Comparative efficacy of non-invasive neurostimulation therapies for poststroke dysphagia: A systematic review and meta-analysis

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.

The effects of repetitive transcranial magnetic and transcranial direct current stimulation on memory functions in older adults with mild cognitive impairment: a systematic review and meta-analysis

Mild cognitive impairment (MCI) is a condition that impairs activities of daily living, and often transforms to dementia. Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) show promise in improving cognitive functions in MCI patients. In this meta-analysis, we aimed to compare the effects of rTMS and tDCS on memory functions in MCI patients. We explored eight databases from their inception to March 16, 2024. We obtained 11 studies with 406 patients with MCI. We used the standardized mean difference (SMD) with a 95% confidence interval (CI) to synthesize the effect size. rTMS and tDCS significantly improved memory functions in MCI patients (SMD = 0.61; 95% CI: 0.41-0.82; p < 0.00001; I2 = 22%). In subgroup analysis of number of stimulation sessions, both rTMS and tDCS over 10 sessions (SMD = 0.84; 95% CI: 0.50-1.17, p < 0.00001, I2 = 0%) significantly improved the memory function in MCI patients. The subgroup analyses on different stimulation types (SMD = 0.78; 95% CI: 0.51-1.06; p < 0.00001; I2 = 0%) and treatment persistent effects (SMD = 0.93; 95% CI: 0.51-1.35, p < 0.0001, I2 = 0%) showed that rTMS was more effective than tDCS. rTMS with a stimulation frequency of 10 Hz (SMD = 0.86; 95% CI: 0.51-1.21; p < 0.00001; I2 = 0%) and over 10 sessions (SMD = 0.98; 95% CI: 0.58-1.38; p < 0.00001; I2 = 0%) at multiple sites (SMD = 0.97; 95% CI: 0.44-1.49; p = 0.0003; I2 = 0%) showed a great improvement in the memory performance of patients with MCI. rTMS was more likely to appear temporary side effects (risk ratio (RR) = 3.18, 95% CI: 1.29-7.83, p = 0.01). This meta-analysis suggests that rTMS and tDCS are safe and efficient tools to improve memory functions in patients with MCI, while rTMS had a larger effect than tDCS. rTMS with a stimulation frequency of 10 Hz targeted on multiple sites over 10 sessions showed the greatest effect. We could not conclude parameters of tDCS because of insufficient data.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024558991.

New and Evolving Treatments for Neurologic Dysphagia

Despite swallowing being a frequently performed daily function, it is highly complex. For a safe swallow to occur, muscles within the head, neck, and thorax need to contract in a concerted pattern, controlled by several swallowing centers at multiple levels of the central nervous system, including the midbrain, cerebral cortex, and cerebellum in addition to five cranial nerves. Dysphagia, or difficulty swallowing, is caused by a long list of pathologic processes and diseases, which can interfere with various stages along the swallowing sensorimotor pathway. When present, dysphagia leads to increased mortality, morbidity, hospital length of stay, and reduced quality of life. Current dysphagia management approaches, such as altering the texture and consistency of foods and fluids and teaching patients rehabilitative exercises, have been broadly unchanged for many years and, in the case of texture modification, are of uncertain effectiveness. However, evidence is emerging in support of new medication-based and neuromodulatory treatment approaches. Regarding medication-based therapies, most research has focused on capsaicinoids, which studies have shown are able to improve swallowing in patients with post-stroke dysphagia. Separately, albeit convergently, in the field of neuromodulation, there is a growing and positive evidential base behind three non-invasive brain stimulation techniques: repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (TDCS), and pharyngeal electrical stimulation (PES). Should some or all of these emerging therapies fulfill their promise, dysphagia-related patient outcomes may be improved. This paper describes the current state of our understanding regarding new medication and neuromodulation-based neurogenic oropharyngeal dysphagia treatments.

Research hotspot and frontiers in post-stroke dysphagia: A bibliometric study and visualisation analysis

BACKGROUND

Dysphagia, a common complication after stroke, significantly hampers the recovery process of patients, both due to dysphagia itself and the additional complications it causes. Although a large number of articles have been published on post-stroke dysphagia (PSD), bibliometric analysis in this field is still lacking. This study aimed to provide a comprehensive understanding of the research hotspots and trends in PSD, thereby guiding future research efforts.

METHODS

The Web of Science Core Collection (WoSCC) database was searched for articles related to PSD from 2003 to 2022. Data were visualised and analysed using CiteSpace and VOSviewer.

RESULTS

A total of 3102 publications were included in the scientometric analysis, with a gradual increase in the number of papers published each year. The United States emerged as the country with the highest number of publications (625 articles), while the University of Manchester led with the most publications among institutions (67 articles). Notably, Dysphagia was both the most published (254 articles) and the most cited journal (11,141 citations). Among authors, Hamdy S emerged as the most prolific (52 articles), with Martino R being the most cited (1042 citations).

CONCLUSION

Based on our findings, we anticipate that research hotspots in PSD will mainly focus on complications due to PSD such as stroke-associated pneumonia, stroke-related sarcopenia. Additionally, exploration into the mechanisms and parameters of noninvasive brain stimulation techniques for the treatment of PSD, as well as the rehabilitation needs of patients with PSD, are expected to be key focal points in future research endeavours.

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.

Efficacy of non-invasive brain stimulation for post-stroke dysphagia: a meta-analysis

BACKGROUND

Given the potential harms of dysphagia after stroke, we noticed the possibility of non-invasive brain stimulation treatments in the management process.

METHODS

The meta-analysis search for articles published before May 2023 in databases. We used STATA 12.0 software to compute the standard mean difference (SMD) and 95% confidence intervals (CI).

RESULTS

The study showed a greater improvement in swallowing function in post-stroke dysphagia given transcranial direct current stimulation (tDCS) immediately after treatment, compared to those given sham tDCS (SMD = 2.99, 95% CI = 1.86-4.11). The study showed a greater improvement in swallowing function in post-stroke dysphagia given tDCS some days after treatment, compared to those given sham tDCS (SMD = 2.01, 95% CI = 0.87-3.16). The study showed a greater improvement in swallowing function in post-stroke dysphagia given repetitive transcranial magnetic stimulation (rTMS) immediately after treatment, compared to those given sham rTMS (SMD = 4.17, 95% CI = 3.11-5.23). The study showed a greater improvement in swallowing function in post-stroke dysphagia given rTMS some days after treatment, compared to those given sham rTMS (SMD = 1.77, 95% CI = 0.94-2.60).

CONCLUSIONS

In conclusion, our study showed the beneficial effects of non-invasive brain stimulation on difficulty swallowing for stroke patients and speculated about the potential application of non-invasive brain stimulation on post-stroke dysphagia improvement.

Efficacy and safety of non-invasive brain stimulation on cognitive function for cognitive impairment associated with schizophrenia: A systematic review and meta-analysis

Based on existing evidence of the effects of the most commonly used non-invasive brain stimulation (NIBS), which includes transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), we conducted a meta-analysis to investigate the cognitive improvement and safety of NIBS on schizophrenia-related cognitive impairment. PubMed, EMBASE, Cochrane Library, and Web of Science were searched. The Cochrane Risk of Bias tool was used to assess the risk of bias of the included RCTs; Review Manager, version 5.4.1, was used to perform the statistical analysis. Twenty double-blind, randomized, sham-controlled trials involving 997 patients were included. As a result, no significant improvement in cognitive function was observed after NIBS treatment. However, the overall treatment effect of the two main NIBS modes (i.e., rTMS and tDCS) was associated with significantly larger improvements in negative symptoms and good tolerability in patients with schizophrenia compared to sham-controls (SMD = -0.56, 95% CI [-1.03, -0.08], p = 0.02, I2 = 88%). NIBS model and stimulus parameters influenced the effect of NIBS. More favorable effects were observed in patients who received rTMS stimulation (SMD = 0.25, 95% CI [0.01, 0.49], p = 0.04, I2 = 0%) in the left dorsolateral prefrontal cortex with a stimulation intensity of 20 Hz (p = 0.004) for a period longer than 1 month (p < 0.05). Yet, due to the limited number of included studies and heterogeneity in both study design and target population, the results of this analysis need to be interpreted with caution.

A translational roadmap for transcranial magnetic and direct current stimulation in stroke rehabilitation: Consensus-based core recommendations from the third stroke recovery and rehabilitation roundtable

BACKGROUND AND AIMS

The purpose of this Third Stroke Recovery and Rehabilitation Roundtable (SRRR3) was to develop consensus recommendations to address outstanding barriers for the translation of preclinical and clinical research using the non-invasive brain stimulation (NIBS) techniques Transcranial Magnetic Stimulation (TMS) and Transcranial Direct Current Stimulation (tDCS) and provide a roadmap for the integration of these techniques into clinical practice.

METHODS

International NIBS and stroke recovery experts (N = 18) contributed to the consensus process. Using a nominal group technique, recommendations were reached via a five-stage process, involving a thematic survey, two priority ranking surveys, a literature review and an in-person meeting.

RESULTS AND CONCLUSIONS

Results of our consensus process yielded five key evidence-based and feasibility barriers for the translation of preclinical and clinical NIBS research, which were formulated into five core consensus recommendations. Recommendations highlight an urgent need for (1) increased understanding of NIBS mechanisms, (2) improved methodological rigor in both preclinical and clinical NIBS studies, (3) standardization of outcome measures, (4) increased clinical relevance in preclinical animal models, and (5) greater optimization and individualization of NIBS protocols. To facilitate the implementation of these recommendations, the expert panel developed a new SRRR3 Unified NIBS Research Checklist. These recommendations represent a translational pathway for the use of NIBS in stroke rehabilitation research and practice.

Effectiveness of Conventional Dysphagia Therapy (CDT), Neuromuscular Electrical Stimulation (NMES), and Transcranial Direct Current Stimulation (tDCS) in Acute Post-Stroke Dysphagia: A Comparative Evaluation

This study aims to compare the effectiveness of conventional dysphagia therapy (CDT), neuromuscular electrical stimulation (NMES), and transcranial direct current stimulation (tDCS) in the treatment of post-stroke dysphagia. A single-blind randomized controlled trial was conducted with 40 acute stroke patients - 18 females and 22 males with a mean age of 65.8 ± 11.9. The subjects were grouped into 4, with 10 individuals in each. The procedures administered to groups were as follows: the first group, sham tDCS and sham NMES; the second group, tDCS and sham NMES; the third group, NMES and sham tDCS; and the fourth group, all therapy procedures. CDT was applied to all groups either as a standalone procedure or combined with one or two of the instrumental techniques. Gugging Swallowing Screen (GUSS) and Videofluoroscopic Swallowing Study (VFSS) were employed to determine the severity of dysphagia and the effectiveness of treatment modalities. Additionally, the Penetration Aspiration Scale (PAS), Functional Oral Intake Scale (FOIS), and Dysphagia Severity Rating Scale (DSRS) were administered to interpret VFSS data. Pre- and post-treatment comparisons of all groups have revealed a statistically significant difference for all parameters except for the PAS scores at International Dysphagia Diet Standardization Initiative (IDDSI)-Level 4 consistencies. However, the differences between pre- and post-treatment scores of the fourth group across all parameters were significant - GUSS (p = 0.005), FOIS (p = 0.004), DSRS (p = 0.005), PAS IDDSI-4 (p = 0.027), PAS IDDSI-0 (p = 0.004). Inter-group comparisons, on the other hand, pointed out that the difference between pre- and post-treatment GUSS, FOIS, DSRS, and PAS scores at IDDSI Level-0 consistencies was statistically significant for all groups - GUSS (p = 0,009), FOIS (p = 0,004), DSRS (p = 0,002), PAS IDDSI-0 (p = 0,049). Closer examination of treatment groups indicated that the tDCS + CDT group, the NMES + CDT group, and the group that underwent the combination of three modalities made better progress than the one that was treated with only CDT. Though not statistically significant, the NMES + CDT group achieved better improvement than the tDCS + CDT group. This study has yielded that the group in which NMES, tDCS, and CDT were applied in combination has achieved better results than all the other groups. All treatment modalities applied to accelerate the general recovery process in acute stroke patients with dysphagia were found to be effective for the treatment of post-stroke swallowing disorders. The use of instrumental treatments such as NMES and tDCS enhanced the effectiveness of the treatment and provided more significant progress. Furthermore, combining treatment modalities such as NMES and tDCS was more effective when compared to using only conventional therapy. As a result, the most effective treatment outcomes were obtained by the group receiving CDT, NMES, and tDCS in combination. Therefore, the use of combined approaches has been recommended in appropriate patients; yet the provisional results should be tested in randomized trials with more participants.

Is the Combination of Robot-Assisted Therapy and Transcranial Direct Current Stimulation Useful for Upper Limb Motor Recovery? A Systematic Review with Meta-Analysis

Stroke is the third leading cause of disability in the world, and effective rehabilitation is needed to improve lost functionality post-stroke. In this regard, robot-assisted therapy (RAT) and transcranial direct current stimulation (tDCS) are promising rehabilitative approaches that have been shown to be effective in motor recovery. In the past decade, they have been combined to study whether their combination produces adjuvant and greater effects on stroke recovery. The aim of this study was to estimate the effectiveness of the combined use of RATs and tDCS in the motor recovery of the upper extremities after stroke. After reviewing 227 studies, we included nine randomised clinical trials (RCTs) in this study. We analysed the methodological quality of all nine RCTs in the meta-analysis. The analysed outcomes were deficit severity, hand dexterity, spasticity, and activity. The addition of tDCS to RAT produced a negligible additional benefit on the effects of upper limb function (SMD -0.09, 95% CI -0.31 to 0.12), hand dexterity (SMD 0.12, 95% CI -0.22 to 0.46), spasticity (SMD 0.04, 95% CI -0.24 to 0.32), and activity (SMD 0.66, 95% CI -1.82 to 3.14). There is no evidence of an additional effect when adding tDCS to RAT for upper limb recovery after stroke. Combining tDCS with RAT does not improve upper limb motor function, spasticity, and/or hand dexterity. Future research should focus on the use of RAT protocols in which the patient is given an active role, focusing on the intensity and dosage, and determining how certain variables influence the success of RAT.

A translational roadmap for transcranial magnetic and direct current stimulation in stroke rehabilitation: Consensus-based core recommendations from the third stroke recovery and rehabilitation roundtable

BACKGROUND AND AIMS

The purpose of this Third Stroke Recovery and Rehabilitation Roundtable (SRRR3) was to develop consensus recommendations to address outstanding barriers for the translation of preclinical and clinical research using the non-invasive brain stimulation (NIBS) techniques Transcranial Magnetic Stimulation (TMS) and Transcranial Direct Current Stimulation (tDCS) and provide a roadmap for the integration of these techniques into clinical practice.

METHODS

International NIBS and stroke recovery experts (N = 18) contributed to the consensus process. Using a nominal group technique, recommendations were reached via a five-stage process, involving a thematic survey, two priority ranking surveys, a literature review and an in-person meeting.

RESULTS AND CONCLUSIONS

Results of our consensus process yielded five key evidence-based and feasibility barriers for the translation of preclinical and clinical NIBS research, which were formulated into five core consensus recommendations. Recommendations highlight an urgent need for (1) increased understanding of NIBS mechanisms, (2) improved methodological rigor in both preclinical and clinical NIBS studies, (3) standardization of outcome measures, (4) increased clinical relevance in preclinical animal models, and (5) greater optimization and individualization of NIBS protocols. To facilitate the implementation of these recommendations, the expert panel developed a new SRRR3 Unified NIBS Research Checklist. These recommendations represent a translational pathway for the use of NIBS in stroke rehabilitation research and practice.

Effectiveness of antidepressant repetitive transcranial magnetic stimulation in a patient with refractory psychogenic dysphagia: A case report and review of literature

BACKGROUND

Dysphagia is a common condition in older as well as young patients, and a variety of treatments have been reported depending on the cause. However, clinicians are challenged when the cause is unclear. This is the case with psychogenic dysphagia, which has typically been treated with supportive psychotherapy, medication, swallowing exercise, and dysphagia rehabilitation therapy. Here, we aimed to relieve the symptoms of a patient with refractory psychogenic dysphagia, who was unresponsive to conventional swallowing therapy, with repetitive transcranial magnetic stimulation (rTMS).

CASE SUMMARY

A relatively calm-looking 35-year-old female patient presented with a 2-year history of dysphagia. She showed little improvement with conventional swallowing treatments over the past 2 years. She was relatively compliant with in-hospital dysphagia therapy, but uncooperative with home exercise and medication. In particular, since she was resistant to drug treatment, we had to take a different approach than the treatment she had been receiving for the past 2 years. After much deliberation, we decided to initiate antidepressant rTMS treatment with her consent (IRB No. 2023-05-021). Antidepressant rTMS treatment was performed twice weekly for a total of 20 sessions over 10 wk. The results showed improvement in subjective symptoms and video fluoroscopic swallowing study findings. To the best of our knowledge, this is the first report of symptomatic improvement using antidepressant rTMS protocol for refractory psychogenic dysphagia.

CONCLUSION

This case demonstrates that rTMS with antidepressant protocol can be used to improve swallowing in patients with refractory psychogenic dysphagia.

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

Dysphagia is one of the most frequent sequelae of stroke. It can result in various complications such as malnutrition, dehydration, aspiration pneumonia, and poor rehabilitation outcomes. Repetitive transcranial magnetic stimulation (rTMS) has been reported to improve dysphagia after a stroke; however, effective treatment protocols have not been established yet. We evaluated the effect of the following rTMS parameters on post-stroke dysphagia: stimulation frequency [high frequency (≥ 3 Hz) or low frequency (1 Hz)] and stimulation site (ipsilesional or contralesional mylohyoid cortex). Outcomes were measured immediately, at 3 weeks, and at 4 weeks after the rTMS session. The PubMed, SCOPUS, Embase, and Cochrane Library databases were systematically searched for relevant studies published between January 01, 1980, and December 13, 2021. Randomized controlled trials on the effects of rTMS on post-stroke dysphagia were included. Six studies were finally included in the analysis. The selected studies included 158 patients (rTMS group: 81 patients; sham group: 77 patients). Regarding the effect of high-frequency rTMS on the ipsilesional cortex, the standardized swallowing assessment (SSA) scores showed significant improvement after rTMS sessions immediately and at 4 weeks [immediate: P = 0.02, standard mean difference (SMD) =  - 0.61, 95% confidence interval (CI) =  - 1.14 to - 0.08; 4 weeks: P = 0.006, SMD =  - 0.74, 95% CI =  - 1.27 to - 0.21]; however, there was no significant reduction in the Penetration-Aspiration Scale (PAS) scores between the rTMS and sham groups (immediate: P = 0.43, SMD = 0.25, 95% CI =  - 0.36, 0.86; 3 weeks: P = 0.39, SMD = 0.37, 95% CI =  - 0.47 to 1.22). After low-frequency rTMS on the ipsilesional cortex, a significantly greater improvement in the SSA scores was found in the rTMS group than in the sham group, both immediately and at 4 weeks after rTMS sessions (immediate: P = 0.03, SMD =  - 0.59, 95% CI =  - 1.12 to - 0.06; 4 weeks: P = 0.001, SMD =  - 0.92, 95% CI =  - 1.48 to - 0.37). In addition, immediately after the rTMS sessions, the PAS scores were significantly reduced in the rTMS group than in the sham group (P = 0.047, SMD =  - 0.60, 95% CI =  - 1.19 to - 0.01). However, at 4 weeks after rTMS sessions, there was no significant reduction in the PAS scores in the rTMS group compared to the sham group (P = 0.48, SMD =  - 0.19, 95% CI =  - 0.71 to 0.33). Both high-frequency rTMS of the ipsilesional cortex and low-frequency rTMS of the contralesional cortex improved some measurements of the swallowing function in stroke patients immediately and at 4 weeks after treatment.

Update on Stroke Rehabilitation for Non-Motor Impairment

Various interventions exist to treat non-motor impairments caused by stroke. Adjuvant treatments such as non-invasive brain stimulation, virtual reality, computer-assisted training, neurostimulation, and biofeedback are being investigated and applied in the areas of cognitive dysfunction, language problems, visual disorders, dysphagia, mood disorders, and post-stroke pain. Most of these treatments have shown efficacy and symptom improvement, but further investigation is required to fully clarify their effects.

The effects of physiotherapy treatments on dysphagia in Parkinson's disease: a systematic review of randomized controlled trials

BACKGROUND

The prevalence of swallowing disorders in Parkinson's disease (PD) is relatively high. Different physiotherapy interventions for swallowing disorders are available but there is a lack of evidence-based medicine for their effectiveness in PD.

OBJECTIVE

The purpose of this systematic review was to investigate the effects of different physiotherapy interventions on dysphagia in PD.

METHODS

This systematic review was conducted according to PRISMA guidelines. We methodically searched databases including PubMed, PEDro, Cochrane Library, Embase, and Web of Science. Studies of any language published up to March 2022 were searched. Randomized controlled trials (RCTs) of non-pharmacological treatment for dysphagia in PD were selected in strict accordance with our exclusion and inclusion criteria.

RESULTS

In total, we identified and included 10 RCTs in patients with PD undergoing dysphagia. This review involved seven rehabilitation treatments, including acupuncture, expiratory muscle strength training (EMST), repetitive transcranial magnetic stimulation (rTMS), video-assisted swallowing therapy (VAST), electrical stimulation, and speech and language therapy (SLT).

CONCLUSION

For physiotherapy treatments, including acupuncture, EMST, high-frequency rTMS and VAST may be effective treatments for dysphagia in patients with PD. However, there was not enough evidence that electrical stimulation has therapeutic effects on dysphagia in patients with PD.

Evaluating the effectiveness of stepwise swallowing training on dysphagia in patients with Alzheimer's disease: study protocol for a randomized controlled trial

BACKGROUND

The high prevalence of dysphagia among Alzheimer's disease (AD) patients has become a public health and economic concern. Therefore, effective and accessible dysphagia treatments are needed. As a fundamental rehabilitation of dysphagia, swallowing muscle exercises have received increased attention. Stepwise swallowing training (SST), integrated with all swallowing organs movement, is expected to improve swallowing dysfunction among AD patients. By using a randomized controlled trial design, we propose a multi-center research to evaluate the effectiveness of SST program among AD patients.

METHODS

A multi-center exploratory randomized controlled trial, with a 4-week follow-up period, will be conducted in three major public psychiatric hospitals in Guangdong, China. Participants in the control group will be assigned to routine dysphagia care, while participants in the intervention group will undergo the same nursing care and additionally receive the SST program. The SST program includes five sections of swallowing organs training: lip movement, facial movement, tongue movement, mandibular movement, and neck movement. Primary outcomes evaluate the swallowing function, namely, Water Swallowing Test (WTS) and Standard Swallowing Assessment (SSA). Secondary outcomes aim at measuring the improvement of negative impacts of dysphagia, namely eating behavior, ability of daily activity, and nutritional status. Data will be collected at baseline (T₁), at 2 weeks (T₂, intervention), and 4 weeks after intervention (T₃, follow-up).

DISCUSSION

This study will offer trial-based evidence of the effectiveness of SST in relieving dysphagia among AD patients. SST program is expected to improve both the swallowing function and reduce the negative impacts of dysphagia, with an exploration of acceptability in the SST program.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2200056481 . Prospectively registered on 6 February 2022.

Repetitive Transcranial Magnetic Stimulation of the Primary Motor Cortex beyond Motor Rehabilitation: A Review of the Current Evidence

Transcranial magnetic stimulation (TMS) has emerged as a novel technique to stimulate the human brain through the scalp. Over the years, identifying the optimal brain region and stimulation parameters has been a subject of debate in the literature on therapeutic uses of repetitive TMS (rTMS). Nevertheless, the primary motor cortex (M1) has been a conventional target for rTMS to treat motor symptoms, such as hemiplegia and spasticity, as it controls the voluntary movement of the body. However, with an expanding knowledge base of the M1 cortical and subcortical connections, M1-rTMS has shown a therapeutic efficacy that goes beyond the conventional motor rehabilitation to involve pain, headache, fatigue, dysphagia, speech and voice impairments, sleep disorders, cognitive dysfunction, disorders of consciousness, anxiety, depression, and bladder dysfunction. In this review, we summarize the latest evidence on using M1-rTMS to treat non-motor symptoms of diverse etiologies and discuss the potential mechanistic rationale behind the management of each of these symptoms.

Transcranial magnetic stimulation versus transcutaneous neuromuscular electrical stimulation in post stroke dysphagia: A clinical randomized controlled trial

OBJECTIVES

To evaluate the efficacy of high-frequency repeated transcranial magnetic stimulation (rTMS) applied contralesionally versus transcutaneous neuromuscular electrical stimulation (TNES) in acute post-stroke dysphagic patients.

MATERIALS AND METHODS

A randomized, parallel, comparative, controlled trial was conducted on patients with acute ischemic stroke who were admitted to our department. Fifteen patients received rTMS, 15 patients received TNES, and 15 patients were recruited as a control group. Between the second and tenth days after a stroke, patients were enrolled. The study and follow-up periods were completed by all patients.

RESULTS

Among the screened patients, 45 (31.47%) right-handed patients were diagnosed with post-stroke dysphagia with a mean age of 60.53 ± 8.23 years. Immediately after intervention both rTMS and TNES groups significantly improve the swallowing disturbance questionnaire (SDQ) and penetration aspiration scale (PAS), compared to the control (p < 0.001 and p = 0.027), respectively. rTMS was more effective than TNES in reducing SDQ and PAS (p < 0.05). rTMS and TNES improved the Yale Pharyngeal Residue Severity Rating Scale (YPRSRS) significantly (p = 0.002); however, their efficacy was comparable (p > 0.05). A significant (p < 0.001) strong negative correlation was observed between the grade of weakness and all scores.

CONCLUSION

Our findings showed that high-frequency rTMS and TNES effectively improved the clinical condition of acute post-stroke dysphagic patients in terms of swallowing disturbance assessed by SDQ, pharyngeal residue assessed by YPRSRS, and the severity of penetration and aspiration events evaluated by PAS, compared to the controls. The outcomes of high-frequency rTMS were more favorable than those of TNES in terms of SDQ and PAS.

Transcranial Magnetic Stimulation for Improving Dysphagia After Stroke: A Meta-Analysis of Randomized Controlled Trials

Background

Rehabilitation of post-stroke dysphagia is an urgent clinical problem, and repetitive transcranial magnetic stimulation (rTMS) has been widely used in the study of post-stroke function. However, there is no reliable evidence-based medicine to support the effect of rTMS on post-stroke dysphagia. This review aims to evaluate the effectiveness and safety of rTMS on post-stroke dysphagia.

Methods

English-language literature published before December 20, 2021, were searched in six electronic databases. Identified articles were screened, data were extracted, and the methodological quality of included trials was assessed. Meta-analysis was performed using RevMan 5.3 software. The GRADE method was used to assess the quality of the evidence.

Results

A total of 10 studies with 246 patients were included. Meta-analysis showed that rTMS significantly improved overall swallowing function (standardized mean difference [SMD]−0.76, 95% confidence interval (CI)−1.07 to−0.46, p < 0.0001, n = 206; moderate-quality evidence), Penetration Aspiration Scale (PAS) (mean difference [MD]−1.03, 95% CI−1.51 to−0.55, p < 0.0001, n = 161; low-quality evidence) and Barthel index scale (BI) (MD 23.86, 95% CI 12.73 to 34.99, p < 0.0001, n = 136; moderate-quality evidence). Subgroup analyses revealed that (1) rTMS targeting the affected hemisphere and targeting both hemispheres significantly enhanced overall swallowing function and reduced aspiration. (2) Low-frequency rTMS significantly enhanced overall swallowing function and reduced aspiration, and there was no significant difference between high-frequency rTMS and control group in reducing aspiration (p = 0.09). (3) There was no statistical difference in the dropout rate (low-quality evidence) and adverse effects (moderate-quality evidence) between the rTMS group and the control group.

Conclusion

rTMS improved overall swallowing function and activity of daily living ability and reduced aspiration in post-stroke patients with good acceptability and mild adverse effects.

Effects of Transcranial Direct Durrent Stimulation on Post-stroke Dysphagia: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

This review aimed to systematically evaluate the effect of transcranial direct current stimulation (tDCS) on post-stroke dysphagia.

DATA SOURCES

PubMed, Cochrane Library (CENTRAL), Web of Science, VIP, CNKI, and Wanfang databases were systematically searched up to June 2021.

STUDY SELECTION

Randomized controlled trials (RCTs) on the effects of tDCS on post-stroke dysphagia DATA EXTRACTION: The extracted data included the author, country of publication, time of publication, key elements of bias risk assessment (such as randomized controlled trials and blind methods), sample size and basic information (age, course of disease, stroke location), intervention measures, treatment methods of tDCS (stimulation location, intensity, and duration), relevant outcome indicators, and relevant data (standard deviations).The Cochrane Risk of Bias Assessment Tool and PEDro Scale were used to assess the risk of bias.

DATA SYNTHESIS

Sixteen RCTs were included in this meta-analysis. Overall, the results revealed a large and statistically significant pooled effect size (0.80, CI 0.45-1.14; p<0.00001). The subgroup that explored the course of the disease yielded a large and significant effect size for the chronic phase group (0.80, CI 0.43-1.16; p<0.0001). For the stimulation intensity, 1 mA and 1.6 mA showed a moderate and significant effect sizes (0.47, CI 0.13-0.81; p=0.006 vs 1.39, CI 0.69-2.08; p<0.0001). In the subgroup analyses, the affected (0.87, CI 0.26-1.48; p=0.005) vs. unaffected (0.61, CI 0.23-0.99; p=0.002) hemisphere showed a significant result, and stimulation of the affected hemisphere had a more obvious effect. Subgroup analysis of stroke location showed that tDCS was effective for dysphagia after unilateral hemispheric stroke, bulbar paralysis, and brainstem stroke but not for dysphagia after ataxic and basal ganglia stroke. However, the subgroup analysis of stroke location revealed a significant result (0.81, CI 0.44-1.18; p<0.001).

CONCLUSION

This meta-analysis demonstrated the height and significant beneficial effect of tDCS on improving post-stroke dysphagia.

Repetitive transcranial magnetic stimulation for upper limb motor function and activities of daily living in patients with stroke: a protocol of a systematic review and Bayesian network meta-analysis

INTRODUCTION

Patients with stroke usually suffer from varying degrees of movement dysfunction, which seriously affects their quality of life, especially for the upper limb dysfunction. Therefore, this study aims to compare the effects of different repetitive transcranial magnetic stimulation (rTMS) modalities on upper limb motor function and daily activities in patients with stroke.

METHODS AND ANALYSIS

Relevant research will be collected systematically from PubMed, Web of Science, Embase, Cochrane Library, ProQuest, Wanfang Database, China National Knowledge Infrastructure and Chinese Scientific and Journal Database (VIP) about randomised controlled trials of rTMS in the stroke treatment range from the establishment to November 2020. Primary outcomes will be obtained from scales measuring the upper limb motor function like Upper Extremity Fugl-Meyer Assessment Scale, Wolf Motor Function Test, Jebsen-Taylor Hand Function Test, Action Research Arm Test and Box and Block Test. The secondary outcomes include modified Barthel Index and adverse events (such as vertigo, headache and epilepsy), with the goal of assessing patients' activities of daily living and the safety of treatment. In order to avoid personal bias in the included studies, two reviewers will conduct the data extraction and quality evaluation independently, and all data analyses will be performed by Generate Mixed Treatment comparison software V.0.14.3 and Stata V.16.0.

ETHICS AND DISSEMINATION

The network meta-analysis (NMA) in this study does not require ethical approval because the data analysis will be used only to evaluate the rTMS treatment efficacy without patients' private information. In addition, the results will be disseminated in international conference reports and peer-reviewed manuscripts.

PROSPERO REGISTRATION NUMBER

CRD42020212253.

Non-invasive brain stimulation in rehabilitation

Non-invasive brain stimulation (NIBS) has been seen more common in rehabilitation settings. It can be used for the treatment of stroke, spinal cord injury, traumatic brain injury and multiple sclerosis, as well as for some diagnostic neurophysiological measurements. Two major modalities of NIBS are transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). As an add-on therapy to conventional rehabilitative treatments, the main goal of NIBS is to create neuromodulation by inhibiting or activating neural activity in the targeted cortical region. Indications for therapeutic NIBS in neurorehabilitation are motor recovery, aphasia, neglect, dysphagia, cognitive disorders, spasticity, and central pain. The NIBS can be regarded a safe technique with appropriate patient selection and defined treatment parameters. This review provides an overview on NIBS modalities, specifically TMS and tDCS, the working mechanisms, the stimulation techniques, areas of use, neuronavigation systems and safety considerations.

Scoping review to identify and map non-pharmacological, non-surgical treatments for dysphagia following moderate-to-severe acquired brain injury

INTRODUCTION

Dysphagia is a common and critical consequence of acquired brain injury (ABI) and can cause severe complications. Dysphagia rehabilitation is transforming from mainly compensatory strategies to the retraining of swallowing function using principles from neuroscience. However, there are no studies that map interventions available to retrain swallowing function in patients with moderate-to-severe ABI.

OBJECTIVE

To systematically map the accessible research literature to answer the research question: Which non-surgical, non-pharmacological interventions are used in the treatment of dysphagia in patients with moderate and severe ABI in the acute and subacute phase? DESIGN: Scoping review based on the methodology of Arksey and O'Malley and methodological advancement by Levac et al. DATA SOURCES: MEDLINE, Embase, Cochrane Library, CINAHL, PsycINFO, Web of Science, OTseeker, speechBITE and PEDro were searched up until 14 March 2021.

ELIGIBILITY CRITERIA

All studies reporting rehabilitative interventions within 6 months of injury for patients with moderate-to-severe ABI and dysphagia were included.

DATA EXTRACTION AND SYNTHESIS

Data was extracted by two independent reviewers and studies were categorised based on treatment modality.

RESULTS

A total of 21 396 records were retrieved, and a final of 26 studies were included. Interventions were categorised into cortical or non-cortical stimulation of the swallowing network. Cortical stimulation interventions were repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation. Non-cortical were complex swallowing interventions, neuromuscular electrical stimulation, pharyngeal electrical stimulation (PES), sensory stimulation, strengthening exercises and respiratory muscle training.

CONCLUSION

This scoping review provides an overview of rehabilitative dysphagia interventions for patients with moderate and severe ABI, predominantly due to stroke, in the acute and subacute phase. Positive tendencies towards beneficial effects were found for rTMS, complex swallowing interventions, PES and cervical strengthening. Future studies could benefit from clear reporting of patient diagnosis and disease severity, the use of more standardised treatment protocols or algorithms and fewer but standardised outcome measures to enable comparison of effects across studies and interventions.