Peripherally induced tremor and parkinsonism
F. Cardoso and J. Jankovic
Department of Neurology, Baylor College of Medicine, Houston, Tex.
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 [18F]-fluorodopa uptake and
raclopride binding measured with positron emission tomography. MAIN OUTCOME
MEASURE: 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.