Abstracts

Rationale: Although STXBP1 mutation has been identified as one of the genetic causes of infantile epileptic enchephalopathy, clinical course of epilepsy harboring this mutation has not been reported in details yet.Methods: We identified five patients with STXBP1 mutation (male 2, female 3; 2-6 years of age) and followed their clinical course for averaged 42 months. In four patients we investigated the changes of ictal and interictal EEGs in details.Results: Seizure started during one month of age in four of five patients, and three patients were diagnosed as Ohtahara syndrome. One patient with seizure onset at five months was diagnosed as West syndrome. All patients had epileptic spasms occurring in clusters and three patients had focal seizure also. In two patients, ictal EEG showed suppression burst (S-B) pattern temporally during the course when seizure got worse. Seizure got in remission in two patients and became less frequent in another. Interictal EEGs changed from S-B pattern or hypsarrhythmia to multifocal spikes on the slow background activity, except in one patient with persisting S-B pattern. All patients were with profound mental retardation, and some patients showed spasticity or involuntary movements. Conclusions: Clinical and EEG changes have variation between patients. Seizure prognosis is not necessarily poor in spite of early onset epileptic encephalopathy.