Abstracts

Rationale: Dravet syndrome (DS) is a rare severe epileptic encephalopathy, of infantile onset and unfavourable prognosis. Mutations or deletions in the SCN1A gene are found in about 70% of cases. To date, there are no systematic neuropathologic studies of DS. Methods: We searched the database of our post mortem series of patients with chronic epilepsy at the Chalfont Centre for Epilepsy, for whom brain tissue is available, for patients with cryptogenic epilepsy, who fulfilled clinical criteria of DS. Case notes and results of investigations were reviewed. DNA was extracted, and SCN1A molecular analysis performed. Neuropathology was reviewed, and immunohistochemistry studies done. Results: Five patients with DS were included in the study, four from our post-mortem series, and one patient, who is still alive, had a brain biopsy specimen available, and was also included. Seizure onset followed vaccination in three cases. Conclusions: This is the first systematic neuropathological study in human Dravet syndrome. We show hippocampi are preserved in these patients despite years of seizures and episodes of status epilepticus. Supported by the MRC and the Wellcome Trust.