Botulinum toxin to reduce saliva flow: Selected indications for ultrasound-guided toxin application into salivary glands

Abstract

Objectives/Hypothesis: The study investigates the effect of local injections of botulinum. toxin type A (Botox) into the major salivary glands of the head in various states of hypersalivation. In particular, we studied pathological states with permanent as well as passing hypersalivation disorders and present new indications for local application of botulinum. toxin to the salivary glands. Study Design: Retrospective clinical investigation. Methods: A total of 55 to 65 units of Botox were injected under sonographic control into the left and right parotid and submandibular glands of four patients with hypersalivation resulting from head and neck carcinoma, tracheostomy, and "idiopathic" hypersalivation disorder. At defined time intervals following injection, flow rate, total protein and immunoglobulin A content, and the enzymatic activities of amylase, acid phosphatase, and kallikrein were determined in the saliva. The patients were clinically examined to assess the severity of their symptoms, including sonographic control of the major salivary glands. Results: All four patients reported distinct improvement of their symptoms within 1 week after injection. Salivary flow rate had considerably dropped, whereas the concentrations of the salivary components were much increased. Sonography did not reveal any changes of the salivary gland parenchyma. Therapeutic side effects were absent. Conclusions: Treatment of hypersalivation by local injections of Botox into the salivary glands of the head is a reliable and efficient therapy without side effects for certain otolaryngological diseases, especially if injections are performed under sonographic control. Extension of this therapeutic concept to other indications is suggested.