Botulinum toxin-A injections vs radiotherapy for drooling in ALS

Botulinum neurotoxin (BoNT) injections in the salivary glands and radiotherapy (RT) on these glands are commonly used to alleviate severe drooling in patients with amyotrophic lateral sclerosis (ALS). This study compares BoNT type A with RT based on patient-rated evaluations.

A prospective randomized controlled pilot study to compare RT (n = 10; on the parotid and the posterior part of the submandibular glands) with BoNT-A treatment (n = 10; in the parotid glands only, because of the risk of increasing oropharyngeal weakness) in patients with ALS. The primary outcome was the drooling status (burden of drooling), and our secondary interests were the degree of salivation, global change of drooling after treatment, and level of satisfaction with the treatment and negative experiences.

There were no statistically significant between-treatment differences for the drooling status after treatment. Only at twelve weeks more saliva reduction was achieved by RT (P = 0.02). Patients treated with RT also described more transient negative experiences (like pain in mandible) directly after treatment. Subgroup analysis showed that patients with very severe dysphagia (no oral intake) were less satisfied and experienced a lower global change of drooling after treatment.

This pilot study showed no significant difference in the burden of drooling between the treatments. However, with RT more saliva reduction was achieved, including negative experiences directly after treatment, but without the risk of decreasing oropharyngeal function. In addition, patients with very severe dysphagia do not seem to benefit from either treatment.