Presenile dementia with motor neuron disease in Japan: clinico-pathological review of 26 cases.

The clinico-pathological findings of 26 cases of presenile dementia with motor neuron disease in Japan are reviewed. The characteristic features include: (1) Progressive dementia with slowly progressive onset in the presenile period. (2) Neurogenic muscular wasting during the course of illness. (3) A duration of illness to death of from one to three years. (4) Absence of extrapyramidal symptoms and definite sensory deficits. (5) No characteristic abnormalities in the CSF or EEG. (6) No known parental consanguinity of familial occurrence. (7) Non-specific mild degenerative changes throughout the CNS without evidence of cerebrovascular disease or primary degenerative dementia, but with the presence of pathological findings of motor neuron disease. The possibility that this is a new disease entity is suggested.