Impact of Transcutaneous Electrical Stimulation on Oral Moisture in Older Adults with and without Xerostomia: A Pilot Study.

Introduction: Xerostomia, or dry mouth, is a prevalent and distressing oral health condition in older adults that is associated with reduced swallow frequency, thereby increasing the risk of dysphagia and aspiration pneumonia in this cohort. This pseudo-experimental study investigated the association between transcutaneous electrical stimulation (TES) and changes in perceived oral moisture, as well as the function of major and minor salivary glands in two groups of older adults, including those with and without xerostomia.

Methods: Ten older adults with self-reported xerostomia and 7 control participants were exposed to two conditions: no TES and motor TES. TES electrodes were placed on cheeks and submental areas, targeting the parotid, submandibular, and sublingual salivary glands. Participants watched a silent nature movie while receiving continuous TES (only for active TES condition) for 15 min while swallowing sounds were recorded using a microphone attached under the cricoid cartilage. Changes in key outcome measures, including perceived oral moisture (measured by a visual analog scale) along with major and minor salivary glands function (measured by stimulated swallow frequency rate and Periotron) were assessed in response to TES.

Results: The findings indicated that TES increased stimulated swallow frequency rate in both groups (F(1,13) = 9.813, p < 0.008, ηp2 = 0.430). Additionally, the perceived oral moisture measures were only improved for patients with xerostomia (F(1,13) = 5.155, p < 0.041, ηp2 = 0.284). However, no significant changes were noted in minor salivary gland flow rate measures.

Conclusion: These preliminary findings suggest an association between TES and increased objective major salivary gland function in both groups and perceived oral moisture in patients with xerostomia. However, due to the cross-sectional nature of this study, further research involving larger cohorts and controlled designs, and follow up is necessary to understand the mechanisms and potential therapeutic effects of TES on xerostomia.