Developmental and Epileptic Encephalopathies in Adults: An Evolving Field.

Abstract

Developmental and epileptic encephalopathies (DEEs) are a heterogeneous group of several rare neurodevelopmental disorders characterized by early-onset refractory seizures, specific EEG abnormalities, developmental delay or regression, and intellectual disability (ID).1 DEEs are classically considered pediatric disorders because most of the literature defines their phenotype in children. With recent advances of symptomatic and supportive treatments, many patients with DEE can now survive into adulthood and exhibit unique abnormalities not seen in children. In 2008, Saitsu et al.2 described de novo STXBP1 sequence variants in 5 children with Ohtahara syndrome. During the past decade, the phenotypic spectrum of STXBP1 -DEE was broadened to include West syndrome, nonsyndromic epilepsy with ID, autism, and movement disorders such as ataxia, spasticity, dyskinesia, and dystonia. Although STXBP1 -DEE is one of the most frequent DEEs, there are very limited studies describing its adult phenotype.