TREATABLE GAIT DISORDER AND POLYNEUROPATHY ASSOCIATED WITH HIGH-TITERSERUM IGM BINDING TO ANTIGENS THAT COPURIFY WITH MYELIN-ASSOCIATED GLYCOPROTEIN

We studied clinical and electrodiagnostic features of 9 patients with very high titers (>1:10,000) of serum IgM binding to a CNS myelin anti gen (CMA) preparation that copurified with myelin-associated glycoprot ein (MAG). We found that 8 of the 9 patients had a combined syndrome o f gait ataxia and polyneuropathy (GAPN) with late-age onset (mean = 70 years of age). in the 8 GAPN patients progressive difficulty with amb ulation led to significant functional disability and frequent falling. Examination showed a wide-based unsteady gait, especially when standi ng stilt or turning. There was mild-to-moderate distal sensory loss wi th involvement of joint position sense only in the toes. Motor changes , when present, were mild and mainly involved distal leg musculature. Treatment of 5 GAPN patients resulted in clear improvement of 2 after intravenous human immunoglobulin and of 3 others after other immunodul ating agents. Immune-mediated GAPN syndromes with high titers of serum IgM binding to CMA appear to be treatable causes of gait disorders in older patients. (C) 1994 John Wiley & Sons, Inc.