Determinant Factors for The Efficacy of Botulinum Toxin Injections on Lower Limb Function in Cerebral Palsy: Two Year Follow-up Study.

Objectives: This study evaluated the factors predicting the effect of long-term intramuscular botulinum toxin-A (BTX-A) treatment on motor and gait functions in children with spastic cerebral palsy (CP). Methods: Two hundred children diagnosed with CP were treated with BTX-A, with particular attention given to the lower limbs. The children were followed up for over two years. The severity of spasticity was evaluated using the Modified Ashworth Scale. The Gross Motor Function Classification System (GMFCS) and Observational Gait Scale (OGS) were used to assess changes in motor and gait function scores. Outcomes at the end of two years were compared with baseline values. Results: After two years, the severity of spasticity and the GMFCS and OGS scores improved with BTX-A treatment. The most important factors predicting improvement in motor scores after treatment were young age, high baseline OGS scores, independent walking, baseline GMFCS scores, and hemiplegia. The determinant factors for improvement in gait scores were the number of injections and a high baseline GMFCS level. Conclusion: The predictors of the efficacy of BTX-A treatment on gait and motor function were young age, independent ambulatory status, gross motor function level, high baseline gait scores, hemiplegic type of CP, and multiple BTX-A injections.