Neurodevelopmental Impact of Epilepsy on Autonomic Function in Dravet Syndrome

All patients will be monitored 24 hours. Whenever possible, duration of the long-term monitoring will be extended to 48 hours, including a second full night polysomnography. These recordings will also allow us to assess sleep architecture and to capture seizures in some patients video , EEEG, EKG, respiration and other polysomnography data will be centralized at Hospices Civils de Lyon. A copy of the EEG-EKG data required to address the objectives related to cardiac features will then be electronically transferred to Partner 2 (Bonn) Evaluation will be performed blind to other data by the Partner 1 (Lyon) for the respiratory data and by the Partner 2 (Bonn) for the EKG data All primary outcomes and secondary outcomes will be assessed with respect to duration of epilepsy and frequency of convulsive seizures during the baseline period.

Blood samples will be collected at V2 in all patients. A total of seven blood samples of 4 ml each will be collected, including five EDTA and two dry. Samples EDTA plasma and serum will then be prepared after centrifugation. In children \< 10 kg, only 5 samples of 4 ml each (22 ml in total), including four EDTA and one dry.