Cognitive development in Dravet syndrome: A retrospective, multicenter study of 26 patients

Summary Purpose: To clarify the role of epilepsy and genetic background in determining the cognitive outcome of patients with Dravet syndrome. Methods: In this retrospective study, we reviewed the clinical history and cognitive development of 26 patients who had been followed with standardized evaluations since seizure onset. The cognitive outcome was quantified as differential general quotient (dGQ) between ages 12 and 60 months. Statistical analysis correlated the dGQ with genotype and epilepsy course. Key Findings: Epilepsy started at the mean age of 5.6 months. All patients experienced prolonged convulsive seizures, whereas absences and myoclonus were reported in 17. Cognitive outcome was poor in almost all patients; the mean dGQ was 33 points, varying from 6–77 points. The analysis of individual cognitive profiles identified seven patients in whom the dGQ was