Progressive epilepsy due to chronic persistent encephalitis: report of four cases

Abstract

Four patients are reported who in the first decade of life developed intractable seizures, progressive dementia and a neurological deficit in the form of hemiplegia or quadriplegia. Pneumoencephalograms showed focal dilatation of lateral ventricles in 3 and generalised dilatation in 1 case. Electroencephalograms showed evidence of focal spike activity in 3 patients. These were operated upon for the relief of intractable seizures and in 1 patient only brain biopsy was done. The first patient with a total duration of illness of 5 years had complete relief from seizures and the EEG became free of spikes following a right temporal lobectomy. In the other 2, where right frontal lobectomy and cortical excision of right parietal lobe were done respectively, only moderate improvement in seizure control occurred and this too was not sustained in the second case. Histopathological study of resected brain tissue revealed areas of necrosis in the cortex associated with gliosis and areas of perivascular lymphocytic infiltration in the cortex and white matter. In 1 case in addition focal areas of inflammatory cellular infiltration of the meninges, composed mainly of lymphocytes and plasma cells, was seen. These changes suggested some form of chronic encephalitis. A viral aetiology could not be proved but was though to be most likely.