Repeat upper limb botulinum toxin A injections: a reflection of clinical practice

Abstract

Management of upper limb spasticity in children with congenital hemiplegia has gained increased attention in the last decade owing to the impact of this type of spasticity on dayto- day functional activities and burden of care. Intramuscular injections of botulinum toxin A (BoNT-A) to the upper limb forms part of the treatment repertoire adjunctive to upper limb training in the management of spasticity. Single dose injections to the upper limb have been reported in a number of randomized controlled trials. Results of a recent systematic review and meta-analysis indicated a small treatment effect favouring BoNT-A and upper limb training compared with upper limb training alone to improve unimanual capacity, and a moderate to strong treatment effect in the achievement of individualized outcomes for children with cerebral palsy. However, single dose BoNT-A and upper limb training does not accurately reflect current clinical practice as many children receive repeat injections over time. Adverse events in response to BoNT-A for upper limb spasticity have been reported in both single and repeat dose studies, which were however, mild, short acting, and reversible.1 Limitations of the study by Olesch et al. and previous upper limb BoNT-A studies are the small sample size and brevity of follow-up. The meta-analysis addresses some of the issues around sample size; however, longer-term follow-up of efficacy and the long-term impact on muscle development are needed. Questions remain about the minimum dosage of therapy required to elicit a treatment effect, particularly relating to unimanual capacity and bimanual performance. Further exploration of the type of upper limb training coupled with BoNTA is required. A greater understanding of all of these factors can only lead to optimizing the investment of time and resources for both service providers and children with congenital hemiplegia.