Efficacy of Botulinum Toxin Type A for Spasticity Management and Motor Function in Children with Cerebral Palsy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Abstract

Background: Spasticity represents a primary motor impairment in children with cerebral palsy (CP), significantly impacting functional abilities and quality of life. Botulinum toxin type A (BoNT-A) is widely used to manage spasticity in children with CP, but questions remain about the magnitude, durability, and functional translation of benefits across heterogeneous trial designs. Objective: To quantify short-term effects of BoNT-A on spasticity and motor function and to synthesize trial evidence qualitatively across dosing strategies, limbs, and rehabilitation contexts. Methods: A comprehensive literature search was conducted across PubMed, Google Scholar, Web of Science, and Cochrane Library databases from January, 2015 to November 2025. Inclusion criteria specified randomized controlled trials (RCT) evaluating pharmacological interventions for spasticity and motor function in pediatric CP populations. Spasticity measured by the Modified Ashworth Scale (MAS) and gross motor function measured by the Gross Motor Function Measure (GMFM) were defined a priori as co-primary outcomes. However, due to the limited number of trials reporting poolable functional data, GMFM was treated as a secondary endpoint in the final quantitative synthesis. Results: The search identified 175 records, after removing 28 duplicates, 147 abstracts were screened, and 43 full-text articles were reviewed. A total of 18 RCTs met the inclusion criteria encompassing 892 participants. Quantitative meta-analysis of spasticity was conducted on a subset of 5 placebo-controlled lower-limb trials. BoNT-A significantly reduced ankle spasticity (MAS pooled mean difference: -0.31, 95% CI -0.43 to -0.19). The effect direction was unchanged when adding upper-limb dose-comparison and pragmatic designs, though heterogeneity increased. Functional synthesis included 2 trials (measuring GMFM-66 and GMFM-88 at 1–3 months) when BoNT-A was embedded within structured rehabilitation. Qualitative synthesis showed consistent short-term tone reduction across licensed doses, limited between-dose separation, attenuation by ~12 weeks, and an acceptable safety profile dominated by mild, transient events (injection site pain). Conclusions: BoNT-A provides statistically significant short-term reductions in spasticity, with preliminary evidence suggesting potential for early functional gains when combined with rehabilitation. Treatment effects are time-limited, requiring repeated administration. Upper limb applications show less consistent functional translation despite spasticity reduction. Evidence supports multimodal approaches combining pharmacological intervention with structured rehabilitation programs for optimal outcomes.