The effectiveness and safety of botulinum toxin treatment for sialorrhea due to severe brain injury

Introduction: Sialorrhea may be a consequence of severe acquired brain injury (ABI). Salivary gland botulinum neurotoxin (SG-BoNT) injections can reduce saliva production, but there is limited evidence for their use in ABI.We reviewed the effectiveness, impact on chest infection frequency, and safety of SG-BoNT for sialorrhea in a cohort of patients with severe ABI.

Materials/methods: Retrospective cohort study of 49 patients, in a specialist ABI care facility, with sialorrhea who received SG-BoNT.Outcome measures included pre- and post-injection Drooling Severity and Frequency Scale (DSFS) scores, pre- and post-injection chest infection frequency, and adverse events.

Results: Forty-nine patients received 79 SG-BoNT treatments (100 to 200 units of botulinum toxin A).Post-treatment the whole group showed significantly reduced mean DSFS scores (z = -6.4, p < 0.00001) and significantly fewer chest infections (z = -3.15, p = 0.0016). A reduction in chest infection frequency was seen in patients who received repeated treatments (2 or more) and/or higher SG-BoNT doses. There were no adverse events.

Conclusions: There is limited evidence for SG-BoNT in the treatment of sialorrhea for people with ABI but this treatment is clinically effective with no detectable adverse effects in this cohort. The reduction in chest infection frequency following repeated SG-BoNT injections is an important novel finding.