Not all SCN1A epileptic encephalopathies are Dravet syndrome

Abstract

To define a distinct SCN1A developmental and epileptic encephalopathy with early onset, profound impairment, and movement disorder. Methods: A case series of 9 children were identified with a profound developmental and epileptic encephalopathy and SCN1A mutation. Results: We identified 9 children 3 to 12 years of age; 7 were male. Seizure onset was at 6 to 12 weeks with hemiclonic seizures, bilateral tonic-clonic seizures, or spasms. All children had profound developmental impairment and were nonverbal and nonambulatory, and 7 of 9 required a gastrostomy. A hyperkinetic movement disorder occurred in all and was characterized by dystonia and choreoathetosis with prominent oral dyskinesia and ..