Identification of the characteristic vascular changes in a sural nerve biopsy of a case with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy' (CADASIL) has recently been identified as a hereditary disorder with characteristic fine structural changes of small intracerebral arteries and arterioles. Electron microscopically there are characteristic perivascular deposits of granular electron-dense material resembling immunoglobulin deposits. The present case from a family with four affected members in three successive generations shows that similar vascular changes as described in the central nervous system are present in blood vessels of the sural nerve, although less pronounced and, therefore, affording electron microscopy for their unequivocal detection. Nevertheless it has been shown for the first time that the diagnosis of CADASIL can be verified by a sural nerve biopsy. Occasional focal accumulation of pinocytotic vesicles opposite the granular deposits suggests exocytosis as one of the possible pathomechanisms for their production.