Comparative Effectiveness of Combined and Single Neurostimulation and Traditional Dysphagia Therapies for Post-Stroke Dysphagia: A Network Meta-Analysis

Abstract

Background Comparative therapeutic benefits of combined and single neurostimulation therapies including neuromuscular electrical stimulation (NMES), pharyngeal electrical stimulation (PES), repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS), and traditional dysphagia therapy (TDT) remain unknown in post-stroke dysphagia (PSD) rehabilitation. Therefore, we performed the first network meta-analysis (NMA) to determine comparative effectiveness of combined and single neurostimulation and traditional dysphagia therapies for PSD. Methods A frequentist NMA model was performed with therapy effect sizes presented as standardized mean differences (SMD) and corresponding 95% confidence interval (95% CI) for therapy comparisons while netrank function ranked the therapies in R-Software. Meta-regression models for study characteristics were analyzed using Bayesian NMA Model. Results Overall, 50 randomized controlled studies with 2250 participants were included. NMES + TDT 3.82 (95% CI, 1.62-6.01), tDCS + TDT 3.34 (95% CI, 1.09-5.59), rTMS + TDT 3.32 (95% CI, 1.18-5.47), NMES 2.69 (95% CI, 0.44-4.93), and TDT 2.27 (95% CI, 0.12-4.41) demonstrated very large effect in improving swallowing function. NMES + TDT −0.50 (95% CI, −0.68 to −0.32, rTMS + TDT −0.44 (95% CI, −0.67 to −0.21), TDT −0.28 (95% CI, −0.46 to −0.10), and NMES −0.19 (95% CI, −0.34 to −0.04) demonstrated medium to small effect in reducing pharyngeal transit time (PTT). rTMS −0.51 (95% CI, −0.93 to −0.08) demonstrated medium effect in reducing oral transit time (OTT). No significant therapy comparison differences were found for reducing aspiration/penetration. The highest ranked therapy was NMES + TDT for better swallowing function and reduction of PTT, rTMS for reduction of OTT, and tDCS + TDT for reduction of aspiration/penetration. Therapeutic effects of the therapies were moderated by frequency, sessions, and duration. Conclusion Combined therapies including NMES + TDT, tDCS + TDT, and rTMS + TDT demonstrate better therapeutic effect for improved swallowing function and reduction of PTT, OTT, and aspiration/penetration for PSD.

The effectiveness of transcranial magnetic stimulation for dysphagia in stroke patients: an umbrella review of systematic reviews and meta-analyses

“…Of the 19 studies included in the analysis, eight SRs investigated the effectiveness of rTMS on post-stroke dysphagia rehabilitation ( Liao et al, 2017 ; Papadopoulou et al, 2018 ; Yang et al, 2021 ; Li H. et al, 2022 ; Qiao et al, 2022 ; Wen et al, 2022 ; Xie et al, 2022a ; Hsiao et al, 2023 ) and 11 investigated various therapeutic methods on the topic, including rTMS ( Yang et al, 2015 ; Pisegna et al, 2016 ; Bath et al, 2018 ; Chiang et al, 2018 ; Cheng et al, 2021 ; Li et al, 2021 ; Wang et al, 2021 ; Balcerak et al, 2022 ; Tan et al, 2022 ; Zhu and Gu, 2022 ; Banda et al, 2023 ). For the specific focus of this umbrella review, from the latter studies, only the information pertaining to the use of rTMS for the treatment of dysphagia post-stroke was analyzed.…”

“…Regarding the impact on swallowing ability, 12 studies reported large effects of rTMS compared to control conditions ( Yang et al, 2015 ; Liao et al, 2017 ; Chiang et al, 2018 ; Li et al, 2021 ; Wang et al, 2021 ; Li H. et al, 2022 ; Qiao et al, 2022 ; Tan et al, 2022 ; Wen et al, 2022 ; Xie et al, 2022a ; Zhu and Gu, 2022 ; Banda et al, 2023 ), two studies found moderate effects ( Pisegna et al, 2016 ; Cheng et al, 2021 ), one study found marginal effects ( Yang et al, 2021 ) and one study reported that rTMS improved swallowing ability -however, the finding could be due to chance, considering no subgroup differences and heterogeneity ( Bath et al, 2018 ).…”

“…Regarding pharyngeal transit time (PPT) and oral transit time (OTT), one study did not find improvements ( Banda et al, 2023 ). With regards to penetration/aspiration, two studies found large effects of rTMS ( Li et al, 2021 ; Xie et al, 2022a ), two studies did not report any benefits ( Bath et al, 2018 ; Banda et al, 2023 ), and one study reported no effects on HF-rTMS applied on the ipsilesional cortex and a medium effect of LF rTMS applied on the contralesional cortex immediately after intervention but not at 4-week follow-up ( Hsiao et al, 2023 ).…”

“…Regarding pharyngeal transit time (PPT) and oral transit time (OTT), one study did not find improvements ( Banda et al, 2023 ). With regards to penetration/aspiration, two studies found large effects of rTMS ( Li et al, 2021 ; Xie et al, 2022a ), two studies did not report any benefits ( Bath et al, 2018 ; Banda et al, 2023 ), and one study reported no effects on HF-rTMS applied on the ipsilesional cortex and a medium effect of LF rTMS applied on the contralesional cortex immediately after intervention but not at 4-week follow-up ( Hsiao et al, 2023 ). Importantly, the study of Xie et al (2022a) , after performing a subgroup analysis of penetration/aspiration, found that bilateral stimulation may produce better therapeutic effects on overall swallowing function in comparison to ipsilesional/contralesional stimulation and that LF-rTMS treatment produced better effects on overall swallowing function than HF-rTMS treatment.…”

“…Table 1 reports on the assessment of methodological quality for the 19 studies conducted using the AMSTAR 2 tool ( Shea et al, 2017 ). Two studies ( Tan et al, 2022 ; Banda et al, 2023 ), received low quality ratings, while the remaining (17), were rated with critically low quality. Furthermore, nine SRs did not incorporate mean scores and standard deviations for both the rTMS and control groups in their MAs (see Supplementary material 4 ).…”