Le syndrome de l'homme raide

Stiff-person syndrome (SPS) is a rare disorder characterized by muscle stiffness and painful spasms. Its prevalence is one to two cases per million inhabitants. The diagnosis is often delayed due to a misleading presentation. Neurophysiology helps with the diagnosis. SPS is an autoimmune disorder: a high level of anti-GAD65 antibodies is frequently but not constantly reported. A minority of cases are paraneoplastic. Guidance for treatment is insufficient due to the rarity of the disorder. Drug therapy using gabaergic (benzodiazepine, baclofen) or immunosuppressive agents is generally proposed. The course is chronic with incomplete improvement. We report the clinical, electrophysiological and therapeutic findings in a 72-year-old woman whose clinically severe anti-GAD65-positive SPS was misdiagnosed after more than 2 years of diagnostic search. The pathophysiological hypotheses are briefly reviewed.