Dentatorubropallidoluysian atrophy: clinicopathological study of dementia and involvement of the nucleus basalis of Meynert in seven autopsy cases.

This report concerns a clinicopathological study including a quantitative pathological study on the nucleus basalis of Meynert (nbM) of seven Japanese autopsy cases (four male, three female) of dentatorubropallidoluysian atrophy (DRPLA) with special reference to the clinicopathological correlation of dementia in DRPLA. In each case the pattern of the inheritance was consistent with that of an autosomal dominant trait. The neurological examination revealed that all seven individuals had cerebellar signs. Six patients had epilepsy and choreoathetoid involuntary movement; myoclonus was evident in five patients. Dementia was noted in all seven patients. Degeneration of the globus pallidus (particularly the lateral segment) and of the dentate nucleus was the principal pathological feature. Brain weights at autopsy ranged from 1020 to 1400 g (average 1241 g: male 1320 g, female 1135 g). The quantitative evaluation revealed no significant loss of neurons in the nbM as compared with a control group. There was no clinicopathological correlation between dementia and involvement of the nbM. We suggest that the dementia of DRPLA is due not to the involvement of the nbM, but to - as yet - unidentified pathology elsewhere.