Epileptic encephalopathy with bilateral continuous spike-waves during slow sleep in a child with vacuolating megalencephalic leukoencephalopathy.

This case report describes the clinical evolution of a symptomatic epileptic encephalopathy with bilateral continuous spike-waves during slow wave sleep (BCSWS) in a 3-year-old girl. Her epilepsy with focal motor seizures during sleep was later complicated by myoclonic, atonic and clonic seizures culminating in BCSWS. The clinical picture, clinical course and magnetic resonance imaging findings were characterstic of primary white matter disease, probably, vacuolated megalencephalic leukoencephalopathy with subcortical cysts (MLC). To the best of our knowledge, this is the first reported case of BSCWS in a patient with leukodystrophies or MLC. This case report indicates that epileptic encephalopathy with BSCWS may be a cause of neurological or neuropsychological deterioration in MLC.