Cerebral activity manipulation of low-frequency repetitive transcranial magnetic stimulation in post-stroke patients with cognitive impairment

Efficacy of repetitive transcranial magnetic stimulation on post-stroke cognitive impairment: A systematic and a network meta-analysis

OBJECTIVES

This study aimed to evaluate the efficacy of different repetitive transcranial magnetic stimulation (rTMS) modes in stroke patients with cognitive impairment, and to rank the best option according to the outcome measures.

METHODS

Literature was searched in PubMed, Cochrane Library, Web of Science, Embase, SinoMed, China National Knowledge Infrastructure, Wanfang Database, and VIP Database, from database inception to September 2023. We included randomized controlled trials (RCTs) investigating the efficacy of all rTMS modes for post-stroke cognitive impairment. The selected studies assessed at least one of the following outcome measures: Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE), P300 latency and amplitude, and modified Barthel Index (MBI) or BI. Two researchers independently conducted data extraction. Quality assessment was performed using RevMan 5.3 software based on the Cochrane Collaboration's tool, and statistical analysis was conducted by GeMTC 0.14.3 software and Stata 17.0 software.

RESULTS

The network meta-analysis included 74 RCTs with a total of 5478 patients. The best probability ranking indicated that intermittent theta burst stimulation (iTBS) was the most effective in enhancing MoCA, MMSE and MBI scores (85%, 54%, 42%, respectively), followed by 10 Hz rTMS (79%, 50%, 39%, respectively), for P300 amplitude, ≤1 Hz rTMS was ranked first (52%).

CONCLUSIONS

The current limited evidence suggests that iTBS may be the optimal approach for improving cognitive and daily life abilities of stroke patients, followed by 10 Hz rTMS, ≤1 Hz rTMS may be the preferred option for enhancing P300 amplitude.

TRAIL REGISTRATION

PROSPERO 2023 CRD42023424771 available from: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=424771.

The Simultaneous Application of Transcranial Magnetic Stimulation and Virtual Reality to Treat Cognitive Deficits Among Stroke Patients: A Randomized Controlled Trial

Background and objective Integrating virtual reality (VR) and transcranial magnetic stimulation (TMS) offers a promising strategy for stroke rehabilitation, as it specifically focuses on reorganizing neural connections and activating brain activity in the cortex. The main goal is to create equitable connections between the brain's two hemispheres to enhance the execution of voluntary movements by stimulating the central executive network (CEN) to strengthen both motor and cognitive abilities. This study aims to propose a therapeutic approach that can improve cognitive recovery and overall quality of life in patients after a stroke. Methods A total of 69 participants were enrolled in the study based on certain inclusion and exclusion criteria. The patients underwent pre-assessment and were randomly allocated into three groups: Group 1 received simultaneous repetitive TMS (rTMS) and virtual reality treatment (VRT), Group 2 received rTMS combined with sham VRT, and Group 3 received sham stimulation with VRT, in a 1:1:1 ratio using opaque, sealed, and stapled envelopes (SNOSE). Post-assessment was carried out using the same measures: the National Institutes of Health Stroke Scale (NIHSS), Addenbrooke's Cognitive Test (ACE III), and Montreal Cognitive Assessment (MOCA). Statistical analysis was conducted to determine the specific outcomes. Data analysis was carried out using IBM SPSS Statistics version 29 (IBM Corp., Armonk, NY), employing student's t-test for within-group comparisons and repeated measures ANOVA for between-group comparisons. The significance level was set at 5%. Results The results demonstrated statistical significance in NIHSS scores across all treatment groups (p<0.001). Regarding cognitive outcomes, improvements were observed in memory, language, and overall cognitive performance (ACE III) within all groups (p<0.05), with significant between-group outcomes (p = 0.009, p = 0.01, p = 0.004, respectively), suggesting variations in treatment effects across cognitive domains. However, no significant differences between groups were found in terms of fluency and visuospatial skills (p = 0.49, p = 0.13), indicating no treatment effects in these domains. Conclusions Based on our findings, the combined intervention involving rTMS and VRT, compared to sham treatments, demonstrates promising outcomes in alleviating stroke severity and improving specific cognitive functions such as memory, language, and overall cognitive performance. Additionally, the combined administration offers a more effective therapy than when they are administered separately.

Clinical application of repetitive transcranial magnetic stimulation in improving functional impairments post-stroke: review of the current evidence and potential challenges

In recent years, the stroke incidence has been increasing year by year, and the related sequelae after stroke, such as cognitive impairment, motor dysfunction, and post-stroke depression, seriously affect the patient's rehabilitation and daily activities. Repetitive transcranial magnetic stimulation (rTMS), as a safe, non-invasive, and effective new rehabilitation method, has been widely recognized in clinical practice. This article reviews the application and research progress of rTMS in treating different functional impairments (cognitive impairment, motor dysfunction, unilateral spatial neglect, depression) after stroke in recent years, and preliminary summarized the possible mechanisms. It has been found that the key parameters that determine the effectiveness of rTMS in improving post-stroke functional impairments include pulse number, stimulated brain areas, stimulation intensity and frequency, as well as duration. Generally, high-frequency stimulation is used to excite the ipsilateral cerebral cortex, while low-frequency stimulation is used to inhibit the contralateral cerebral cortex, thus achieving a balance of excitability between the two hemispheres. However, the specific mechanisms and the optimal stimulation mode for different functional impairments have not yet reached a consistent conclusion, and more research is needed to explore and clarify the best way to use rTMS. Furthermore, we will identify the issues and challenges in the current research, explore possible mechanisms to deepen understanding of rTMS, propose future research directions, and offer insightful insights for better clinical applications.

Efficacy of repetitive transcranial magnetic stimulation with different application parameters for post-stroke cognitive impairment: a systematic review

Background

Cognitive impairment is a prevalent consequence of stroke, seriously affecting recovery and quality of life while imposing substantial burdens on both patients' families and society. Repetitive transcranial magnetic stimulation (rTMS) has emerged as an effective intervention for post-stroke cognitive impairment (PSCI). However, the a lack of standardized and explicit guidelines regarding rTMS application parameters. Therefore, this study systematically evaluated the efficacy of various parameters of rTMS in treating PSCI and explored its potential mechanism.

Methods

We conducted a comprehensive search across seven scientific databases, namely China National Knowledge Infrastructure (CNKI), Wanfang Data Knowledge Service Platform (Wanfang), China Science and Technology Journal Database (VIP), Web of Science, PubMed, Embase, and Cochrane Library, to identify randomized controlled trials (RCTs) investigating the efficacy of rTMS for PSCI. The search encompassed the period from database creation until July 28, 2023. To evaluate the risk of bias in included studies, we employed the Cochrane recommended risk of bias assessment tool. Furthermore, we extracted relevant clinical application parameters associated with rTMS and performed comparative analyses to assess their therapeutic effects under different parameter settings.

Results

The present study included 45 RCTs involving a total of 3,066 patients with PSCI. Both high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) and low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) demonstrated safety and efficacy, yet failed to exhibit significant differentiation in terms of cognitive improvement. Furthermore, intermittent theta burst stimulation (iTBS), although yielding positive results, did not surpass traditional rTMS in effectiveness. Combining HF-rTMS with LF-rTMS resulted in superior efficacy compared to single rTMS intervention. Moreover, the combination of rTMS with other cognitive therapies exhibited potential for enhanced benefits among patients.

Conclusion

rTMS can effectively and safely enhance cognitive function, improve quality of life, and enhance activities of daily living in patients with PSCI. Furthermore, the combination of rTMS with other conventional rehabilitation methods can yield additional positive effects. However, due to insufficient evidence, an optimal parameter protocol for rTMS can not be currently recommended. Future research should prioritize orthogonal experimental design methods that incorporate multiple parameters and levels to determine the optimal parameter protocol for rTMS in PSCI.

Cognitive Effect of Transcranial Direct Current Stimulation on Left Dorsolateral Prefrontal Cortex in Mild Alzheimer's Disease: A Randomized, Double-Blind, Cross-Over Small-Scale Exploratory Study

Background

Transcranial direct current stimulation (tDCS) is considered a potential therapeutic instrument for Alzheimer's disease (AD) because it affects long-term synaptic plasticity through the processes of long-term potentiation and long-term depression, thereby improving cognitive ability. Nevertheless, the efficacy of tDCS in treating AD is still debated. Dorsal lateral prefrontal cortex is the main role in executive functions.

Objective

We investigate the cognitive effects of tDCS on AD patients.

Methods

Thirty mild AD patients aged 66-86 years (mean = 75.6) were included in a double-blind, randomized, sham-controlled crossover study. They were randomly assigned to receive 10 consecutive daily sessions of active tDCS (2 mA for 30 min) or a sham intervention and switched conditions 3 months later. The anodal and cathodal electrodes were placed on the left dorsal lateral prefrontal cortex and the right supraorbital area, respectively. Subjects underwent various neuropsychological assessments before and after the interventions.

Results

The results showed that tDCS significantly improved Cognitive Abilities Screening Instrument scores, especially on the items of "concentration and calculation", "orientation", "language ability", and "categorical verbal fluency". Mini-Mental State Examination and Wisconsin Card Sorting Test scores in all domains of "concept formation", "abstract thinking", "cognitive flexibility", and "accuracy" also improved significantly after tDCS. For the sham condition, no difference was found between the baseline scores and the after-intervention scores on any of the neuropsychological tests.

Conclusion

>: Using tDCS improves the cognition of AD patients. Further large size clinical trials are necessary to validate the data.

Efficacy of Repetitive Transcranial Magnetic Stimulation (rTMS) Combined with Psychological Interventions: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

(1) Background: Psychological interventions are effective in alleviating neuropsychiatric symptoms, though results can vary between patients. Repetitive transcranial magnetic stimulation (rTMS) has been proven to improve clinical symptoms and cognition. It remains unclear whether rTMS can augment the efficacy of psychological interventions. (2) Methods: We examined the effects of rTMS combined with psychological interventions on clinical, functional, and cognitive outcomes from randomized controlled trials conducted in healthy and clinical populations. We searched PubMed, EMBASE, Cochrane Library, and PsycINFO databases up to April 2023. (3) Results: Twenty-seven studies were ultimately included. Compared to sham rTMS combined with psychological interventions, active rTMS combined with psychological interventions significantly improved overall clinical symptoms (k = 16, SMD  =  0.31, CIs 0.08 to 0.54, p  <  0.01). We found that 10 or more sessions of rTMS combined with cognitive behavioural therapy significantly improved clinical outcomes overall (k = 3, SMD  =  0.21, CIs  0.05 to 0.36, Z = 2.49, p  <  0.01). RTMS combined with cognitive training (CT) significantly improved cognition overall compared to sham rTMS combined with CT (k = 13, SMD  =  0.28, CIs 0.15 to 0.42, p  <  0.01), with a significant effect on global cognition (k = 11, SMD  =  0.45, CIs 0.21 to 0.68, p  < 0.01), but not on the other cognitive domains. (4) Conclusion: The current results provide preliminary support for the augmentation effects of active rTMS on clinical and cognitive outcomes across diverse populations. Future clinical trials are required to confirm these augmentation effects for specific psychological interventions in specific clinical populations.

Current evidence, clinical applications, and future directions of transcranial magnetic stimulation as a treatment for ischemic stroke

Transcranial magnetic stimulation (TMS) is a non-invasive brain neurostimulation technique that can be used as one of the adjunctive treatment techniques for neurological recovery after stroke. Animal studies have shown that TMS treatment of rats with middle cerebral artery occlusion (MCAO) model reduced cerebral infarct volume and improved neurological dysfunction in model rats. In addition, clinical case reports have also shown that TMS treatment has positive neuroprotective effects in stroke patients, improving a variety of post-stroke neurological deficits such as motor function, swallowing, cognitive function, speech function, central post-stroke pain, spasticity, and other post-stroke sequelae. However, even though numerous studies have shown a neuroprotective effect of TMS in stroke patients, its possible neuroprotective mechanism is not clear. Therefore, in this review, we describe the potential mechanisms of TMS to improve neurological function in terms of neurogenesis, angiogenesis, anti-inflammation, antioxidant, and anti-apoptosis, and provide insight into the current clinical application of TMS in multiple neurological dysfunctions in stroke. Finally, some of the current challenges faced by TMS are summarized and some suggestions for its future research directions are made.