Abstracts

Rationale: Sturge-Weber syndrome (SWS) is a congenital neurocutaneous disorders with portwine nevus, glaucoma, and leptomeningeal angioma of the brain. Almost half of the patients with SWS have epilepsy, and some need epilepsy surgery. However, the epileptogenicity of SWS has never been elucidated. Difficulty to find out the mechanism of epileptogenicity in SWS is due to the fact that scalp EEG's does not show apparent epileptic discharges. In this study, we analyzed interictal and ictal discharges from intracranial subdural EEG recording of patients with SWS to elucidate epileptogenicity in SWS. Methods: Five patients aged from one to 9-year old were enrolled in this study. The patients had intractable seizure and mental retardation. After the non-invasive diagnostic protocol for epilepsy, we implanted subdural electrodes over the leptomeningeal angioma. An investigator who did not know patient's background evaluated the interictal and ictal discharges by visual inspection. We examined the followings, seizure onset zone, seizure propagation speed, and seizure duration. Results: We recorded 21 seizures from invasive EEG monitoring in five patients. Usually the seizures presented as motionless staring and respiratory distress. All the seizures started from the cortex under the leptomeningeal angioma. Average seizure propagation speed was 3.1 ± 3.6 cm/min. and seizure duration was 17 ± 29 minutes. Conclusions: Seizures of patients with SWS was inconspicuous, seizure propagation was very slow and seizures duration was very long period. Invasive EEG monitoring is one of the tools for elucidating epileptogenicity of SWS.