Background: 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.
Design: Case series.
Subjects/patients: Six patients with Parkinson’s disease having deep brain stimulation experiencing disabling foot dystonia.
Methods: Dystonic foot and ankle muscles were identified and injected with 250–400 units botulinum toxin and recoded 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).
Results: 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.
Conclusion: Botox injection significantly improved foot dystonia, pain and lower limb functional outcomes in patients with Parkinson’s disease with deep brain stimulation.