[Early infantile epileptic encephalopathy (Ohtahara syndrome) with poly-microgyria]

A boy, born after normal pregnancy and delivery, began to have fits at 3 days. The seizures were composed of tonic or tonic-clonic convulsions at the upper extremities but myoclonus was absent. These attacks were not easy to control. There was gross developmental delay. Laboratory investigations were almost normal except for cerebrospinal fluid: pleocytosis and high protein content. EEG showed "suppression-burst" and MRI revealed high signal intensity in the left temporo-occipital region on T2 weighted image. At three and a half months of age, EEG changed into hypsarrhythmia. The child died at 5 months of age. At post mortem neuropathological examination, the cortical ribbon in the bilateral parieto-occipital regions appeared thick, as if there were pachygyria. Microscopically polymicrogyria was noted in these areas as well as in the insular cortex. This lesion showed a symmetrical distribution. The cytoarchitectonic features of the polymicrogyric cortex did not consist of 4 layers. The other structures of the central nervous system were almost devoid of lesion. The number of clinico-pathological reports on Ohtahara's syndrome is very limited and the etiopathogenesis of polymicrogyria is discussed.