Botulinum toxin and Gross Motor Function Classification System: a 17-year Retrospective Study on Target Muscles and Doses
DOI:
https://doi.org/10.25759/spmfr.566Keywords:
Pediatric Rehabilitation, Botulinum Toxin, Neurotoxin, Spasticity, Cerebral Palsy, Gross Motor Function Classification SystemAbstract
Background: Botulinum toxin type A (BoNT-A) is widely used to manage focal spasticity in children with cerebral palsy (CP), the leading cause of spasticity in childhood. Injections aim to improve function, gait, positioning, hygiene, appearance, and pain control.
Objectives: This single-center retrospective study analyzed the use of anobotulinumtoxinA and abobotulinumtoxinA in children with CP, using each injection session as the unit of analysis. We examined the relationship between Gross Motor Function Classification System (GMFCS) levels and the muscles targeted, and secondarily described demographics, doses, and adverse reactions.
Methods: All injection sessions performed between 2007 and 2023 in patients under 19 years old were reviewed. Ambulatory children were defined as those walking independently or with walking aids (GMFCS ≤ III), while nonambulatory children required a wheelchair for mobility (GMFCS > III). Duplicate records were removed prior to analysis. Between-group comparisons were performed using the Mann-Whitney U test(IBM SPSS v.28). Statistical significance was set at p< 0.05 with effects reported using 95% confidence intervals.
Results: A total of 883 BoNT-A injection sessions were analyzed in 163 children (median age 8.2 IQR 5.1-12.3). OnabotulinumtoxinA (627 sessions) and abobotulinumtoxinA (256 sessions) were administered at mean doses of 187 IU (95% CI 179-194) and 564 IU (95% CI 544-586). Doses were significantly higher in non-ambulatory children for both total and weight-adjusted values (p< 0.001). The most frequently injected muscles in non-ambulatory children were the adductors and hamstrings, while ambulatory children more often received injections in the gastrocnemius, soleus, and tibialis posterior. No severe adverse events were reported.
Conclusions: BoNT-A is a safe and effective treatment for pediatric spasticity across all GMFCS levels. Adapting muscle selection and dosing according to functional level optimizes therapeutic outcomes and helps prevent deformities. Clinically, this supports individualized toxin protocols integrated into long-term rehabilitation programs. The main limitation is the retrospective, single-center design, which may restrict generalizability.
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Dressler D, Adib Saberi F. Botulinum toxin: mechanisms of action. Arq Neuropsiquiatr. 2005;63(1):180-185. doi:10.1590/S0004-282X2005000100035.
Blumetti FC, Belloti JC, Tamaoki MJS, Pinto JA. Botulinum toxin type A in the treatment of lower limb spasticity in children with cerebral palsy. Cochrane Database Syst Rev. 2019;(10):CD001408. doi:10.1002/14651858.CD001408.pub2.
Kaya Keles CS, Ates F. Botulinum toxin intervention in cerebral palsy-induced spasticity management: projected and contradictory effects on skeletal muscles. Toxins (Basel). 2022;14(11):772. doi:10.3390/toxins14110772.
Oskoui M, Coutinho F, Dykeman J, Jetté N, Pringsheim T. An update on the prevalence of cerebral palsy: a systematic review and meta-analysis. Dev Med Child Neurol. 2013;55(6):509-519. doi:10.1111/dmcn.12080.
Rosenbaum P, Paneth N, Leviton A, Goldstein M, Bax M, Damiano D, et al. A report: the definition and classification of cerebral palsy, April 2006. Dev Med Child Neurol Suppl. 2007;109:8-14. doi:10.1111/j.1469-8749.2007.tb12610.x.
Palisano R, Rosenbaum P, Walter S, Russell D, Wood E, Galuppi B. Development and reliability of a system to classify gross motor function in children with cerebral palsy. Dev Med Child Neurol. 1997;39(4):214-223. doi:10.1111/j.1469-8749.1997.tb07414.x.
Palisano RJ, Rosenbaum P, Bartlett D, Livingston MH. Content validity of the expanded and revised Gross Motor Function Classification System. Dev Med Child Neurol. 2008;50(10):744-750. doi:10.1111/j.1469-8749.2008.03089.x.
Novak I, McIntyre S, Morgan C, Campbell L, Dark L, Morton N, et al. A systematic review of interventions for children with cerebral palsy: state of the evidence. Dev Med Child Neurol. 2013;55(10):885-910. doi:10.1111/dmcn.12246.
Novak I, Morgan C, Fahey M, Finch-Edmondson M, Galea C, Hines A, et al. State of the evidence traffic lights 2019: systematic review of interventions for preventing and treating children with cerebral palsy. Curr Neurol Neurosci Rep. 2020;20(2):3. doi:10.1007/s11910-020-1022-z.
Lin CY, Chung CH, Matthews DJ, Chu HY, Chen LC, Yang SS, et al. Long-term effect of botulinum toxin A on the hip and spine in cerebral palsy: a national retrospective cohort study in Taiwan. PLoS One. 2021;16(7):e0255143. doi:10.1371/journal.pone.0255143.
Flemban A, Elsayed W. Effect of combined rehabilitation program with botulinum toxin type A injections on gross motor function scores in children with spastic cerebral palsy. J Phys Ther Sci. 2018;30(7):902-905. doi:10.1589/jpts.30.902.
Heinen F, Desloovere K, Schroeder AS, Berweck S, Borggraefe I, van Campenhout A, et al. The updated European consensus 2009 on the use of botulinum toxin for children with cerebral palsy. Eur J Paediatr Neurol. 2010;14(1):45-66. doi:10.1016/j.ejpn.2009.09.005.
Choi JY, Kim SK, Park ES. The effect of botulinum toxin injections on gross motor function for lower limb spasticity in children with cerebral palsy. Toxins (Basel). 2019;11(11):651. doi:10.3390/toxins11110651.
Strobl W, Theologis T, Brunner R, Kocer S, Viehweger E, Pascual-Pascual I, et al. Best clinical practice in botulinum toxin treatment for children with cerebral palsy. Toxins (Basel). 2015;7(5):1629-1648. doi:10.3390/toxins7051629.
Multani I, Manji J, Hastings-Ison T, Khot A, Graham HK. Botulinum toxin in the management of children with cerebral palsy. Paediatr Drugs. 2019;21(4):261-281. doi:10.1007/s40272-019-00344-8.
Franzén M, Hägglund G, Alriksson-Schmidt AI. Treatment with botulinum toxin A in a total population of children with cerebral palsy: a retrospective cohort registry study. BMC Musculoskelet Disord. 2017;18:520. doi:10.1186/s12891-017-1880-y.
Vova JA, et al. A consensus statement on the use of botulinum toxin in pediatric patients. PM R. 2022. doi:10.1002/pmrj.12713.
Ipsen Biopharmaceuticals. Dysport® (abobotulinumtoxinA) prescribing information. Silver Spring (MD): US Food and Drug Administration; 2023. Available from: https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/125274s100lbl.pdf
Allergan Inc. Botox® (onabotulinumtoxinA) prescribing information. Silver Spring (MD): US Food and Drug Administration; 2021. Available from: https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/103000s5306lbl.pdf
Brin MF, Nelson M, Ashourian N, Brideau-Andersen A, Maltman J. Update on non-interchangeability of botulinum neurotoxin products. Toxins (Basel). 2024;16(6):266. doi:10.3390/toxins16060266.
Field M, Splevins A, Picaut P, van der Schans M, Langenberg J, Noort D, Snyder D, Foster K. AbobotulinumtoxinA (Dysport®), onabotulinumtoxinA (Botox®), and incobotulinumtoxinA (Xeomin®) neurotoxin content and potential implications for duration of response in patients. Toxins (Basel). 2018;10(12):535. doi:10.3390/toxins10120535.
Deshpande N, Gormley ME, Deshpande S. Safety of botulinum toxin injections in children less than one year old: a retrospective chart review. J Pediatr Rehabil Med. 2024;17(1):67-73. doi:10.3233/PRM-220003.
Pascual-Pascual SI, Pascual-Castroviejo I. Safety of botulinum toxin type A in children younger than 2 years. Eur J Paediatr Neurol. 2009;13(6):511-515. doi:10.1016/j.ejpn.2008.10.006.
Edwards P, Sakzewski L, Copeland L, Gascoigne-Pees L, McLennan K, Thorley M, et al. Safety of botulinum toxin type A for children with nonambulatory cerebral palsy. Pediatrics. 2015;136(5):895-904. doi:10.1542/peds.2015-0749.
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