The Long-Term Maintenance of Upper Limb Motor Improvements Following Transcranial Direct Current Stimulation Combined with Rehabilitation in People with Stroke: A Systematic Review of Randomized Sham-Controlled Trials

Molecular Changes in the Ischemic Brain as Non-Invasive Brain Stimulation Targets-TMS and tDCS Mechanisms, Therapeutic Challenges, and Combination Therapies

Ischemic stroke is one of the leading causes of death and disability. As the currently used neurorehabilitation methods present several limitations, the ongoing research focuses on the use of non-invasive brain stimulation (NIBS) techniques such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). NIBS methods were demonstrated to modulate neural excitability and improve motor and cognitive functioning in neurodegenerative diseases. However, their mechanisms of action are not fully elucidated, and the clinical outcomes are often unpredictable. This review explores the molecular processes underlying the effects of TMS and tDCS in stroke rehabilitation, including oxidative stress reduction, cell death, stimulation of neurogenesis, and neuroprotective phenotypes of glial cells. A highlight is put on the newly emerging therapeutic targets, such as ferroptotic and pyroptotic pathways. In addition, the issue of interindividual variability is discussed, and the role of neuroimaging techniques is investigated to get closer to personalized medicine. Furthermore, translational challenges of NIBS techniques are analyzed, and limitations of current clinical trials are investigated. The paper concludes with suggestions for further neurorehabilitation stroke treatment, putting the focus on combination and personalized therapies, as well as novel protocols of brain stimulation techniques.

Post-stroke rehabilitation in the peri-pandemic COVID-19 era

The coronavirus disease 2019 (COVID-19), which arose in late 2019, caused extensive destruction, impacting a substantial proportion of the worldwide population and leading to millions of deaths. Although COVID-19 is mainly linked to respiratory and pulmonary complications, it has the potential to affect neurologic structures as well. Neurological involvement may manifest as minimal and reversible; however, a notable proportion of cases have exhibited pronounced neurological consequences, such as strokes. Endothelial inflammation, hypercoagulation, renin-angiotensin-aldosterone system alterations, and cardiogenic embolism are the pathophysiological mechanisms of stroke under COVID-19 circumstances. Physical activity and exercise have improved several aspects of post-stroke recovery, including cardiovascular health, walking capacity, and upper limb strength. They are commonly used to assist stroke survivors in overcoming their motor restrictions. Furthermore, stroke rehabilitation can incorporate a range of specific techniques, including body-weight-supported treadmill applications, constraint-induced movement therapy, robotic rehabilitation interventions, transcranial direct current stimulation, transcranial magnetic stimulation, and prism adaptation training. Under pandemic conditions, there were several barriers to neurological rehabilitation. The most significant of these were individual's fear of infection, which caused them to postpone their rehabilitation applications and rehabilitation areas being converted into COVID-19 units. The primary emphasis had turned to COVID-19 treatment. Several valuable data and views were gained in reorganizing rehabilitation during the pandemic, contributing to establishing future views in this regard.

Efficacy of a Rehabilitation Program Using Mirror Therapy and Cognitive Therapeutic Exercise on Upper Limb Functionality in Patients with Acute Stroke

Applying evidence-based therapies in stroke rehabilitation plays a crucial role in this process, as they are supported by studies and results that demonstrate their effectiveness in improving functionality, such as mirror therapy (MT), cognitive therapeutic exercise (CTE), and task-oriented training. The aim of this study was to assess the effectiveness of MT and CTE combined with task-oriented training on the functionality, sensitivity, range, and pain of the affected upper limb in patients with acute stroke. A longitudinal multicenter study recruited a sample of 120 patients with acute stroke randomly and consecutively, meeting specific inclusion and exclusion criteria. They were randomly allocated into three groups: a control group only for task-oriented training (TOT) and two groups undergoing either MT or CTE, both combined with TOT. The overall functionality of the affected upper limb, specific functionality, sensitivity, range of motion, and pain were assessed using the Fugl-Meyer Assessment Upper Extremity (FMA-UE) scale validated for the Spanish population. An initial assessment was conducted before the intervention, a second assessment after completing the 20 sessions, and another three months later. ANCOVA analysis revealed statistically significant differences between the assessments and the experimental groups compared to the control group, indicating significant improvement in the overall functionality of the upper limb in these patients. However, no significant differences were observed between the two experimental groups. The conclusion drawn was that both therapeutic techniques are equally effective in treating functionality, sensitivity, range of motion, and pain in the upper limb following a stroke.

Transcranial direct current stimulation combined with bodyweight support-tai chi footwork for motor function of stroke survivors: a study protocol of randomised controlled trial

INTRODUCTION

Our previous studies have proposed the bodyweight support-t'ai chi (BWS-TC) footwork training for stroke survivors with severe motor dysfunction and fear of falling, and have proven its positive effects for motor function. Transcranial direct current stimulation (tDCS) provides a non-invasive and safe way to modulate neuronal activity and provoke neuroplastic changes and to improve the motor function of stroke survivors. However, it is unclear whether the integration of BWS-TC and tDCS has synergistic effects on improving motor function of the stroke survivors.

METHODS AND ANALYSIS

This study will be an assessor-blinded randomised controlled trial involving 12-week intervention and 6-month follow-up. One hundred and thirty-five individuals with stroke will be randomly divided in a ratio of 1:1:1 into three groups. Control group A, control group B and intervention group C will receive tDCS and conventional rehabilitation programmes (CRPs), BWS-TC and CRP, tDCS-BWS-TC and CRP for 12 weeks, respectively. The primary outcome measures will include the efficacy (Fugl-Meyer Assessment), acceptability and safety of these interventions. The secondary outcome measures will include balance ability (ie, limits of stability and modified clinical test of sensory integration), walking function, brain structure and function, risk of falling, Barthel Index and 36-Item Short Form Survey. All outcomes will be assessed at baseline, 6 and 12 weeks during intervention, and 1, 3 and 6 months during the follow-up period. Two-way analysis of variance with repeated measures will be applied to examine the main effects of the group and the time factor and group-time interaction effects for all outcome measures.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the ethics committee of the Shanghai Seventh People's Hospital (2021-7th-HIRB-017). The results of the study will be published in a peer-reviewed journal and presented at scientific conferences.

TRIAL REGISTRATION NUMBER

ChiCTR2200059329.

May Dual Transcranial Direct Current Stimulation Enhance the Efficacy of Robot-Assisted Therapy for Promoting Upper Limb Recovery in Chronic Stroke?

OBJECTIVE

To assess whether dual transcranial direct current stimulation (tDCS) may enhance the efficacy of exoskeleton robotic training on upper limb motor functions in patients with chronic stroke.

METHODS

A prospective, bi-center, double-blind, randomized clinical trial study was performed. Patients with moderate-to-severe stroke (according to The National Institute of Health Stroke Scale) were randomly assigned to receive dual or sham tDCS immediately before robotic therapy (10 sessions, 2 weeks). The primary outcome was the Fugl-Meyer for Upper Extremity, assessed before, after, and at the 12-week follow-up. Neurophysiological evaluation of corticospinal projections to upper limb muscles was performed by recording motor evoked potentials (MEPs). ClinicalTrials.gov-NCT03026712.

RESULTS

Two hundred and sixty individuals were tested for eligibility, of which 80 were enrolled and agreed to participate. Excluding 14 dropouts, 66 patients were randomly assigned into the 2 groups. Results showed that chronic patients were stable before treatment and significantly improved after that. The records within subject improvements were not significantly different between the 2 groups. However, a post-hoc analysis subdividing patients in 2 subgroups based on the presence or absence of MEPs at the baseline showed a significantly higher effect of real tDCS in patients without MEPs when compared to patients with MEPs (F = 4.6, P = .007).

CONCLUSION

The adjunction of dual tDCS to robotic arm training did not further enhance recovery in the treated sample of patients with chronic stroke. However, a significant improvement in the subgroup of patients with a severe corticospinal dysfunction (as suggested by the absence of MEPs) suggests that they could benefit from such a treatment combination.

Ultrasound-Guided Median Nerve Electrical Stimulation to Promote Upper Limb Function Recovery after Stroke

Peripheral electrical nerve stimulation enhances hand function during stroke rehabilitation. Here, we proposed a percutaneous direct median nerve stimulation guided by ultrasound (ultrasound‐guided median nerve electrical stimulation, UG-MNES) and evaluated its feasibility and effectiveness in the treatment of stroke patients with upper limb extremity impairments. Sixty-three stroke patients (2-3 months of onset) were randomly divided into control and UG-MNES groups. Both groups received routine rehabilitation and the UG-MNES group received an additional ultrasound-guided electrical stimulation of the median nerve at 2 Hz, 0.2 ms pulse-width for 20 minutes with gradual intensity enhancement. The Fugl-Meyer Assessment for upper extremity motor function (FMA-UE) was used as the primary outcome. The secondary outcomes were the Functional Test for the Hemiplegic Upper Extremity (FTHUE-HK), Hand Function Rating Scale, Brunnstrom Stages, and Barthel Index scores for motor and daily functions. All the participants completed the trial without any side effects or adverse events during the intervention. After 4 weeks of intervention, the functions of the upper limbs on the hemiplegic side in both groups achieved significant recovery. Compared to the control group, all evaluation indices used in this trial were improved significantly in the UG-MNES group after 2 and 4 weeks of intervention; particularly, the first intervention of UG-MNES immediately improved all the assessment items significantly. In conclusion, the UG-MNES is a safe and feasible treatment for stroke patients with upper limb extremity impairments and could significantly improve the motor function of the affected upper limb, especially in the first intervention. The UG-MNES could be an effective alternative intervention for stroke with upper limb extremity impairments.