Neuropathology of early-infantile epileptic encephalopathy with suppression-bursts; comparison with those of early myoclonic encephalopathy and West syndrome.

For the critical lesions and pathomechanism of early-infantile epileptic encephalopathy (EIEE) with suppression-bursts, we investigated the brains of EIEE, early myoclonic encephalopathy (EME), and West syndrome (WS) patients using immunohistochemical technique and neuropathological examination. We could compare with the results of these diseases. The EIEE patients had the most severe lesions, which were in the putamen, thalamus, hippocampus as well as the tegmentum of the brainstem. Among the syndromes, EIEE brains showed the most expanded lesions. Tyrosine hydroxylase-immunopositive cells and fibers were not demonstrated in EIEE, but were detected in WS. Reduced tyrosine hydroxylase immunoexpression in the EIEE brains was in the putamen, globus pallidus, and substantia nigra. Tryptophan hydroxylase immunoreactivity was reduced in the three epileptic syndromes, but especially in EIEE. Reduced expression of tyrosine hydroxylase and tryptophan hydroxylase may demonstrate dysfunction of the catecholaminergic and serotonergic neurons. From this study, the lesions in EIEE were widespread, including in the lower brainstem and cerebellum, compared with in EME and WS. Dysfunction of the catecholaminergic and serotonergic systems could be suggested. These characteristic changes may lead to the pathophysiology of EIEE.