[A clinicopathologic study of progressive subcortical vascular encephalopathy of the Binswanger type (PSVE)].

From an electron microscopic study I indicated that the number of nerve fibres per unit area in the frontal white matter was significantly less in PSVE than that in controls. The white matter pallor in PSVE is mainly based on the loss of nerve fibres. The dementia in PSVE is probably related to the loss of nerve fibres in the cerebral white matter. The extent of frontal white matter pallor tended to be less broad in vascular parkinsonism (VP) than in PSVE without parkinsonism. The relatively slight damage of the white matter may contribute to VP observed in PSVE. The number of oligodendrocytes and of astrocytes was decreased in PSVE showing half of that in the deep white matter of the controls. This suggests that the loss of oligodendrocytes and astrocytes can play a role to the process of nerve fibres loss in PSVE. Not only the severe hyalinotic changes in the white matter arterioles, but also the diffuse atherosclerotic lesions in the main stem of cerebral arteries were the characteristic arterial lesions in PSVE. On the basis of these arteriosclerotic lesions, we speculated that the repeated hypotension or the greater variability of casual blood pressure could induce PSVE in the elderly hypertensives. However, the retrospective analysis of casual blood pressure did not support our hypothesis.