Familial ataxia with abnormal CSF, with special reference to an autopsy case from three affected siblings.

We report here the clinical features of 3 affected siblings and neuropathological findings of the CNS from an autopsied case among them. Their common clinical features consisted of cerebellar ataxia and tremors through movements and postures. Two of the 3 siblings showed autonomic abnormalities, hard-of-hearing, pyramidal sign and areflexia. Then they always had xanthochromia and an elevated protein without pleocytosis in their CSFs. Neuropathologically, intracytoplasmic eosinophilic inclusion bodies were found in the neurons of some restricted nuclei or nerve cell groups of the brain stem, cerebellum and spinal cord. Similar bodies appeared also in glial, ependymal and choroid plexus epithelial cells. Such eosinophilic bodies are thought to consist of protein-rich substances from histochemical properties, and result from an unknown inherited metabolic error.