Life expectancy in adults with congenital heart disease (ACHD) has increased. As these patients g... more Life expectancy in adults with congenital heart disease (ACHD) has increased. As these patients grow older, they experience aging-related diseases more than their healthy peers. To better characterize this field, we launched the multi-disciplinary BACH (Brain Aging in Congenital Heart disease) San Donato study, that aimed at investigating signs of brain injury in ACHD. Twenty-three adults with repaired tetralogy of Fallot and 23 age- and sex-matched healthy controls were prospectively recruited and underwent brain magnetic resonance imaging. White matter hyperintensities (WMHs) were segmented using a machine-learning approach and automatically split into periventricular and deep. Cerebral microbleeds were manually counted. A subset of 14 patients were also assessed with an extensive neuropsychological battery. Age was 41.78 ± 10.33 years (mean ± standard deviation) for patients and 41.48 ± 10.28 years for controls (p = 0.921). Albeit not significantly, total brain (p = 0.282) and br...
Purpose Imaging of brain involvement in infective endocarditis can drive the clinical management ... more Purpose Imaging of brain involvement in infective endocarditis can drive the clinical management of this serious condition. MRI is very sensitive, but CT is more readily available. In this retrospective study, we compared the detection rates of CT and MRI. Methods After Ethics Committee approval, we retrospectively reviewed a series of 20 patients (13 males, median age 64 years) who underwent both CT and MRI either before or after cardiac surgery for definite infective endocarditis. Plain CT and MRI were evaluated for acute ischemic lesions, both punctuate and large, intraparenchymal hemorrhages, cerebral microbleeds, subarachnoid hemorrhages, abscesses, microabscesses, and meningitis. Qualitative assessment and McNemar test were performed. The value of contrast-enhanced scans (MRI, n = 14; CT, n = 9) and cognitive status were also assessed. Results A total of 166 lesions were identified on either technique: 137 (83%) on MRI only, 4 (2%) on CT only, and 25 (15%) on both techniques (...
A priority in Parkinson disease research is the identification of a reliable in vivo marker for s... more A priority in Parkinson disease research is the identification of a reliable in vivo marker for supporting early diagnosis, monitoring disease progression, and driving therapeutic interventions. Diagnosis of Parkinson disease is based on clinical criteria (1) and can be supported by functional nuclear medicine neuroimaging of dopamine radioligands. Indeed, in clinical practice, iodine 123-2b-carbomethoxy-3b-(4iodophenyl)-N-(3-fluoropropyl)-nortropane (123 I-FP-CIT) SPECT (DaTSCAN; GE Healthcare, Chicago, Ill) is mostly used as a confirmatory test (2). These studies use radioactive tracers, are influenced by physiologic or pharmacologic mechanisms (3), and are expensive; thus, their use as markers of disease progression is limited. The role of MRI in the diagnosis of Parkinson disease is limited to the exclusion of other primary or secondary parkinsonisms. Recent developments show that MRI can help assess the substantia nigra, the primary site of neurodegeneration in Parkinson disease. On the basis of seminal studies showing that melanin has particular iron-binding properties leading to T1 relaxation shortening (4,5), Sasaki et al (6) developed what they called a neuromelanin-sensitive scan using a short-echo T1-weighted sequence at 3 T. The scan depicted the substantia nigra and locus coeruleus in vivo as hyperintense areas in the mesencephalon and showed a reduced hyperintense area in participants with Parkinson disease compared with healthy control participants. Adding a magnetization transfer (MT) pulse to the sequence, Schwarz et al (7) confirmed a decreased substantia nigra
BackgroundFrontotemporal Spectrum Disorder (FTSD) and Amyotrophic Lateral Sclerosis (ALS) are neu... more BackgroundFrontotemporal Spectrum Disorder (FTSD) and Amyotrophic Lateral Sclerosis (ALS) are neurodegenerative diseases often considered as a continuum from clinical, epidemiologic and genetic perspectives. We used localized brain volume alterations to evaluate common and specific features of FTSD, FTSD-ALS and ALS patients to further understand this clinical continuum.MethodsWe used voxel-based morphometry on structural MRI images to localize volume alterations in group comparisons: patients (20 FTSD, seven FTSD-ALS, 18 ALS) versus healthy controls (39 CTR), and patient groups between themselves. We used mean whole-brain cortical thickness to assess whether its correlations with local brain volume could propose mechanistic explanations of the heterogeneous clinical presentations. We also assessed whether volume reduction can explain cognitive impairment, measured with frontal assessment battery, verbal fluency and semantic fluency.ResultsCommon (mainly frontal) and specific areas ...
Brain Vascular Changes in Adults with Congenital Heart Disease: a systematic review Highlights ... more Brain Vascular Changes in Adults with Congenital Heart Disease: a systematic review Highlights The number of adults with congenital heart disease is increasing rapidly. There is considerable concern regarding global health outcomes in this population. Evidence shows that patients with congenital heart disease are more prone to cerebrovascular accidents. Neuroimaging tools may aid the detection of subtle vascular brain changes before cognitive impairment occurs.
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADAS... more Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common familial cerebral small vessel disease, caused by NOTCH3 gene mutations. The aim of our study was to identify clinical and neuroradiological features which would be useful in identifying which patients presenting with lacunar stroke and TIA are likely to have CADASIL. Patients with lacunar stroke or TIA were included in the present study. For each patient, demographic and clinical data were collected. MRI images were centrally analysed for the presence of lacunar infarcts, microbleeds, temporal lobe involvement, global atrophy and white matter hyperintensities. 128 patients (mean age 56.3 ± 12.4 years) were included. A NOTCH3 mutation was found in 12.5% of them. A family history of stroke, the presence of dementia and external capsule lesions on MRI were the only features significantly associated with the diagnosis of CADASIL. Although thalamic, temporal pole glios...
Alzheimer disease (AD) and vascular dementia (VaD) together represent the majority of dementia ca... more Alzheimer disease (AD) and vascular dementia (VaD) together represent the majority of dementia cases. Since their neuropsychological profiles often overlap and white matter lesions are observed in elderly subjects including AD, differentiating between VaD and AD can be difficult. Characterization of these different forms of dementia would benefit by identification of quantitative imaging biomarkers specifically sensitive to AD or VaD. Parameters of microstructural abnormalities derived from diffusion tensor imaging (DTI) have been reported to be helpful in differentiating between dementias, but only few studies have used them to compare AD and VaD with a voxelwise approach. Therefore, in this study a whole brain statistical analysis was performed on DTI data of 93 subjects (31 AD, 27 VaD, and 35 healthy controls-HC) to identify specific white matter patterns of alteration in patients affected by VaD and AD with respect to HC. Parahippocampal tracts were found to be mainly affected i...
Purpose To evaluate the feasibility of a standardized protocol for acquisition and analysis of dy... more Purpose To evaluate the feasibility of a standardized protocol for acquisition and analysis of dynamic contrast material-enhanced (DCE) and dynamic susceptibility contrast (DSC) magnetic resonance (MR) imaging in a multicenter clinical setting and to verify its accuracy in predicting glioma grade according to the new World Health Organization 2016 classification. Materials and Methods The local research ethics committees of all centers approved the study, and informed consent was obtained from patients. One hundred patients with glioma were prospectively examined at 3.0 T in seven centers that performed the same preoperative MR imaging protocol, including DCE and DSC sequences. Two independent readers identified the perfusion hotspots on maps of volume transfer constant (K), plasma (v) and extravascular-extracellular space (v) volumes, initial area under the concentration curve, and relative cerebral blood volume (rCBV). Differences in parameters between grades and molecular subtype...
First International IEEE EMBS Conference on Neural Engineering, 2003. Conference Proceedings.
In 10 right-handed volunteers, BOLD f-MRI activity was acquired during a protocol of mental speec... more In 10 right-handed volunteers, BOLD f-MRI activity was acquired during a protocol of mental speech production tasks. A task lasted 30 sec and consisted in recalling as many as possible animals (AN) or tools (TO). The protocol include 3 AN tasks and 3 TO tasks, each preceded by 30 sec rest (RE). By means of EPI the cerebral volume was acquired with a repetition time of 3 sec. After adjustment in stereotactic coordinates, spatial and temporal filtering, the time series of average activity in spherical regions with a 5 mm radius were extracted relevant to Broca's (BR) area, the left mesial WFG) and lateral (LFG) fusiform gyrus. An interaction model, estimating a modulation index of the connection between either MGF or LFG with BR was able to detect an increased MFG/BR connectivity during TO and increased LFG/BR connectivity during AN; however, this model failed in a subject by subject analysis. On the contrary a simpler correlation model, which separately analyzed the two tasks, was able to detect consistent changes in 7/10 MSG areas and in 9/10 LFG areas. We conclude that with an appropriate data analysis model the application of functional imaging can be widened from pure physiological studies to the clinical analysis in lesions or pathologies involving semantic memory and speech areas.
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by a severe derangement of... more Alzheimer's disease (AD) is a neurodegenerative disorder characterized by a severe derangement of cognitive functions, primarily memory, in elderly subjects. As far as the functional impairment is concerned, growing evidence supports the "disconnection syndrome" hypothesis. Recent investigations using fMRI have revealed a generalized alteration of resting state networks (RSNs) in patients affected by AD and mild cognitive impairment (MCI). However, it was unclear whether the changes in functional connectivity were accompanied by corresponding structural network changes. In this work, we have developed a novel structural/functional connectomic approach: resting state fMRI was used to identify the functional cortical network nodes and diffusion MRI to reconstruct the fiber tracts to give a weight to internodal subcortical connections. Then, local and global efficiency were determined for different networks, exploring specific alterations of integration and segregation patterns in AD and MCI patients compared to healthy controls (HC). In the default mode network (DMN), that was the most affected, axonal loss, and reduced axonal integrity appeared to compromise both local and global efficiency along posterior-anterior connections. In the basal ganglia network (BGN), disruption of white matter integrity implied that main alterations occurred in local microstructure. In the anterior insular network (AIN), neuronal loss probably subtended a compromised communication with the insular cortex. Cognitive performance, evaluated by neuropsychological examinations, revealed a dependency on integration and segregation of brain networks. These findings are indicative of the fact that cognitive deficits in AD could be associated not only with cortical alterations (revealed by fMRI) but also with subcortical alterations (revealed by diffusion MRI) that extend beyond the areas primarily damaged by neurodegeneration, toward the support of an emerging concept of AD as a "disconnection syndrome." Since only AD but not MCI patients were characterized by a significant decrease in structural connectivity, integrated structural/functional connectomics could provide a useful tool for assessing disease progression from MCI to AD.
Functional magnetic resonance imaging (fMRI), which has high spatial resolution, is increasingly ... more Functional magnetic resonance imaging (fMRI), which has high spatial resolution, is increasingly used to evaluate cerebral functions in neurological and psychiatric diseases. The main limitation of fMRI is that it detects neural activity indirectly, through the associated slow hemodynamic variations. Because neurovascular coupling can be regionally altered by pathological conditions or drugs, fMRI responses may not truly reflect neural activity. Electroencephalography (EEG) recordings, which directly detect neural activity with optimal temporal resolution, can now be obtained during fMRI data acquisition. Therefore, there is a growing interest in combining the techniques to obtain simultaneous EEG-fMRI recordings. The EEG-fMRI approach has several promising clinical applications. The first is the detection of cortical areas involved in interictal and ictal epileptic activity. Second, combining evoked potentials with fMRI could be an accurate way to study eloquent cortical areas for the planning of neurosurgery or rehabilitation, circumventing the above-mentioned limitation of fMRI. Finally, the use of this approach to evaluate the functional connectivity of resting-state networks would extend the applications of EEG-fMRI to uncooperative or unconscious patients. Integration of multimodal neuroimaging methods: a rationale for clinical applications of simultaneous EEG-fMRI.
Background and Purpose— Lombardia GENS is a multicentre prospective study aimed at diagnosing 5 s... more Background and Purpose— Lombardia GENS is a multicentre prospective study aimed at diagnosing 5 single-gene disorders associated with stroke (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, Fabry disease, MELAS [mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes], hereditary cerebral amyloid angiopathy, and Marfan syndrome) by applying diagnostic algorithms specific for each clinically suspected disease Methods— We enrolled a consecutive series of patients with ischemic or hemorrhagic stroke or transient ischemic attack admitted in stroke units in the Lombardia region participating in the project. Patients were defined as probable when presenting with stroke or transient ischemic attack of unknown etiopathogenic causes, or in the presence of <3 conventional vascular risk factors or young age at onset, or positive familial history or of specific clinical features. Patients fulfilling diagnostic algorithms specific...
The 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Aim of this work is to describe temporally and spatially the activation of the cerebral areas inv... more Aim of this work is to describe temporally and spatially the activation of the cerebral areas involved in reading processes by combining fMRI and reading-related potentials (RRPs). RRPs and fMR images were recorded in separate studies during a specifically designed experimental procedure. The protocol consisted of three visual tasks of increasing complexity. In the first two tasks subjects were asked
Cortex; a journal devoted to the study of the nervous system and behavior, Jan 14, 2015
The non-fluent/agrammatic variant of primary progressive aphasia (nfvPPA) and the behavioral vari... more The non-fluent/agrammatic variant of primary progressive aphasia (nfvPPA) and the behavioral variant frontotemporal dementia (bvFTD) are focal neurodegenerative disorders belonging to the FTD-spectrum clinical syndromes. NfvPPA is characterized by effortful speech and/or agrammatism and left frontal atrophy, while bvFTD is characterized by social-emotional dysfunction often accompanied by right-lateralized frontal damage. Despite their contrasting clinical presentations, both disorders show prominent left anterior insula atrophy. We investigated differential patterns of insular sub-region atrophy in nfvPPA and bvFTD. Based on knowledge of insular connectivity and physiology, we hypothesized that the left superior precentral region of the dorsal anterior insula (SPGI) would be more atrophic in nvfPPA due to its critical role in motor speech, whereas the ventral anterior region would be more atrophied in bvFTD reflecting its known role in social-emotional-autonomic functions. Early st...
We have demonstrated that Stochastic Resonance can be used as a tool to quantify the ability of h... more We have demonstrated that Stochastic Resonance can be used as a tool to quantify the ability of human observers to detect details in a noisy visual stimulation(E. Simonotto, et al., Phys. Rev. Lett.) 78, 1186 (1997). This technique gives consistently reproducible results and allows a quantitative comparison between different subjects. We have begun fMRI studies to investigate the underlying processes
Life expectancy in adults with congenital heart disease (ACHD) has increased. As these patients g... more Life expectancy in adults with congenital heart disease (ACHD) has increased. As these patients grow older, they experience aging-related diseases more than their healthy peers. To better characterize this field, we launched the multi-disciplinary BACH (Brain Aging in Congenital Heart disease) San Donato study, that aimed at investigating signs of brain injury in ACHD. Twenty-three adults with repaired tetralogy of Fallot and 23 age- and sex-matched healthy controls were prospectively recruited and underwent brain magnetic resonance imaging. White matter hyperintensities (WMHs) were segmented using a machine-learning approach and automatically split into periventricular and deep. Cerebral microbleeds were manually counted. A subset of 14 patients were also assessed with an extensive neuropsychological battery. Age was 41.78 ± 10.33 years (mean ± standard deviation) for patients and 41.48 ± 10.28 years for controls (p = 0.921). Albeit not significantly, total brain (p = 0.282) and br...
Purpose Imaging of brain involvement in infective endocarditis can drive the clinical management ... more Purpose Imaging of brain involvement in infective endocarditis can drive the clinical management of this serious condition. MRI is very sensitive, but CT is more readily available. In this retrospective study, we compared the detection rates of CT and MRI. Methods After Ethics Committee approval, we retrospectively reviewed a series of 20 patients (13 males, median age 64 years) who underwent both CT and MRI either before or after cardiac surgery for definite infective endocarditis. Plain CT and MRI were evaluated for acute ischemic lesions, both punctuate and large, intraparenchymal hemorrhages, cerebral microbleeds, subarachnoid hemorrhages, abscesses, microabscesses, and meningitis. Qualitative assessment and McNemar test were performed. The value of contrast-enhanced scans (MRI, n = 14; CT, n = 9) and cognitive status were also assessed. Results A total of 166 lesions were identified on either technique: 137 (83%) on MRI only, 4 (2%) on CT only, and 25 (15%) on both techniques (...
A priority in Parkinson disease research is the identification of a reliable in vivo marker for s... more A priority in Parkinson disease research is the identification of a reliable in vivo marker for supporting early diagnosis, monitoring disease progression, and driving therapeutic interventions. Diagnosis of Parkinson disease is based on clinical criteria (1) and can be supported by functional nuclear medicine neuroimaging of dopamine radioligands. Indeed, in clinical practice, iodine 123-2b-carbomethoxy-3b-(4iodophenyl)-N-(3-fluoropropyl)-nortropane (123 I-FP-CIT) SPECT (DaTSCAN; GE Healthcare, Chicago, Ill) is mostly used as a confirmatory test (2). These studies use radioactive tracers, are influenced by physiologic or pharmacologic mechanisms (3), and are expensive; thus, their use as markers of disease progression is limited. The role of MRI in the diagnosis of Parkinson disease is limited to the exclusion of other primary or secondary parkinsonisms. Recent developments show that MRI can help assess the substantia nigra, the primary site of neurodegeneration in Parkinson disease. On the basis of seminal studies showing that melanin has particular iron-binding properties leading to T1 relaxation shortening (4,5), Sasaki et al (6) developed what they called a neuromelanin-sensitive scan using a short-echo T1-weighted sequence at 3 T. The scan depicted the substantia nigra and locus coeruleus in vivo as hyperintense areas in the mesencephalon and showed a reduced hyperintense area in participants with Parkinson disease compared with healthy control participants. Adding a magnetization transfer (MT) pulse to the sequence, Schwarz et al (7) confirmed a decreased substantia nigra
BackgroundFrontotemporal Spectrum Disorder (FTSD) and Amyotrophic Lateral Sclerosis (ALS) are neu... more BackgroundFrontotemporal Spectrum Disorder (FTSD) and Amyotrophic Lateral Sclerosis (ALS) are neurodegenerative diseases often considered as a continuum from clinical, epidemiologic and genetic perspectives. We used localized brain volume alterations to evaluate common and specific features of FTSD, FTSD-ALS and ALS patients to further understand this clinical continuum.MethodsWe used voxel-based morphometry on structural MRI images to localize volume alterations in group comparisons: patients (20 FTSD, seven FTSD-ALS, 18 ALS) versus healthy controls (39 CTR), and patient groups between themselves. We used mean whole-brain cortical thickness to assess whether its correlations with local brain volume could propose mechanistic explanations of the heterogeneous clinical presentations. We also assessed whether volume reduction can explain cognitive impairment, measured with frontal assessment battery, verbal fluency and semantic fluency.ResultsCommon (mainly frontal) and specific areas ...
Brain Vascular Changes in Adults with Congenital Heart Disease: a systematic review Highlights ... more Brain Vascular Changes in Adults with Congenital Heart Disease: a systematic review Highlights The number of adults with congenital heart disease is increasing rapidly. There is considerable concern regarding global health outcomes in this population. Evidence shows that patients with congenital heart disease are more prone to cerebrovascular accidents. Neuroimaging tools may aid the detection of subtle vascular brain changes before cognitive impairment occurs.
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADAS... more Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common familial cerebral small vessel disease, caused by NOTCH3 gene mutations. The aim of our study was to identify clinical and neuroradiological features which would be useful in identifying which patients presenting with lacunar stroke and TIA are likely to have CADASIL. Patients with lacunar stroke or TIA were included in the present study. For each patient, demographic and clinical data were collected. MRI images were centrally analysed for the presence of lacunar infarcts, microbleeds, temporal lobe involvement, global atrophy and white matter hyperintensities. 128 patients (mean age 56.3 ± 12.4 years) were included. A NOTCH3 mutation was found in 12.5% of them. A family history of stroke, the presence of dementia and external capsule lesions on MRI were the only features significantly associated with the diagnosis of CADASIL. Although thalamic, temporal pole glios...
Alzheimer disease (AD) and vascular dementia (VaD) together represent the majority of dementia ca... more Alzheimer disease (AD) and vascular dementia (VaD) together represent the majority of dementia cases. Since their neuropsychological profiles often overlap and white matter lesions are observed in elderly subjects including AD, differentiating between VaD and AD can be difficult. Characterization of these different forms of dementia would benefit by identification of quantitative imaging biomarkers specifically sensitive to AD or VaD. Parameters of microstructural abnormalities derived from diffusion tensor imaging (DTI) have been reported to be helpful in differentiating between dementias, but only few studies have used them to compare AD and VaD with a voxelwise approach. Therefore, in this study a whole brain statistical analysis was performed on DTI data of 93 subjects (31 AD, 27 VaD, and 35 healthy controls-HC) to identify specific white matter patterns of alteration in patients affected by VaD and AD with respect to HC. Parahippocampal tracts were found to be mainly affected i...
Purpose To evaluate the feasibility of a standardized protocol for acquisition and analysis of dy... more Purpose To evaluate the feasibility of a standardized protocol for acquisition and analysis of dynamic contrast material-enhanced (DCE) and dynamic susceptibility contrast (DSC) magnetic resonance (MR) imaging in a multicenter clinical setting and to verify its accuracy in predicting glioma grade according to the new World Health Organization 2016 classification. Materials and Methods The local research ethics committees of all centers approved the study, and informed consent was obtained from patients. One hundred patients with glioma were prospectively examined at 3.0 T in seven centers that performed the same preoperative MR imaging protocol, including DCE and DSC sequences. Two independent readers identified the perfusion hotspots on maps of volume transfer constant (K), plasma (v) and extravascular-extracellular space (v) volumes, initial area under the concentration curve, and relative cerebral blood volume (rCBV). Differences in parameters between grades and molecular subtype...
First International IEEE EMBS Conference on Neural Engineering, 2003. Conference Proceedings.
In 10 right-handed volunteers, BOLD f-MRI activity was acquired during a protocol of mental speec... more In 10 right-handed volunteers, BOLD f-MRI activity was acquired during a protocol of mental speech production tasks. A task lasted 30 sec and consisted in recalling as many as possible animals (AN) or tools (TO). The protocol include 3 AN tasks and 3 TO tasks, each preceded by 30 sec rest (RE). By means of EPI the cerebral volume was acquired with a repetition time of 3 sec. After adjustment in stereotactic coordinates, spatial and temporal filtering, the time series of average activity in spherical regions with a 5 mm radius were extracted relevant to Broca's (BR) area, the left mesial WFG) and lateral (LFG) fusiform gyrus. An interaction model, estimating a modulation index of the connection between either MGF or LFG with BR was able to detect an increased MFG/BR connectivity during TO and increased LFG/BR connectivity during AN; however, this model failed in a subject by subject analysis. On the contrary a simpler correlation model, which separately analyzed the two tasks, was able to detect consistent changes in 7/10 MSG areas and in 9/10 LFG areas. We conclude that with an appropriate data analysis model the application of functional imaging can be widened from pure physiological studies to the clinical analysis in lesions or pathologies involving semantic memory and speech areas.
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by a severe derangement of... more Alzheimer's disease (AD) is a neurodegenerative disorder characterized by a severe derangement of cognitive functions, primarily memory, in elderly subjects. As far as the functional impairment is concerned, growing evidence supports the "disconnection syndrome" hypothesis. Recent investigations using fMRI have revealed a generalized alteration of resting state networks (RSNs) in patients affected by AD and mild cognitive impairment (MCI). However, it was unclear whether the changes in functional connectivity were accompanied by corresponding structural network changes. In this work, we have developed a novel structural/functional connectomic approach: resting state fMRI was used to identify the functional cortical network nodes and diffusion MRI to reconstruct the fiber tracts to give a weight to internodal subcortical connections. Then, local and global efficiency were determined for different networks, exploring specific alterations of integration and segregation patterns in AD and MCI patients compared to healthy controls (HC). In the default mode network (DMN), that was the most affected, axonal loss, and reduced axonal integrity appeared to compromise both local and global efficiency along posterior-anterior connections. In the basal ganglia network (BGN), disruption of white matter integrity implied that main alterations occurred in local microstructure. In the anterior insular network (AIN), neuronal loss probably subtended a compromised communication with the insular cortex. Cognitive performance, evaluated by neuropsychological examinations, revealed a dependency on integration and segregation of brain networks. These findings are indicative of the fact that cognitive deficits in AD could be associated not only with cortical alterations (revealed by fMRI) but also with subcortical alterations (revealed by diffusion MRI) that extend beyond the areas primarily damaged by neurodegeneration, toward the support of an emerging concept of AD as a "disconnection syndrome." Since only AD but not MCI patients were characterized by a significant decrease in structural connectivity, integrated structural/functional connectomics could provide a useful tool for assessing disease progression from MCI to AD.
Functional magnetic resonance imaging (fMRI), which has high spatial resolution, is increasingly ... more Functional magnetic resonance imaging (fMRI), which has high spatial resolution, is increasingly used to evaluate cerebral functions in neurological and psychiatric diseases. The main limitation of fMRI is that it detects neural activity indirectly, through the associated slow hemodynamic variations. Because neurovascular coupling can be regionally altered by pathological conditions or drugs, fMRI responses may not truly reflect neural activity. Electroencephalography (EEG) recordings, which directly detect neural activity with optimal temporal resolution, can now be obtained during fMRI data acquisition. Therefore, there is a growing interest in combining the techniques to obtain simultaneous EEG-fMRI recordings. The EEG-fMRI approach has several promising clinical applications. The first is the detection of cortical areas involved in interictal and ictal epileptic activity. Second, combining evoked potentials with fMRI could be an accurate way to study eloquent cortical areas for the planning of neurosurgery or rehabilitation, circumventing the above-mentioned limitation of fMRI. Finally, the use of this approach to evaluate the functional connectivity of resting-state networks would extend the applications of EEG-fMRI to uncooperative or unconscious patients. Integration of multimodal neuroimaging methods: a rationale for clinical applications of simultaneous EEG-fMRI.
Background and Purpose— Lombardia GENS is a multicentre prospective study aimed at diagnosing 5 s... more Background and Purpose— Lombardia GENS is a multicentre prospective study aimed at diagnosing 5 single-gene disorders associated with stroke (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, Fabry disease, MELAS [mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes], hereditary cerebral amyloid angiopathy, and Marfan syndrome) by applying diagnostic algorithms specific for each clinically suspected disease Methods— We enrolled a consecutive series of patients with ischemic or hemorrhagic stroke or transient ischemic attack admitted in stroke units in the Lombardia region participating in the project. Patients were defined as probable when presenting with stroke or transient ischemic attack of unknown etiopathogenic causes, or in the presence of <3 conventional vascular risk factors or young age at onset, or positive familial history or of specific clinical features. Patients fulfilling diagnostic algorithms specific...
The 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Aim of this work is to describe temporally and spatially the activation of the cerebral areas inv... more Aim of this work is to describe temporally and spatially the activation of the cerebral areas involved in reading processes by combining fMRI and reading-related potentials (RRPs). RRPs and fMR images were recorded in separate studies during a specifically designed experimental procedure. The protocol consisted of three visual tasks of increasing complexity. In the first two tasks subjects were asked
Cortex; a journal devoted to the study of the nervous system and behavior, Jan 14, 2015
The non-fluent/agrammatic variant of primary progressive aphasia (nfvPPA) and the behavioral vari... more The non-fluent/agrammatic variant of primary progressive aphasia (nfvPPA) and the behavioral variant frontotemporal dementia (bvFTD) are focal neurodegenerative disorders belonging to the FTD-spectrum clinical syndromes. NfvPPA is characterized by effortful speech and/or agrammatism and left frontal atrophy, while bvFTD is characterized by social-emotional dysfunction often accompanied by right-lateralized frontal damage. Despite their contrasting clinical presentations, both disorders show prominent left anterior insula atrophy. We investigated differential patterns of insular sub-region atrophy in nfvPPA and bvFTD. Based on knowledge of insular connectivity and physiology, we hypothesized that the left superior precentral region of the dorsal anterior insula (SPGI) would be more atrophic in nvfPPA due to its critical role in motor speech, whereas the ventral anterior region would be more atrophied in bvFTD reflecting its known role in social-emotional-autonomic functions. Early st...
We have demonstrated that Stochastic Resonance can be used as a tool to quantify the ability of h... more We have demonstrated that Stochastic Resonance can be used as a tool to quantify the ability of human observers to detect details in a noisy visual stimulation(E. Simonotto, et al., Phys. Rev. Lett.) 78, 1186 (1997). This technique gives consistently reproducible results and allows a quantitative comparison between different subjects. We have begun fMRI studies to investigate the underlying processes
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