Botulinum Toxin Type A: Efficacy  in the management of Lower Limb Spasticity in Children with Genetic Disorders

Background: Botulinum toxin type A (BoNT) is a well-established therapeutic modality for the treatment of lower limb spasticity in children with cerebral palsy. Objective: To assess the functional outcomes and tolerability of BoNT injection for the treatment of lower limb spasticity in children with neurometabolic/genetic disorders. Methods: We conducted a retrospective chart review for history, demographic data, comorbidities, neurological examination, and neuroimaging findings for all patients diagnosed with neurometabolic/genetic disorders from December 2020 to December 2022. The outcomes were assessed by recording the Gross Motor Function Classification system (GMFCS) for Cerebral Palsy "Initially and after 6 months' post-treatment", the Modified Ashworth scale (MAS) "initially and at 1,3,6 month post-treatment" and the achieved preset functional goals using the Goal Attainment Scaling (GAS) at 4-6 months post-treatment. Results: A total of 90% of the patients showed improvement in their GAS scores, with 20% achieving the preset goal, 55% achieving a better outcome than anticipated and 15% achieving the best possible outcome. Furthermore, the GMFCS and MAS scores showed a significant statistical improvement after six months post-injection (p=0.02, p=0.03), respectively. None of the patients developed serious adverse effects except one who had mitochondrial cytopathy. Conclusion: BoNT injections were effective and showed a high safety profile in children with neurometabolic/genetic disorders. To our knowledge, this is the first study that specifically targets this patient population, filling a gap in the literature and providing valuable insights into the potential benefits of BoNT injections for this group. However, further large-scale studies are recommended to confirm these findings.