Familial subcortical dementia with arteriopathic leukoencephalopathy. A clinico-pathological case]

A 54-year-old man died after a subcortical dementia that had developed over 7 years with focal neurological signs and a stepwise course. Clinical and radiological features were similar to those of Binswanger's disease but there was no vascular risk factor, especially no hypertension. Three similar cases had occurred in the family affecting the patient's mother, her brother and sister, suggesting an autosomal dominant hereditary disease. Postmortem examination disclosed an arteriopathic leukoencephalopathy. The white matter was mainly affected in the periventricular areas of the frontal and parietal lobes with myelin loss and pallor, sparing the U fibers. The vascular changes involved the small vessels and were not arteriosclerotic. There was severe thickening of the internal lamina and degradation products of the elastic fibers. There was no amyloid. This vascular leukoencephalopathy was different from Binswanger's disease and amyloid angiopathy. We think that the vascular lesions could correspond to a genetically transmitted specific degenerative pathology of the small arteries of the brain.