A case of stiff limb syndrome responsive to plasma exchange

Stiff limb syndrome is a recently described, rare condition that is characterised by rigidity within the limbs that progresses in a relapsing and remitting fashion, often with involvement of the sphincters and brain stem.1 2 The axial muscles are spared in the early stages of the illness, which helps distinguish it from stiff man syndrome, although it may still represent a similar pathogenic mechanism to that proposed in stiff man syndrome, in which anti-GAD antibodies are typically seen in about 60% of patients.3 However, patients with stiff limb syndrome seem to have different neurophysiological abnormalities from stiff man syndrome2 and fewer of these patients have anti-GAD antibodies; they also typically show a poorly sustained response to baclofen and diazepam. The response to immunotherapy in stiff limb syndrome is not known, whereas patients with stiff man syndrome may respond to intravenous immunoglobulin4 5 as well as possibly plasma exchange.6-8 We now report on a patient with stiff limb syndrome who responded dramatically to plasma exchange and in whom an antiaxonal antibody was isolated, suggesting that this condition may have an immunological basis.

A 50 year old retired auxiliary nurse presented with a 10 year history of progressive pain, stiffness, and flexion contractures in her hands, followed by increasing immobility. Her …