Cognitive and behavioral characteristics of children with Dravet syndrome: an overview.

We report an overview on early development of children with Dravet syndrome. After a historical outline of literature data, we refer to an Italian multicentric project, partially still in course. Because in the first year of life development seems impaired in Dravet syndrome as studies on precognitive abilities would show, defects in early development of visual function were detected heralding the subsequent cognitive decline. The delay of cognitive development, due to stagnation rather than a real deterioration, begins after the second year of life, although the age of onset varies. The extreme variability of development phenotype is confirmed and widened including also cognitive decline and severity of different defects of neuropsychological abilities as well as behavioral problems, especially associated with the cognitive decline. Mechanisms underlying neurodevelopment disorders and possible role of genetics are discussed. Wiley Periodicals, Inc.