Motor and behavioral phenotype of Dravet syndrome in adulthood.

In a comparative cross-sectional study, 26 adult individuals with clinically typical, genetically confirmed Dravet syndrome (DS) and an equal number of individuals with early onset, problematic epilepsy, and intellectual disability (ID) of comparable severity were included. The aim of the study was to find out whether patients with DS could be clearly distinguished from the comparison group with regard to neurological and behavioral symptoms. Significant differences were found in that individuals with DS clearly more frequently exhibited a symptom cluster characterized by bradykinesia, hypomimia, hypophonia, (spastic) increased muscle tone, ataxia, sthenic perseveration, and a special interest in colors. To these symptoms must be added, according to the findings of previous examinations, mastication, camptocormia/antecollis on the one hand, and the tendency to visual hallucinations on the other hand, in order to define one neuropsychiatric phenotype of DS in adulthood. To these symptoms must be added, according to the findings of previous investigations, crouch gait with camptocormia/antecollis on the one hand, and the tendency to visual hallucinations on the other hand, in order to define one outlined neuropsychiatric phenotype of DS in adulthood.