Can botulinum toxin type A injection technique influence the clinical outcome of patients with post-stroke upper limb spasticity? A randomized controlled trial comparing manual needle placement and ultrasound-guided injection techniques

Background Botulinum toxin type A is a first-line treatment for post-stroke focal spasticity, and the accuracy in delivering the toxin to the target muscles may influence the treatment outcome. Our aim was to compare the reduction of spasticity and the related finger position at rest improvement in post-stroke patients treated with botulinum toxin type A in upper limb muscles using ultrasound guidance and manual needle placement.

Methods In a randomized clinical trial, two groups of 15 stroke patients were treated with botulinum toxin type A injections in the wrist and finger flexor muscles of the affected upper limb using ultrasound guidance or manual needle placement. The Modified Ashworth Scale and the finger position at rest were measured at baseline and one month after toxin injections.

Results After one month of follow-up from toxin injections, the Modified Ashworth Scale and finger position at rest significantly improved in both treatment groups, although these clinical outcomes were significantly better in patients treated under ultrasound guidance than in patients injected using manual needle placement.

Conclusion Ultrasound guidance for botulinum toxin type A injections could improve clinical outcome measures better than manual needle placement in post-stroke patients with spasticity.