Introduction

The stiff-man syndrome is a rare disorder of the central nervous system (CNS) characterized by progressive fluctuating rigidity and painful spasms of the body musculature. It was first described in 1956 by Moersch & Woltman, although they observed the first case of this condition much earlier, in 1924. Ironically, they nicknamed the disorder ‘stiff-man syndrome’ to ‘associate it with a memorable and descriptive term that could not be taken by anyone to be final’. Recently, evidence has accumulated that the stiff-man syndrome is an autoimmune disease directed against neurones secreting the inhibitory neurotransmitter, gamma-aminobutyric acid (GABA) (Solimena et al., 1990). The syndrome usually develops spontaneously and often occurs in association with other autoimmune diseases, particularly type I (insulin-dependent) diabetes mellitus. However, it may also occur as a paraneoplastic syndrome complicating remote malignancy.

Clinical features

General clinical features and diagnosis

The characteristic clinical picture is the insidious development of muscular tightness, stiffness and rigidity, initially involving the axial musculature (neck, paraspinal and abdominal muscles) and later spreading to affect proximal limb muscles (Moersch & Woltman, 1956; Gordon, Januszko & Kaufman, 1967; Lorish, Thorsteinsson & Howard, 1989). Mobility is restricted by the simultaneous contraction of agonist and antagonist muscles, so that the patient may be observed to walk or fall like ‘a wooden man’.