Limb contractures in levodopa-responsive parkinsonism: a clinical and investigational study of seven new cases

We describe six patients with classical levodopa-responsive Parkinson's dis ease (PD) and one case of levodopa-responsive familial juvenile dystonia-pa rkinsonism with fixed contractures of the hands, feet or legs. In most pati ents contractures became established over a short period (2 months-2 years) but a considerable time after onset of parkinsonism (mean 13 years). Mean disease duration was 17 years, and all patients had severe levodopa-induced dyskinesias, either biphasic or peak dose, in the affected limb prior to o nset of the contracture. Nerve conduction studies excluded peripheral ulnar nerve lesions in all patients with one exception, who was found to have a mild bilateral ulnar entrapment neuropathy. Transcranial magnetic stimulati on performed in five of the seven patients showed shorter mean central moto r conduction time in the affected than in the unaffected limb. Results of m agnetic resonance imaging of the brain performed in a subgroup of patients were normal, with no evidence to suggest multiple system atrophy, cerebral infarction or focal abnormalities of the basal ganglia. We conclude that ha nd and feet contractures are not necessarily restricted to parkinson plus s yndromes and may complicate otherwise typical PD in the absence of a struct ural or peripheral nervous cause. Striatal dopaminergic deficiency, particu larly long-standing, may have a role in the pathogenesis of limb contractur es in PD.