THE CAUSALGIA-DYSTONIA SYNDROME

We report 18 patients (16 women and two men) with causalgia and dyston ia, triggered by peripheral injuries in 15 cases and occurring spontan eously in three. The injury was often trivial, and did not cause overt peripheral nerve lesions. The mean age at presentation was 28.5 years . None had a family history of dystonia. The leg was affected initiall y in 12 patients, the arm in the remaining six cases. All had burning pain, allodynia and hyperpathia, along with vasomotor, sudomotor and t rophic changes. All developed dystonic muscle spasms in the affected p art Dystonia always appeared at the same time or after the causalgia. The spasms were typically sustained, producing a 'fixed' dystonic post ure, in contrast to the mobile spasms characteristic of idiopathic tor sion dystonia. There was spread of the causalgia and of the dystonia f rom its initial site both in the affected limb and to other extremitie s, the latter in hemiplegic, transverse and triplegic distribution. Al l investigations were normal. All modes of conventional treatment fail ed to relieve either the pain or the dystonia, but two patients recove red spontaneously. At present it is impossible to decide whether this distressing syndrome is a true functional disorder of the central nerv ous system, or is of psychogenic origin.