Atypical multifocal Dravet syndrome lacks generalized seizures and may show later cognitive decline

Abstract

Aim: To show that atypical multifocal Dravet syndrome is a recognizable, electroclinical syndrome associated with sodium channel gene (SCN1A) mutations that readily escapes diagnosis owing to later cognitive decline and tonic seizures. Method: Eight patients underwent electroclinical characterization. SCN1A was sequenced and copy number variations sought by multiplex ligation-dependent probe amplification. Results: All patients were female (age range at assessment 5-26y) with median seizure onset at 6.5 months (range 4-19mo). The initial seizure was brief in seven and status epilepticus only occurred in one; three were febrile. Focal seizures occurred in four patients and bilateral convulsio..