Broadening the phenotype of childhood-onset dopa-responsive dystonia

Abstract

Background: Dopa-responsive dystonia (DRD) may cause early-onset dystonia, with extrapyramidal or pyramidal tract dysfunction.

Objective: To broaden the phenotype of DRD.

Setting: Tertiary referral university hospital.

Patients: We describe 4 female siblings with genetically confirmed DRD, 3 of whom presented with "unsteadiness" and 1 with scoliosis. All had dystonia and pyramidal tract signs, 3 had additional extrapyramidal features (resting tremor, bradykinesia, or rigidity), and at least 2 had definite signs of cerebellar dysfunction.

Main outcome measures: The subjective response to treatment with 62.5 mg of a combination product of levodopa and carbidopa 3 times daily was assessed at both 6- and 12-month follow-up visits with the 7-item Patient's Global Impression of Change Scale as very much improved, much improved, a little improved, no different, a little worse, much worse, or very much worse.

Results: All patients showed a good response to levodopa therapy 41 to 49 years after symptom onset.

Conclusion: Cerebellar signs may be observed in patients with DRD and may improve in response to levodopa.