Modification of altered ankle motor control after stroke using focal application of Botulinum toxin type A

Abstract

Study designBlinded, placebo-controlled, prospective clinical trial. PurposeTo examine the effects of botulinum toxin type A (BTX-A) injections into plantar flexor muscles in stroke patients with equinovarus gait. Subjects15 post-stroke and 10 matched neurologically intact subjects. MethodsModified Ashworth Scale (MAS) and Fugl–Meyer assessment of physical function scale scores along with surface EMG collected before and up to 12weeks after BTX-A injections to plantar flexor muscle motor points in stroke subjects. Saline placebo injections were performed in a subset of stroke subject group. ResultsMAS scores were decreased at 4, 8 and 12weeks but F–M scores did not improve until 12weeks post injection. Multi-muscle EMG patterns showed the return of volitional dorsiflexor activity in 11 and a decrease of antagonistic and distant coactivation in all but one of the 15. ConclusionsBTX-A is effective in reducing antagonistic and distant muscle activation that impedes volitional dorsiflexion.