[Show abstract][Hide abstract] ABSTRACT:
The controlled evidence favoring botulinum toxin A (BtA) treatment for spasticity in cerebral palsy is based on short-term studies.
We conducted a randomized, double-blind, placebo-controlled, parallel-group study of BtA (Dysport) for leg spasticity in 64 children with cerebral palsy. For 2 years, the children received trial injections of up to 30 mu/kg every 3 months if clinically indicated.
For the primary endpoints of Gross Motor Function Measure (GMFM) and Pediatric Evaluation of Disability Index (PEDI) scaled scores at 2 years (trough rather than peak effect), there were no differences between the mean change scores of each group. For the GMFM total score, the 95% CI of -4.81 to 1.90 excluded a 5-point difference in either direction, and a 2-point benefit with 95% confidence. There were no differences in adverse events.
There was no evidence of cumulative or persisting benefit from repeated botulinum toxin A (BtA) at the injection cycle troughs at 1 year or 2 years. The dose was not enough to change spasticity measures and thus GMFM in this heterogeneous group. Ceiling effects in GMFM and Pediatric Evaluation of Disability Index (PEDI) may have reduced responsiveness. This finding does not deny the value, individually, of single injection cycles or prove that repeating them is unhelpful. In this regard, BtA treatment can be viewed in the same light as other temporary measures to relieve spasticity, such as oral or intrathecal agents: there is no evidence of continuing benefit if the treatment ceases. The study provides long-term, fully controlled adverse event data and has not revealed any long-term adverse effects.
[Show abstract][Hide abstract] ABSTRACT:
To determine whether botulinum toxin (BtA) is an effective and safe treatment for lower limb spasticity in children with cerebral palsy. Functional outcomes are of particular interest.
Studies for inclusion in the review were identified using the Movement Disorders Review Group trials register, the Cochrane Controlled Trials Register, MEDLINE, pharmaceutical company databases, communication with other researchers in the field and reference lists of papers found using above search strategies.
Studies were considered eligible for inclusion in the review if they evaluated the efficacy of BtA for the treatment of leg spasticity in children with cerebral palsy. They must have been randomised and include a concurrent control group receiving another intervention.
A paper pro forma was used to collect data from the included studies using double extraction by two independent reviewers. Each trial was assessed for internal validity by each of the two reviewers. Meta-analysis was not possible because results were presented in an incompatable form. A Peto odds ratio was calculated where this was appropriate, otherwise a descriptive summary of the results of the individual studies was compiled.
Three eligible studies were found each with small numbers of subjects. They were short term, used single injection sessions with follow-up of between 4 and 26 weeks. One study (Koman), of twelve ambulant children, compared BtA with injection of a placebo and found non-significant improvements in gait in the BtA group compared to the placebo group. Two studies (Corry, Flett) compared BtA with the use of casts. Each included 20 ambulant children and found improvements in gait, range of ankle movement and muscle tone in both the BtA and cast groups. However there were no significant differences between the groups in either trial. One of these trials (Flett) also assessed motor function using the gross motor function measure (GMFM) (Russell, 1989) and found significant improvements in each group compared to baseline but no significant differences between the groups. The other trial (Corry) performed 3D gait analysis on those children able to co-operate. Maximal plantar flexion and maximal dorsiflexion during walking were both found to be significantly greater in the BtA group compared to the cast group. In all other dimensions there were no significant differences between the groups.
This systematic review has not revealed strong controlled evidence to support or refute the use of BtA for the treatment of leg spasticity in cerebral palsy. Ongoing randomised controlled trials are likely to provide useful data on the short term effects of BtA for leg spasticity. Future research should also assess the longer term use of BtA. Ideally studies should be pragmatic in their approach to dose and distribution of toxin to reflect practise. Outcome measures assessing function and disability would give the most useful information.