Compensatory Effects of Sequential 4-Channel Neuromuscular Electrical Stimulation for the Treatment of Acute, Subacute, and Chronic Dysphagia in a Prospective, Double-Blinded Randomized Clinical Trial

• Published in: Neurorehabilitation and neural repair 2021-09, Vol.35 (9), p.801-811
• Main Authors: Lee, So Young, Park, Donghwi, Jang, Joonyoung, Jang, Eun Gyeong, Lee, Jun Chang, Park, Yulhyun, Cho, Seon, Kim, Won-Seok, Park, Jihong, Kim, Bo Ryun, Seo, Kyoung-Ho, Park, Sungwon, Ryu, Ju Seok
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Deglutition Disorders - physiopathology; Deglutition Disorders - therapy; Double-Blind Method; Electric Stimulation Therapy; Female; Humans; Male; Middle Aged; Prospective Studies; Treatment Outcome
• ISSN: 1545-9683; 1552-6844
• DOI: 10.1177/15459683211029891

Background. The precise mechanism of 2-channel neuromuscular electrical stimulation (NMES) treatment is unknown, and controversy remains over its efficacy. The sequential 4-channel NMES was newly developed based on normal contractile sequences of swallowing-related muscles. Objective. To assess the clinical efficacy of sequential 4-channel NMES during swallowing. Methods. In this prospective RCT, 52 inpatients with dysphagia (acute, subacute, and chronic state) after stroke, brain tumor, or encephalitis were enrolled. Participants who underwent a videofluoroscopic swallowing study (VFSS) and clinical evaluation were enrolled and were randomly assigned to the 4-channel NMES or sham group. The 4-channel NMES and sham groups swallowed thin and honey-like fluids under NMES (sequential stimulation on suprahyoid and infrahyoid) and sham stimulation, respectively. The procedures were evaluated with the VFSS. Pre- and post-treatment evaluations were performed with the videofluoroscopic dysphagia scale (VDS), penetration–aspiration scale (PAS), Likert scale, and kinematic analysis. Results. The 4-channel NMES group showed significantly greater improvements than the sham group with respect to oral VDS, pharyngeal VDS, total VDS, and PAS (P < .05). Furthermore, the Likert scale for satisfaction, easiness, and discomfort for swallowing showed favorable results for the 4-channel NMES group (P < .05). In the kinematic analysis, the peak speed point, distance, and velocity of hyoid movement were significantly greater in the 4-channel NMES group (P < .05). Conclusions. Sequential 4-channel NMES activating the suprahyoid, thyrohyoid, and other infrahyoid muscles during swallowing showed significant clinical improvement with respect to VDS, PAS, and kinematic analysis. Therefore, sequential 4-channel NMES is a potential new functional electrical stimulation system for the treatment of dysphagia.