- Email: [email protected]
P2.6 Electroencephalography in malformations of cortical development
S62 Results: The findings showed that on average, patients who had an attack during VEM had an average attack frequency of 6.6 attacks per week (compared to 2.9 for those who had no attack). No clinical events were detected for patients with an average attack frequency of less than 1 attack every 6 weeks; therefore a 100% diagnostic-yield was achieved for patients admitted with an average attack frequency of more than 1 attack per 6 weeks. Applying a cut-off point of more than 1 attack per week, gives a diagnostic yield of 93.3% and avoids 17 VEM admissions. A stricter limit of 1 attack per week reduces the yield to 91.7%, and avoids 25 admissions. Conclusions: Since most patients who had an attack during VEM admission had an attack frequency greater than 1 2 attacks every 2 weeks, this is the most practical and economical attack frequency cut-off point. No patients should be admitted with an average attack frequency of less than 1 attack in 6 weeks. Each VEM unit should carefully consider the trade-off between efficient use of the service and loss of diagnostic-yield when deciding which limit to set. P2.5 Somatosensory evoked spikes on the EEG: evolutive clinical and electroencephalographic aspects in 313 children G. Tedrus1 , L. Fonseca1 Pontificia Universidade Catolica de Campinas, Campinas, Brazil
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Introduction: Somatosensory evoked spikes (ESp) are high voltage potentials registered on the EEG, which accompany each of the percussions of the feet or hands. There are controversies about the ESp as markers of epilepsy and about its prognostic value. Objectives: The objective of this research was to study the evolutive clinical and electroencephalographic aspects of children with ESp. Methods: Three hundred and thirteen children, 53.7% male, showing ESp on the EEG and with an initial average age of 6.82 (range from 2 to 14) were accompanied for a mean period of 35.7 months. Results: In the initial evaluation, 118 (37.7%) of the children had a history of non-febrile epileptic fits (ES). Epileptiform activity (EA) was observed on the EEG in 61% of the cases, and showed a significantly greater occurrence in children with (ES) than in those without (p = 0.000). Of the 118 children showing fits as from the start, 53 (44.9%) continued to have them, whereas of the 195 without fits at the start, only 13 (6.67%) developed them. Thus only 66 (21.1%) children showed ES during the continuation of the trial. The ESp disappeared in 237 (75.7%) of the cases and EA in 221 (70.6%). In the children with ES, it was found that the presence of EA on the 1st EEG did not define continuation of the ES throughout the remaining period, whilst the thirteen children who presented their first ES in the later period showed a greater occurrence of EA on the initial EEG than in those who did not develop ES (p = 0.001). Conclusions: ESp, EA and ES tend to disappear, suggesting an agedependent phenomenon. The finding of ESp, particularly in the absence of any evidence of cerebral injury, indicates a low association with ES and benign evolution. P2.6 Electroencephalography in malformations of cortical development E. Lainez1 , J. Conill1 , K. Rahnama1 , M. Raspall2 , I. Delgado3 , E. Vazquez3 , M. Roig4 1 Clinical Neurophysiology, Vall d’Hebron Hospital, Barcelona, Spain, 2 Pediatric Neurology Department, Vall d’Hebron Hospital, Barcelona, Spain, 3 Pediatric Neuroradiology, Vall d’Hebron Hospital, Barcelona, Spain, 4 Pediatric Neurology, Vall d’Hebron Hospital, Barcelona, Spain Introduction: Malformations of the cerebral cortex (MCC) are often associated with severe epilepsy, with onset during childhood and developmental delay. About 40% of drug-resistant epilepsies are caused by MCC. They are classified in 3 groups: a) abnormal neuronal and glial proliferation or apoptosis, b) abnormal neuronal migration and c) abnormal cortical migration. In literature we find neuroimaging and histopathology features of these disorders but iconography of Electroencephalography (EEG) recordings is less frequent. Objective: We present the EEG patterns associated to clinical and Magnetic Resonance imaging in patients with MCC attended in our hospital from the last 6 years. Methods: We reviewed the video-EEG recordings of MCC patients, including hemimegalencephaly, focal cortical dysplasia (FCD), dysembrioplastic neuroepithelial tumor (DNET), lissencephaly, subcortical band
Poster presentations: Poster session 2. EEG
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heterotopia (SBH), polymicrogyria, schizencephaly, holoprosencephaly and Aicardi Syndrome. Results: EEG patterns in lissencephaly show diffuse high amplitude fast rhythms with abnormal basal activity. SBH recordings demonstrate multifocal abnormalities, as well as in hemimegalencephaly. In polymicrogyria, FCD and DNET we found focal or multifocal abnormalities over the area of lesion. Schinzencephaly and Aicardi Syndrome patients presented inadequate organization of basal activity, with or without suppression bursts and focal paroxysms. And in holoprosencephaly hypsarrythmic pattern was observed. Conclusion: MCC are frequently associated with epilepsy and some of them present EEG patterns suggestive of an underlying area of cortical dysplasia. EEG recordings could help in early diagnosis of MCC and are useful to characterize the epileptic syndrome and even co-localization of the structural abnormality if surgical treatment is planned. P2.7 Pattern-related changes of visual evoked potentials in epileptic children with pattern-sensitivity M. Brinciotti1 , M. Matricardi2 , B. Venuti2 , A.M. Bonanni2 , C. De Angelis2 , A. Mittica2 1 Department of Pediatrics & Child Neuropsychiatry, “Sapienza” Rome University, Rome, Italy, 2 Department of Pediatrics & Child Neuropsychiatry, “Sapienza” Rome University, Rome, Italy Introduction: High-contrast visual patterns may represent triggering factors of epileptic EEG activity and seizures (pattern-sensitivity). Even if closely related to photosensitivity, the pathogenetic mechanisms underlying this paroxysmal response remain to be clarified. Objectives: To examine the responsiveness of the visual cortex in epileptic children with pattern-sensitivity. Methods: We studied 31 epileptic children (14 males, 17 females; age 2 18 years, mean age 10.9±4.7 years) with pattern-sensitivity alone (5) or with photosensitivity (26). All children had visually induced reflex seizures (22 associated with spontaneous seizures, 9 alone). In all patients, video-EEGs (21 channels) were recorded according to the international 10 20 system with standardized Intermittent Photic Stimulation and Pattern-Stimulation (checks, vertical stripes, horizontal stripes; different spatial frequency; black/white and red/blue). For each block, signals from O1 and O2 were averaged and evaluated off-line to obtain VEP for each stimulus condition. Peak latencies (N75, P100, N135) and peak-to-peak amplitudes (N75 P100, P100 N135) were determined and analyzed (ANOVA), grouping the responses within each pattern in Activating Stimulus (AS) and No-Activating Stimulus (No-AS) according to the occurrence of stimulus-related epileptic abnormalities. Results: Mean amplitudes of VEPs were higher during AS compared to No-AS, with significant differences for N75-P100 at full-field black/white checks at low spatial frequency (O2: 20.16±9.17 ms vs 12.39±6.02 ms; p 0.0268) and at medium spatial frequency (O1: 18.09±10.59 ms vs 9.051±5.31 ms; p 0.0169; O2: 20.08±11.47 ms vs 10.20±5.36; p 0.153). No differences were found for latencies. Conclusions: Pattern-sensitive epileptic patients showed an increased amplitude of VEP, especially in the N75 P100 component, while viewing epileptogenic images. This finding may originate from an abnormal excitability and reactivity of the occipital cortex. P2.8 Multimodality approach in presurgical evaluation of epilepsy S.F. Storti1 , E. Formaggio1,2 , L. Bongiovanni1 , A. Fiaschi1,2 , P. Manganotti1,2 1 Department of Neurological, Neuropsychological, Morphological and Movement Sciences, Section of Clinical Neurology, “Gianbattista Rossi” Hospital, University of Verona, Verona, Italy, 2 IRCCS S. Camillo, Venice, Italy Introduction: Both Electroencephalography-functional Magnetic Resonance Imaging (EEG-fMRI) coregistration and high density EEG (hdEEG) map abnormal brain activation elicited by epileptic processes. EEG-fMRI is an imaging technique which provides localizing Blood Oxygenation Level Dependent (BOLD) information of irritative regions. Conversely, the source analysis estimates the current density of the source that generates a measured electric potential. Objectives: Clinical assessment of these techniques is done in patients with focal epilepsy who subsequently underwent epilepsy surgery.
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Introduction: Somatosensory evoked spikes (ESp) are high voltage potentials registered on the EEG, which accompany each of the percussions of the feet or hands. There are controversies about the ESp as markers of epilepsy and about its prognostic value. Objectives: The objective of this research was to study the evolutive clinical and electroencephalographic aspects of children with ESp. Methods: Three hundred and thirteen children, 53.7% male, showing ESp on the EEG and with an initial average age of 6.82 (range from 2 to 14) were accompanied for a mean period of 35.7 months. Results: In the initial evaluation, 118 (37.7%) of the children had a history of non-febrile epileptic fits (ES). Epileptiform activity (EA) was observed on the EEG in 61% of the cases, and showed a significantly greater occurrence in children with (ES) than in those without (p = 0.000). Of the 118 children showing fits as from the start, 53 (44.9%) continued to have them, whereas of the 195 without fits at the start, only 13 (6.67%) developed them. Thus only 66 (21.1%) children showed ES during the continuation of the trial. The ESp disappeared in 237 (75.7%) of the cases and EA in 221 (70.6%). In the children with ES, it was found that the presence of EA on the 1st EEG did not define continuation of the ES throughout the remaining period, whilst the thirteen children who presented their first ES in the later period showed a greater occurrence of EA on the initial EEG than in those who did not develop ES (p = 0.001). Conclusions: ESp, EA and ES tend to disappear, suggesting an agedependent phenomenon. The finding of ESp, particularly in the absence of any evidence of cerebral injury, indicates a low association with ES and benign evolution. P2.6 Electroencephalography in malformations of cortical development E. Lainez1 , J. Conill1 , K. Rahnama1 , M. Raspall2 , I. Delgado3 , E. Vazquez3 , M. Roig4 1 Clinical Neurophysiology, Vall d’Hebron Hospital, Barcelona, Spain, 2 Pediatric Neurology Department, Vall d’Hebron Hospital, Barcelona, Spain, 3 Pediatric Neuroradiology, Vall d’Hebron Hospital, Barcelona, Spain, 4 Pediatric Neurology, Vall d’Hebron Hospital, Barcelona, Spain Introduction: Malformations of the cerebral cortex (MCC) are often associated with severe epilepsy, with onset during childhood and developmental delay. About 40% of drug-resistant epilepsies are caused by MCC. They are classified in 3 groups: a) abnormal neuronal and glial proliferation or apoptosis, b) abnormal neuronal migration and c) abnormal cortical migration. In literature we find neuroimaging and histopathology features of these disorders but iconography of Electroencephalography (EEG) recordings is less frequent. Objective: We present the EEG patterns associated to clinical and Magnetic Resonance imaging in patients with MCC attended in our hospital from the last 6 years. Methods: We reviewed the video-EEG recordings of MCC patients, including hemimegalencephaly, focal cortical dysplasia (FCD), dysembrioplastic neuroepithelial tumor (DNET), lissencephaly, subcortical band
Poster presentations: Poster session 2. EEG
1
heterotopia (SBH), polymicrogyria, schizencephaly, holoprosencephaly and Aicardi Syndrome. Results: EEG patterns in lissencephaly show diffuse high amplitude fast rhythms with abnormal basal activity. SBH recordings demonstrate multifocal abnormalities, as well as in hemimegalencephaly. In polymicrogyria, FCD and DNET we found focal or multifocal abnormalities over the area of lesion. Schinzencephaly and Aicardi Syndrome patients presented inadequate organization of basal activity, with or without suppression bursts and focal paroxysms. And in holoprosencephaly hypsarrythmic pattern was observed. Conclusion: MCC are frequently associated with epilepsy and some of them present EEG patterns suggestive of an underlying area of cortical dysplasia. EEG recordings could help in early diagnosis of MCC and are useful to characterize the epileptic syndrome and even co-localization of the structural abnormality if surgical treatment is planned. P2.7 Pattern-related changes of visual evoked potentials in epileptic children with pattern-sensitivity M. Brinciotti1 , M. Matricardi2 , B. Venuti2 , A.M. Bonanni2 , C. De Angelis2 , A. Mittica2 1 Department of Pediatrics & Child Neuropsychiatry, “Sapienza” Rome University, Rome, Italy, 2 Department of Pediatrics & Child Neuropsychiatry, “Sapienza” Rome University, Rome, Italy Introduction: High-contrast visual patterns may represent triggering factors of epileptic EEG activity and seizures (pattern-sensitivity). Even if closely related to photosensitivity, the pathogenetic mechanisms underlying this paroxysmal response remain to be clarified. Objectives: To examine the responsiveness of the visual cortex in epileptic children with pattern-sensitivity. Methods: We studied 31 epileptic children (14 males, 17 females; age 2 18 years, mean age 10.9±4.7 years) with pattern-sensitivity alone (5) or with photosensitivity (26). All children had visually induced reflex seizures (22 associated with spontaneous seizures, 9 alone). In all patients, video-EEGs (21 channels) were recorded according to the international 10 20 system with standardized Intermittent Photic Stimulation and Pattern-Stimulation (checks, vertical stripes, horizontal stripes; different spatial frequency; black/white and red/blue). For each block, signals from O1 and O2 were averaged and evaluated off-line to obtain VEP for each stimulus condition. Peak latencies (N75, P100, N135) and peak-to-peak amplitudes (N75 P100, P100 N135) were determined and analyzed (ANOVA), grouping the responses within each pattern in Activating Stimulus (AS) and No-Activating Stimulus (No-AS) according to the occurrence of stimulus-related epileptic abnormalities. Results: Mean amplitudes of VEPs were higher during AS compared to No-AS, with significant differences for N75-P100 at full-field black/white checks at low spatial frequency (O2: 20.16±9.17 ms vs 12.39±6.02 ms; p 0.0268) and at medium spatial frequency (O1: 18.09±10.59 ms vs 9.051±5.31 ms; p 0.0169; O2: 20.08±11.47 ms vs 10.20±5.36; p 0.153). No differences were found for latencies. Conclusions: Pattern-sensitive epileptic patients showed an increased amplitude of VEP, especially in the N75 P100 component, while viewing epileptogenic images. This finding may originate from an abnormal excitability and reactivity of the occipital cortex. P2.8 Multimodality approach in presurgical evaluation of epilepsy S.F. Storti1 , E. Formaggio1,2 , L. Bongiovanni1 , A. Fiaschi1,2 , P. Manganotti1,2 1 Department of Neurological, Neuropsychological, Morphological and Movement Sciences, Section of Clinical Neurology, “Gianbattista Rossi” Hospital, University of Verona, Verona, Italy, 2 IRCCS S. Camillo, Venice, Italy Introduction: Both Electroencephalography-functional Magnetic Resonance Imaging (EEG-fMRI) coregistration and high density EEG (hdEEG) map abnormal brain activation elicited by epileptic processes. EEG-fMRI is an imaging technique which provides localizing Blood Oxygenation Level Dependent (BOLD) information of irritative regions. Conversely, the source analysis estimates the current density of the source that generates a measured electric potential. Objectives: Clinical assessment of these techniques is done in patients with focal epilepsy who subsequently underwent epilepsy surgery.