The effects of botulinum toxin treatment on associated reactions of the upper limb on hemiplegic gait - a pilot study

Purpose: The involuntary movements of the paretic arm during ambulation and other motor activities are known as associated upper limb reactions (ARs). ARs occur in 80% of stroke patients with spastic hemiplegia and often interfere with balance and safe mobilization. It is hypothesized that the treatment of localized muscle spasticity with botulinum toxin type A (BtxA) would abolish the ARs and improve balance and mobility. Method: This hypothesis will need to be tested in a randomized controlled trial (RCT). The aim of the present pilot study is to obtain preliminary data to inform the design of a future RCT. Eight patients received a single injection of 500 units of BtxA (Dysport(R) Ipsen, Ltd) into the biceps brachii of the paretic arm. The patients' balance and mobility were assessed before and 2, 4 and 6 weeks after treatment using observational gait analysis and other subjective assessment scales. Results: There was a significant reduction of the ARs after treatment but this did not appear to improve the patients' balance or mobility as assessed by the clinicians. Interestingly, seven out of the eight patients reported improvement in their walking. Conclusion: The discrepancy between the observed and reported effects of treatment could be due to the poor sensitivity of the outcome measures used in this study.