Functional outcome of botulinum toxin A injections to the lower limbs in cerebral palsy.

We evaluated gross motor function following botulinum toxin A (BTX-A) injections in the lower limbs of children with spastic cerebral palsy in a randomized clinical trial, using a cross-over design. Forty-nine children (24 males, 25 females, age range 22 to 80 months) were randomly allocated to two groups: group 1 received BTX-A and physiotherapy, and group 2 received physiotherapy alone for 6 months. At the end of this period, group 2 received BTX-A and physiotherapy and group 1 continued with physiotherapy alone. Assessment measures were the Gross Motor Function Measure (GMFM), the Vulpe Assessment Battery (VAB), joint range of movement, the Modified Ashworth Scale, and a parental questionnaire. Sustained gains in gross motor function were found in both groups of children but the only additional benefit found in group 1 was a significant increase in fine motor rating on the VAB. By contrast, parents rated the benefit of treatment highly. It is likely that assessment at 3 and 6 months post injection was too late to demonstrate peak gross motor function response and that changes in GMFM are not sustained over 6 months with a single dose. Further studies should investigate changes over shorter time periods and consider covariables such as BTX-A dosage, number of injection sites, and the role of repeated injections combined with other interventions such as casting.