Botulinum toxin A treatment of the lower extremities in children with cerebral palsy

Objectives In the last 2 decades, BTX-A is increasingly being used in the management of spasticity in children with Cerebral Palsy (CP) and there is no doubt about its effect on range of motion, spasticity reduction and gait pattern in this patient population. However, in daily practice, there is still an ongoing search for the best way to apply BTX-A. Two studies were set up to evaluate how successful an integrated multilevel treatment approach is in children with CP. The first study identifies crucial factors within the treatment strategy which may predict the outcome. The second study evaluates the efficacy of repeated BTX-A injections. Methods Patient selection was based on following criteria: diagnosis of CP, lower limb BTX-A treatment, age at time of treatment <24 years, no combined surgery at the time of BTX-A injections, 3D gait analysis and clinical evaluation pre and 2 months post BTX-A injections. The first study included the last treatment of 577 patients. In the second study, the first and last BTX-A treatment of 222 children were included. The Goal Attainment Scale (GAS) was used to evaluate the functional outcome of each treatment session. Results In the first study, the mean GAS score of the total group was 51.7 (+/- 7.5). Considering a converted total score of 50 as cut-off score for successful treatment, 67.1 % of the treatments were successful. Significantly higher GAS scores were found in mildly involved children compared to more involved children (p < 0.0001) and for multilevel injections or injections in the distal muscle groups only compared to injections in the proximal muscles of the lower limb only (p < 0.0001). Other crucial factors for a successful outcome were amount of physical therapy per week (p=0.0026), post injection casting (p=0.005) and frequency of using day and night orthoses after injection (p < 0.0001). In the second study, the mean GAS score of the total group decreased from 54.8 (+/- 6.8) at the first treatment to 50.7 (+/- 6.9) at the last treatment, indicating that on average, repeated BTX-A treatment is successful. Conclusion The integrated multilevel BTX-A approach is successful in children with CP. Several factors might help the clinician to select patients that are most likely to benefit from the treatment, to assure the most optimal treatment strategy and to predict the outcome. Each treatment should be carefully planned and goals should be well chosen, because the effectiveness of the BTX-A treatment may decrease with increasing number of treatments in the same patient.