Up-to-date report of botulinum toxin therapy in patients with drooling caused by different etiologies.

PURPOSE

In this study, we evaluated the clinical data for patients with drooling caused by various diseases, treated by injection of botulinum toxin A. We also present a controlled follow-up study documenting efficiency, possible adverse events, and duration of the effect of treatment.

PATIENTS AND METHODS

Thirteen patients with drooling caused by head and neck carcinoma, neurodegenerative diseases, or stroke received injections of 50 to 65 U botulinum toxin A (Botox; Allergan, Irvine, CA) in both submandibular and both parotid glands under sonographic control. We measured whole salivary flow rate and the salivary analytes of total protein, alpha-amylase, acid phosphatase, kallikrein, and immunoglobulin A at various times before and after injection. The patients were examined for severity of symptoms, including sonographic investigation of cephalic salivary glands.

RESULTS

All 13 patients reported a distinct improvement of their symptoms within 2 weeks after toxin injection. Three patients noted a return of high salivation rates after 12 weeks. Duration of toxin effect varied widely between individuals. In general, salivary flow rates dropped sharply within 1 week after injection but had risen again after 12 weeks. Conversely, analyte concentrations increased in the first stages of treatment and later decreased, returning to pretherapy levels. Sonography did not reveal any major changes of salivary gland parenchyma, and side effects were absent.

CONCLUSIONS

Local injection of botulinum toxin A into the salivary glands proved to be a dependable therapy for drooling caused by various etiologies, as shown in 13 patients. Adverse events were not seen. The effect of toxin application lasted for about 3 months. To further clarify this aspect, long-term studies are under way.