Impact of botulinum toxin type A on disability and carer burden due to arm spasticity after stroke: a randomised double blind placebo controlled trial

Abstract

Objectives: After stroke, abnormal arm posture due to spasticity in a functionally useless arm may interfere with self care tasks. In these patients botulinum toxin treatment presents an opportunity to reduce disability. The purpose was to investigate whether reduction in spasticity after botulinum toxin treatment translates into reduction in disability and carer burden.

Methods: Forty patients with stroke with spasticity in a functionally useless arm (median duration 3.1 years) were randomised to receive intramuscular botulinum toxin type A (BT-A; Dysport) (n=20) or placebo (n=20) in a total dose of 1000 MU divided between elbow, wrist, and finger flexors. Spasticity (using the modified Ashworth scale), muscle power, joint movement, and pain were assessed. Disability and carer burden were measured using an eight item and a four item scale respectively. Two baseline and three post-treatment assessments (weeks 2, 6, and 12) were made. Concurrent treatments as far as possible remained unchanged and not optimised.

Results: Disability improved at week 6 with BT-A compared with placebo. This effect, present at week 2, wore off by week 12. Reduction in carer burden was seen at week 6 with BT-A and continued for at least 12 weeks. Forearm flexor spasticity was reduced with BT-A up to 12 weeks after treatment. Although significant improvement in elbow flexor spasticity was seen at week 2 with BT-A compared with placebo, this effect was not evident at weeks 6 and 12. Arm pain was not improved after BT-A. Grip strength was reduced with BT-A. No serious BT-A related adverse effects were reported.

Conclusion: BT-A is useful for treating patients with stroke who have self care difficulties due to arm spasticity. The decision to treat should also include relief of carer burden. As muscle weakness may occur, its potential impact on functional activities must be assessed before intervention.