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P800: Slow spindles’ cortical generators overlap with the epileptogenic zone in temporal epileptic patients: an electrical source imaging study
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Abstracts of Poster Presentations / Clinical Neurophysiology 125, Supplement 1 (2014) S1–S339
P798 An investigation of fear potentiated transcranial magnetic stimulation, blink and audiogenic startle reflex after successful surgery of mesial temporal lobe epilepsy S. Goekdemir, M.E. Kızıltan, Ç. Özkara Istanbul University, Neurology, Istanbul, Turkey Fearful facial expressions are danger signals that rapidly trigger a cascade of neurobiological processes defensibly associated with action preparation. Direct evidence for the activating effects of fearful facial expressions on the motor system has been shown with transcranial magnetic stimulation (TMS) and auditory startle reflex (ASR) studies[1,2]. The present study investigated blink reflex (BR), fear-potentiated motor evoked potentials (MEP) and ASR results after successful surgery of mesial temporal lobe epilepsy. We have included 15 healthy volunteers and 12 operated mesial temporal sclerosis (MTS) patients without seizures. Mean age for patients was 36.9±8.9 and 29.8±9.3 for controls. The current TMS and ASR study investigated whether fearful facial expressions selectively increase corticospinal motor tract (CST) excitability in patients with hippocampal sclerosis (HS) who successfully underwent selective amigdalohipocampectomy operation. BR responses of patients were also compared with those of healthy controls. Changes in CST excitability using the MEP and ASR data were recorded. Results showed significant selective increases in MEP and changes in ASR data to fearful facial expressions in healthy volunteers but not in the patients (P=0.96). All though blink response results were in normal range in both groups, a statistically significant difference was investigated between the healthy volunteers and the patients. These findings provide evidence for selective increases in ST excitability to threat and the importance of amygdala in CST excitability. References: [1] Schutter, D.J., D. Hofman, and J. Van Honk, Fearful faces selectively increase corticospinal motor tract excitability: a transcranial magnetic stimulation study. Psychophysiology, 2008. 45(3): p. 345-8. [2] Koch, M. and U. Ebert, Enhancement of the acoustic startle response by stimulation of an excitatory pathway from the central amygdala/basal nucleus of Meynert to the pontine reticular formation. Exp Brain Res, 1993. 93(2): p. 231-41.
P799 Electroclinical characterization of SLC2A1 mutation in three pediatric patients A. Martínez de la Ossa Vela 1 , M. Vicente Rasoamalala 1 , V. Thonon 1 , A. Macaya Ruíz 2 , E. Laínez Semper 1 1 Hospital Universitari Vall d’Hebron, Clinical Neurophysiology, Barcelona, Spain; 2 Hospital Universitari Vall d’Hebron, Pediatric Neurology, Barcelona, Spain Question: Glucose transporter 1 deficiency syndrome (GLUT1DS) is a metabolic disorder manifesting as cognitive impairment, acquired microcephaly, epilepsy, and/or movement disorder caused by mutations in the SLC2A1 gene. Since its first description, many EEG findings have been described including normal findings, slow background activity, ictal and/or interictal generalized and/or focal epileptic discharges and fluctuations over time. We aim to describe the different VIDEO-EEG findings in three patients with the SLC2A1 gene mutation, being twins two of them. Methods: VIDEO-EEG recording of three patients with the SLC2A1 de novo gene mutation. Patients 1 and 2: Two fourteen year old boys, monozygotic brothers, who described episodes of progressive weakness and incoordination, related to exercise more or less prolonged; they also explained daily episodes of brief decreased attention and stare, interrupting briefly activity, diagnosed of absence epilepsy at the age of 8 years old. Patient 3: Ten year old girl, who was studied for delayed psychomotor development since 2 year old. At the age of 7 year old staring spells, consistent in eye closure, blink along with cephalic fall, up to 20 per day, were observed with partial response to VPA. Results: VIDEO-EEG recordings for patient 1 and 2 showed the following anomalies: focal intermittent slow waves in anterior regions and 2.5 4Hz generalized spike-wave (frontal prevalence) that worsen while the hyperventilation was performed and associated with clinical absence.
Additionally, a benign variant normality was found. These pathological findings disappeared for a short amount of time after the administration of oral glucose. Patient 3 VIDEO-EEG recordings showed focal delta bursts with occasional superimposed sharp waves in posterior regions, ictal and interictal 3 Hz spike-wave generalized discharges which worsen during sleep and a background activity that fluctuates over time. Conclusions: EEG findings in GLULT1DS are still variable although serial recordings over ages show changes that suggest this syndrome. Screening diagnose is recommended in patients with clinical absence epilepsy with characteristic clinical features and suggestive EEG findings over time.
P800 Slow spindles’ cortical generators overlap with the epileptogenic zone in temporal epileptic patients: an electrical source imaging study A. Del Felice 1 , C. Arcaro 1 , S.F. Storti 1 , P. Manganotti 1,2,3 1 University of Verona, Department of Neurological and Motor Sciences, Verona, Italy; 2 AOUI, Department of Neurology, Verona, Italy; 3 IRCCS San Camillo, Department of Neurophysiology, Venice, Italy Question: To determine whether temporal epileptic patients and normal volunteers display similar sleep spindles’ cortical generators as determined by electrical source imaging (ESI), and whether such generators overlap in epilepsy patients with the epileptogenic zone identified by ESI. Methods: Thirteen healthy subjects and eight temporal lobe pharmacoresistant epileptic patients underwent a 256-channel EEG recording during a daytime nap. Spindles were visually scored and marked; categorization in slow (10-12 HZ) and fast (12-14 Hz) ones was done by independently bandpass filtering in the appropriate frequency band. EEG was segmented on the marker position, and segments separately averaged for each category. Cortical sources were estimated using LORETA on the MNI brain. Maximal intra- and inter-individual intensities were compared through the Wilcoxon matched pairs test (p<0.05). The same procedure was performed for averaged epileptic spikes, obtaining their cortical source. Source generators localizations were statistically compared between epileptics and controls via a χ2 test, and source intensities through a Mann-Whitney t test for independent samples (p<0.05). Overlap of spindles generators and spike generator was performed via a binomial distribution test (p<0.05). Results: Multiple, concomitant and equipotent generators were detected in both populations for slow and fast spindles. While in normal subjects slow spindles had a persistent source over the frontal cortex, in temporal epileptics they displayed a preferential localization over the temporal cortices (p=0.035), as well as higher source amplitude in comparison to healthy volunteers (p=0.042). Interestingly, at least one of slow spindles’ generators overlapped with the epileptogenic zone (p=0.016) as obtained by ESI. Conclusion: Slow spindles, but not fast ones, in temporal epilepsy are mainly generated over the affected temporal lobe cortex, and display overall higher intensities than spindles generators in healthy individuals. These results point to the strict relation between physiological sleep and epilepsy, and could underlie cognitive implications.
P802 Transcranial parenchymal sonography in adolescents and young adults with juvenile myoclonic epilepsy N. Jovic 1 , M. Mijajlovic 2 , M. Babic 1 Clinic of Neurology and Psychiatry for Children and Youth, Neurology, Belgrade, Serbia; 2 Clinical center of Serbia, Clinic of Neurology, Belgrade, Serbia
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Question: Abnormal neural networks in the thalamus, limbic areas, brainstem and cerebellum seem to be associated with JME. Cognitive and behavioral difficulties in JME are suggested to involve alterations in basal ganglia (BG) and midbrain structures. Method: Forty-two JME patients (13 male, 29 female, aged from 15.5 to 42 years (mean 27.6) and 30 gender and age-matched control subjects were studied. Trans-cranial sonography (TCS) study by trans-temporal approach was performed using a color-coded phased array ultrasound system, equipped with a 2.5 MHz transducer, with preauricular position. Influence of clinical parameters in the JME group was analyzed. Results: Substantia nigra was markedly hyperechogenic in 6 pts with size ranged 0.26-0.39 cm2 , while its hyper-echogenicity was moderate and mainly unilateral in additional 9 (>0.19 cm2 ). In all but 4 pts, hy-
Abstracts of Poster Presentations / Clinical Neurophysiology 125, Supplement 1 (2014) S1–S339
P798 An investigation of fear potentiated transcranial magnetic stimulation, blink and audiogenic startle reflex after successful surgery of mesial temporal lobe epilepsy S. Goekdemir, M.E. Kızıltan, Ç. Özkara Istanbul University, Neurology, Istanbul, Turkey Fearful facial expressions are danger signals that rapidly trigger a cascade of neurobiological processes defensibly associated with action preparation. Direct evidence for the activating effects of fearful facial expressions on the motor system has been shown with transcranial magnetic stimulation (TMS) and auditory startle reflex (ASR) studies[1,2]. The present study investigated blink reflex (BR), fear-potentiated motor evoked potentials (MEP) and ASR results after successful surgery of mesial temporal lobe epilepsy. We have included 15 healthy volunteers and 12 operated mesial temporal sclerosis (MTS) patients without seizures. Mean age for patients was 36.9±8.9 and 29.8±9.3 for controls. The current TMS and ASR study investigated whether fearful facial expressions selectively increase corticospinal motor tract (CST) excitability in patients with hippocampal sclerosis (HS) who successfully underwent selective amigdalohipocampectomy operation. BR responses of patients were also compared with those of healthy controls. Changes in CST excitability using the MEP and ASR data were recorded. Results showed significant selective increases in MEP and changes in ASR data to fearful facial expressions in healthy volunteers but not in the patients (P=0.96). All though blink response results were in normal range in both groups, a statistically significant difference was investigated between the healthy volunteers and the patients. These findings provide evidence for selective increases in ST excitability to threat and the importance of amygdala in CST excitability. References: [1] Schutter, D.J., D. Hofman, and J. Van Honk, Fearful faces selectively increase corticospinal motor tract excitability: a transcranial magnetic stimulation study. Psychophysiology, 2008. 45(3): p. 345-8. [2] Koch, M. and U. Ebert, Enhancement of the acoustic startle response by stimulation of an excitatory pathway from the central amygdala/basal nucleus of Meynert to the pontine reticular formation. Exp Brain Res, 1993. 93(2): p. 231-41.
P799 Electroclinical characterization of SLC2A1 mutation in three pediatric patients A. Martínez de la Ossa Vela 1 , M. Vicente Rasoamalala 1 , V. Thonon 1 , A. Macaya Ruíz 2 , E. Laínez Semper 1 1 Hospital Universitari Vall d’Hebron, Clinical Neurophysiology, Barcelona, Spain; 2 Hospital Universitari Vall d’Hebron, Pediatric Neurology, Barcelona, Spain Question: Glucose transporter 1 deficiency syndrome (GLUT1DS) is a metabolic disorder manifesting as cognitive impairment, acquired microcephaly, epilepsy, and/or movement disorder caused by mutations in the SLC2A1 gene. Since its first description, many EEG findings have been described including normal findings, slow background activity, ictal and/or interictal generalized and/or focal epileptic discharges and fluctuations over time. We aim to describe the different VIDEO-EEG findings in three patients with the SLC2A1 gene mutation, being twins two of them. Methods: VIDEO-EEG recording of three patients with the SLC2A1 de novo gene mutation. Patients 1 and 2: Two fourteen year old boys, monozygotic brothers, who described episodes of progressive weakness and incoordination, related to exercise more or less prolonged; they also explained daily episodes of brief decreased attention and stare, interrupting briefly activity, diagnosed of absence epilepsy at the age of 8 years old. Patient 3: Ten year old girl, who was studied for delayed psychomotor development since 2 year old. At the age of 7 year old staring spells, consistent in eye closure, blink along with cephalic fall, up to 20 per day, were observed with partial response to VPA. Results: VIDEO-EEG recordings for patient 1 and 2 showed the following anomalies: focal intermittent slow waves in anterior regions and 2.5 4Hz generalized spike-wave (frontal prevalence) that worsen while the hyperventilation was performed and associated with clinical absence.
Additionally, a benign variant normality was found. These pathological findings disappeared for a short amount of time after the administration of oral glucose. Patient 3 VIDEO-EEG recordings showed focal delta bursts with occasional superimposed sharp waves in posterior regions, ictal and interictal 3 Hz spike-wave generalized discharges which worsen during sleep and a background activity that fluctuates over time. Conclusions: EEG findings in GLULT1DS are still variable although serial recordings over ages show changes that suggest this syndrome. Screening diagnose is recommended in patients with clinical absence epilepsy with characteristic clinical features and suggestive EEG findings over time.
P800 Slow spindles’ cortical generators overlap with the epileptogenic zone in temporal epileptic patients: an electrical source imaging study A. Del Felice 1 , C. Arcaro 1 , S.F. Storti 1 , P. Manganotti 1,2,3 1 University of Verona, Department of Neurological and Motor Sciences, Verona, Italy; 2 AOUI, Department of Neurology, Verona, Italy; 3 IRCCS San Camillo, Department of Neurophysiology, Venice, Italy Question: To determine whether temporal epileptic patients and normal volunteers display similar sleep spindles’ cortical generators as determined by electrical source imaging (ESI), and whether such generators overlap in epilepsy patients with the epileptogenic zone identified by ESI. Methods: Thirteen healthy subjects and eight temporal lobe pharmacoresistant epileptic patients underwent a 256-channel EEG recording during a daytime nap. Spindles were visually scored and marked; categorization in slow (10-12 HZ) and fast (12-14 Hz) ones was done by independently bandpass filtering in the appropriate frequency band. EEG was segmented on the marker position, and segments separately averaged for each category. Cortical sources were estimated using LORETA on the MNI brain. Maximal intra- and inter-individual intensities were compared through the Wilcoxon matched pairs test (p<0.05). The same procedure was performed for averaged epileptic spikes, obtaining their cortical source. Source generators localizations were statistically compared between epileptics and controls via a χ2 test, and source intensities through a Mann-Whitney t test for independent samples (p<0.05). Overlap of spindles generators and spike generator was performed via a binomial distribution test (p<0.05). Results: Multiple, concomitant and equipotent generators were detected in both populations for slow and fast spindles. While in normal subjects slow spindles had a persistent source over the frontal cortex, in temporal epileptics they displayed a preferential localization over the temporal cortices (p=0.035), as well as higher source amplitude in comparison to healthy volunteers (p=0.042). Interestingly, at least one of slow spindles’ generators overlapped with the epileptogenic zone (p=0.016) as obtained by ESI. Conclusion: Slow spindles, but not fast ones, in temporal epilepsy are mainly generated over the affected temporal lobe cortex, and display overall higher intensities than spindles generators in healthy individuals. These results point to the strict relation between physiological sleep and epilepsy, and could underlie cognitive implications.
P802 Transcranial parenchymal sonography in adolescents and young adults with juvenile myoclonic epilepsy N. Jovic 1 , M. Mijajlovic 2 , M. Babic 1 Clinic of Neurology and Psychiatry for Children and Youth, Neurology, Belgrade, Serbia; 2 Clinical center of Serbia, Clinic of Neurology, Belgrade, Serbia
1
Question: Abnormal neural networks in the thalamus, limbic areas, brainstem and cerebellum seem to be associated with JME. Cognitive and behavioral difficulties in JME are suggested to involve alterations in basal ganglia (BG) and midbrain structures. Method: Forty-two JME patients (13 male, 29 female, aged from 15.5 to 42 years (mean 27.6) and 30 gender and age-matched control subjects were studied. Trans-cranial sonography (TCS) study by trans-temporal approach was performed using a color-coded phased array ultrasound system, equipped with a 2.5 MHz transducer, with preauricular position. Influence of clinical parameters in the JME group was analyzed. Results: Substantia nigra was markedly hyperechogenic in 6 pts with size ranged 0.26-0.39 cm2 , while its hyper-echogenicity was moderate and mainly unilateral in additional 9 (>0.19 cm2 ). In all but 4 pts, hy-