Presenile dementia combined with amyotrophy: a review of 34 Japanese cases.

Thirty-four Japanese cases exhibiting presenile dementia combined with amyotrophy were reviewed with four case reports. The clinical feature of dementia was generally unspecific and could not be clearly diagnosed as Pick's disease or Alzheimer's disease. But most of these patients did not exhibit manifest visual agnosia or apraxia suggesting 'posterior dementia'. Brain CTs showed mild diffuse atrophy with non-circumscribed fronto-temporal accentuation. PSD (periodic synchronous discharge on EEG) as seen in Creutzfeldt-Jakob disease (CJD) was not noted in any of these cases. Although individual neurological findings were not contradictory to amyotrophy lateral sclerosis (ALS), the clinicopathologic findings, on the whole, could be regarded as indicative of an atypical spinal progressive muscular atrophy. The brain pathology lacked specific changes. A mild to moderate degree of glial proliferation, subcortical gliosis and a moderate spongy state of the upper cortical layers were seen mainly in the fronto-temporal area. Nigral degeneration was observed in half of the cases. No Pick's cells, Pick's balls, Alzheimer's neurofibrillary changes or senile plaques were observed except in two cases, in whom it could be regarded as physiological. Brain weight was lighter than that of normal Japanese but heavier than that of Pick's disease, Alzheimer's disease or CJD. The brain pathology was similar to that of progressive subcortical gliosis. We have concluded that the disease under discussion might be a new disease entity.