Chronic idiopathic ataxic neuropathy

AbstractFifteen patients with chronic sensory ataxia caused by a large‐fiber sensory neuropathy were studied and followed up for a period of 17.4 years (range, 4 to 41). When first seen, they had distal paresthesias and sensory ataxia of slow onset and progression, areflexia, normal strength, and a profound loss of proprioceptive and kinesthetic sensation extending up to the most proximal joints. Needle electromyogram and motor‐nerve conduction velocity findings were normal in most of the patients and sensory potentials were absent in all. Nerve biopsy showed severe loss of the large myelinated fibers. Nine patients had a serum monoclonal or polyclonal gammopathy (3 with IgMκ, 1 with IgAκ, and 5 with a polyclonal increase of IgG, IgA, or IgM), and 8 had elevated cerebrospinal fluid γgM globulin levels in spite of low normal total cerebrospinal fluid protein levels. No circulating antibodies to ganglionic neurons were found. Therapy with immunosuppressants or plasmapheresis was unsuccessful. All patients are disabled and their conditions have continued to worsen without signs of malignancy or systemic illness during a mean follow‐up period of 17.4 years.Chronic idiopathic ataxic neu