Associate Professor University Institute Hospital ItalianoChild Neurology Service - University Institute (IUHI) - Hospital Italiano de Buenos Aires Address: Argentina
In construing meaning, the brain recruits multimodal (conceptual) systems and embodied (modality-... more In construing meaning, the brain recruits multimodal (conceptual) systems and embodied (modality-specific) mechanisms. Yet, no consensus exists on how crucial the latter are for the inception of semantic distinctions. To address this issue, we combined electroencephalographic (EEG) and intracranial EEG (iEEG) to examine when nouns denoting facial body parts (FBPs) and nonFBPs are discriminated in face-processing and multimodal networks. First, FBP words increased N170 amplitude (a hallmark of early facial processing). Second, they triggered fast (~100 ms) activity boosts within the face-processing network, alongside later (~275 ms) effects in multimodal circuits. Third, iEEG recordings from face-processing hubs allowed decoding ~80% of items before 200 ms, while classification based on multimodal-network activity only surpassed ~70% after 250 ms. Finally, EEG and iEEG connectivity between both networks proved greater in early (0–200 ms) than later (200–400 ms) windows. Collectively,...
The purpose of this study is to identify specific clinical-electroencephalogram (EEG) patterns at... more The purpose of this study is to identify specific clinical-electroencephalogram (EEG) patterns at seizure onset in patients with hippocampal sclerosis (HS). Sixty-six ictal video-EEG recordings corresponding to 26 patients with HS have been reviewed, focusing on the EEG features found during the first 30 ictal s. The EEG activity has been classified into the following groups: (A) according to spatial distribution: type 1: temporal electrodes on one side; type 2: temporal and adjacent frontal electrodes on one side; and type 3: non-lateralizing electrographic activity; and (B) according to morphology; subtype (a): regular 5-9 Hz rhythmic activity (RA); subtype (b): low-voltage rapid activity, followed by a 5-9 Hz RA; and subtype (c): irregular EEG sharp waves. We analyzed the clinical symptoms sequence and established the relationship with the ictal EEG patterns. Considering spatial distribution and morphology, the most frequent ictal EEG patterns were type 1 (57%), type 2 (37%), and subtype (a): 62%; subtype (b): 27%; and subtype (c): 11%. The sequence of clinical symptoms observed was: aura-->behavioral arrest-->oro-alimentary automatisms-->unilateral hand automatisms. All seizures with aura and including two or more symptoms of the clinical sequence (65%) were associated with a 1a, 1b, 2a or 2b EEG pattern. The identification of a specific clinical-EEG pattern provides a useful tool for the epileptogenic zone localization in non-invasive pre-surgical assessment of patients with hippocampal sclerosis. The identification of a specific clinical-EEG pattern associated to neuroimaging findings and neuropsychological testing allows indicating surgery for the treatment of epilepsy in patients with hippocampal sclerosis, without performing any further complementary studies.
American Journal of Medical Genetics Part C: Seminars in Medical Genetics, 2020
The genetic and phenotypic heterogeneity of neurogenetic diseases forces patients and their famil... more The genetic and phenotypic heterogeneity of neurogenetic diseases forces patients and their families into a “diagnostic odyssey.” An increase in the variability of genetic disorders and the corresponding gene‐disease associations suggest the need to periodically re‐evaluate the significance of variants of undetermined pathogenicity. Here, we report the diagnostic and clinical utility of Targeted Gene Panel Sequencing (TGPS) and Whole Exome Sequencing (WES) in 341 patients with suspected neurogenetic disorders from centers in Buenos Aires and Cincinnati over the last 4 years, focusing on the usefulness of reinterpreting variants previously classified as of uncertain significance. After a mean of ±2years (IC 95:0.73–3.27), approximately 30% of the variants of uncertain significance were reclassified as pathogenic. The use of next generation sequencing methods has facilitated the identification of both germline and mosaic pathogenic variants, expanding the diagnostic yield. These results demonstrate the high clinical impact of periodic reanalysis of undetermined variants in clinical neurology.
La cirugía de las epilepsias ha dejado de ser el últimorecurso terapéutico, en aquellos pacientes... more La cirugía de las epilepsias ha dejado de ser el últimorecurso terapéutico, en aquellos pacientes, que a pesardel mejor tratamiento farmacológico ofrecido persisten concrisis que afectan su calidad de vida. Aproximadamenteentre un 20 a un 30% de los individuos que sufren epilep-sia son refractarios a los medicamentos antiepilépticos.Los avances en las neuroimágenes han revoluciona-do la identificación y evaluación de los posibles candida-tos a una cirugía. Pacientes que hasta hace una décadaeran rechazados para su evaluación, hoy son admitidospara la misma.El propósito de esta guía es orientar al neurólogo y clíni-co general, en conocer las indicaciones para las cirugíasdel lóbulo temporal, así como en regiones extratemporalesy los requerimientos mínimos para que un centro sea califi-cado para realizar cirugía de las epilepsias.En la elaboración de estas Guías se consideró enespecial las guías del Grupo Latinoamericano de Ciru-gía de la Epilepsia, de la Liga Internacional contra laE...
The association between psychotic disorders and epilepsy has been controversial. Different subtyp... more The association between psychotic disorders and epilepsy has been controversial. Different subtypes of psychotic disorders in epilepsy patients have been described according to temporal relationship with seizures-postictal (PIP), interictal (IIP) and bimodal (BP) psychoses are described in literature. Determine clinical characteristics of patients with refractory partial epilepsy and psychoses and compare the results with a control group of patients with refractory partial epilepsy without psychoses. A total of 57 patients with refractory partial epilepsy and psychotic disorders (psychotic group [PG]) and 56 patients with refractory partial epilepsy and without psychoses (control group, CG) were evaluated according to DSM-IV criteria and SCID-I. All patients underwent complete neurological, neuroimaging, neuropsychological, and psychiatric assessment. Clinical, demographic and neuroimaging data were compared between patients in CG and PG. In PG 15 patients (26 %) had criteria for PI...
Magnetic resonance imaging (MRI) has become an essential tool in the work-up of epilepsy. Since i... more Magnetic resonance imaging (MRI) has become an essential tool in the work-up of epilepsy. Since its appearance it has been possible to identify pathologies, such as hippocampal sclerosis (HS), that had previously only been detected by histopathological assays. The aim of this study was to analyze the clinical manifestations, EEG and the outcome of patients with HS as shown by MRI. We revised the clinical histories of 384 outpatients from the Epilepsy Center, Ramos Mejía Hospital, who had been studied by MRI. Thirty five of them (15.5%) had a diagnosis of HS, based on the structural changes observed on the images. Six patients were excluded because of incomplete clinical data. Therefore, we studied 29 patients including 15 men. The mean age was 32.7 +/- 10.2 years (range: 19-58). All of them had partial seizures. Ten subjects had had febrile convulsions (34.5%) in childhood. Neurological examination was normal in all subjects. Interictal EEG showed focal abnormalities that were coinc...
Neural synchrony in the γ-band is considered a fundamental process in cortical computation and co... more Neural synchrony in the γ-band is considered a fundamental process in cortical computation and communication and it has also been proposed as a crucial correlate of consciousness. However, the latter claim remains inconclusive, mainly due to methodological limitations, such as the spectral constraints of scalp-level electroencephalographic recordings or volume-conduction confounds. Here, we circumvented these caveats by comparing γ-band connectivity between two global states of consciousness via intracranial electroencephalography (iEEG), which provides the most reliable measurements of high-frequency activity in the human brain. Non-REM Sleep recordings were compared to passive-wakefulness recordings of the same duration in three subjects with surgically implanted electrodes. Signals were analyzed through the weighted Phase Lag Index connectivity measure and relevant graph theory metrics. We found that connectivity in the high-γ range (90-120 Hz), as well as relevant graph theory p...
In construing meaning, the brain recruits multimodal (conceptual) systems and embodied (modality-... more In construing meaning, the brain recruits multimodal (conceptual) systems and embodied (modality-specific) mechanisms. Yet, no consensus exists on how crucial the latter are for the inception of semantic distinctions. To address this issue, we combined electroencephalographic (EEG) and intracranial EEG (iEEG) to examine when nouns denoting facial body parts (FBPs) and nonFBPs are discriminated in face-processing and multimodal networks. First, FBP words increased N170 amplitude (a hallmark of early facial processing). Second, they triggered fast (~100 ms) activity boosts within the face-processing network, alongside later (~275 ms) effects in multimodal circuits. Third, iEEG recordings from face-processing hubs allowed decoding ~80% of items before 200 ms, while classification based on multimodal-network activity only surpassed ~70% after 250 ms. Finally, EEG and iEEG connectivity between both networks proved greater in early (0–200 ms) than later (200–400 ms) windows. Collectively,...
The purpose of this study is to identify specific clinical-electroencephalogram (EEG) patterns at... more The purpose of this study is to identify specific clinical-electroencephalogram (EEG) patterns at seizure onset in patients with hippocampal sclerosis (HS). Sixty-six ictal video-EEG recordings corresponding to 26 patients with HS have been reviewed, focusing on the EEG features found during the first 30 ictal s. The EEG activity has been classified into the following groups: (A) according to spatial distribution: type 1: temporal electrodes on one side; type 2: temporal and adjacent frontal electrodes on one side; and type 3: non-lateralizing electrographic activity; and (B) according to morphology; subtype (a): regular 5-9 Hz rhythmic activity (RA); subtype (b): low-voltage rapid activity, followed by a 5-9 Hz RA; and subtype (c): irregular EEG sharp waves. We analyzed the clinical symptoms sequence and established the relationship with the ictal EEG patterns. Considering spatial distribution and morphology, the most frequent ictal EEG patterns were type 1 (57%), type 2 (37%), and subtype (a): 62%; subtype (b): 27%; and subtype (c): 11%. The sequence of clinical symptoms observed was: aura-->behavioral arrest-->oro-alimentary automatisms-->unilateral hand automatisms. All seizures with aura and including two or more symptoms of the clinical sequence (65%) were associated with a 1a, 1b, 2a or 2b EEG pattern. The identification of a specific clinical-EEG pattern provides a useful tool for the epileptogenic zone localization in non-invasive pre-surgical assessment of patients with hippocampal sclerosis. The identification of a specific clinical-EEG pattern associated to neuroimaging findings and neuropsychological testing allows indicating surgery for the treatment of epilepsy in patients with hippocampal sclerosis, without performing any further complementary studies.
American Journal of Medical Genetics Part C: Seminars in Medical Genetics, 2020
The genetic and phenotypic heterogeneity of neurogenetic diseases forces patients and their famil... more The genetic and phenotypic heterogeneity of neurogenetic diseases forces patients and their families into a “diagnostic odyssey.” An increase in the variability of genetic disorders and the corresponding gene‐disease associations suggest the need to periodically re‐evaluate the significance of variants of undetermined pathogenicity. Here, we report the diagnostic and clinical utility of Targeted Gene Panel Sequencing (TGPS) and Whole Exome Sequencing (WES) in 341 patients with suspected neurogenetic disorders from centers in Buenos Aires and Cincinnati over the last 4 years, focusing on the usefulness of reinterpreting variants previously classified as of uncertain significance. After a mean of ±2years (IC 95:0.73–3.27), approximately 30% of the variants of uncertain significance were reclassified as pathogenic. The use of next generation sequencing methods has facilitated the identification of both germline and mosaic pathogenic variants, expanding the diagnostic yield. These results demonstrate the high clinical impact of periodic reanalysis of undetermined variants in clinical neurology.
La cirugía de las epilepsias ha dejado de ser el últimorecurso terapéutico, en aquellos pacientes... more La cirugía de las epilepsias ha dejado de ser el últimorecurso terapéutico, en aquellos pacientes, que a pesardel mejor tratamiento farmacológico ofrecido persisten concrisis que afectan su calidad de vida. Aproximadamenteentre un 20 a un 30% de los individuos que sufren epilep-sia son refractarios a los medicamentos antiepilépticos.Los avances en las neuroimágenes han revoluciona-do la identificación y evaluación de los posibles candida-tos a una cirugía. Pacientes que hasta hace una décadaeran rechazados para su evaluación, hoy son admitidospara la misma.El propósito de esta guía es orientar al neurólogo y clíni-co general, en conocer las indicaciones para las cirugíasdel lóbulo temporal, así como en regiones extratemporalesy los requerimientos mínimos para que un centro sea califi-cado para realizar cirugía de las epilepsias.En la elaboración de estas Guías se consideró enespecial las guías del Grupo Latinoamericano de Ciru-gía de la Epilepsia, de la Liga Internacional contra laE...
The association between psychotic disorders and epilepsy has been controversial. Different subtyp... more The association between psychotic disorders and epilepsy has been controversial. Different subtypes of psychotic disorders in epilepsy patients have been described according to temporal relationship with seizures-postictal (PIP), interictal (IIP) and bimodal (BP) psychoses are described in literature. Determine clinical characteristics of patients with refractory partial epilepsy and psychoses and compare the results with a control group of patients with refractory partial epilepsy without psychoses. A total of 57 patients with refractory partial epilepsy and psychotic disorders (psychotic group [PG]) and 56 patients with refractory partial epilepsy and without psychoses (control group, CG) were evaluated according to DSM-IV criteria and SCID-I. All patients underwent complete neurological, neuroimaging, neuropsychological, and psychiatric assessment. Clinical, demographic and neuroimaging data were compared between patients in CG and PG. In PG 15 patients (26 %) had criteria for PI...
Magnetic resonance imaging (MRI) has become an essential tool in the work-up of epilepsy. Since i... more Magnetic resonance imaging (MRI) has become an essential tool in the work-up of epilepsy. Since its appearance it has been possible to identify pathologies, such as hippocampal sclerosis (HS), that had previously only been detected by histopathological assays. The aim of this study was to analyze the clinical manifestations, EEG and the outcome of patients with HS as shown by MRI. We revised the clinical histories of 384 outpatients from the Epilepsy Center, Ramos Mejía Hospital, who had been studied by MRI. Thirty five of them (15.5%) had a diagnosis of HS, based on the structural changes observed on the images. Six patients were excluded because of incomplete clinical data. Therefore, we studied 29 patients including 15 men. The mean age was 32.7 +/- 10.2 years (range: 19-58). All of them had partial seizures. Ten subjects had had febrile convulsions (34.5%) in childhood. Neurological examination was normal in all subjects. Interictal EEG showed focal abnormalities that were coinc...
Neural synchrony in the γ-band is considered a fundamental process in cortical computation and co... more Neural synchrony in the γ-band is considered a fundamental process in cortical computation and communication and it has also been proposed as a crucial correlate of consciousness. However, the latter claim remains inconclusive, mainly due to methodological limitations, such as the spectral constraints of scalp-level electroencephalographic recordings or volume-conduction confounds. Here, we circumvented these caveats by comparing γ-band connectivity between two global states of consciousness via intracranial electroencephalography (iEEG), which provides the most reliable measurements of high-frequency activity in the human brain. Non-REM Sleep recordings were compared to passive-wakefulness recordings of the same duration in three subjects with surgically implanted electrodes. Signals were analyzed through the weighted Phase Lag Index connectivity measure and relevant graph theory metrics. We found that connectivity in the high-γ range (90-120 Hz), as well as relevant graph theory p...
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