Abstracts

Rationale: Malignant rolandic-sylvian epilepsy (MRSE) in children (Otsubo et al. in 2001) has been defined as a form of epilepsy characterized by sensorimotor seizures, medical refractoriness, normal MRI, frontocentrotemporal EEG spikes, rolandic-sylvian spike sources on MEG, and cognitive problems. We present clinical and neuroimaging analysis of 5 patients that fit the definitions of MRSE in order to see if its clinical and neurophysiological features are similar enough to represent an identifiable syndrome. Methods: Five patients ranging from 7 to 14 year-old were included in this study. Patients’ seizures were videotaped with EEG monitoring. FDG-PET, iomazenil-SPECT, ictal ECD-SPECT, MEG, MRI, IQ test were applied to characterize patients’ epilepsy.Results: MEG demonstrated that spike sources clustered on the bilateral postrolandic region in pts 1-3, and lt. postrolandic in pt 4 and rt. postrolandic in pt 5. IQ score was abnormal ranging from 35 to 75. Patients were divided into two subgroups. Group 1 (pts 1-2) had frequent seizures appeared every 10 minutes that were characterized by blinking, facial twitching, and head dropping lasting 1-3 seconds. Ictal EEG showed bilaterally synchronous spike-waves bursts. CSWS pattern was observed. Ictal SPECT showed hyperperfusion in the bilateral thalamus, basal ganglia and brain stem. Dysarthria, disturbed writing, dyscalculia and dysphagia were recognized during frequent seizure-period. Multiple antiepileptic drugs were ineffective. However, ethosuximide (ESM) had finally substantial effect in controlling seizures and improving EEG findings as well as cognitive problems. Group 2 (pts 3-5) had hemi-facial seizure (pt 3), lt. arm sensory seizure (pt 4) and versive/postural tonic seizures (pt 5) that appeared daily or weekly and lasted 15-25 seconds. Multiple antiepileptic drugs proved ineffective. Ictal EEG showed localized fast waves or spikes bursts originated from central region. CSWS was not observed. Ictal SPECT showed localized hyperpefusion in the rolandic region. Patient 3 revealed SCN1A missense mutation. Conclusions: Although this is a preliminary analysis with very limited number of patients, MRSE in children may be divided into two subgroup; Group 1 characterized by CSWS, frequent rolandic seizure, synchronous ictal spike-waves bursts, subcortical propagation of ictal phenomena and effectiveness of ESM, Group 2 characterized by non-CSWS, versive/posutural tonic seizure or hemiconvulsion, local seizure onset associated with ictal hyperpefusion in the rolandic region. Interestingly, in contrast to benign rolandic epilepsy where spike sources on MEG has anterior/superior direction, all in MRSE showed posterior/inferior direction, that was useful in differentiating these two epilepsy syndrome. CSWS was associated with group 1. Ictal SPECT suggests participation of subcortical structures in the appearance of very frequent seizures and may explain why ESM was effective in patients of Group 1. SCN1A mutation should be also considered in patients with MRSE if patients are fever-sensitive.