Neurostimulation for Dysphagia in Acute and Critical Care: A Systematic Review, Pairwise and Network Meta-Analysis

The clinical benefits of neurostimulation therapies for treating dysphagia in acute and critical care patients remain controversial. This study aims to comprehensively review the literature to assess the effectiveness of neurostimulation therapies.

Databases including PubMed, Cochrane Library, Embase, Ovid, CINAHL, Web of Science, Wanfang, CNKI, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform were searched up to April 16, 2025. Eligible randomised clinical trials (RCTs) involving acutely and critically ill patients with dysphagia were identified. Details of study population, treatments and outcomes were extracted.

Forty-four studies involving 2198 patients were selected. These studies encompassed five types of neurostimulation therapies: transcutaneous auricular vagus nerve stimulation (ta-VNS), neuromuscular electrical stimulation (NMES), repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS) and pharyngeal electrical stimulation (PES). The pairwise meta-analysis indicated that compared to traditional dysphagia therapy (TDT), usual care or sham stimulation, neurostimulation therapies significantly improved swallowing function post-treatment (SMD = -0.74, 95% CI: -0.90 to -0.58), increased the rate of patients regaining the ability to take food orally (RR = 1.39, 95% CI: 1.12-1.74) and enhanced swallowing function at 1 month (SMD = -1.28, 95% CI: -1.76 to -0.81) and 2 months (SMD = -2.24, 95% CI: -3.25 to -1.23). Additionally, neurostimulation was associated with a reduction in pneumonia incidence (RR = 0.62, 95% CI: 0.39-0.98). However, neurostimulation did not show significant improvements in swallowing function at 3 months post-treatment (SMD = -0.43, 95% CI: -1.08 to 0.22) or decannulation (RR = 3.47, 95% CI: 0.60-20.23), nor did it reduce aspiration post-intervention (RR = 0.67, 95% CI: 0.36-1.26) or shorten hospital stays (MD = -1.74, 95% CI: -4.78 to 1.30). The network meta-analysis revealed that NMES + TDT (SMD = -1.69, 95% CI: -2.83 to -0.58), NMES (SMD = -1.31, 95% CI: -2.61 to -0.02), rTMS + TDT (SMD = -1.58, 95% CI: -2.71 to -0.49), rTMS (SMD = -1.15, 95% CI: -1.79 to -0.53), tDCS + TDT (SMD = -1.19, 95% CI: -2.31 to -0.09), PES + TDT (SMD = -1.53, 95% CI: -2.97 to -0.15) and PES (SMD = -0.71, 95% CI: -1.45 to -0.06) were effective in improving swallowing function. NMES + TDT may be the most potentially effective neurostimulation therapy. The efficacy of ta-VNS + TDT (SMD = -1.89, 95% CI: -3.47 to -0.33) remains to be further validated. Among these, ta-VNS + TDT (SMD = -1.89, 95% CI: -3.47 to -0.33) was supported by only one study, necessitating further validation of its therapeutic efficacy.

Our findings suggest that NMES + TDT, rTMS + TDT, NMES, tDCS + TDT, rTMS, PES + TDT and PES are effective therapies for improving swallowing function in acute and critical care patients, while the effectiveness of ta-VNS + TDT requires further investigation. Among the five neurostimulation therapies, NMES + TDT may be the most effective, according to probability rankings.