Stiff man syndrome (SMS) is a rare, severe progressive motor disorder characterised by painful spasms, symmetric axial muscle rigidity, and uncontrollable contractions leading to distorted posturing. The disorder has been associated with the autoantigens, glutamic acid decarboxylase (GAD), and amphiphysin, which are cytoplasmic proteins in neurons of the CNS. A large series of patients with SMS found that most have autoantibodies against GAD,1whereas amphiphysin is presumably the predominant autoantigen in paraneoplastic SMS.2 Recently, Brownet al 3 presented four patients with a stiff leg syndrome marked by progressive rigidity and spasms of the lower extremities. This group of patients tested negative for anti-GAD antibody by immunoprecipitation and demonstrated distinct electrophysiological features. By contrast, another report described two patients with stiff leg syndrome who tested positive for anti-GAD antibody.4 Finally, in presenting a group of 13 patients, Barker et al 5 proposed that the nomenclature “stiff limb syndrome” refers to the focal form of SMS when one or more distal limbs are involved; two of their patients were also anti-GAD antibody positive, but none were tested for antibodies …