Effect of repetition of rTMS at different frequencies on the efficacy of swallowing disorders after stroke: A systematic review and meta-analysis

BACKGROUND: To systematically evaluate the curative effect of repeated transcranial magnetic stimulation at different frequencies on swallowing disorders after stroke. METHODS: A search was conducted for randomized controlled trials of repeated transcranial magnetic stimulation for stroke patients in CNKI, Wanfang, VIP, ProQuest, PubMed, Cochrane Library, Scopus, and Web of Science databases until December 2022. The 2 researchers strictly screened and checked the included documents, extracted relevant data, assessed the risk quality of the literature using the Cochrane manual, and conducted a network meta-analysis of the data using State16.0. RESULTS: Eighteen studies included 680 participants. The results of the reticular meta-analysis showed that in the leakage-aspiration scale (PAS) indicators, 1 Hz, 3 Hz, 5 Hz, and 10 Hz were all better treatment effects compared with the control group, and there was a statistically significant difference (P < .05). In the standard swallowing function assessment (SSA) index, 3 Hz, 5 Hz, and 10 Hz compared with the control group were statistically significant (P < .05); there was no difference between 1 Hz and the control group (P > .05). The cumulative probability ranking results showed that the intervention effect of 3 Hz was the best in the PAS index, much greater than that of other frequencies, and the intervention effects of 10 Hz and 5 Hz were similar. For the SSA index, the intervention effect was optimal at 10 Hz, followed by 5 Hz. Note that the treatment effect of 1 Hz ranked last, even lower than that of the control group. The results of the 5 Hz treatment site grouping analysis showed that the affected side was > bilateral > healthy in PAS and > bilateral > healthy in SSA. CONCLUSION SUBSECTIONS: Based on the current study, the optimal frequency and site selection results of the 2 evaluation indicators are not uniform, but from the combination of the 2 evaluation indicators, the treatment effect of 10H is good, and the effect of bilateral stimulation for the selection of stimulation sites is good. The above conclusions need to be verified in high-quality studies.