Ohtahara syndrome – early infantile epileptic encephalopathy with characteristic pattern on electroencephalograph - "suppression burst"

Ohtahara syndrome (OS) is the earliest type of infantile epileptic encephalopathy, the age of onset is during the first three months of life. It is characterized by frequent tonic spasms, suppression- burst pattern in electroencephalograph (EEG) recording and resistance to drug treatment. The aim of this study is to evaluate clinical symptoms, EEG characteristics, etiology and transition into other epileptic syndromes. We describe 9 children with OS. The most common cause of OS were anomalies of the cortical development and the most common type of seizures tonic spasms. The EEG pattern of OS was a suppression burst (S-B) pattern in all children. Follow-up during infancy showed that OS evolved into West syndrome (WS) and Lenox Gastaut syndrome (L-GS). OS is early epileptic encephalopathy with a characteristic clinic picture, heterogenic etiology, characteristic EEG pattern of suppression – burst, and different neurologic outcome requiering special and detailed investigation.