Effects of bihemispheric transcranial direct current stimulation on motor recovery in subacute stroke patients: a double-blind, randomized sham-controlled trial

Effects of home-based neurostimulation on outcomes after stroke: a systematic review and meta-analysis

BACKGROUND

Home-based rehabilitation is a cost-effective means of making services available for patients. The aim of this study is to determine the evidence in the literature on the effects of home-based neurostimulation in patients with stroke.

METHOD

We searched PubMED, Embase, Web of Science, Scopus, and CENTRAL for randomized controlled trials on the subject matter using keywords such as stroke, electrical stimulation and transcranial direct current stimulation. Information on participants' characteristics and mean scores on the outcomes of interest were extracted. Risks of bias and methodological quality of the included studies were assessed using Cochrane Risks of bias tool and PEDro scale respectively. The data was analyzed using both narrative and quantitative syntheses. In the quantitative synthesis, meta-analysis was carried out using random effect model analysis.

RESULT

The results showed that, home-based neurostimulation is superior to the control at improving upper limb muscle strength (SMD = 0.72, 95% CI = 0.08 to 1.32, p = 0.03), functional mobility (SMD = -0.39, 95% CI = -0.65 to 0.14, p = 0.003) and walking endurance (SMD = 0.33, 95% CI = 0.08 to 0.59, p = 0.01) post intervention; and upper limb motor function (SMD = 0.9, 95% CI = 0.10 to 1.70, p = 0.03), functional mobility (SMD = -0.30, 95% CI = -0.56 to -0.05, p = 0.02) and walking endurance (SMD = 0.33, 95% CI = 0.08 to 0.59, p = 0.01) at follow-up.

CONCLUSIONS

Home-based neurostimulation can be used to improve upper and lower limb function after stroke.

The effect of transcranial direct current stimulation combined with task-specific training on spatio-temporal gait parameters and functional mobility in individuals with stroke: a systematic review and meta-analysis

INTRODUCTION

Transcranial direct current stimulation (tDCS) has a priming effect on post- stroke motor rehabilitation.

OBJECTIVE

We verified whether tDCS combined with task-specific training was superior to nonintervention, task-specific training, or simulated intervention in improving spatio-temporal gait parameters and functional mobility in stroke patients.

METHODS

We searched MEDLINE, EMBASE, CINAHL, Scopus, Cochrane Central, Web of Science, and LILACS for articles published until May 2024, using terms related to stroke, tDCS, and task-specific training. The risk of bias was assessed using the PEDro scale. The Grading of Recommendations, Assessment, Development, and Evaluation methodology was used to classify the certainty of the evidence for each outcome. Meta-analysis was performed using a random-effects model.

RESULTS

A total of 1,685 studies were identified, of which 18 were included in the qualitative analysis. Seven studies were included in the meta-analysis; all outcomes were classified as "very low quality." Improvements in walking speed only were associated with tDCS combined with task-specific training (mean difference [MD], 0.06; 95% confidence interval [CI]: 0.04, 0.07; p < 0.001; I  = 0%). There were no differences in other spatio-temporal gait parameters or functional mobility.

CONCLUSION

This systematic review provides low-quality evidence that tDCS, in combination with task-specific training, increases speed in individuals after stroke. Both interventions, tDCS and task-specific training, are inexpensive and easy to implement; therefore, the mean estimate may be considered clinically worthwhile, although the CIs spans both clinically trivial and worthwhile effects.

REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO; number CRD42023396021).

Research trends and hotspots of post-stroke upper limb dysfunction: a bibliometric and visualization analysis

Background

The global prevalence of stroke has been increasing. Motor dysfunction is observed in approximately 55 to 75% of stroke patients, with upper limb impairment affecting around 85% of them. Following upper limb dysfunction, the body's recovery time is not only slower compared to the lower limbs, but the restoration of its fine motor skills is significantly more challenging, greatly impacting the daily lives of patients. Consequently, there is an increasing urgency for study on the upper limb function in stroke.

Methods

A search was conducted in the Web of Science Core Collection: Science Citation Index Expanded (SCI-Expanded) database for material published from January 1, 2004 to December 31, 2023. We included all relevant literature reports and conducted an analysis of annual publications, countries/regions, institutions, journals, co-cited references, and keywords using the software packages CiteSpace, VOSviewer, and Bibliometrix R. Next, we succinctly outlined the research trends and hotspots in post-stroke upper limb dysfunction.

Results

This analysis comprised 1,938 articles from 1,897 institutions, 354 journals, and 53 countries or regions. A yearly rise in the production of publications was noted. The United States is the foremost nation on the issue. Northwestern University has the most amounts of papers compared to all other institutions. The journal Neurorehabilitation and Neural Repair is a highly significant publication in this field, with Catherine E. Lang serving as the principal author. The majority of the most-cited references focus on subjects such as the reliability and validity of assessment instruments, RCT of therapies, systematic reviews, and meta-analyses. The intervention measures primarily comprise three types of high-frequency phrases that are related, as determined by keyword analysis: intelligent rehabilitation, physical factor therapy, and occupational therapy. Current areas of focus in research include randomized clinical trials, neurorehabilitation, and robot-assisted therapy.

Conclusion

Current research has shown a growing interest in studying upper limb function assessment, occupational therapy, physical therapy, robot-assisted therapy, virtual reality, brain-computer interface, telerehabilitation, cortical reorganisation, and neural plasticity. These topics have become popular and are expected to be the focus of future research.

Potentiation of cortico-spinal output via targeted electrical stimulation of the motor thalamus

Cerebral white matter lesions prevent cortico-spinal descending inputs from effectively activating spinal motoneurons, leading to loss of motor control. However, in most cases, the damage to cortico-spinal axons is incomplete offering a potential target for therapies aimed at improving volitional muscle activation. Here we hypothesize that, by engaging direct excitatory connections to cortico-spinal motoneurons, stimulation of the motor thalamus could facilitate activation of surviving cortico-spinal fibers thereby immediately potentiating motor output. To test this hypothesis, we identify optimal thalamic targets and stimulation parameters that enhance upper-limb motor-evoked potentials and grip forces in anesthetized monkeys. This potentiation persists after white matter lesions. We replicate these results in humans during intra-operative testing. We then design a stimulation protocol that immediately improves strength and force control in a patient with a chronic white matter lesion. Our results show that electrical stimulation targeting surviving neural pathways can improve motor control after white matter lesions.

Investigating functional connectivity related to stroke recovery: A systematic review

INTRODUCTION

Stroke recovery is a complex process influenced by various factors, including specific neural reorganization. The objective of this systematic review was to identify important functional connectivity (FC) changes in resting-state fMRI data that were often correlated with motor, emotional, and cognitive outcome improvement.

METHOD

A systematic search using PubMed and SCOPUS databases was conducted to identify relevant studies published between 2010 and 2023.

RESULTS

A total of 766 studies were identified, of which 20 studies (602 S individuals) met the inclusion criteria. Fourteen studies focussed on motor recovery while six on cognitive recovery. All studies reported interhemispheric FC to be strongly associated with motor and cognitive recovery. The preservation and changes of M1-M1 (eight incidences) and M1-SMA (nine incidences) FC were found to be strongly correlated with motor function improvement. For cognitive recovery, restoration and preservation of FC with and between default mode network (DMN)-related regions were important for the process.

CONCLUSIONS

This review identified specific patterns of FC that were consistently reported with recovery of motor and cognitive function. The findings may serve in refining future management strategies to enhance patient outcomes.

Investigating combined acupuncture and transcranial direct current stimulation in patients with poststroke shoulder pain from China: protocol for a randomised controlled trial

INTRODUCTION

Poststroke shoulder pain is a common complication that severely affects the recovery of upper limb motor function. Acupuncture has positive analgesic effects in treating poststroke shoulder pain, and studies have demonstrated the efficacy of transcranial direct current stimulation (tDCS) in treating patients with this pain. However, whether acupuncture combined with tDCS has a superior rehabilitation effect on poststroke shoulder pain is currently unknown. We aimed to observe the effect of the combined intervention on poststroke shoulder pain and explore its possible central analgesic mechanism.

METHODS AND ANALYSIS

This study describes a randomised controlled trial using assessor blinding. A total of 135 poststroke patients with shoulder pain will be randomly assigned in a 1:1:1 ratio to the tDCS group, acupuncture group and combined group (acupuncture plus tDCS). All three groups will undergo conventional rehabilitation treatment. Participants in the tDCS group will receive tDCS stimulation on the M1 area for 20 min, while the acupuncture group will receive 20 min of acupuncture. The combined treatment group will receive both. All treatments will be performed five times per week for 4 weeks. The primary outcome indicator in this study is the Visual Analogue Scale pain score. Secondary outcome indicators include shoulder mobility, Shoulder Pain and Disability Index, Fugl-Meyer Motor Function Scale, Modified Barthel Index Scale, Self-Rating Anxiety and Depression Scale and functional MRI. All scale results will be assessed at baseline and at 2 weeks and 4 weeks, and during follow-up at 1 month, 3 months and 6 months postdischarge. A repeated analysis of variance will be conducted to observe the group×time interaction effects of the combined intervention. Moreover, functional MRI will be applied to explore the central analgesic mechanism.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics Committee of the Affiliated Rehabilitation Hospital of Fujian University of Traditional Chinese Medicine (2023KY-039-001). The results of the study will be published in a peer-reviewed journal and presented at scientific conferences.

TRIAL REGISTRATION NUMBER

ChiCTR2300078270.

Comparative efficacy of different noninvasive brain stimulation protocols on upper-extremity motor function and activities of daily living after stroke: a systematic review and network meta-analysis

The objectives of the study were to systematically evaluate the rehabilitation effect of noninvasive brain stimulation (NIBS) on upper extremity motor function and activities of daily living in stroke patients and to prioritize various stimulation protocols for reliable evidence-based medical recommendations in patients with upper extremity motor dysfunction after stroke. Web of Science, PubMed, Embase, Cochrane Library, CNKI, Wanfang, VIP, and CBM were searched to collect all randomized controlled trials (RCTs) of NIBS to improve upper extremity motor function in stroke patients. The retrieval time was from the establishment of all databases to May 2023. According to the Cochrane system evaluation manual, the quality of the included studies was evaluated, and the data were extracted. Statistical analysis was carried out by using RevMan 5.3, R 4.3.0, and Stata 17.0 software. Finally, 94 RCTs were included, with a total of 5546 patients. Meta-analysis showed that NIBS improved the Fugl-Meyer assessment (FMA) score (mean difference (MD) = 6.51, 95% CI 6.20 ~ 6.82, P < 0.05), MBI score (MD = 7.69, 95% CI 6.57 ~ 8.81, P < 0.05), ARAT score (MD = 5.06, 95% CI 3.85 ~ 6.27, P < 0.05), and motor evoked potential (MEP) amplitude. The modified Ashworth scale score (MD =  - 0.37, 95% CI - 0.60 to - 0.14, P < 0.05), National Institutes of Health Stroke Scale score (MD =  - 2.17, 95% CI - 3.32 to - 1.11, P < 0.05), incubation period of MEP (MD =  - 0.72, 95% CI - 1.06 to - 0.38, P < 0.05), and central motor conduction time (MD =  - 0.90, 95% CI - 1.29 to - 0.50, P < 0.05) were decreased in stroke patients. Network meta-analysis showed that the order of interventions in improving FMA scores from high to low was anodal-transcranial direct current stimulation (tDCS) (surface under the cumulative ranking curve (SUCRA) = 83.7%) > cathodal-tDCS (SUCRA = 80.2%) > high-frequency (HF)-repetitive transcranial magnetic stimulation (rTMS) (SUCRA = 68.5%) > low-frequency (LF)-rTMS (SUCRA = 66.5%) > continuous theta burst stimulation (cTBS) (SUCRA = 54.2%) > bilateral-tDCS (SUCRA = 45.2%) > intermittent theta burst stimulation (iTBS) (SUCRA = 34.1%) > sham-NIBS (SUCRA = 16.0%) > CR (SUCRA = 1.6%). In terms of improving MBI scores, the order from high to low was anodal-tDCS (SUCRA = 88.7%) > cathodal-tDCS (SUCRA = 85.4%) > HF-rTMS (SUCRA = 63.4%) > bilateral-tDCS (SUCRA = 56.0%) > LF-rTMS (SUCRA = 54.2%) > iTBS (SUCRA = 32.4%) > sham-NIBS (SUCRA = 13.8%) > CR (SUCRA = 6.1%). NIBS can effectively improve upper extremity motor function and activities of daily living after stroke. Among the various NIBS protocols, anodal-tDCS demonstrated the most significant intervention effect, followed by cathodal-tDCS and HF-rTMS.

The stratified effects of repetitive transcranial magnetic stimulation in upper limb motor impairment recovery after stroke: a meta-analysis

Background

The recovery of upper extremity motor impairment after stroke remains a challenging task. The clinical effectiveness of repetitive transcranial magnetic stimulation (rTMS), which is believed to aid in the recovery process, is still uncertain.

Methods

A systematic search was conducted in Medline (Ovid), Cochrane and Embase electronic databases from March 28, 2014, to March 28, 2023. The inclusion criteria consisted of randomized controlled trials that assessed the effects of rTMS on the recovery of upper limb motor impairment among stroke patients. Various measurements, including the Fugl Meyer Assessment Upper Extremity Scale (FMA-UE), Brunnstrom recovery stage, Action Research Arm Test (ARAT), and Barthel index, were evaluated both before and after the intervention.

Results

Nineteen articles with 865 patients were included. When considering only the rTMS parameters, both inhibitory and excitatory rTMS improved FMA-UE (MD = 1.87, 95% CI = [0.88]-[2.86], p < 0.001) and Barthel index (MD = 9.73, 95% CI = [4.57]-[14.89], p < 0.001). When considering only the severity of upper limb hemiplegia, both less severe (MD = 1.56, 95% CI = [0.64]-[2.49], p < 0.001) and severe (MD = 2.05, 95% CI = [1.09]-[3.00], p < 0.001) hemiplegia benefited from rTMS based on FMA-UE. However, when considering the rTMS parameters, severity of hemiplegia and stroke stages simultaneously, inhibitory rTMS was found to be significantly effective for less severe hemiplegia in the acute and subacute phases (MD = 4.55, 95% CI = [2.49]-[6.60], p < 0.001), but not in the chronic phase based on FMA-UE. For severe hemiplegia, inhibitory rTMS was not significantly effective in the acute and subacute phases, but significantly effective in the chronic phase (MD = 2.10, 95% CI = [0.75]-[3.45], p = 0.002) based on FMA-UE. Excitatory rTMS was found to be significantly effective for less severe hemiplegia in the acute and subacute phases (MD = 1.93, 95% CI = [0.58]-[3.28], p = 0.005) based on FMA-UE. The improvements in Brunnstrom recovery stage and ARAT need further research.

Conclusion

The effectiveness of rTMS depends on its parameters, severity of hemiplegia, and stroke stages. It is important to consider all these factors together, as any single grouping method is incomplete.

Dual-tDCS combined with sensorimotor training promotes upper limb function in subacute stroke patients: A randomized, double-blinded, sham-controlled study

BACKGROUND

Dual transcranial direct current stimulation (tDCS) over the bilateral primary somatosensory cortex (PSC) has potential benefits in stroke. In addition, compared with traditional rehabilitation training, sensorimotor training can significantly improve the sensorimotor function of patients. However, the efficacy of dual-tDCS combined with sensorimotor training in patients with subacute stroke is unknown.

OBJECTIVE

To assess whether dual-tDCS may enhance the efficacy of sensorimotor training on the upper limb functions in patients with subacute stroke. In addition, this study aims to explore the potential clinical mechanism of this combination therapy.

METHODS

We randomized 52 individuals with first-ever, unilateral subcortical stroke into the experimental group (n = 26) and the control group (n = 26). Patients in the experimental group received 20 min of dual-tDCS over the PSC and 40 min of sensorimotor training each session, while patients in the control group received sham dual-tDCS. The treatment cycle was a 1-h session of therapy each day, 5 days per week for 4 weeks. The Fugl-Meyer Assessment of Upper Extremity (FMA-UE) subscale, Action Research Arm Test (ARAT), Box and Block test (BBT), Erasmus MC revised Nottingham sensory assessment scale (Em-NSA), Neurometer sensory nerve quantitative detector (CPT), the Barthel index (BI), and Hospital Anxiety and Depression Scale (HADS) were used to assess upper limb function, activities of daily living (ADL), and mental health before and after the 4-week treatment period. In addition, functional near-infrared spectroscopy (fNIRS) was used to explore potential clinical brain mechanisms.

RESULTS

Both groups showed significant improvement in all clinical scales (All p < 0.05) after treatment. Compared with sham-tDCS plus sensorimotor training, active dual-tDCS coupled with sensorimotor training can significantly improve the FMA-UE, ARAT, Em-NSA-Stereognosis, and CPT-2K Hz. In addition, dual-tDCS combined with sensorimotor training can significantly activate the left pre-Motor and supplementary motor cortex (PM-SMC) and enhance the functional connection between the left somatosensory association cortex (SAC) and RPM-SMC. Furthermore, the difference of FMA-UE in the experimental group was positively correlated with the functional connectivity of RPM-SMC-LSAC (r = 0.815, p < 0.001).

CONCLUSION

Dual-tDCS over the PSC combined with sensorimotor training can improve upper limb sensory and motor dysfunction, enhance ADL, and alleviate depression and anxiety for subacute stroke patients. Our results indicated that RPM-SMC-LSAC may be potential therapeutic targets for dual-tDCS in upper limb rehabilitation on stroke.

Transcutaneous auricular vagus nerve stimulation with task-oriented training improves upper extremity function in patients with subacute stroke: a randomized clinical trial

Background

Transcutaneous auricular vagus nerve stimulation (taVNS) has emerged as a promising brain stimulation modality in poststroke upper extremity rehabilitation. Although several studies have examined the safety and reliability of taVNS, the mechanisms underlying motor recovery in stroke patients remain unclear.

Objectives

This study aimed to investigate the effects of taVNS paired with task-oriented training (TOT) on upper extremity function in patients with subacute stroke and explore the potential underlying mechanisms.

Methods

In this double-blinded, randomized, controlled pilot trial, 40 patients with subacute stroke were randomly assigned to two groups: the VNS group (VG), receiving taVNS during TOT, and the Sham group (SG), receiving sham taVNS during TOT. The intervention was delivered 5 days per week for 4 weeks. Upper extremity function was measured using the Fugl-Meyer Assessment-Upper Extremity (FMA-UE), the Action Research Arm Test (ARAT). Activities of daily living were measured by the modified Barthel Index (MBI). Motor-evoked potentials (MEPs) were measured to evaluate cortical excitability. Assessments were administered at baseline and post-intervention. Additionally, the immediate effect of taVNS was detected using functional near-infrared spectroscopy (fNIRS) and heart rate variability (HRV) before intervention.

Results

The VG showed significant improvements in upper extremity function (FMA-UE, ARAT) and activities of daily living (MBI) compared to the SG at post-intervention. Furthermore, the VG demonstrated a higher rate of elicited ipsilesional MEPs and a shorter latency of MEPs in the contralesional M1. In the VG, improvements in FMA-UE were significantly associated with reduced latency of contralesional MEPs. Additionally, fNIRS revealed increased activation in the contralesional prefrontal cortex and ipsilesional sensorimotor cortex in the VG in contrast to the SG. However, no significant between-group differences were found in HRV.

Conclusion

The combination of taVNS with TOT effectively improves upper extremity function in patients with subacute stroke, potentially through modulating the bilateral cortex excitability to facilitate task-specific functional recovery.