Botulinum toxin in upper limb spasticity after acquired brain injury: a randomized trial comparing dilution techniques.

Objective: To compare the efficacy of two different volume preparations of the same dose of botulinum toxin-A in relieving spasticity in wrist and finger flexors secondary to acquired brain injury.

Design: Thirteen adult patients who had modified Ashworth scale scores of 3 for both wrist and finger flexors were included in this randomized, controlled trial. Wrist and finger flexors were each injected. Blinded modified Ashworth scale ratings of wrist and finger flexor spasticity were measured.

Results: Spasticity in both muscles decreased significantly in both treatment groups. However, the high-volume and low-volume groups did not differ significantly in spasticity reduction.

Conclusions: Because this preliminary study found no difference in spasticity reduction between high- and low-volume preparations of a 60-unit dose of botulinum toxin-A, a larger-sample study seems warranted to compare the efficacy of high-volume and low-volume preparations.