Adverse events after different forms of botulinum neurotoxin A injections in children with cerebral palsy: An 8-year retrospective study.

AIM: To compare the risks of adverse events 3 months after Onabotulinumtoxin-A and Lanbotulinumtoxin-A injections in children with cerebral palsy (CP) and to identify risk factors and associations. METHOD: A total of 1037 children (682 males, 355 females; mean age 5 years 2 months [SD 3 years]; age range 2 years-17 years 10 months) with CP underwent 1013 Onabotulinumtoxin-A injections and 418 Lanbotulinumtoxin-A injections from 2012 to 2021. Information was recorded in a purpose-built database. RESULTS: The adverse event rates of Onabotulinumtoxin-A and Lanbotulinumtoxin-A were reported as 13.92% and 11.96% respectively. Most adverse events were mild and self-limiting. Children in Gross Motor Function Classification System (GMFCS) levels IV to V had a higher risk of adverse events than those in GMFCS levels I to III (odds ratio [OR] [95% confidence interval {CI}] = 3.65 [1.56, 5.40], p < 0.01). The history of recent illness and higher dose increased the likelihood of adverse events (OR [95% CI] = 2.00 [1.55, 3.00] and 2.20 [1.53, 3.07] respectively, p < 0.01). Sex, age, and the number of injections had no significant effect on adverse event rates (p > 0.05). The incidence of upper respiratory tract infection and lower respiratory tract infection after injections was weakly correlated with the incidence before injections (r = 0.36 and r = 0.27 respectively, p < 0.01). INTERPRETATION: Occurrence of adverse events was similar between Onabotulinumtoxin-A and Lanbotulinumtoxin-A in children with CP. Dose, GMFCS level, and health background were risk factors. WHAT THIS PAPER ADDS: The prevalence of adverse events was similar between Onabotulinumtoxin-A and Lanbotulinumtoxin-A in children with cerebral palsy (CP). The prevalence of adverse events increased with the severity of CP and the injected dose. Sex, age, and number of injections had no significant effect on the prevalence of adverse events.