Botulinum toxin for children with cerebral palsy: a delicate balance between clinical benefits and muscular harm

Intramuscular Botulinum Neuro-Toxin type A (BoNT) injections, causing temporal chemo-denervation, has become a widely used first-line intervention to treat focal spasticity in children with cerebral palsy (CP). The clinical benefits of BoNT treatment include reduced spasticity, increased joint mobility and improved gait. Yet, an increasing number of animal studies have raised concerns that BoNT may compromise muscle size and quality. This project will tackle three research challenges that will allow us to determine whether the clinical benefits of BoNT counterweigh the potential risks at the muscular level. First, due to early progressive alterations, CP muscles are already impaired by the time of the first BoNT-session. Through a longitudinal follow-up of macro- and microscopic muscle properties post BoNT, we will define to what extent BoNT contributes to this process and further impairs muscle growth. Second, the mechanisms involved in the intramuscular changes following BoNT injection have only been described in animal studies and will now be investigated in children with CP. Third, we will investigate a new promising treatment to accelerate muscle recovery post BoNT, by combining strength training with protein supplements, thoughtfully planned following the temporary period of chemo-denervation. These studies are of great interest to fully understand the muscular impact of BoNT, to optimize BoNT treatment protocols, and eventually improve patient-tailored BoNT treatment.