Effect of Botulinum Toxin Type A on Functional Mobility in Cerebral Palsy with Lower Limb Spasticity

Introduction: Children with Cerebral Palsy often start walking much later than typically developing children and they do so with a slower speed and higher energy cost. Mobility varies across different environmental settings and Functional Mobility Scale (FMS) was devised to illustrate functional mobility in these children over three distinct distances, chosen to represent mobility in the home, at school and in the wider community. Botulinum toxin A injections into the gastrocnemius muscle for equinus foot deformity, as well as multilevel lower limb injections have shown improvements in gait, however, there is paucity of literature on its effect on functional mobility. Aim: To study the efficacy of Botulinum toxin A injection in Cerebral Palsy (CP) with lower limb spasticity in terms of reduction in spasticity and effect on functional mobility. Materials and Methods: A total of 31 children were enrolled and evaluated for various outcome measures just before injection and at 4 and 12 weeks after injection. Change in FMS on follow-up was analysed using Wilcoxon signed-rank test. Spearman's correlation analysis was performed between the number of injected muscles in each child and change in FMS scores on follow-up. A p-value of <0.05 was considered statistically significant. Analyses were done using SPSS version 21.0 statistical software (IBM Corp., Armonk, NY). Results: At distances of 5, 50 and 500 meters, FMS showed statistically significant improvement at 4 weeks (p-value <0.001 at 5; 0.002 at 50; 0.006 at 500 meters) and at 12 weeks (p-value <0.001 at 5; 0.001 at 50; 0.002 at 500 meters) compared with baseline but no significant change from 4 to 12 weeks (p-value = 0.102 at 5; 1.000 at 50; 0.157 at 500 meters). There was moderate positive correlation between the number of injected muscles in each child and the change in FMS from baseline to 12 weeks at 5 meters distance; however, a moderate negative correlation was observed for the same at 500 meters. Conclusion: Local injection of Botulinum toxin A is effective in reducing the lower limb (gastrocnemius, hamstring, adductor) spasticity in CP children. It also improves the FMS in CP children.