Combined effects of transcranial direct current stimulation (tDCS) and transcutaneous spinal direct current stimulation (tsDCS) on robot-assisted gait training in patients with chronic stroke: A pilot, double blind, randomized controlled trial

Spinal Cord Stimulation for Poststroke Hemiparesis: A Scoping Review

IMPORTANCE

Spinal cord stimulation (SCS) is a neuromodulation technique that can improve paresis in individuals with spinal cord injury. SCS is emerging as a technique that can address upper and lower limb hemiparesis. Little is understood about its effectiveness with the poststroke population.

OBJECTIVE

To summarize the evidence for SCS after stroke and any changes in upper extremity and lower extremity motor function.

DATA SOURCES

PubMed, Web of Science, Embase, and CINAHL. The reviewers used hand searches and reference searches of retrieved articles. There were no limitations regarding publication year.

STUDY SELECTION AND DATA COLLECTION

This review followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist. The inclusion and exclusion criteria included a broad range of study characteristics. Studies were excluded if the intervention did not meet the definition of SCS intervention, used only animals or healthy participants, did not address upper or lower limb motor function, or examined neurological conditions other than stroke.

FINDINGS

Fourteen articles met the criteria for this review. Seven studies found a significant improvement in motor function in groups receiving SCS.

CONCLUSIONS AND RELEVANCE

Results indicate that SCS may provide an alternative means to improve motor function in the poststroke population. Plain-Language Summary: The results of this study show that spinal cord stimulation may provide an alternative way to improve motor function after stroke. Previous neuromodulation methods have targeted the impaired supraspinal circuitry after stroke. Although downregulated, spinal cord circuitry is largely intact and offers new possibilities for motor recovery.

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.

Study protocol of a double-blind randomized control trial of transcranial direct current stimulation in post-stroke fatigue

Rationale

Post-stroke fatigue (PSF) is a frequent problem in stroke survivors and often hinders their rehabilitation. PSF is difficult to treat, and pharmacological therapy is often ineffective. Transcranial direct current stimulation (tDCS) can modulate motor, sensory, cognitive and behavioral responses, as it alters neuronal activity by delivering a small amount of current via the scalp to the cortex, resulting in prolonged alterations to brain function. tDCS has been studied for the treatment of fatigue associated with other neurological diseases, namely, multiple sclerosis, Parkinson's disease and post-polio syndrome.

Aims

This proposed project will examine the effect of tDCS on PSF.

Sample size estimates

We will recruit 156 participants aged 18 to 80 with chronic stroke and allocate them equally to two groups (i.e., n = 78 per group).

Methods and design

This proposed project will be a double-blind randomized control trial. The participants will be randomly divided into two groups. The control group will receive sham tDCS, and the treatment group will receive active tDCS. The latter treatment will involve application of a constant 2-mA current via one 5 × 5-cm anodal electrode positioned on the scalp over the C3 or C4 positions (motor cortex) of the lesioned hemisphere and one cathodal electrode positioned at the ipsilateral shoulder in two 20-min sessions per day for 5 days. The period of follow-up will be 4 weeks.

Study outcomes

The primary outcome measure will be a change in fatigue severity, as measured using the modified fatigue impact scale (MFIS). The participants' scores on the MFIS (total score and physical, cognitive and psychosocial subscores) will be collected before treatment (T0), after 10 treatment sessions, i.e., 1 day after the fifth treatment day (T1), and 1 week (T2), 2 weeks (T3) and 4 weeks (T4) thereafter. Both per-protocol analysis and intention-to-treat analysis will be performed.

Discussion

This proposed project will provide proof-of-concept, i.e., demonstrate the benefits of tDCS for the treatment of PSF. The beneficiaries are the subjects participated in the study. This will stimulate further research to optimize tDCS parameters for the treatment of PSF.

Clinical trial registration

www.Chictr.org.cn, identifier: ChiCTR2100052515.

Improving Upper Limb and Gait Rehabilitation Outcomes in Post-Stroke Patients: A Scoping Review on the Additional Effects of Non-Invasive Brain Stimulation When Combined with Robot-Aided Rehabilitation

Robot-aided rehabilitation (RAR) and non-invasive brain stimulation (NIBS) are the two main interventions for post-stroke rehabilitation. The efficacy of both approaches in combination has not been well established yet. The importance of coupling these interventions, which both enhance brain plasticity to promote recovery, lies in augmenting the rehabilitation potential to constrain the limitation in daily living activities and the quality of life following stroke. This review aimed to evaluate the evidence of NIBS coupled with RAR in improving rehabilitation outcomes of upper limb and gait motor impairment in adult individuals with stroke. We included 18 clinical trials in this review. All studies were highly heterogeneous concerning the technical characteristics of robotic devices and NIBS protocols. However, the studies reported a global improvement in body structure and function and activity limitation for the upper limb, which were non-significant between the active and control groups. Concerning gait training protocols, the active group outperformed the control group in improving walking capacity and recovery. According to this review, NIBS and RAR in combination are promising but not yet largely recommendable as a systematic approach for stroke rehabilitation as there is not enough data about this. Therefore, more homogenous clinical trials are required, pointing out the best characteristics of the combined therapeutic protocols.

Transcranial direct current stimulation for gait recovery following stroke: A systematic review of current literature and beyond

Background

Over the last decade, transcranial direct current stimulation (tDCS) has set promise contributing to post-stroke gait rehabilitation. Even so, results are still inconsistent due to low sample size, heterogeneity of samples, and tDCS design differences preventing comparability. Nonetheless, updated knowledge in post-stroke neurophysiology and stimulation technologies opens up opportunities to massively improve treatments.

Objective

The current systematic review aims to summarize the current state-of-the-art on the effects of tDCS applied to stroke subjects for gait rehabilitation, discuss tDCS strategies factoring individual subject profiles, and highlight new promising strategies.

Methods

MEDLINE, SCOPUS, CENTRAL, and CINAHL were searched for stroke randomized clinical trials using tDCS for the recovery of gait before 7 February 2022. In order to provide statistical support to the current review, we analyzed the achieved effect sizes and performed statistical comparisons.

Results

A total of 24 records were finally included in our review, totaling n = 651 subjects. Detailed analyses revealed n = 4 (17%) studies with large effect sizes (≥0.8), n = 6 (25%) studies with medium ones (≥0.5), and n = 6 (25%) studies yielding low effects sizes (≤ 0.2). Statistically significant negative correlations (rho = −0.65, p = 0.04) and differences (p = 0.03) argued in favor of tDCS interventions in the sub-acute phase. Finally, significant differences (p = 0.03) were argued in favor of a bifocal stimulation montage (anodal M1 ipsilesional and cathodal M1 contralesional) with respect to anodal ipsilesional M1.

Conclusion

Our systematic review highlights the potential of tDCS to contribute to gait recovery following stroke, although also the urgent need to improve current stimulation strategies and subject-customized interventions considering stroke severity, type or time-course, and the use of network-based multifocal stimulation approaches guided by computational biophysical modeling.

Systematic review registration

PROSPERO: CRD42021256347.

Non-invasive brain stimulation for improving gait, balance, and lower limbs motor function in stroke

Objectives

This systematic review and meta-analysis aim to summarize and analyze the available evidence of non-invasive brain stimulation/spinal cord stimulation on gait, balance and/or lower limb motor recovery in stroke patients.

Methods

The PubMed database was searched from its inception through to 31/03/2021 for randomized controlled trials investigating repetitive transcranial magnetic stimulation or transcranial/trans-spinal direct current/alternating current stimulation for improving gait, balance and/or lower limb motor function in stroke patients.

Results

Overall, 25 appropriate studies (including 657 stroke subjects) were found. The data indicates that non-invasive brain stimulation/spinal cord stimulation is effective in supporting recovery. However, the effects are inhomogeneous across studies: (1) transcranial/trans-spinal direct current/alternating current stimulation induce greater effects than repetitive transcranial magnetic stimulation, and (2) bilateral application of non-invasive brain stimulation is superior to unilateral stimulation.

Conclusions

The current evidence encourages further research and suggests that more individualized approaches are necessary for increasing effect sizes in stroke patients.

Five-Session Dual-Transcranial Direct Current Stimulation With Task-Specific Training Does Not Improve Gait and Lower Limb Performance Over Training Alone in Subacute Stroke: A Pilot Randomized Controlled Trial

OBJECTIVE

To determine the effect of five-session dual-transcranial direct current stimulation (dual-tDCS) combined with task-specific training on gait and lower limb motor performance in individuals with subacute stroke.

MATERIALS AND METHODS

Twenty-five participants who had a stroke in the subacute phase with mild motor impairment were recruited, randomized, and allocated into two groups. The active group (n = 13) received dual-tDCS with anodal over the lesioned hemisphere M1 and cathodal over the nonlesioned hemisphere, at 2 mA for 20 min before training for five consecutive days, while the sham group (n = 12) received sham mode before training. Gait speed as a primary outcome, temporospatial gait variables, lower-limb functional tasks (sit-to-stand and walking mobility), and muscle strength as secondary outcomes were collected at preintervention and postintervention (day 5), one-week follow-up, and one-month follow-up.

RESULTS

The primary outcome and most of the secondary outcomes were improved in both groups, with no significant difference between the two groups, and most of the results indicated small to moderate effect sizes of active tDCS compared to sham tDCS.

CONCLUSION

The combined intervention showed no benefit over training alone in improving gait variables and lower-limb performance. However, some performances were saturated at some point, as moderate to high function participants were recruited in the present study. Future studies should consider recruiting participants with more varied motor impairment levels and may need to determine the optimal stimulation protocols and parameters to improve gait and lower-limb performance.

Trans-Spinal Direct Current Stimulation Targets Ca2+ Channels to Induce Persistent Motor Unit Responses

Trans-spinal direct current stimulation (tsDCS) is a neuromodulatory approach to augment spinal cord activity to improve function after neurological disease and injury. Little is known about the mechanisms underlying tsDCS actions on the motor system. The purpose of this study is to determine the role for a persistent inward current (PIC)-like response in motoneurons in mediating tsDCS actions. We recorded single motor units from the extensor and flexor carpi radialis muscles in healthy sedated rats and measured unit activity changes produced by cervical enlargement cathodal and anodal tsDCS (c-tsDCS; a-tsDCS). Both c-tsDCS and a-tsDCS immediately increased spontaneous motor unit firing during stimulation. After c-tsDCS was stopped, spontaneous firing persisted for a substantial period (165 ± 5s), yet after a-tsDCS activity shortly returned to baseline (27 ± 7s). Administration of the L-type calcium channel blocker Nimodipine reduced spontaneous motor unit firing during c-tsDCS and blocked the persistent response. By contrast, Nimodipine did not change unit firing during a-tsDCS but the short persistent response was blocked. Computer simulation using a two-compartment neuronal model replicated the main experimental observations: larger and more persistent responses during and after c-tsDCS than a-tsDCS. Using reduced Ca²⁺ conductance to model Nimodipine action, a reduced response during c-tsDCS and elimination of the persistent response was observed. Our experimental findings, supported by computer simulation, show that c-tsDCS can target Ca²⁺ conductances to augment motoneuron activity. As tsDCS is well-tolerated in humans, this knowledge informs therapeutic treatment strategies to achieve rehabilitation goals after injury; in particular, to increase muscle force.

Combining Robot-Assisted Gait Training and Non-Invasive Brain Stimulation in Chronic Stroke Patients: A Systematic Review

Gait impairment is one of the most common disorders of patients with chronic stroke, which hugely affects the ability to carry out the activities of daily living and the quality of life. Recently, traditional rehabilitation techniques have been associated with non-invasive brain stimulation (NIBS) techniques, which enhance brain plasticity, with the aim of promoting recovery in patients with chronic stroke. NIBS effectiveness in improving gait parameters in patients with chronic stroke has been in several studies evaluated. Robotic devices are emerging as promising tools for the treatment of stroke-related disabilities by performing repetitive, intensive, and task-specific treatments and have been proved to be effective for the enhancement of motor recovery in patients with chronic stroke. To date, several studies have examined the combination of NIBS with robotic-assisted gait training, but the effectiveness of this approach is not yet well established. The main purpose of this systematic review is to clarify whether the combination of NIBS and robot-assisted gait training may improve walking function in patients with chronic stroke. Our systematic review was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Studies eligible for review were identified through PubMed/MEDLINE, Embase, Scopus, and PEDro from inception to March 15, 2021, and the outcomes considered were gait assessments. Seven studies were included in the qualitative analysis of this systematic review, with a total population of 186 patients with chronic stroke. All studies specified technical characteristics of robotic devices and NIBS used, with high heterogeneity of protocols. Methodological studies have shown a significantly greater improvement in walking capacity recorded with 6MWT. Finally, research studies have highlighted a positive effect on walking recovery by combination of robot-assisted gait training with non-invasive brain stimulation. Furthermore, future studies should identify the best characteristics of the combined therapeutic protocols.

Review of tDCS Configurations for Stimulation of the Lower-Limb Area of Motor Cortex and Cerebellum

This article presents an exhaustive analysis of the works present in the literature pertaining to transcranial direct current stimulation(tDCS) applications. The aim of this work is to analyze the specific characteristics of lower-limb stimulation, identifying the strengths and weaknesses of these works and framing them with the current knowledge of tDCS. The ultimate goal of this work is to propose areas of improvement to create more effective stimulation therapies with less variability.

Targeting Sensory and Motor Integration for Recovery of Movement After CNS Injury

The central nervous system (CNS) integrates sensory and motor information to acquire skilled movements, known as sensory-motor integration (SMI). The reciprocal interaction of the sensory and motor systems is a prerequisite for learning and performing skilled movement. Injury to various nodes of the sensorimotor network causes impairment in movement execution and learning. Stimulation methods have been developed to directly recruit the sensorimotor system and modulate neural networks to restore movement after CNS injury. Part 1 reviews the main processes and anatomical interactions responsible for SMI in health. Part 2 details the effects of injury on sites critical for SMI, including the spinal cord, cerebellum, and cerebral cortex. Finally, Part 3 reviews the application of activity-dependent plasticity in ways that specifically target integration of sensory and motor systems. Understanding of each of these components is needed to advance strategies targeting SMI to improve rehabilitation in humans after injury.

Effects of Combining Online Anodal Transcranial Direct Current Stimulation and Gait Training in Stroke Patients: A Systematic Review and Meta-Analysis

Objective: Combining transcranial direct current stimulation (tDCS) and repetitive gait training may be effective for gait performance recovery after stroke; however, the timing of stimulation to obtain the best outcomes remains unclear. We performed a systematic review and meta-analysis to establish evidence for changes in gait performance between online stimulation (tDCS and repetitive gait training simultaneously) and offline stimulation (gait training after tDCS). Methods: We comprehensively searched the electronic databases Medline, Cochrane Central Register of Controlled Trials, Physiotherapy Evidence Database, and Cumulative Index to Nursing and Allied Health Literature, and included studies that combined cases of anodal tDCS with motor-related areas of the lower limbs and gait training. Nine studies fulfilled the inclusion criteria and were included in the systematic review, of which six were included in the meta-analysis. Result: The pooled effect estimate showed that anodal tDCS significantly improved the 10-m walking test (p = 0.04; I ² = 0%) and 6-min walking test (p = 0.001; I ² = 0%) in online stimulation compared to sham tDCS. Conclusion: Our findings suggested that simultaneous interventions may effectively improve walking ability. However, we cannot draw definitive conclusions because of the small sample size. More high-quality studies are needed on the effects of online stimulation, including various stimulation parameters.

Robot-Assisted Gait Training Plan for Patients in Poststroke Recovery Period: A Single Blind Randomized Controlled Trial

Background

Walking dysfunction exists in most patients after stroke. Evidence regarding gait training in two weeks is scarce in resource-limited settings; this study was conducted to investigate the effects of a short-term robot-assisted gait training plan for patients with stroke.

Methods

85 patients were randomly assigned to one of two treatment groups, with 31 patients in withdrawal before treatment. The training program comprised 14 2-hour sessions, for 2 consecutive weeks. Patients allocated to the robot-assisted gait training group were treated using the Gait Training and Evaluation System A3 from NX (RT group, n = 27). Another group of patients was allocated to the conventional overground gait training group (PT group, n = 27). Outcome measurements were assessed using time-space parameter gait analysis, Fugl-Meyer Assessment (FMA), and Timed Up and Go test (TUG) scores.

Results

In the time-space parameter analysis of gait, the two groups exhibited no significant changes in time parameters, but the RT group exhibited a significant effect on changes in space parameters (stride length, walk velocity, and toe out angle, P < 0.05). After training, FMA scores (20.22 ± 2.68) of the PT group and FMA scores (25.89 ± 4.6) of the RT group were significant. In the Timed Up and Go test, FMA scores of the PT group (22.43 ± 3.95) were significant, whereas those in the RT group (21.31 ± 4.92) were not. The comparison between groups revealed no significant differences.

Conclusion

Both the RT group and the PT group can partially improve the walking ability of stroke patients within 2 weeks.

Design of a Novel Paired Associative Nerve Stimulation System and Treatment Strategy for Incomplete Spinal Cord Injury: A Preliminary Study

Paired associative nerve stimulation (PANS) was proposed as a potential nerve rehabilitation treatment strategy. However, few relevant documents are available regarding the strategy, and only a few clinical studies have involved healthy people. To determine the feasibility of the neurorehabilitation treatment and to estimate the effect of PANS on nerve plasticity for individuals with incomplete spinal cord injury (iSCI), a design combining repetitive transcranial magnetic stimulation (rTMS) with trans-spinal electrical stimulation was developed for treating individuals with iSCI in this pilot case study. First, a novel PANS system with multiple stimulation modes was designed and verified with resistors and a metal coil as load. Then, the system was applied to three individuals with iSCI, and five types of paired associative stimulation was performed to confirm the feasibility of the system and determine the most effective treatment strategy. The preliminary result showed that 20-Hz rTMS combined with cathodal trans-spinal direct current stimulation (tsDCS) had the greatest effect on corticospinal excitability. Next, stimulations of 20-Hz rTMS (brain) and sham (spine) as well as sham (brain) and cathode tsDCS (spine) were administered to individuals with iSCI, and the results revealed that paired associative stimulation of brain and spine was more effective than only 20-Hz rTMS brain stimulation or cathodal tsDCS stimulation for corticospinal plasticity.

The Effects of Transcranial Direct Current Stimulation on Balance and Gait in Stroke Patients: A Systematic Review and Meta-Analysis

Objective: Balance dysfunction after stroke often results in individuals unable to maintain normal posture, limits the recovery of gait and functional independence. We explore the short-term effects of transcranial direct current stimulation (tDCS) on improving balance function and gait in stroke patients.

Methods: We systematically searched on PubMed, Web of Science, EMBASE, Cochrane Central Register of Controlled Trials, and Google Scholar for studies that explored the effects of tDCS on balance after stroke until August 2020. All involved studies used at least one measurement of balance, gait, or postural control as the outcome.

Results: A total of 145 studies were found, of which 10 (n = 246) met the inclusion criteria and included in our studies. The present meta-analysis showed that active tDCS have beneficial effects on timed up and go test (TUGT) [mean difference (MD): 0.35; 95% confidence interval (CI): 0.11 to 0.58] and Functional Ambulation Category (FAC) (MD: −2.54; 95% CI: −3.93 to −1.15) in stroke patients. However, the results were not significant on the berg balance scale (BBS) (MD: −0.20; 95% CI: −1.44 to 1.04), lower extremity subscale of Fugl-Meyer Assessment (FMA-LE) (MD: −0.43; 95% CI: −1.70 to 0.84), 10-m walk test (10 MWT) (MD: −0.93; 95% CI: −2.68 to 0.82) and 6-min walking test (6 MWT) (MD: −2.55; 95% CI: −18.34 to 13.23).

Conclusions: In conclusion, we revealed that tDCS might be an effective option for restoring walking independence and functional ambulation for stroke patients in our systematic review and meta-analysis.

Systematic Review Registration: CRD42020207565.

A narrative review on non-invasive stimulation of the cerebellum in neurological diseases

IMPORTANCE

The cerebellum plays an important role in motor, cognitive, and affective functions owing to its dense interconnections with basal ganglia and cerebral cortex. This review aimed at summarizing the non-invasive cerebellar stimulation (NICS) approaches used to modulate cerebellar output and treat cerebellar dysfunction in the motor domain.

OBSERVATION

The utility of NICS in the treatment of cerebellar and non-cerebellar neurological diseases (including Parkinson's disease, dementia, cerebellar ataxia, and stroke) is discussed. NICS induces meaningful clinical effects from repeated sessions alone in both cerebellar and non-cerebellar diseases. However, there are no conclusive data on this issue and several concerns need to be still addressed before NICS could be considered a valuable, standard therapeutic tool.

CONCLUSIONS AND RELEVANCE

Even though some challenges must be overcome to adopt NICS in a wider clinical setting, this tool might become a useful strategy to help patients with lesions in the cerebellum and cerebral areas that are connected with the cerebellum whether one could enhance cerebellar activity with the intention of facilitating the cerebellum and the entire, related network, rather than attempting to facilitate a partially damaged cortical region or inhibiting the homologs' contralateral area. The different outcome of each approach would depend on the residual functional reserve of the cerebellum, which is confirmed as a critical element to be probed preliminary in order to define the best patient-tailored NICS.

Effects of home-based dual-hemispheric transcranial direct current stimulation combined with exercise on upper and lower limb motor performance in patients with chronic stroke

PURPOSE

This study aimed to determine the effects of home-based dual-hemispheric transcranial direct current stimulation (dual-tDCS) combined with exercise on motor performance in patients with chronic stroke.

MATERIALS AND METHODS

We allocated 24 participants to the active or sham group. They completed 1-h home-based exercise after 20-min dual-tDCS at 2-mA, thrice a week for 4 weeks. The patients were assessed using the Fugl-Meyer Assessment (FMA), Wolf Motor Function Test, Timed Up and Go test, Five Times Sit-to-Stand Test, Six-meter Walk Test, and muscle strength assessment.

RESULTS

Compared with the sham group, the active group showed improved FMA scores, which were sustained for at least 1 month. There was no between-group difference in the outcomes of the functional tasks.

CONCLUSION

Home-based dual-tDCS could facilitate motor recovery in patients with chronic stroke with its effect lasting for at least 1 month. However, its effects on functional tasks remain unclear. tDCS is safe and easy for home-based self-administration for patients who can use their paretic arms. This could benefit patients without access to health care centres or in situations requiring physical distancing. This home-based tDCS combined with exercise has the potential to be incorporated into telemedicine in stroke rehabilitation.IMPLICATIONS FOR REHABILITATIONTwelve sessions of home-based dual-tDCS combined with exercises (3 days/week for 4 weeks) facilitated upper and lower limb motor recovery in patients with chronic stroke compared with exercise alone, with a post-effect for at least 1 month.Home-based tDCS could be safe and easily self-administrable by patients who can use their paretic arms.This intervention could be beneficial for patients living in the community without easy access to a health care centre or in situations where physical distancing is required.

Spinal direct current stimulation (tsDCS) in hereditary spastic paraplegias (HSP): A sham-controlled crossover study

Objective: Hereditary spastic paraplegia (HSP) represents a heterogeneous group of neurodegenerative diseases characterized by progressive spasticity and lower limb weakness. We assessed the effects of transcutaneous spinal direct current stimulation (tsDCS) in HSP.Design: A double-blind, randomized, crossover and sham-controlled study.Setting: Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico, Milan.Participants: eleven patients with HSP (six men, mean age ± SD: 37.3 ± 8.1 years), eight affected by spastin/SPG4,1 by atlastin1/SPG3a, 1 by paraplegin/SPG7 and 1 by ZFYVE26/SPG15.Interventions: tsDCS (anodal or sham, 2.0 mA, 20', five days) delivered over the thoracic spinal cord (T10-T12).Outcome measures: Motor-evoked potentials (MEPs), the H-reflex (Hr), F-waves, the Ashworth scale for clinical spasticity, the Five Minutes Walking test and the Spastic Paraplegia Rating Scale (SPRS) were assessed. Patients were evaluated before tsDCS (T₀), at the end of the stimulation (T₁), after one week (T₂), one month (T₃) and two months (T₄).Results: The score of the Ashworth scale improved in the anodal compared with sham group, up to two months following the end of stimulation (T₁, P = .0137; T₄, P = .0244), whereas the Five Minutes Walking test and SPRS did not differ between the two groups. Among neurophysiological measures, both anodal and sham tsDCS left Hr, F-waves and MEPs unchanged over time.Conclusions: Anodal tsDCS significantly decreases spasticity and might be a complementary strategy for the treatment of spasticity in HSP.

Transcranial direct current stimulation (tDCS) for improving activities of daily living, and physical and cognitive functioning, in people after stroke

BACKGROUND

Stroke is one of the leading causes of disability worldwide. Functional impairment, resulting in poor performance in activities of daily living (ADL) among stroke survivors is common. Current rehabilitation approaches have limited effectiveness in improving ADL performance, function, muscle strength, and cognitive abilities (including spatial neglect) after stroke, with improving cognition being the number one research priority in this field. A possible adjunct to stroke rehabilitation might be non-invasive brain stimulation by transcranial direct current stimulation (tDCS) to modulate cortical excitability, and hence to improve these outcomes in people after stroke.

OBJECTIVES

To assess the effects of tDCS on ADL, arm and leg function, muscle strength and cognitive abilities (including spatial neglect), dropouts and adverse events in people after stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register, CENTRAL, MEDLINE, Embase and seven other databases in January 2019. In an effort to identify further published, unpublished, and ongoing trials, we also searched trials registers and reference lists, handsearched conference proceedings, and contacted authors and equipment manufacturers.

SELECTION CRITERIA

This is the update of an existing review. In the previous version of this review, we focused on the effects of tDCS on ADL and function. In this update, we broadened our inclusion criteria to compare any kind of active tDCS for improving ADL, function, muscle strength and cognitive abilities (including spatial neglect) versus any kind of placebo or control intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and risk of bias, extracted data, and applied GRADE criteria. If necessary, we contacted study authors to ask for additional information. We collected information on dropouts and adverse events from the trial reports.

MAIN RESULTS

We included 67 studies involving a total of 1729 patients after stroke. We also identified 116 ongoing studies. The risk of bias did not differ substantially for different comparisons and outcomes. The majority of participants had ischaemic stroke, with mean age between 43 and 75 years, in the acute, postacute, and chronic phase after stroke, and level of impairment ranged from severe to less severe. Included studies differed in terms of type, location and duration of stimulation, amount of current delivered, electrode size and positioning, as well as type and location of stroke. We found 23 studies with 781 participants examining the effects of tDCS versus sham tDCS (or any other passive intervention) on our primary outcome measure, ADL after stroke. Nineteen studies with 686 participants reported absolute values and showed evidence of effect regarding ADL performance at the end of the intervention period (standardised mean difference (SMD) 0.28, 95% confidence interval (CI) 0.13 to 0.44; random-effects model; moderate-quality evidence). Four studies with 95 participants reported change scores, and showed an effect (SMD 0.48, 95% CI 0.02 to 0.95; moderate-quality evidence). Six studies with 269 participants assessed the effects of tDCS on ADL at the end of follow-up and provided absolute values, and found improved ADL (SMD 0.31, 95% CI 0.01 to 0.62; moderate-quality evidence). One study with 16 participants provided change scores and found no effect (SMD -0.64, 95% CI -1.66 to 0.37; low-quality evidence). However, the results did not persist in a sensitivity analysis that included only trials with proper allocation concealment. Thirty-four trials with a total of 985 participants measured upper extremity function at the end of the intervention period. Twenty-four studies with 792 participants that presented absolute values found no effect in favour of tDCS (SMD 0.17, 95% CI -0.05 to 0.38; moderate-quality evidence). Ten studies with 193 participants that presented change values also found no effect (SMD 0.33, 95% CI -0.12 to 0.79; low-quality evidence). Regarding the effects of tDCS on upper extremity function at the end of follow-up, we identified five studies with a total of 211 participants (absolute values) without an effect (SMD -0.00, 95% CI -0.39 to 0.39; moderate-quality evidence). Three studies with 72 participants presenting change scores found an effect (SMD 1.07; 95% CI 0.04 to 2.11; low-quality evidence). Twelve studies with 258 participants reported outcome data for lower extremity function and 18 studies with 553 participants reported outcome data on muscle strength at the end of the intervention period, but there was no effect (high-quality evidence). Three studies with 156 participants reported outcome data on muscle strength at follow-up, but there was no evidence of an effect (moderate-quality evidence). Two studies with 56 participants found no evidence of effect of tDCS on cognitive abilities (low-quality evidence), but one study with 30 participants found evidence of effect of tDCS for improving spatial neglect (very low-quality evidence). In 47 studies with 1330 participants, the proportions of dropouts and adverse events were comparable between groups (risk ratio (RR) 1.25, 95% CI 0.74 to 2.13; random-effects model; moderate-quality evidence).  AUTHORS' CONCLUSIONS: There is evidence of very low to moderate quality on the effectiveness of tDCS versus control (sham intervention or any other intervention) for improving ADL outcomes after stroke. However, the results did not persist in a sensitivity analyses including only trials with proper allocation concealment. Evidence of low to high quality suggests that there is no effect of tDCS on arm function and leg function, muscle strength, and cognitive abilities in people after stroke. Evidence of very low quality suggests that there is an effect on hemispatial neglect. There was moderate-quality evidence that adverse events and numbers of people discontinuing the treatment are not increased. Future studies should particularly engage with patients who may benefit the most from tDCS after stroke, but also should investigate the effects in routine application. Therefore, further large-scale randomised controlled trials with a parallel-group design and sample size estimation for tDCS are needed.

Electromechanical-assisted training for walking after stroke

BACKGROUND

Electromechanical- and robot-assisted gait-training devices are used in rehabilitation and might help to improve walking after stroke. This is an update of a Cochrane Review first published in 2007 and previously updated in 2017.

OBJECTIVES

Primary • To determine whether electromechanical- and robot-assisted gait training versus normal care improves walking after stroke Secondary • To determine whether electromechanical- and robot-assisted gait training versus normal care after stroke improves walking velocity, walking capacity, acceptability, and death from all causes until the end of the intervention phase SEARCH METHODS: We searched the Cochrane Stroke Group Trials Register (last searched 6 January 2020); the Cochrane Central Register of Controlled Trials (CENTRAL; 2020 Issue 1), in the Cochrane Library; MEDLINE in Ovid (1950 to 6 January 2020); Embase (1980 to 6 January 2020); the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 20 November 2019); the Allied and Complementary Medicine Database (AMED; 1985 to 6 January 2020); Web of Science (1899 to 7 January 2020); SPORTDiscus (1949 to 6 January 2020); the Physiotherapy Evidence Database (PEDro; searched 7 January 2020); and the engineering databases COMPENDEX (1972 to 16 January 2020) and Inspec (1969 to 6 January 2020). We handsearched relevant conference proceedings, searched trials and research registers, checked reference lists, and contacted trial authors in an effort to identify further published, unpublished, and ongoing trials.

SELECTION CRITERIA

We included all randomised controlled trials and randomised controlled cross-over trials in people over the age of 18 years diagnosed with stroke of any severity, at any stage, in any setting, evaluating electromechanical- and robot-assisted gait training versus normal care.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed methodological quality and risk of bias, and extracted data. We assessed the quality of evidence using the GRADE approach. The primary outcome was the proportion of participants walking independently at follow-up.

MAIN RESULTS

We included in this review update 62 trials involving 2440 participants. Electromechanical-assisted gait training in combination with physiotherapy increased the odds of participants becoming independent in walking (odds ratio (random effects) 2.01, 95% confidence interval (CI) 1.51 to 2.69; 38 studies, 1567 participants; P < 0.00001; I² = 0%; high-quality evidence) and increased mean walking velocity (mean difference (MD) 0.06 m/s, 95% CI 0.02 to 0.10; 42 studies, 1600 participants; P = 0.004; I² = 60%; low-quality evidence) but did not improve mean walking capacity (MD 10.9 metres walked in 6 minutes, 95% CI -5.7 to 27.4; 24 studies, 983 participants; P = 0.2; I² = 42%; moderate-quality evidence). Electromechanical-assisted gait training did not increase the risk of loss to the study during intervention nor the risk of death from all causes. Results must be interpreted with caution because (1) some trials investigated people who were independent in walking at the start of the study, (2) we found variation between trials with respect to devices used and duration and frequency of treatment, and (3) some trials included devices with functional electrical stimulation. Post hoc analysis showed that people who are non-ambulatory at the start of the intervention may benefit but ambulatory people may not benefit from this type of training. Post hoc analysis showed no differences between the types of devices used in studies regarding ability to walk but revealed differences between devices in terms of walking velocity and capacity.

AUTHORS' CONCLUSIONS

People who receive electromechanical-assisted gait training in combination with physiotherapy after stroke are more likely to achieve independent walking than people who receive gait training without these devices. We concluded that eight patients need to be treated to prevent one dependency in walking. Specifically, people in the first three months after stroke and those who are not able to walk seem to benefit most from this type of intervention. The role of the type of device is still not clear. Further research should consist of large definitive pragmatic phase 3 trials undertaken to address specific questions about the most effective frequency and duration of electromechanical-assisted gait training, as well as how long any benefit may last. Future trials should consider time post stroke in their trial design.

Cortical priming strategies for gait training after stroke: a controlled, stratified trial

BACKGROUND

Stroke survivors experience chronic gait impairments, so rehabilitation has focused on restoring ambulatory capacity. High-intensity speed-based treadmill training (HISTT) is one form of walking rehabilitation that can improve walking, but its effectiveness has not been thoroughly investigated. Additionally, cortical priming with transcranial direct current stimulation (tDCS) and movement may enhance HISTT-induced improvements in walking, but there have been no systematic investigations. The objective of this study was to determine if motor priming can augment the effects of HISTT on walking in chronic stroke survivors.

METHODS

Eighty-one chronic stroke survivors participated in a controlled trial with stratification into four groups: 1) control-15 min of rest (n = 20), 2) tDCS-15 min of stimulation-based priming with transcranial direct current stimulation (n = 21), 3) ankle motor tracking (AMT)-15 min of movement-based priming with targeted movements of the ankle and sham tDCS (n = 20), and 4) tDCS+AMT-15 min of concurrent tDCS and AMT (n = 20). Participants performed 12 sessions of HISTT (40 min/day, 3 days/week, 4 weeks). Primary outcome measure was walking speed. Secondary outcome measures included corticomotor excitability (CME). Outcomes were measured at pre, post, and 3-month follow-up assessments.

RESULTS

HISTT improved walking speed for all groups, which was partially maintained 3 months after training. No significant difference in walking speed was seen between groups. The tDCS+AMT group demonstrated greater changes in CME than other groups. Individuals who demonstrated up-regulation of CME after tDCS increased walking speed more than down-regulators.

CONCLUSIONS

Our results support the effectiveness of HISTT to improve walking; however, motor priming did not lead to additional improvements. Upregulation of CME in the tDCS+AMT group supports a potential role for priming in enhancing neural plasticity. Greater changes in walking were seen in tDCS up-regulators, suggesting that responsiveness to tDCS might play an important role in determining the capacity to respond to priming and HISTT.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT03492229. Registered 10 April 2018 - retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03492229 .

Interfacing With Alpha Motor Neurons in Spinal Cord Injury Patients Receiving Trans-spinal Electrical Stimulation

Trans-spinal direct current stimulation (tsDCS) provides a non-invasive, clinically viable approach to potentially restore physiological neuromuscular function after neurological impairment, e.g., spinal cord injury (SCI). Use of tsDCS has been hampered by the inability of delivering stimulation patterns based on the activity of neural targets responsible to motor function, i.e., α-motor neurons (α-MNs). State of the art modeling and experimental techniques do not provide information about how individual α-MNs respond to electrical fields. This is a major element hindering the development of neuro-modulative technologies highly tailored to an individual patient. For the first time, we propose the use of a signal-based approach to infer tsDCS effects on large α-MNs pools in four incomplete SCI individuals. We employ leg muscles spatial sampling and deconvolution of high-density fiber electrical activity to decode accurate α-MNs discharges across multiple lumbosacral segments during isometric plantar flexion sub-maximal contractions. This is done before, immediately after and 30 min after sub-threshold cathodal stimulation. We deliver sham tsDCS as a control measure. First, we propose a new algorithm for removing compromised information from decomposed α-MNs spike trains, thereby enabling robust decomposition and frequency-domain analysis. Second, we propose the analysis of α-MNs spike trains coherence (i.e., frequency-domain) as an indicator of spinal response to tsDCS. Results showed that α-MNs spike trains coherence analysis sensibly varied across stimulation phases. Coherence analyses results suggested that the common synaptic input to α-MNs pools decreased immediately after cathodal tsDCS with a persistent effect after 30 min. Our proposed non-invasive decoding of individual α-MNs behavior may open up new avenues for the design of real-time closed-loop control applications including both transcutaneous and epidural spinal electrical stimulation where stimulation parameters are adjusted on-the-fly.

Rewiring the Lesioned Brain: Electrical Stimulation for Post-Stroke Motor Restoration

Electrical stimulation has been extensively applied in post-stroke motor restoration, but its treatment mechanisms are not fully understood. Stimulation of neuromotor control system at multiple levels manipulates the corresponding neuronal circuits and results in neuroplasticity changes of stroke survivors. This rewires the lesioned brain and advances functional improvement. This review addresses the therapeutic mechanisms of different stimulation modalities, such as noninvasive brain stimulation, peripheral electrical stimulation, and other emerging techniques. The existing applications, the latest progress, and future directions are discussed. The use of electrical stimulation to facilitate post-stroke motor recovery presents great opportunities in terms of targeted intervention and easy applicability. Further technical improvements and clinical studies are required to reveal the neuromodulatory mechanisms and to enhance rehabilitation therapy efficiency in stroke survivors and people with other movement disorders.

Beyond the target area: an integrative view of tDCS-induced motor cortex modulation in patients and athletes

Transcranial Direct Current Stimulation (tDCS) is a non-invasive technique used to modulate neural tissue. Neuromodulation apparently improves cognitive functions in several neurologic diseases treatment and sports performance. In this study, we present a comprehensive, integrative review of tDCS for motor rehabilitation and motor learning in healthy individuals, athletes and multiple neurologic and neuropsychiatric conditions. We also report on neuromodulation mechanisms, main applications, current knowledge including areas such as language, embodied cognition, functional and social aspects, and future directions. We present the use and perspectives of new developments in tDCS technology, namely high-definition tDCS (HD-tDCS) which promises to overcome one of the main tDCS limitation (i.e., low focality) and its application for neurological disease, pain relief, and motor learning/rehabilitation. Finally, we provided information regarding the Transcutaneous Spinal Direct Current Stimulation (tsDCS) in clinical applications, Cerebellar tDCS (ctDCS) and its influence on motor learning, and TMS combined with electroencephalography (EEG) as a tool to evaluate tDCS effects on brain function.

Searching for the optimal tDCS target for motor rehabilitation

BACKGROUND

Transcranial direct current stimulation (tDCS) has been investigated over the years due to its short and also long-term effects on cortical excitability and neuroplasticity. Although its mechanisms to improve motor function are not fully understood, this technique has been suggested as an alternative therapeutic method for motor rehabilitation, especially those with motor function deficits. When applied to the primary motor cortex, tDCS has shown to improve motor function in healthy individuals, as well as in patients with neurological disorders. Based on its potential effects on motor recovery, identifying optimal targets for tDCS stimulation is essential to improve knowledge regarding neuromodulation as well as to advance the use of tDCS in clinical motor rehabilitation.

METHODS AND RESULTS

Therefore, this review discusses the existing evidence on the application of four different tDCS montages to promote and enhance motor rehabilitation: (1) anodal ipsilesional and cathodal contralesional primary motor cortex tDCS, (2) combination of central tDCS and peripheral electrical stimulation, (3) prefrontal tDCS montage and (4) cerebellar tDCS stimulation. Although there is a significant amount of data testing primary motor cortex tDCS for motor recovery, other targets and strategies have not been sufficiently tested. This review then presents the potential mechanisms and available evidence of these other tDCS strategies to promote motor recovery.

CONCLUSIONS

In spite of the large amount of data showing that tDCS is a promising adjuvant tool for motor rehabilitation, the diversity of parameters, associated with different characteristics of the clinical populations, has generated studies with heterogeneous methodologies and controversial results. The ideal montage for motor rehabilitation should be based on a patient-tailored approach that takes into account aspects related to the safety of the technique and the quality of the available evidence.

Effects of two different protocols of cerebellar transcranial direct current stimulation combined with transcutaneous spinal direct current stimulation on robot-assisted gait training in patients with chronic supratentorial stroke: A single blind, randomized controlled trial

BACKGROUND

The neural organization of locomotion involves motor patterns generated by spinal interneuronal networks and supraspinal structures, which are approachable by noninvasive stimulation techniques. Recent evidences supported the hypothesis that transcranial direct current stimulation (combined with transcutaneous spinal direct current stimulation) may actually enhance the effects of robot-assisted gait training in chronic stroke patients. The cerebellum has many connections to interact with neocortical areas and may provide some peculiar plasticity mechanisms. So, it has been proposed as "non-lesioned entry" to the motor or cognitive system for the application of noninvasive stimulation techniques in patients with supratentorial stroke.

OBJECTIVE

To compare the effects of two different protocols of cerebellar transcranial direct current stimulation combined with transcutaneous spinal direct current stimulation on robotic gait training in patients with chronic supratentorial stroke.

METHODS

Forty patients with chronic supratentorial stroke were randomly assigned into two groups. All patients received ten, 20-minute robotic gait training sessions, five days a week, for two consecutive weeks. Group 1 underwent cathodal transcranial direct current stimulation over the contralesional cerebellar hemisphere + cathodal transcutaneous spinal direct current stimulation in combination with robotic training. Group 2 underwent cathodal transcranial direct current stimulation over the ipsilesional cerebellar hemisphere + cathodal transcutaneous spinal direct current stimulation in combination with robotic training. The primary outcome was the 6-minute walk test performed before, after, and at follow-up at 2 and 4 weeks post-treatment.

RESULTS

No significant difference in the 6-minute walk test between groups was found at the first post-treatment evaluation (P = 0.976), as well as at the 2-week (P = 0.178) and the 4-week (P = 0.069) follow-up evaluations. Both groups showed significant within-group improvements in the 6-minute walk test at all time points.∥Conclusions: Our findings support the hypothesis that cathodal transcranial direct current stimulation over the contralesional or ipsilesional cerebellar hemisphere in combination with cathodal transcutaneous spinal direct current stimulation may lead to similar effects on robotic gait training in chronic supratentorial stroke patients.

Effects of Transcranial Direct Current Stimulation (tDCS) Combined With Wrist Robot-Assisted Rehabilitation on Motor Recovery in Subacute Stroke Patients: A Randomized Controlled Trial

Both transcranial direct current stimulation (tDCS) and wrist robot-assisted training have demonstrated to be promising approaches for stroke rehabilitation. However, the effects of the combination of the two treatments in subacute stroke patients are not clear yet. To investigate the effectiveness of combining tDCS and wrist robot-assisted rehabilitation in subacute stroke patients in comparison with the wrist robotic training only, a single-blind, randomized, sham-controlled trial was performed with 40 subacute stroke patients (25 ± 7 days from stroke onset time). Patients were randomly assigned to experimental group (EG, n = 20 ) where patients receive real tDCS [2 mA, 20 min, and the anodal electrode on the primary motor cortex-M1-area of the affected hemisphere (C3/C4 in the 10-20 EEG system and the cathodal electrode on the contralateral orbit bone)] or control group (CG, n = 20 ) where patients receive sham tDCS (5 s) during wrist robotic rehabilitation training. The effects of the treatment were evaluated by means of the upper extremity, shoulder-elbow, and wrist subsections of the Fugl-Meyer assessment scale, Modified Ashworth Scale, Motricity Index and Box and Block Test together with kinematic parameters. One out of 20 patients in the CG did not complete the treatment. All the clinical outcome measures except the Modified Ashworth Scale showed a significant increase after the treatment in both groups. However, no significant difference in the average changes after treatment between groups was observed. The movement velocity and smoothness showed significant increases after the training, even though no significant difference between groups was observed. The combination of wrist robot-assisted training and tDCS did not show additional effects in comparison with wrist robot-assisted training only in subacute stroke patients. The negative results found in this paper are specific for the specific intervention. The timing of delivering the tDCS and the robot-assisted therapy has to be deeply investigated to enhance the effectiveness of the training.

Noninvasive brain stimulation combined with other therapies improves gait speed after stroke: a systematic review and meta-analysis

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) are noninvasive brain stimulation (NIBS) techniques able to modulate cortical excitability.

OBJECTIVE

To determine the effects of NIBS combined with other therapies on gait speed after stroke.

METHODS

Electronic databases searched were PUBMED, EMBASE, COCHRANE, SCOPUS, SCIELO and PEDro. Eligibility criteria were randomized controlled trials that reported the effects of tDCS and rTMS combined with other therapies for improving gait speed, walking cadence, functional ambulation category (FAC) and motricity index (MI-LE) after stroke. Risk of bias was assessed by Cochrane risk of bias assessment tool. Mean differences (MD) and 95% confidence intervals were calculated. Quality of evidence was assessed by Grades of Researches, Assessment, Development and Evaluation approach.

RESULTS

Ten studies (226 subjects) were included in the meta-analysis. NIBS combined with other therapies was effective for improving gait speed (MD 0.09 m/s [95% CI, 0.05 to 0.13; I² 0%, p < 0.0001]). Gait speed improved in both acute/subacute (MD 0.08 m/s [95% CI, 0.02 to 0.14]) and chronic phases (MD 0.08 m/s [95% CI, 0.03 to 0.13]). Furthermore, inhibitory (MD 0.09 m/s [95% CI, 0.04 to 0.14]) and excitatory (MD 0.07 m/s [95% CI, 0.02 to 0.12]) protocols were effective to improve gait speed. NIBS was also effective to improve walking cadence but was unable to modify other outcomes (FAC and MI-LE).

CONCLUSIONS

This systematic review with meta-analysis synthesizes moderate-quality evidence that NIBS combined with other therapies are effective to improve gait speed after stroke. Systematic Review registration number: PROSPERO registration number CDR42015024237.

Combined effects of cerebellar transcranial direct current stimulation and transcutaneous spinal direct current stimulation on robot-assisted gait training in patients with chronic brain stroke: A pilot, single blind, randomized controlled trial

BACKGROUND

Preliminary evidence showed additional effects of anodal transcranial direct current stimulation over the damaged cerebral hemisphere combined with cathodal transcutaneous spinal direct current stimulation during robot-assisted gait training in chronic stroke patients. This is consistent with the neural organization of locomotion involving cortical and spinal control. The cerebellum is crucial for locomotor control, in particular for avoidance of obstacles, and adaptation to novel conditions during walking. Despite its key role in gait control, to date the effects of transcranial direct current stimulation of the cerebellum have not been investigated on brain stroke patients treated with robot-assisted gait training.

OBJECTIVE

To evaluate the effects of cerebellar transcranial direct current stimulation combined with transcutaneous spinal direct current stimulation on robot-assisted gait training in patients with chronic brain stroke.

METHODS

After balanced randomization, 20 chronic stroke patients received ten, 20-minute robot-assisted gait training sessions (five days a week, for two consecutive weeks) combined with central nervous system stimulation. Group 1 underwent on-line cathodal transcranial direct current stimulation over the contralesional cerebellar hemisphere + cathodal transcutaneous spinal direct current stimulation. Group 2 received on-line anodal transcranial direct current stimulation over the damaged cerebral hemisphere + cathodal transcutaneous spinal direct current stimulation. The primary outcome was the 6-minute walk test performed before, after, and at follow-up at 2 and 4 weeks post-treatment.

RESULTS

The significant differences in the 6-minute walk test noted between groups at the first post-treatment evaluation (p = 0.041) were not maintained at either the 2-week (P = 0.650) or the 4-week (P = 0.545) follow-up evaluations.

CONCLUSION

Our preliminary findings support the hypothesis that cathodal transcranial direct current stimulation over the contralesional cerebellar hemisphere in combination with cathodal transcutaneous spinal direct current stimulation might be useful to boost the effects of robot-assisted gait training in chronic brain stroke patients with walking impairment.

Effects of transcranial direct current stimulation on walking ability after stroke: A systematic review and meta-analysis

BACKGROUND

As a promising technique, transcranial direct current stimulation (tDCS) has gained so much attention in its potential effects on functional recovery of lower limb following stroke. However, individual studies have yielded inconsistent or conflicting results.

OBJECTIVE

To investigate the efficacy and safety of tDCS for the functional recovery of lower limb following stroke reported in the randomized controlled trials by using a meta-analysis.

METHODS

MEDLINE, EMBASE, CINAHL, PsycINFO, Web of Science, CENTRAL, and Physiotherapy Evidence Database was comprehensively searched for randomized controlled trials published until April 2017 that investigated the effects of tDCS on lower limb function. Main outcomes included walking speed, walking endurance, mobility, balance function, muscle strength of lower limb and adverse events.

RESULTS

A total of 10 trials (n = 194) met the inclusion criteria. Meta-analysis demonstrated a significant effect of tDCS on mobility (SMD 0.44, 95% CI: 0.01 to 0.87, P = 0.04) and muscle strength of lower limb (SMD 1.54, 95% CI: 0.29 to 2.78, P = 0.02). No significant effects were found in walking speed (SMD 0.39, 95% CI: -0.06 to 0.85, P = 0.09), walking endurance (SMD 0.28, 95% CI: -0.28 to 0.84, P = 0.33) and balance function (SMD 0.44, 95% CI: -0.06 to 0.94, P = 0.08).

CONCLUSION

tDCS might have beneficial effects on improving mobility and muscle strength of lower limb among individuals with stroke. Future studies with larger sample sizes and an adequate follow-up period are needed.

Early robot-assisted gait retraining in non-ambulatory patients with stroke: a single blind randomized controlled trial

BACKGROUND

Restoration of walking function is a primary concern of neurorehabilitation with respect to the aspired social and vocational reintegration. To date, the best practice for improving gait early after stroke is still object of debate. On one hand, repetitive task-specific approaches with higher intensities of walking have been observed to result in greater improvements of gait after stroke. Conversely there is some evidence that conventional gait training would be more effective for facilitating walking ability after stroke.

AIM

To compare the effects of an early treatment protocol of add-on robot-assisted gait training with add-on conventional overground physiotherapy for improving locomotion in non-ambulatory adult stroke patients.

DESIGN

Single-blind randomized controlled trial.

SETTING

Neurorehabilitation hospital.

POPULATION

Seventy-four subacute patients with first-ever ischemic stroke.

METHODS

The patients were randomized into two groups. The training program consisted of forty, 2-hour sessions (including 45 minutes basic training, 45 minutes add-on training plus rest periods), 5 days a week, for 8 consecutive weeks. Patients allocated to the add-on robot-assisted gait training were treated by means of the Lokomat. Patients allocated to the add-on conventional overground gait training aimed at improving postural control during gait, body weight transfer, stability during the stance phase, free swing phase, adequate heel contact and gait pattern. Primary outcome was the modified Emory Functional Ambulation Profile. Secondary outcomes were the Rivermead Motor Index, the Mobility Milestones and the Hochzirl Walking Aids Profile.

RESULTS

No significant difference was observed between groups with regards to age (P=0.661), time from stroke onset (P=0.413) and the primary outcome (P=0.854) at baseline evaluation. As to the primary outcome, no significant differences were found between groups at the end of the study. As During the 8-week training, within-group comparisons showed significant improvements of mean modified Emory Functional Ambulation Profile in both groups (P<0.001).

CONCLUSIONS

Our results support the hypothesis that an early treatment protocol of robot-assisted gait retraining is not superior to add-on conventional gait training intervention for improving locomotion in non-ambulatory stroke patients.

CLINICAL REHABILITATION IMPACT

This study might help to better understand the role of robot-assisted gait training in early phase stroke rehabilitation.

Literature Review on the Effects of tDCS Coupled with Robotic Therapy in Post Stroke Upper Limb Rehabilitation

Today neurological diseases such as stroke represent one of the leading cause of long-term disability. Many research efforts have been focused on designing new and effective rehabilitation strategies. In particular, robotic treatment for upper limb stroke rehabilitation has received significant attention due to its ability to provide high-intensity and repetitive movement therapy with less effort than traditional methods. In addition, the development of non-invasive brain stimulation techniques such as transcranial Direct Current Stimulation (tDCS) has also demonstrated the capability of modulating brain excitability thus increasing motor performance. The combination of these two methods is expected to enhance functional and motor recovery after stroke; to this purpose, the current trends in this research field are presented and discussed through an in-depth analysis of the state-of-the-art. The heterogeneity and the restricted number of collected studies make difficult to perform a systematic review. However, the literature analysis of the published data seems to demonstrate that the association of tDCS with robotic training has the same clinical gain derived from robotic therapy alone. Future studies should investigate combined approach tailored to the individual patient's characteristics, critically evaluating the brain areas to be targeted and the induced functional changes.

Electromechanical-assisted training for walking after stroke

BACKGROUND

Electromechanical- and robotic-assisted gait-training devices are used in rehabilitation and might help to improve walking after stroke. This is an update of a Cochrane Review first published in 2007.

OBJECTIVES

To investigate the effects of automated electromechanical- and robotic-assisted gait-training devices for improving walking after stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched 9 August 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2016, Issue 8), MEDLINE in Ovid (1950 to 15 August 2016), Embase (1980 to 15 August 2016), CINAHL (1982 to 15 August 2016), AMED (1985 to 15 August 2016), Web of Science (1899 to 16 August 2016), SPORTDiscus (1949 to 15 September 2012), the Physiotherapy Evidence Database (PEDro) (searched 16 August 2016), and the engineering databases COMPENDEX (1972 to 16 November 2012) and Inspec (1969 to 26 August 2016). We handsearched relevant conference proceedings, searched trials and research registers, checked reference lists, and contacted authors in an effort to identify further published, unpublished, and ongoing trials.

SELECTION CRITERIA

We included all randomised controlled trials and randomised controlled cross-over trials in people over the age of 18 years diagnosed with stroke of any severity, at any stage, in any setting, evaluating electromechanical- and robotic-assisted gait training versus normal care.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed methodological quality and risk of bias, and extracted the data. The primary outcome was the proportion of participants walking independently at follow-up.

MAIN RESULTS

We included 36 trials involving 1472 participants in this review update. Electromechanical-assisted gait training in combination with physiotherapy increased the odds of participants becoming independent in walking (odds ratio (random effects) 1.94, 95% confidence interval (CI) 1.39 to 2.71; P < 0.001; I² = 8%; moderate-quality evidence) but did not significantly increase walking velocity (mean difference (MD) 0.04 m/s, 95% CI 0.00 to 0.09; P = 0.08; I² = 65%; low-quality evidence) or walking capacity (MD 5.84 metres walked in 6 minutes, 95% CI -16.73 to 28.40; P = 0.61; I² = 53%; very low-quality evidence). The results must be interpreted with caution because 1) some trials investigated people who were independent in walking at the start of the study, 2) we found variations between the trials with respect to devices used and duration and frequency of treatment, and 3) some trials included devices with functional electrical stimulation. Our planned subgroup analysis suggested that people in the acute phase may benefit, but people in the chronic phase may not benefit from electromechanical-assisted gait training. Post hoc analysis showed that people who are non-ambulatory at intervention onset may benefit, but ambulatory people may not benefit from this type of training. Post hoc analysis showed no differences between the types of devices used in studies regarding ability to walk, but significant differences were found between devices in terms of walking velocity.

AUTHORS' CONCLUSIONS

People who receive electromechanical-assisted gait training in combination with physiotherapy after stroke are more likely to achieve independent walking than people who receive gait training without these devices. We concluded that seven patients need to be treated to prevent one dependency in walking. Specifically, people in the first three months after stroke and those who are not able to walk seem to benefit most from this type of intervention. The role of the type of device is still not clear. Further research should consist of large definitive pragmatic phase III trials undertaken to address specific questions about the most effective frequency and duration of electromechanical-assisted gait training as well as how long any benefit may last.

Robotic gait rehabilitation and substitution devices in neurological disorders: where are we now?

Gait abnormalities following neurological disorders are often disabling, negatively affecting patients' quality of life. Therefore, regaining of walking is considered one of the primary objectives of the rehabilitation process. To overcome problems related to conventional physical therapy, in the last years there has been an intense technological development of robotic devices, and robotic rehabilitation has proved to play a major role in improving one's ability to walk. The robotic rehabilitation systems can be classified into stationary and overground walking systems, and several studies have demonstrated their usefulness in patients after severe acquired brain injury, spinal cord injury and other neurological diseases, including Parkinson's disease, multiple sclerosis and cerebral palsy. In this review, we want to highlight which are the most widely used devices today for gait neurological rehabilitation, focusing on their functioning, effectiveness and challenges. Novel and promising rehabilitation tools, including the use of virtual reality, are also discussed.