The effect of injecting botulinum toxin type a into the calf muscles on freezing of gait in Parkinson's disease: a double blind placebo-controlled pilot study.

OBJECTIVE To assess the effect on freezing of gait (FOG) of botulinum toxin type A (BTX-A) injections in advanced Parkinson's disease (PD) patients. METHOD BTX-A 150 IU or normal saline was injected into each leg's calf muscles by a blinded investigator. FOG severity was assessed at set intervals (6-month follow-up). RESULTS Eleven age- and disease severity-matched PD patients with disabling FOG participated. Six patients received BTX-A and 5 received saline. No improvement was observed in either group over time. Leg weakness and falls lead to early termination. CONCLUSION BTX-A injections to the legs did not improve FOG and might increase fall risk.