Teaching NeuroImages: Ohtahara Syndrome due to Unilateral Perisylvian Polymicrogyria

A 10-month-old boy, born of nonconsanguineous parents, without any perinatal insult, presented with tonic spasms from the 13th day of life. He started having tonic seizures from 4 months of age, with global developmental delay. On examination, there were no neurocutaneous markers, facial dysmorphism, or focal neurologic deficits. EEG (figure) showed generalized and multifocal epileptiform discharges along with burst-suppression pattern. MRI of brain revealed left perisylvian polymicrogyria (figure).