INDUCED TREMOR AND PARKINSONISM

Objective: Trauma to the peripheral nervous system is a well-recognized cause of dystonia and tremor, but peripherally induced parkinsonism has not previously been documented. We seek to characterize peripherally induced tremor and parkinsonism and propose possible mechanisms for this phenomenon. Design: Review of records of patients evaluated in the Movement Disorders Clinic between 1977 and 1993. In addition to demographic and clinical information, the records were screened for any potential predisposing factors. Patients: Twenty-eight patients in whom the onset of tremor, parkinsonism, or both was anatomically and temporally related to local injury. Intervention: The type and site of injury were verified by history and examination of records whenever possible. Severity of tremor and parkinsonism was assessed by clinical rating scales. Three patients with tremor and parkinsonism had their striatal [F-18]-fluorodopa uptake and raclopride binding measured with positron emission tomography. Main Outcome Measurer Response to conventional antitremor and antiparkinsonian medication was assessed by a clinical rating scale. Results: Severe local injury preceded the onset of movement disorder by 47.5 +/- 74.7 days (mean +/- SD). The mean age at onset of movement disorder was 46.5 +/- 14.1 years. Tremor was present in all 28 patients, 11 of whom exhibited additional parkinsonian features. In 20 patients, the movement disorder spread beyond the original site. Possible predisposing factors were identified in 13 patients; nine had essential tremor or a family history of essential tremor. In addition to tremor, dystonia and myoclonus were evident in 13 and three patients, respectively. Reflex sympathetic dystrophy was present in six patients. Tremor did not improve with medications, and only seven patients with parkinsonism responded to therapy with levodopa. Conclusion: Central reorganization in response to peripheral injury may give rise to a motor disturbance, including tremor and parkinsonism.