Efficacy, safety, and tolerability of bilateral transcranial direct current stimulation combined to a resistance training program in chronic stroke survivors: A double-blind, randomized, placebo-controlled pilot study

Transcranial direct current stimulation in physical therapy treatment for adults after stroke: A systematic review

BACKGROUND

Stroke is a clinical syndrome that can cause neurological disorders due to a reduction or interruption in the blood flow at the brain level. Transcranial direct current stimulation (TDCS) is a non-invasive electrotherapy technique with the ability to modulate the function of nervous tissue.

OBJECTIVE

The aim of this review is to analyze the effects derived from the application of the TDCS for post-stroke patients on functionality and mobility.

METHODS

The data search was conducted in PubMed, PEDro, Cochrane Library, Web of Science and Scopus between July and August 2023. The search focused on randomized clinical trials conducted in the period of 2019-2023, and according to the selection criteria, seven studies were obtained.

RESULTS

The results found are mainly focused on the analysis of the scales Fugl-Meyer Assessment for Upper Extremity and Wolf Motor Function Test.

CONCLUSION

The application of TDCS presents benefits in post-stroke individuals on functionality, mobility and other secondary studied variables.

Do Higher Transcranial Direct Current Stimulation Doses Lead to Greater Gains in Upper Limb Motor Function in Post-Stroke Patients?

Objective: To investigate whether a higher number of transcranial direct current stimulation (tDCS) sessions results in a greater improvement in upper limb function in chronic post-stroke patients. Materials and methods: A randomized, sham-controlled, double-blind clinical trial was conducted in 57 chronic post-stroke patients (≥ 3 months after their injuries). The patients were allocated to receive sessions of tDCS combined with physiotherapy and divided into three groups (anodal, cathodal, and sham). The Fugl-Meyer Assessment of Upper Extremity (FMA-UE) was used to assess the sensorimotor impairment of the patients’ upper limbs before (baseline) and after five and ten sessions. The percentage of patients who achieved a clinically significant improvement (> five points on the FMA-UE) was also analyzed. Results: The FMA-UE score increased after five and ten sessions in both the anodal and cathodal tDCS groups, respectively, compared to the baseline. However, in the sham group, the FMA-UE score increased only after ten sessions. When compared to the sham group, the mean difference from the baseline after five sessions was higher in the anodal tDCS group. The percentage of individuals who achieved greater clinical improvement was higher in the stimulation groups than in the sham group and after ten sessions when compared to five sessions. Conclusions: Our results suggest that five tDCS sessions are sufficient to augment the effect of standard physiotherapy on upper limb function recovery in chronic post-stroke patients, and ten sessions resulted in greater gains.

Multimodal physical training combined with tDCS improves physical fitness components in people after stroke: a double-blind randomized controlled trial

BACKGROUND

Transcranial direct current stimulation (tDCS) seems to be a potential tool to optimize the long-term effects of multimodal physical training (MPT) on fitness components in post-stroke patients.

OBJECTIVE

We investigated the effects of cortical tDCS combined with MPT on motor function reflected by strength, motor performance, and cardiorespiratory capacity in chronic stroke patients.

METHODS

This double-blind randomized controlled trial included 18 volunteers (55 ± 10 y, 72 ± 13 kg), who underwent MPT preceded by either sham stimulation (SHAM) or 2 mA bi-hemispheric tDCS. MPT consisted of 24 sessions of 60-70 min performed 2 d/wk within 12-16 weeks, with individualized intensity. Outcomes were Fugl-Meyer scores for lower limbs (FM-LL), and total (FM-Total); speed in the 10-m walk test (10MWT); oxygen uptake and work output at maximal effort (VO_2max and W_max), and gas exchange threshold (VO₂-GET and W-GET); peak torque of isokinetic knee extension (PT-EXT) and flexion (PT-FLEX) of paretic and non-paretic limbs; bilateral strength deficit during knee extension (DS-EXT) and flexion (DS-FLEX).

RESULTS

Pre- vs. post-intervention improvements were detected in tDCS vs. SHAM (p < 0.05) for FM-total (29.6% vs. 15.9%; effect size [ES] = 0.78), FM-LL (35.9% vs. 9.0%; ES = 1.23), 10MWT (10.6% vs. 3.8%; ES = 0.67), W_max (75.0% vs. 4.3%; ES = 1.68), W-GET (91.6% vs. 12.4%; ES = 1.62), PT-EXT (25.6% vs. -6.5%; ES = 1.94) and PT-FLEX (26.3% vs. 9.8%; ES = 0.65) of the paretic limb, and DS-EXT (-13.7% vs. 2.5; ES = 1.43).

CONCLUSION

Bi-hemispheric cortical tDCS optimized the effects of MPT performed with moderate volume and intensity upon muscle strength, motor function, and cardiorespiratory performance in stroke hemiparetic survivors. (Registration number RBR-22rh3p).

Effect of Transcranial Direct Current Stimulation Augmented with Motor Imagery and Upper-Limb Functional Training for Upper-Limb Stroke Rehabilitation: A Prospective Randomized Controlled Trial

BACKGROUND

Combining transcranial direct current stimulation (tDCS) with other therapies is reported to produce promising results in patients with stroke. The purpose of the study was to determine the effect of combining tDCS with motor imagery (MI) and upper-limb functional training for upper-limb rehabilitation among patients with chronic stroke.

METHODS

A single-center, prospective, randomized controlled trial was conducted among 64 patients with chronic stroke. The control group received sham tDCS with MI, while the experimental group received real tDCS with MI. Both groups performed five different upper-limb functional training exercises coupled with tDCS for 30 min, five times per week for two weeks. Fugl-Meyer's scale (FMA) and the Action Research Arm Test (ARAT) were used to measure the outcome measures at baseline and after the completion of the 10th session.

RESULTS

Analysis of covariance showed significant improvements in the post-test mean scores for FMA (F (414.4) = 35.79, p < 0.001; η² = 0.37) and ARAT (F (440.09) = 37.46, p < 0.001; η² = 0.38) in the experimental group compared to the control group while controlling for baseline scores.

CONCLUSIONS

Anodal tDCS stimulation over the affected primary motor cortex coupled with MI and upper-limb functional training reduces impairment and disability of the upper limbs among patients with chronic stroke.

Barriers to Enrollment in Post-Stroke Brain Stimulation in a Racially and Ethnically Diverse Population

BACKGROUND AND PURPOSE

Brain stimulation is an adjuvant strategy to promote rehabilitation after stroke. Here, we evaluated the influence of inclusion/exclusion criteria on enrollment in a transcranial direct current stimulation (tDCS) trial in the context of a racially/ethnically diverse acute stroke service at University of Texas Southwestern (UTSW).

METHODS

3124 (59.7 ± 14.5 years) racially/ethnically diverse (38.4% non-Hispanic white, (W), Hispanic (H) 22%, African American (AA) 33.5%, Asian (A) 2.3%) patients were screened in the acute stroke service at UTSW. Demographics, stroke characteristics, and reasons for exclusion were recorded prospectively.

RESULTS

2327 (74.5%) patients had a verified stroke. Only 44 of them (1.9%) were eligible. Causes for exclusion included in order of importance: (1) magnitude of upper extremity (UE) motor impairment, (2) prior strokes (s), (3) hemorrhagic stroke, (4) psychiatric condition or inability to follow instructions, and (5) old age, of these (2) and (4) were more common in AA patients but not in other minorities. 31 of the 44 eligible individuals were enrolled (W 1.68%, H 1.37%, AA .77%, A 3.774%). 90.5% of verified stroke patients did not exhibit contraindications for stimulation.

CONCLUSIONS

3 main conclusions emerged: (a) The main limitations for inclusion in brain stimulation trials of motor recovery were magnitude of UE motor impairments and stroke lesion characteristics, (b) most stroke patients could be stimulated with tDCS without safety concerns and (c) carefully tailored inclusion criteria could increase diversity in enrollment.Clinical Trial Registration-URL: http://clinicaltrials.gov. Unique identifier: NCT01007136.

Effect of a tailored upper extremity strength training intervention combined with direct current stimulation in chronic stroke survivors: A Randomized Controlled Trial

Strengthening exercises are recommended for managing persisting upper limb (UL) weakness following a stroke. Yet, strengthening exercises often lead to variable gains because of their generic nature. For this randomized controlled trial (RCT), we aimed to determine whether tailoring strengthening exercises using a biomarker of corticospinal integrity, as reflected in the amplitude of motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS), could optimize training effects in the affected UL. A secondary aim was to determine whether applying anodal transcranial direct current stimulation (tDCS) could enhance exercise-induced training effects. For this multisite RCT, 90 adults at the chronic stage after stroke (>6 months) were recruited. Before training, participants underwent TMS to detect the presence of MEPs in the affected hand. The MEP amplitude was used to stratify participants into three training groups: (1) low-intensity, MEP <50 μV, (2) moderate-intensity, 50 μV < MEP < 120 μV, and (3) high-intensity, MEP>120 μV. Each group trained at a specific intensity based on the one-repetition maximum (1 RM): low-intensity, 35–50% 1RM; moderate-intensity, 50–65% 1RM; high-intensity, 70–85% 1RM. The strength training targeted the affected UL and was delivered 3X/week for four consecutive weeks. In each training group, participants were randomly assigned to receive either real or sham anodal tDCS (2 mA, 20 min) over the primary motor area of the affected hemisphere. Pre-/post-intervention, participants underwent a clinical evaluation of their UL to evaluate motor impairments (Fugl-Meyer Assessment), manual dexterity (Box and Blocks test) and grip strength. Post-intervention, all groups exhibited similar gains in terms of reduced impairments, improved dexterity, and grip strength, which was confirmed by multivariate and univariate analyses. However, no effect of interaction was found for tDCS or training group, indicating that tDCS had no significant impact on outcomes post-intervention. Collectively, these results indicate that adjusting training intensity based on the size of MEPs in the affected extremity provides a useful approach to optimize responses to strengthening exercises in chronic stroke survivors. Also, the lack of add-on effects of tDCS applied to the lesioned hemisphere on exercise-induced improvements in the affected UL raises questions about the relevance of combining such interventions in stroke.

Safety and Adverse Events following Non-invasive Electrical Brain Stimulation in Stroke: A Systematic Review

BACKGROUND

Noninvasive electrical stimulation (ES) could have therapeutic potential in stroke recovery. However, there is no comprehensive evaluation of adverse events. This study systematically searched the literature to document frequency and prevalence of adverse events. A secondary aim was to explore associations between adverse events and ES parameters or participant characteristics.Methods: Databases were searched for studies evaluating ES in adults with stroke. All included studies were required to report on adverse events. Extracted data were: (1) study design; (2) adverse events; (3) participant characteristics; (4) ES parameters.

RESULTS

Seventy-five studies were included. Adverse events were minor in nature. The most frequently reported adverse events were tingling (37.3% of papers), burning (18.7%), headaches (14.7%) and fatigue (14.7%). Cathodal stimulation was associated with greater frequency of itching (p = .02), intensities of 1-2 mA with increased tingling (p = .04) and discomfort (p = .03), and current density <0.4mA/cm2 with greater discomfort (p = .03). Tingling was the most prevalent adverse event (18.1% of participants), with prevalence data not differing between active and control conditions (all p ≥ 0.37). Individual participants were more likely to report adverse events with increasing current density (r = 0.99, p = .001). Two severe adverse events were noted (a seizure and percutaneous endoscopic gastrostomy placement).

CONCLUSION

ES appears safe in people with stroke as reported adverse events were predominantly minor in nature. An adverse events questionnaire is proposed to enable a more comprehensive and nuanced analysis of the frequency and prevalence of adverse events.

Influence of Transcranial Direct Current Stimulation Dosage and Associated Therapy on Motor Recovery Post-stroke: A Systematic Review and Meta-Analysis

Purpose

(1) To determine the impact of transcranial direct current stimulation (tDCS) applied alone or combined with other therapies on the recovery of motor function after stroke and (2) To determine tDCS dosage effect.

Methods

Randomized controlled trials comparing the effects of tDCS with sham, using the Barthel Index (BI), the upper and lower extremity Fugl–Meyer Assessment (FMA), and the Modified Ashworth Scale (MAS), were retrieved from PubMed, Medline (EBSCO), and Cumulative Index to Nursing and Allied Health Literature (CINAHL) from their inception to June 2021. Calculations for each assessment were done for the overall effect and associated therapy accounting for the influence of stroke severity or stimulation parameters.

Results

A total of 31 studies involving metrics of the BI, the upper extremity FMA, the lower extremity FMA, and the MAS were included. tDCS combined with other therapies was beneficial when assessed by the BI (mean difference: 6.8; P < 0.01) and these studies typically had participants in the acute stage. tDCS effects on the upper and lower extremity FMA are unclear and differences between the sham and tDCS groups as well as differences in the associated therapy type combined with tDCS potentially influenced the FMA results. tDCS was not effective compared to sham for the MAS. Stimulation types (e.g., anodal vs. cathodal) did not influence these results and dosage parameters were not associated with the obtained effect sizes. Conventional therapy associated with tDCS typically produced greater effect size than assisted therapy. The influence of stroke severity is unclear.

Conclusion

Potential benefits of tDCS can vary depending on assessment tool used, duration of stroke, and associated therapy. Mechanistic studies are needed to understand the potential role of stimulation type and dosage effect after stroke. Future studies should carefully conduct group randomization, control for duration of stroke, and report different motor recovery assessments types.

Systematic Review Registration

[https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD42021290670].

Safety and efficacy of transcranial direct current stimulation in upper extremity rehabilitation after tetraplegia: protocol of a multicenter randomized, clinical trial

STUDY DESIGN

A multisite, randomized, controlled, double-blinded phase I/II clinical trial.

OBJECTIVE

The purpose of this clinical trial is to evaluate the safety, feasibility and efficacy of pairing noninvasive transcranial direct current stimulation (tDCS) with rehabilitation to promote paretic upper extremity recovery and functional independence in persons living with chronic cervical spinal cord injury (SCI).

SETTING

Four-site trial conducted across Cleveland Clinic, Louis Stokes Veterans Affairs Medical Center of Cleveland and MetroHealth Rehabilitation Rehabilitation Institute of Ohio, and Kessler Foundation of New Jersey.

METHODS

Forty-four adults (age ≥18 years) with tetraplegia following cervical SCI that occurred ≥1-year ago will participate. Participants will be randomly assigned to receive anodal tDCS or sham tDCS given in combination with upper extremity rehabilitation for 15 sessions each over 3-5 weeks. Assessments will be made twice at baseline separated by at least a 3-week interval, once at end-of-intervention, and once at 3-month follow-up.

PRIMARY OUTCOME MEASURE(S)

Primary outcome measure is upper extremity motor impairment assessed using the Graded Redefined Assessment of Strength, Sensibility and Prehension (GRASSP) scale. Functional abilities will be assessed using Capabilities of Upper Extremity-Test (CUE-T), while functional independence and participation restrictions will be evaluated using the self-care domain of Spinal Cord Independent Measure (SCIM), and Canadian Occupational Performance Measure (COPM).

SECONDARY OUTCOME MEASURES

Treatment-associated change in corticospinal excitability and output will also be studied using transcranial magnetic stimulation (TMS) and safety (reports of adverse events) and feasibility (attrition, adherence etc.) will also be evaluated.

TRIAL REGISTRATION

ClincalTrials.gov identifier NCT03892746. This clinical trial is being performed at four sites within the United States: Cleveland Clinic (lead site), Louis Stokes Cleveland Veterans Affairs Medical Center (VAMC) and MetroHealth Rehabilitation Institute in Ohio, and Kessler Foundation in New Jersey. The U.S. Army Medical Research Acquisition Activity, 820 Chandler Street, Fort Detrick MD 21702-5014 is the awarding and administering acquisition office.

Neuroprotection by Transcranial Direct Current Stimulation in Rodent Models of Focal Ischemic Stroke: A Meta-Analysis

Infarct size is associated with stroke severity in clinical studies, so reducing it has become an important target and research hotspot in the treatment of ischemic stroke. Some preclinical studies have shown transcranial direct current stimulation (tDCS) reduced infarct size and improved neurological deficit, but others have not found beneficial effects. Besides, the optimal pattern of tDCS for ischemic stroke remains largely unknown. To shed light on the current circumstance and future research directions, the systematic review evaluated the effect of different tDCS paradigms in reducing infarct size and improving neurological deficit in rodent models of ischemic stroke and assessed the methodological quality of current literature. We searched the MEDLINE (via PubMed), EMBASE, Web of Science, and Scopus from their inception to August 18, 2021, to identify studies evaluating the effects of tDCS in rodent models of ischemic stroke. Eight studies were included, of which seven studies were included in the meta-analysis. The results showed cathodal tDCS, rather than anodal tDCS, reduced infarct size mainly measured by tetrazolium chloride and magnetic resonance imaging (standardized mean difference: -1.13; 95% CI: -1.72, -0.53; p = 0.0002) and improved neurological deficit assessed by a modified neurological severity score (standardized mean difference: -2.10; 95% CI: -3.78, -0.42; p = 0.01) in an early stage of focal ischemic stroke in rodent models. Subgroup analyses showed effects of cathodal tDCS on infarct size were not varied by ischemia duration (ischemia for 1, 1.5, and 2 h or permanent ischemia) and anesthesia (involving isoflurane and ketamine). The overall quality of studies included was low, thus the results must be interpreted cautiously. Published studies suggest that cathodal tDCS may be a promising avenue to explore for augmenting rehabilitation from focal ischemic stroke. Considering the methodological limitations, it is unreliable to blindly extrapolate the animal data to the clinical practice. Future research is needed to investigate the mechanism of tDCS in a randomized and blinded fashion in clinically relevant stroke models, such as elderly animals, female animals, and animals with comorbidities, to find an optimal treatment protocol.

Effect of Transcranial Direct Current Stimulation Combined with Rehabilitation on Arm and Hand Function in Stroke Patients: A Systematic Review and Meta-Analysis

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that may enhance motor recovery after stroke. We performed a systematic review and meta-analysis to assess the efficacy of tDCS combined with rehabilitation on arm and hand function after stroke. Electronic databases were searched from their inception to September 2021. We performed a systematic review of selected randomized controlled trials, and methodological qualities were measured using the PEDro (Physiotherapy Evidence Database) scale. We calculated the standardized mean difference for effect size using the Comprehensive Meta-Analysis 3.0 software. We selected 28 studies for the systematic review and 20 studies for the meta-analysis. The overall effect size was 0.480 (95% CI [0.307; 0.653], p < 0.05), indicating a moderate effect size of tDCS combined with rehabilitation for upper extremity function in stroke survivors. The tDCS with occupational therapy/physical therapy (0.696; 95% CI [0.390; 1.003], p < 0.05) or virtual reality therapy (0.510; 95% CI [0.111; 0.909], p < 0.05) was also significantly more effective than other treatments. This meta-analysis of 20 randomized controlled trials provides further evidence that tDCS combined with rehabilitation, especially occupational therapy/physical therapy and virtual reality therapy, may benefit upper extremity function of the paretic upper limb in stroke patients.

Efficacy and safety of transcranial direct current stimulation for post-stroke spasticity: A meta-analysis of randomised controlled trials

OBJECTIVES

To evaluate the efficacy and safety of transcranial direct current stimulation for post-stroke spasticity and to assess its evidence using a meta-analysis.

METHODS

We searched the Cochrane Library, EMBASE, MEDLINE (via PubMed), PEDro, CBM, CNKI and Wan Fang Data from their inception to June 2021 for randomised clinical trials published in English or Chinese, which aimed to explore the effects of transcranial direct current stimulation on post-stroke spasticity. Two reviewers independently extracted the data and evaluated the methodological quality and overall evidence quality.

RESULTS

Thirteen randomised clinical trials comprising 924 patients were included, 12 of which were included in the meta-analysis. The results showed that anodal stimulation (standard mean difference = -0.91; [95% CI; -1.63 to -0.19]) combined with other therapies was more effective in improving upper limb spasticity. More than 20 minutes of stimulation were found to be effective in improving spasticity. Transcranial direct current stimulation was superior to the control treatments for subacute (standard mean difference = -1.16; -1.75 to -0.57) and chronic stroke (standard mean difference = -0.68; -1.13 to -0.22) patients aged under 60 (standard mean difference = -1.07; -1.54 to -0.60). No severe adverse events were reported in any of the included studies.

CONCLUSIONS

Low-quality evidence demonstrates that anodal transcranial direct current stimulation as an adjunct is effective and safe in reducing upper limb post-stroke spasticity when applied for more than 20 minutes in subacute and chronic stroke survivors aged under 60. Further high-quality studies are needed to explore its long-term efficacy and safety.

Evidence-Based Guidelines and Secondary Meta-Analysis for the Use of Transcranial Direct Current Stimulation in Neurological and Psychiatric Disorders

BACKGROUND

Transcranial direct current stimulation has shown promising clinical results, leading to increased demand for an evidence-based review on its clinical effects.

OBJECTIVE

We convened a team of transcranial direct current stimulation experts to conduct a systematic review of clinical trials with more than 1 session of stimulation testing: pain, Parkinson's disease motor function and cognition, stroke motor function and language, epilepsy, major depressive disorder, obsessive compulsive disorder, Tourette syndrome, schizophrenia, and drug addiction.

METHODS

Experts were asked to conduct this systematic review according to the search methodology from PRISMA guidelines. Recommendations on efficacy were categorized into Levels A (definitely effective), B (probably effective), C (possibly effective), or no recommendation. We assessed risk of bias for all included studies to confirm whether results were driven by potentially biased studies.

RESULTS

Although most of the clinical trials have been designed as proof-of-concept trials, some of the indications analyzed in this review can be considered as definitely effective (Level A), such as depression, and probably effective (Level B), such as neuropathic pain, fibromyalgia, migraine, post-operative patient-controlled analgesia and pain, Parkinson's disease (motor and cognition), stroke (motor), epilepsy, schizophrenia, and alcohol addiction. Assessment of bias showed that most of the studies had low risk of biases, and sensitivity analysis for bias did not change these results. Effect sizes vary from 0.01 to 0.70 and were significant in about 8 conditions, with the largest effect size being in postoperative acute pain and smaller in stroke motor recovery (nonsignificant when combined with robotic therapy).

CONCLUSION

All recommendations listed here are based on current published PubMed-indexed data. Despite high levels of evidence in some conditions, it must be underscored that effect sizes and duration of effects are often limited; thus, real clinical impact needs to be further determined with different study designs.

Corticospinal and spinal adaptations to motor skill and resistance training: Potential mechanisms and implications for motor rehabilitation and athletic development

Optimal strategies for enhancing strength and improving motor skills are vital in athletic performance and clinical rehabilitation. Initial increases in strength and the acquisition of new motor skills have long been attributed to neurological adaptations. However, early increases in strength may be predominantly due to improvements in inter-muscular coordination rather than the force-generating capacity of the muscle. Despite the plethora of research investigating neurological adaptations from motor skill or resistance training in isolation, little effort has been made in consolidating this research to compare motor skill and resistance training adaptations. The findings of this review demonstrated that motor skill and resistance training adaptations show similar short-term mechanisms of adaptations, particularly at a cortical level. Increases in corticospinal excitability and a release in short-interval cortical inhibition occur as a result of the commencement of both resistance and motor skill training. Spinal changes show evidence of task-specific adaptations from the acquired motor skill, with an increase or decrease in spinal reflex excitability, dependant on the motor task. An increase in synaptic efficacy of the reticulospinal projections is likely to be a prominent mechanism for driving strength adaptations at the subcortical level, though more research is needed. Transcranial electric stimulation has been shown to increase corticospinal excitability and augment motor skill adaptations, but limited evidence exists for further enhancing strength adaptations from resistance training. Despite the logistical challenges, future work should compare the longitudinal adaptations between motor skill and resistance training to further optimise exercise programming.

Evaluating the effects of tDCS in stroke patients using functional outcomes: a systematic review

Background and purpose: Transcranial direct current stimulation (tDCS) has been extensively studied over the past 20 years to promote functional motor recovery after stroke. However, tDCS clinical relevance still needs to be determined. The present systematic review aims to determine whether tDCS applied to the primary motor cortex (M1) in stroke patients can have a positive effect on functional motor outcomes.Materials and methods: Two databases (Medline & Scopus) were searched for randomized, double-blinded, sham-controlled trials pertaining to the use of M1 tDCS on cerebral stroke patients, and its effects on validated functional motor outcomes. When data were provided, effect sizes were calculated. PROSPERO registration number: CRD42018108157Results: 46 studies (n = 1291 patients) met inclusion criteria. Overall study quality was good (7.69/10 on the PEDro scale). Over half (56.5%) the studies were on chronic stroke patients. There seemed to be a certain pattern of recurring parameters, but tDCS protocols still remain heterogeneous. Overall results were positive (71.7% of studies found that tDCS has positive results on functional motor outcomes). Effect-sizes ranged from 0 to 1.33. No severe adverse events were reported.Conclusion: Despite heterogeneous stimulation parameters, outcomes and patient demographics, tDCS seems to be complementary to classical and novel rehabilitation approaches. With minimal adverse effects (if screening parameters are respected), none of which were serious, and a high potential to improve recovery when using optimal parameters (i.e.: 20 min of stimulation, at 2 mA with 25 or 35cm² electrodes that are regularly humidified), tDCS could potentially be ready for clinical applications.Implications for RehabilitationtDCS could potentially be ready for clinical application.Evidence of very low to very high quality is available on the effectiveness of tDCS to improve motor control following stroke.This should with caution be focused on the primary motor cortex.