Abstracts

Rationale: Atypical benign partial epilepsy (ABPE) is characterized by centro-temporal EEG spikes, continuous spike and waves during sleep (CSWS) and multiple seizure types, including epileptic negative myoclonus (ENM) but not tonic seizures. Ethosuximide (ESM) has efficacy in ENM, atypical absences and CSWS in patients with ABPE. Interictal and ictal magnetoencephalography (MEG) findings were previously reported in only one patient with ABPE. This paper presents clinical features and MEG spike sources (MEGSSs) of ABPE patients in multiple centers.Methods: We retrospectively analyzed seizure profiles, scalp video EEG (VEEG), MEG and seizure outcomes in ABPE patients.Results: Eighteen ABPE patients were identified (nine girls and nine boys). Seizure onset ranged from 1.3 to 8.8 years (median, 2.9 years). Initial seizures consisted of focal motor seizures (15 patients) and absences/atypical absences (3). Seventeen patients had multiple seizure types including drop attacks (16), focal motor seizures (16), ENM (14), absences/atypical absences (11), and focal myoclonic seizures (10). VEEG showed centro-temporal spikes and CSWS in all patients. MRI was reported as normal in all patients. MEGSSs were localized over both Rolandic-sylvian regions (8), peri-sylvian region (5), peri-Rolandic region (4), parieto-occipital region (1), bilateral (10) and unilateral (8). All patients were on more than two antiepileptic medications. ENM and absences/atypical absences were controlled in 14 patients treated with adjunctive ESM. Conclusions: MEG adds to the diagnostic arsenal for ABPE by localizing centro-temporal spikes and CSWS to spike sources in the Rolandic-sylvian regions. Centro-temporal spikes, Rolandic-sylvian spike sources and focal motor seizures are evidence that ABPE is an epilepsy with Rolandic-sylvian onset seizures. Yet, CSWS with probable secondary bilateral synchrony, absences/atypical absences and ESM efficacy in ENM suggest that thalamo-cortical circuitry is involved in the epileptic network of ABPE. ABPE is a unique age-related epilepsy with Rolandic-sylvian plus thalamo-cortical epileptic networks in the developing brain in children.