Botulinum toxin for foot dystonia in patients with Parkinson's disease having deep brain stimulation: A case series and a pilot study.

Abstract

Six patients with Parkinson's disease with deep brain stimulation who were experiencing disabling foot dystonia were referred to the spasticity clinic for a trial of botulinum toxin. The foot and ankle muscles were injected with onabotulinum toxin (Botox) to determine the effects on foot dystonia, pain and lower limb functional outcomes. Case series. Six patients with Parkinson's disease with deep brain stimulation experiencing disabling foot dystonia. Dystonic foot and ankle muscles were identified and injected with 250-400 units botulinum toxin and re-coded pre- and 3 weeks post-injection with the Burke Fahn Marsden Dystonia score, visual analogue score of pain, Unified Parkinson's Disease Rating Scale (UPDRS) - lower limb score, Timed up and Go test (TUG), 6-Minute Walk Test (6MWT), gait velocity, cadence in an instrumented walkway, and Goal Attainment Scale (GAS). Three weeks after botulinum toxin injection, significant improvements were noted in dystonia, pain, UPDRS, 6MWT, gait velocity, and cadence. Five out of 6 patients improved on the TUG test. Patients also reported improvements in their GAS goals. Botox injection significantly improved foot dystonia, pain and lower limb functional outcomes in patients with Parkinson's disease with deep brain stimulation.