Botulinum toxin for lower limb spasticity in children with cerebral palsy: a single-blinded trial comparing dilution techniques.

Abstract

To compare the effect of equivalent doses of botulinum toxin type A given in high-volume or low-volume injections on lower limb spasticity in children with cerebral palsy. A total of 17 subjects whose modified Ashworth scale scores in the calf flexors bilaterally ranged from 2 to 3 were enrolled. The right gastrocnemius was injected with botulinum toxin type A using a high-volume preparation (100 IU/4 ml), and the left gastrocnemius was injected with a low-volume preparation (100 IU/1 ml). The amplitude and area of the compound muscle action potential for both medial gastrocnemius muscles, the dynamic muscle range, static muscle range, modified Ashworth scale for both ankles, and the Gross Motor Functional Classification System were assessed before and after treatment. Spasticity was reduced in both legs. There was no significant difference in the changes in the amplitude and area of compound muscle action potential (P = 0.74 and 0.30, respectively), dynamic muscle range (P = 0.7), static muscle range (P = 0.65), and modified Ashworth scale (P = 1) in the right vs. left legs after botulinum toxin type A injection. The high-volume preparation did not cause more pain. A higher volume preparation with a 4-fold dilution of botulinum toxin type A does not yield better results than a low-volume preparation.