Chronic idiopathic ataxic neuropathy: neuropathology of a case.

A case of chronic, sporadic, slowly progressive, purely sensory, ataxic neuropathy is reported. In previously published similar cases only muscle and nerve biopsies have been available for study. In the present case the patient died of an unrelated illness 39 years after onset of the neuropathy. A full neuropathological study was performed. The disease process was limited to the dorsal root ganglia and their central and peripheral processes. Large myelinated fibers were preferentially involved. Involvement of the dorsal root ganglia has also been reported in certain toxic ganglioneuropathies and in the sensory neuropathy associated with carcinoma. The long duration and insidious development set the present case apart from those conditions. An inflammatory component was lacking. Except for a microscopic focus of adenocarcinoma of the prostate no malignancy was present. The etiology of chronic idiopathic ataxic neuropathy is unknown, but it is likely that the dorsal root ganglion is the main target for the disease process in most if not all cases.