Analgesic effect of botulinum toxin in children with cerebral palsy: A systematic review

This review aims to determine the analgesic efficacy of botulinum toxin (BTX) for the management of pain in children with cerebral palsy (CP). During July and August 2020, a systematic literature search was performed using a mixture of subject headings and free text. The eligibility criteria for inclusion in the review were: (1) interventional studies, (2) participants: children aged 0-18 with CP, (3) participants were treated with BTX, (4) an outcome measure of pain or satisfaction with pain management, and (5) published in an English-language peer-reviewed journal. Eleven studies met the eligibility criteria; nine studies explored analgesic effects of BTX for hypertonia related pain and two for postoperative pain. The studies were of level II to level IV evidence. We identified one high-quality study, which provides level II evidence, and two observational studies that supported BTX therapy for muscle hypertonia related pain in non-ambulant children with CP (GMFCS levels IV and V). For children in GMFCS levels I to III, the evidence for the analgesic effects of BTX was contradictory possibly due to the heterogeneity of the studies and/or weak study design. Mixed evidence for the use of BTX to reduce pain after hip surgery was found likely due to differences in the surgical method, injection protocols, and outcome measures.