Antiglutamic Acid Decarboxylase 65 Antibody–Associated Hemiataxia

Autoimmune and paraneoplastic movement disorders are increasingly recognized as a result of improved methods in detecting antibodies directed against intracellular, membrane, and other antigens.1 High concentrations of anti-glutamic acid decarboxylase 65 (GAD65) antibodies are associated with several neurologic syndromes including stiff-person syndrome, epilepsy, limbic encephalitis, and cerebellar ataxia.2 Anti-GAD65-associated cerebellar ataxia is typically generalized with prominent gait disturbance and eye movement abnormalities.1 Limb ataxia is present in 60-70% of patients.3 Here we present 2 unusual cases of hemiataxia associated with high concentrations of anti-GAD65 antibodies.