Behavioral Interventions Targeting Insufficient Upper Esophageal Sphincter Opening During Swallowing: A Scoping Review

Abstract

The upper esophageal sphincter (UES) plays a central role in safe swallowing. Impaired UES opening is commonly observed in individuals presenting with impaired swallowing and various interventions are available aiming to improve bolus passage across the UES during swallowing. This scoping review addressed the following question: Which behavioral interventions are available to improve UES opening for deglutition? We searched MEDLINE, CINAHL, Ovid Emcare, Web of Science, SCOPUS and ProQuest for studies that met the following criteria: i. behavioral interventions targeting UES opening ii. performed over a period of time, which iii. were assessed using UES specific outcome measures. Study quality was assessed using the Joanna Briggs Institute and GRADE frameworks. Data were extracted and synthesized into dominant themes. Of the 357 studies originally identified, 15 met inclusion criteria and reported interventions that were grouped into four intervention types: (1) floor of mouth exercises that were sub-categorized into the Shaker exercise and other strengthening exercises, (2) Mendelsohn maneuver, (3) lingual exercises and (4) mixed exercise paradigms. Across the included studies, varying levels of success in improving various aspects of UES opening metrics were reported. Nine of 15 studies evaluated patients with demonstrated swallowing impairment, whereas six studies evaluated healthy adults. Quality assessment revealed significant variability in study quality, unclear reporting of participant training and treatment fidelity, as well as training dosage. The evidence base for the four behavioral intervention approaches targeting deglutitive UES opening is limited. The translation of existing evidence to clinical practice is hindered by small sample sizes and methodological limitations. Further research in this space is warranted.

Keywords: Deglutition; Deglutition disorders; Dysphagia; Exercise; Rehabilitation; Swallowing; Upper esophageal sphincter.