Botulinum toxin A for children with salivary control problems

The aim of this study was to review the response of children who have received botulinum toxin A (BtA) injections for saliva control in our institution.

Retrospective case series of children attending a saliva control clinic in a paediatric tertiary referral hospital. Children were identified from the saliva control database, which has been in place since its creation in 2006. Prior to receiving BtA all the children in the study had previously undertaken a 3-month trial of pharmacological therapy, with no effect. All BtA injections were performed freehand to the parotid and submandibular glands. The background diagnosis, comorbidities for the child, age at presentation, dose of BtA, the response, and any complications were recorded.

97 children were identified and 175 BtA doses were given (median per child: 1, mean: 1.9). 59 (61%) were male. The age range was between 2 months and 18 years (mean 8.6 years, median 8.8 years). The dose injected varied between 0.52 units/kg and 21.28 unit/kg (mean 5 units/kg, median 4.2 units/kg). These were performed using local anaesthetic on 131 (75%) occasions. The remainder were performed under general anaesthetic. Responses to BtA were classed as effective 109 (62%), partially effective 14 (8%) or not effective 50 (29%). The response duration was between 0.25 and 18 months (mean 4 months). Complications were seen following 22 injections (10.9%). Data modelled using binary logistic regression found that male gender and children with cerebral palsy are statistically predicted to have a better response to BtA.

Botulinum A injected under local anaesthetic is a safe, effective treatment for children with sialorrhoea. Ultrasound guidance is not necessary as long as anatomical landmarks are used for placement. The main adverse effect that can result is dysphagia, which is of concern in children that can swallow independently prior to injection. Male sex and cerebral palsy are statistically independent positive predictive factors for successful outcome of BtA injections for sialorrhoea, however this does not preclude other children from receiving or benefitting from it. Children that respond well to BtA initially, are likely to respond well in the future.