: To assess the effects of continuous positive airway pressure (CPAP) therapy on glycosylated haemoglobin (HbA1c) level, insulin sensitivity and body mass index (BMI) in patients with OSA and T2DM. METHODS: MEDLINE, EMBASE and the Cochrane Library were searched to identify prospective studies involving patients with OSA and T2DM who had received CPAP, and data on primary outcome (change in HbA1c) and/or secondary outcomes (changes in insulin sensitivity and BMI) were reported. All relevant studies published before 31 January 2014 were included. RESULTS: Six studies were included in the systematic review and meta-analysis. The numbers of patients ranged from 9 to 44 (total = 128), and mean age ranged from 50.7 to 66.1 years. For the change in HbA1c (six studies, 128 patients), the combined standardised paired difference revealed no significant effect of CPAP (−0.071, 95% confidence interval (CI) = − 0.245, 0.103; P = 0.421). Similarly, there was no significant effect of CPAP on the change in BMI (−0.102, 95% CI = − 0.296, 0.092; P = 0.302; five studies, 103 patients). In contrast, there was a significant effect of CPAP on the change (improvement) in insulin sensitivity (0.330, 95% CI = 0.001, 0.658; P = 0.049; three studies, 39 patients). CONCLUSION: The limited available evidence from randomised controlled trials and prospective observational studies suggests that CPAP does not decrease HbA1c level or BMI in patients with OSA and T2DM but may improve insulin sensitivity.

Clinical trials have demonstrated the superiority of coordinated interdisciplinary stroke unit care over conventional treatment of stroke patients on general medical wards. The evidence is so strong that several national bodies have recommended that stroke unit care be widely implemented. Translation of these research findings and care guidelines into clinical practice, however, represents a challenge for health care systems unaccustomed to managing stroke in a coordinated manner. This report describes the organization, operation and outcomes of the Acute Stroke Unit at the Queen Elizabeth II Health Sciences Centre in Halifax. By replicating and adapting the core characteristics identified in the randomized trials, we have been able to demonstrate the effectiveness of stroke unit care in a routine clinical setting. Our experience may help facilitate the development of organized stroke care in Canada.

To determine if total lifetime physical activity (PA) is associated with better cognitive functioning with aging and if cerebrovascular function mediates this association. A sample of 226 (52.2% female) community dwelling middle-aged and older adults (66.5±6.4 years) in the Brain in Motion Study, completed the Lifetime Total Physical Activity Questionnaire and underwent neuropsychological and cerebrovascular blood flow testing. Multiple robust linear regressions were used to model the associations between lifetime PA and global cognition after adjusting for age, sex, North American Adult Reading Test results (i.e., an estimate of premorbid intellectual ability), maximal aerobic capacity, body mass index and interactions between age, sex, and lifetime PA. Mediation analysis assessed the effect of cerebrovascular measures on the association between lifetime PA and global cognition. Post hoc analyses assessed past year PA and current fitness levels relation to global cognition and cere...