Botulinum neurotoxin treatment in children with cerebral palsy: validation of a needle placement protocol using passive muscle stretching and relaxing

Abstract

Aim: To validate a detailed intramuscular needle placement protocol using passive muscle stretching and relaxing for botulinum neurotoxin type A (BoNT-A) treatment in the lower extremity of children with spastic cerebral palsy (CP), with verification by electrical stimulation. Method: A prospective observational study was performed in 75 children with spastic CP who received regular BoNT-A treatment under general anaesthesia (52 males, 23 females; mean age 8y 9mo, SD 3y 7mo, range 4–18y; mean body mass index 16.2, SD 3.7, range 7.7–26.7). A total of 1084 intramuscular needle placements using passive muscle stretching and relaxing were verified by electrical stimulation. Primary outcome was the positive predictive value. Results: Intramuscular needle placement in the muscles adductor brevis, adductor longus, gracilis, semimembranosus, semitendinosus, biceps femoris, rectus femoris, and lateral and medial heads of the gastrocnemius and soleus had a positive predictive value ranging from 85.7% to 100% (95% confidence interval ranging from 71.5–89.9% to 91.4–100%). Interpretation: This validated detailed protocol for intramuscular needle placement using passive muscle stretching and relaxing for BoNT-A treatment in the lower extremity of children with spastic CP is reliable and has a high positive predictive value.