Stiff Person Syndrome and Acetylcholine Receptor Ganglionic Neuronal Antibodies.

The association between stiff person syndrome and paraneoplastic syndromes has been described, linking intracellular or extracellular antibodies. We describe the case of a 64-year-old woman with stiff person syndrome and positivity for acetylcholine receptor ganglionic neuronal antibodies, which can also be seen in muscular hyperexcitability conditions, as well as other paraneoplastic syndromes. The relevance of this report is the possible direct elevation of this antibody due to a direct immunological cause. Acetylcholine receptor ganglionic neuronal antibodies have been reported with autoimmune autonomic neuropathy and paraneoplastic syndromes linked to lung cancer and myastheniform syndromes, as well as in some muscular hyperexcitability states, but not in stiff person syndrome.