Progressive dementia with motor neuron disease. An additional case report and neuropathological review of 20 cases in Japan.

A 68-year-old male had the characteristic clinical features of progressive dementia accompanied by motor neuron disease. The duration of his illness was 26 months. The chief findings from light microscopic studies were: diffue neuronal degeneration characterized by a simple atrophy and a mild disappearance of nerve cells throughout the CNS. Status spongiosus was observed in the basal ganglia. There were lesions similar to those of a motor neuron disease in the brain stem and spinal cord. Although there were no clinical symptoms of an extrapyramidal disease, severe involvement was seen in the substantia nigra. This patient belongs to the same group of cases of presenile dementia with motor neuron disease described by the author. A neuropathological review of 20 similar cases reported in Japan is discussed and the possibility of a new disease entity for these cases is suggested.