Ultrasound-Guided Botulinum Toxin Injections into the Salivary Glands for the Treatment of Drooling

Background: Drooling is the unintentional loss of saliva from the mouth, usually caused by poor coordination of the swallowing mechanism. It is commonly seen in patients with chronic neurologic disorders, such as Parkinson's disease, amyotrophic lateral sclerosis (ALS), cerebral palsy, and stroke, as well as in patients with cognitive impairment and dementia. Objectives: To evaluate the efficacy and safety of ultrasound guided botulinum toxin injections into the parotid and submandibular salivary glands for the treatment of drooling. Methods: We conducted a retrospective analysis of the medical records of 12 consecutive patients treated with botulinum toxin injections into the parotid and submandibular glands for the first time. The primary outcome variable was the subjective improvement of drooling on a 5-point scale. Secondary outcome variables were duration of the therapeutic effect, request to undergo additional treatment, and adverse events. Results: Of 12 patients, 8 (67%) reported considerable improvement after treatment, 3 reported slight improvement, and 1 reported development of dry mouth. All patients stated that they felt the effects 1 week after the injections; the mean duration of the therapeutic effect was 4.5 months (range 3-9 months). One patient suffered from local hematoma and ecchymosis that did not require medical care. Another patient complained of difficulty swallowing, which did not require medical treatment and resolved spontaneously within 1 month. Conclusions: Ultrasound-guided botulinum toxin injections into the parotid and submandibular glands seem to be a safe and effective therapy for the treatment of drooling. Further long-term prospective studies with varying doses are warranted.