Effect of Repetitive Transcranial Magnetic Stimulation on Post-stroke Dysphagia: A Meta-analysis of Stimulation Frequency, Stimulation Site, and Timing of Outcome Measurement

Repetitive Transcranial Magnetic Stimulation Strategies for Poststroke Dysphagia: A Systematic Review and Network Meta-analysis

OBJECTIVE

Repetitive transcranial magnetic stimulation (rTMS) is a promising approach in improving swallowing function after stroke. However, comparative efficacy of different rTMS protocols for poststroke dysphagia (PSD) remains unclear.

DATA SOURCES

PubMed, Embase, and Cochrane database were systematically searched for eligible random controlled trials (RCTs) from inception to August 30, 2024.

STUDY SELECTION

RCTs comparing rTMS with control or head-to-head comparisons of 2 rTMS protocols in patients with PSD.

DATA EXTRACTION

Data were extracted by 2 independent reviewers. A network meta-analysis combining direct and indirect evidence was conducted to assess the pooled findings of RCTs with standard mean difference (SMD) with 95% credible interval (CrI).

DATA SYNTHESIS

Eighteen RCTs involving 760 participants (mean age of 62.4 [range 49.7-74.7] years; 45.7% women) were included. Pooled data showed that high frequency (HF)/ipsilesional hemisphere (ipsi-hemi) (SMD, -0.94; 95% CrI, -1.51 to -0.44), HF/bilateral hemisphere (bi-hemi) (SMD, -2.59; 95% CrI, -3.50 to -1.72), HF/ipsilesional cerebellar (ipsi-CRB) (SMD, -0.79; 95% CrI, -1.55 to -0.10), HF/bilateral cerebellar (bi-CRB) (SMD, -1.02; 95% CrI, -1.83 to -0.29), and HF/ipsi-hemi + low frequency (LF)/contralesional hemisphere (contra-hemi) (SMD, -2.72; 95% CrI, -4.12 to -1.41) rTMS all significantly improved swallowing function compared with control. For patients with acute stroke, HF/ipsi-hemi rTMS had a positive effect (SMD, -1.36; 95% CrI, -2.86 to -0.02); in subacute stage, HF/ipsi-hemi + LF/contra-hemi rTMS showed the best efficacy (SMD, -2.68; 95% CrI, -4.26 to -1.26). However, rTMS failed to improve swallowing function in chronic stage.

CONCLUSIONS

This network meta-analysis showed that most of the rTMS protocols (HF/ipsi-hemi, HF/bi-hemi, HF/ipsi-CRB, HF/bi-CRB, and HF/ipsi-hemi + LF/contra-hemi) may improve swallowing function in patients with PSD. The HF/ipsi-hemi rTMS had a positive effect in acute stage and the HF/ipsi-hemi + LF/contra-hemi protocol seemed to have the best efficacy when applied in subacute stroke.

The relationship between oropharyngeal dysphagia and dehydration in older adults

BACKGROUND

Relationship between dysphagia and dehydration has not been studied widely. The aim of this study is to determine the frequency of dysphagia and dehydration in geriatric outpatient clinic, to evaluate the relationship between these two conditions.

METHODS

The cross-sectional study included 1345 patients. Plasma osmolarity (Posm) was calculated using the following formula: [1.86 x (Na + K) + 1.15 x glucose + urea + 14]. Overt dehydration was defined as a calculated Posm of > 300 mmol/L. Eating Assessment Tool (EAT-10) score of ≥ 3 was accepted as dysphagia. Associations between dehydration and dysphagia was evaluated.

RESULTS

Mean age was 78 ± 8 years, and 71% were females. Dysphagia was observed in 27% of patients. Dysphagia was associated with a higher number of drug exposure, dependency on basic activities of daily living and geriatric depression (p < 0.05). Overt dehydration was found in 29% of patients with dysphagia, and 21% of patients with no dysphagia (p = 0.002); and dysphagia was significantly associated with overt dehydration mmol/L (OR 1.49, 95% CI 1.13-1.96, p = 0.005) after adjustments for age and sex. In another model, EAT-10 score was found as one of the independent predictors of overt dehydration (OR1.03, 95% CI 1.00-1.06, p = 0.38), along with diabetes mellitus (OR 2.32, 95% CI 1.72-3.15, p < 0.001), chronic kidney disease (OR 3.05, 95% CI 2.24-4.15, p < 0.001), and MNA score (OR 0.97, 95% CI 0.94-1.00, p = 0.031).

CONCLUSION

EAT-10 scale was independently associated with overt dehydration among older adults, as MNA score was. Correction of both dysphagia and malnutrition might improve overt dehydration to a better extent than correction either of these factors alone. Future studies are needed to test cause and effect relationships.

Repetitive transcranial magnetic stimulation as a therapy for post-stroke dysphagia: An overview of systematic reviews and meta-analysis

OBJECTIVE

Post-stroke dysphagia is a common swallowing disorder that occurs after a stroke, leading to an increased risk of aspiration pneumonia and malnutrition. There is a pressing need for effective and safe interventions for its rehabilitation. This review aims to answer two key scientific questions: (1) What is the efficacy of repetitive transcranial magnetic stimulation in the rehabilitation of post-stroke dysphagia? (2) Is repetitive transcranial magnetic stimulation a safe intervention for post-stroke dysphagia?

DATA SOURCES

A comprehensive search was conducted across four electronic databases: PubMed, Cochrane Library, Web of Science, and Embase. The search aimed to identify relevant studies concerning our topic of interest and was completed on 28 May 2024.

REVIEW METHODS

In accordance with the PRISMA checklist, a comprehensive search of four databases was conducted, which identified 13 relevant systematic reviews. The inclusion criteria were systematic reviews that evaluated the efficacy and safety of repetitive transcranial magnetic stimulation for post-stroke dysphagia. Exclusion criteria were reviews that did not focus on post-stroke dysphagia or did not evaluate repetitive transcranial magnetic stimulation as a therapeutic intervention. The quality, bias, reporting, and overall evidence quality of these reviews were assessed using validated tools, including the AMSTAR 2 tool for assessing the methodological quality of systematic reviews, the ROBIS tool for assessing the risk of bias, and the GRADE approach for evaluating the overall quality of evidence. This rigorous approach ensures that our review provides a comprehensive and reliable overview of the current state of knowledge on the use of repetitive transcranial magnetic stimulation for post-stroke dysphagia.

RESULTS

The sample sizes for the individual studies included in the systematic reviews/meta-analyses ranged from 66 to 555. The total number of participants across all studies included in the overall analyses was 752. The evidence was limited by the methodological flaws and heterogeneity of the systematic reviews. The quality of the evidence varied from high to low, with most outcomes having moderate quality. Future research should adopt more rigorous, standardized, and comprehensive designs to confirm the efficacy and safety of repetitive transcranial magnetic stimulation for post-stroke dysphagia. The main reason for downgrading the evidence quality was the small sample size and high heterogeneity of the primary studies.

CONCLUSION

This overview synthesized research on repetitive transcranial magnetic stimulation for dysphagia, aiming to inform clinical and policy decisions. However, the current evidence does not conclusively establish the safety and efficacy of repetitive transcranial magnetic stimulation for post-stroke dysphagia rehabilitation. The studies reviewed varied in quality, and many were of poor quality. Therefore, while some studies suggest potential benefits of repetitive transcranial magnetic stimulation, these findings should be interpreted with caution. There is a pressing need for more rigorous, high-quality research to validate the use of repetitive transcranial magnetic stimulation for post-stroke dysphagia rehabilitation. The implications of these findings for clinical practice and policy will be clearer once we have more robust, evidence-based recommendations.

Global research trends in transcranial magnetic stimulation for stroke (1994-2023): promising, yet requiring further practice

Background

Scholars have been committed to investigating stroke rehabilitation strategies over many years. Since its invention, transcranial magnetic stimulation (TMS) has been increasingly employed in contemporary stroke rehabilitation research. Evidence has shown the significant potential of TMS in stroke research and treatment.

Objective

This article reviews the research conducted on the use of TMS in stroke from 1994 to 2023. This study applied bibliometric analysis to delineate the current research landscape and to anticipate future research hotspots.

Method

The study utilized the Web of Science Core Collection to retrieve and acquire literature data. Various software tools, including VOSviewer (version 1.6.19), CiteSpace (version 6.3.R1), Scimago Graphica (version 1.0.36), and WPS (version 11572), were used for data analysis and visualization. The review included analyses of countries, institutions, authors, journals, articles, and keywords.

Results

A total of 3,425 articles were collected. The top three countries in terms of publication output were the United States (953 articles), China (546 articles), and Germany (424 articles). The United States also had the highest citation counts (56,764 citations), followed by Germany (35,211 citations) and the United Kingdom (32,383 citations). The top three institutions based on the number of publications were Harvard University with 138 articles, the University of Auckland with 81 articles, and University College London with 80 articles. The most prolific authors were Abo, Masahiro with 54 articles, Fregni, Felipe with 53 articles, and Pascual-Leone, Alvaro with 50 articles. The top three journals in terms of article count were Neurorehabilitation and Neural Repair with 139 articles, Clinical Neurophysiology with 128 articles, and Frontiers in Neurology with 110 articles. The most frequently occurring keywords were stroke (1,275 occurrences), transcranial magnetic stimulation (1,119 occurrences), and rehabilitation (420 occurrences).

Conclusion

The application of TMS in stroke research is rapidly gaining momentum, with the USA leading in publications. Prominent institutions, such as Harvard University and University College London, show potential for collaborative research. The key areas of focus include post-stroke cognitive impairment, aphasia, and dysphagia, which are expected to remain significant hotspots in future research. Future research should involve large-scale, randomized, and controlled trials in these fields. Additionally, identifying more effective combined therapies with rTMS should be a priority.

Clinical implementation, barriers, and unmet needs of rTMS and neuro-navigation systems in stroke rehabilitation: a nationwide survey in South Korea

Objective

The objective of this study was to determine the implementation, clinical barriers, and unmet needs of repetitive transcranial magnetic stimulation (rTMS) and neuro-navigation systems for stroke rehabilitation.

Design

We employed a nationwide survey via Google Forms (web and mobile) consisting of 36 questions across rTMS and neuro-navigation systems, focusing on their implementation, perceptions, and unmet needs in stroke recovery. The survey targeted physiatrists registered in the Korean Society for Neuro-rehabilitation and in rehabilitation hospitals in South Korea.

Results

Of 1,129 surveys distributed, 122 responses were analyzed. Most respondents acknowledged the effectiveness of rTMS in treating post-stroke impairments; however, they highlighted significant unmet needs in standardized treatment protocols, guidelines, education, device usability, and insurance coverage. Unmet needs for neuro-navigation were also identified; only 7.4% of respondents currently used such systems, despite acknowledging their potential to enhance treatment accuracy. Seventy percent of respondents identified lack of prescription coverage, time and errors in preparation, and device cost as barriers to clinical adoption of neuro-navigation systems.

Conclusion

Despite recognition of the potential of rTMS in stroke rehabilitation, there is a considerable gap between research evidence and clinical practice. Addressing these challenges, establishing standardized protocols, and advancing accessible neuro-navigation systems could significantly enhance the clinical application of rTMS, offering a more personalized, effective treatment modality for stroke recovery.

Dysphagia after stroke: research advances in treatment interventions

After a stroke, most patients have dysphagia, which can lead to aspiration pneumonia, malnutrition, and adverse functional outcomes. Protective interventions aimed at reducing these complications remain the cornerstone of treatment. Dietary adjustments and oral hygiene help mitigate the risk of aspiration pneumonia, and nutritional supplementation, including tube feeding, might be needed to prevent malnutrition. Rehabilitative interventions aim to enhance swallowing function, with different behavioural strategies showing promise in small studies. Investigations have explored the use of pharmaceutical agents such as capsaicin and other Transient-Receptor-Potential-Vanilloid-1 (TRPV-1) sensory receptor agonists, which alter sensory perception in the pharynx. Neurostimulation techniques, such as transcranial direct current stimulation, repetitive transcranial magnetic stimulation, and pharyngeal electrical stimulation, might promote neuroplasticity within the sensorimotor swallowing network. Further advancements in the understanding of central and peripheral sensorimotor mechanisms in patients with dysphagia after a stroke, and during their recovery, will contribute to optimising treatment protocols.

Effects of Cerebellar Repetitive Transcranial Magnetic Stimulation in the Treatment of Post-Stroke Dysphagia: A Meta-Analysis and Systematic Review of Randomized Controlled Trials

INTRODUCTION

This study aimed to comprehensively evaluate the therapeutic efficacy of cerebellar repetitive transcranial magnetic stimulation (rTMS) in the rehabilitation of post-stroke dysphagia (PSD).

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we systematically searched PubMed, Cochrane Library, Embase, and Web of Science to identify relevant randomized controlled trials (RCTs) investigating the application of cerebellar rTMS in the treatment of PSD. Inclusion and exclusion criteria were rigorously applied during the screening process, and pertinent characteristics of the included RCTs were meticulously extracted. The I2 statistic was employed to assess heterogeneity, and meta-analysis was conducted using Stata 17 software. The Cochrane Risk of Bias 2 tool and PEDro scale were utilized to evaluate bias risk and literature quality.

RESULTS

Our analysis encompassed a total of 5 RCTs involving 673 patients with dysphagia who met the inclusion criteria. The findings indicated a significant positive impact of cerebellar rTMS when combined with traditional swallowing exercises on PSD, demonstrating superior efficacy compared to conventional swallowing exercises in isolation. Furthermore, the study revealed no statistically significant differences based on stimulation site (unilateral vs. bilateral cerebellum), stimulation mode (rTMS vs. intermittent theta-burst stimulation), and stimulation frequency (5 Hz vs. 10 Hz).

CONCLUSION

The amalgamation of cerebellar rTMS with conventional swallowing exercises demonstrates notable efficacy, surpassing the outcomes achievable with traditional exercises alone. The sustained effectiveness observed underscores the potential of cerebellar rTMS as an innovative avenue in the field of neurorehabilitation for PSD. This study contributes valuable insights into the prospect of utilizing cerebellar rTMS as an adjunctive therapeutic strategy in the management of PSD, emphasizing its relevance for further exploration and clinical application.

Repetitive Transcranial Magnetic Stimulation in Stroke: A Literature Review of the Current Role and Controversies of Neurorehabilitation Through Electromagnetic Pulses

Repetitive transcranial magnetic stimulation (rTMS) is an effective method used for the treatment of various neurological diseases, including stroke, epilepsy, and movement disorders. The pathophysiological mechanism for the effect of TMS is not clear. In this literature review, we conducted a detailed search regarding the effect of rTMS on neurotransmission and neuronal plasticity through the modulation of neuronal excitability. Evidence suggests that intramolecular subatomic mechanisms, including genetic changes related to neuronal prevention and death, play an important role. We also discuss the use of rTMS in the rehabilitation of patients with stroke and its main complications, as well as alternative mechanisms related to recovery, emphasizing the findings of available evidence and touching on possible controversies and limitations of the method.