Stiff-person syndrome (originally known as stiff-man syndrome) was first described by Moersch and Woltman in 1956.¹ They reported several cases of “progressive fluctuating muscular rigidity and spasm”. Their first patient was a 49-year-old Iowa farmer who presented to the Mayo Clinic, Rochester, Minnesota in 1924 with “muscle stiffness and difficulty walking”. He also complained of rigidity of insidious onset that began in the neck, back and shoulder musculature and progressed over a period of years to involve the abdominal and thigh muscles. Superimposed on the rigidity were intermittent painful spasms so severe that he might “fall like a wooden man”.

As the syndrome gained recognition, many considered it to be a functional disorder, in part because of its rarity and also because of its complex psychiatric overlay and relative lack of objective neurological findings in the initial stages. However, consensus gradually shifted to an organic basis with the discovery of a link with autoantibodies, the association of other autoimmune diseases with the syndrome, and effective therapy with immunomodulatory agents.

DIAGNOSIS

Classic stiff-person syndrome affects women more than men (∼2:1) and generally presents in the fourth to sixth decade.² The onset is typically insidious and the course is usually progressive. Classic stiff-person syndrome is characterised by predominant spine and leg rigidity, with lumbar hyperlordosis as a key feature. Limb rigidity can cause full extension of the legs, making walking difficult. Along with the background rigidity, patients often experience painful spasms that may be precipitated by sudden noise, stress or touch. Indeed, patients come to recognise that emotional …