Dystonia and tremor induced by peripheral trauma: predisposing factors.
Movement disorders are usually of central origin, but sometimes involuntary movements occur after peripheral trauma. Twenty eight patients, 13 women and 15 men, mean age 37 years (range 15-78), were studied with dystonia or tremor in whom the onset of abnormal movements was related, in time and in distribution, to injury of a body part. Among 23 patients with latency of less than one year after injury, focal dystonia of the involved body part was found in 18, nine of whom had associated reflex sympathetic dystrophy (RSD). One of five patients with peripherally induced tremor had RSD. Abnormal electromyography or nerve conduction velocities were found in the affected limb in four patients, but other electrophysiologic techniques provided evidence for disturbed central function. In 15 patients (65%) possible predisposing factors may have contributed to the pathogenesis of the trauma induced abnormal involuntary movements.