Active tDCS Research Articles

Comparison of responders and nonresponders with knee osteoarthritis after transcranial direct current stimulation.

The study compared responders and nonresponders to transcranial direct current stimulation (tDCS) regarding clinical pain outcomes in knee osteoarthritis (OA) patients. Sixty participants received home-based active tDCS, and clinical pain outcomes were compared between responders and nonresponders. Latent class growth analyses classified 41 participants as responders and 19 as nonresponders. Responders showed significantly greater decreases in pain intensity from baseline to post intervention than nonresponders (p < .001). Participants with higher BMI (p = .02) and weight (p = .005) were more likely to respond, while no significant sociodemographic differences were found. Identifying characteristics of nonresponsive tDCS subgroups can tailor treatments for each group. www.clinicaltrials.gov identifier is NCT04016272.

Exploring whether home-based neuromodulation can boost the analgesic effects of exercise in people with knee osteoarthritis: protocol for a double-blinded, pilot randomised controlled trial

IntroductionKnee osteoarthritis (OA) represents a leading cause of disability globally. Exercise has been demonstrated to improve pain and function in people with knee OA. However, when in pain, commencement of...

Transcranial Direct Current Stimulation Combined With Repetitive Transcranial Magnetic Stimulation for Depression: A Randomized Clinical Trial.

Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) are both recognized as effective treatments for depression when applied individually. However, it is unknown whether rTMS combined with tDCS has better efficacy in the treatment of major depressive disorder (MDD). To investigate the clinical effectiveness and safety of rTMS, tDCS, tDCS + rTMS, and sham tDCS + sham rTMS after 2 weeks of treatment in patients with MDD. This double-blind, sham-controlled randomized clinical trial was conducted from November 2021 to April 2023 at 3 hospitals in China (Kangning Hospital affiliated with Ningbo University, Lishui Second People's Hospital, and Taizhou Second People's Hospital). Adult patients (aged 18-65 years) who were diagnosed with major depressive disorder were recruited. Participants were randomly assigned to 1 of 4 interventions: active tDCS + active rTMS, sham tDCS + active rTMS, active tDCS + sham rTMS, and sham tDCS + sham rTMS. Data analysis followed an intention-to-treat approach. Patients received a 2-week course of treatment. The tDCS was administered using a 2-mA direct current stimulator with electrodes placed on the left and right dorsolateral prefrontal cortex (DLPFC). Each tDCS session lasted 20 minutes and was conducted 30 to 60 minutes prior to the rTMS session for a total of 10 sessions. The rTMS was delivered at a frequency of 10 Hz using a figure-8 coil placed on the left DLPFC, with each session consisting of 1600 pulses. Treatments were administered 5 times per week for 2 weeks. Sham treatments were performed with a pseudostimulation coil and emitted only sound. The primary outcome was the change in total score from baseline to week 2 on the 24-item Hamilton Depression Rating Scale (HDRS-24; score range: 0-52, with the highest score indicating more severe symptoms). A total of 240 participants (139 females [57.9%]; mean [SD] age, 32.50 [15.18] years) were included. As a primary outcome, patients who received active tDCS + active rTMS showed a significantly greater reduction in mean (SD) HDRS-24 total scores compared with patients in the other 3 groups (active tDCS + active rTMS: 18.33 [5.39], sham tDCS + active rTMS: 14.86 [5.59], active tDCS + sham rTMS: 9.21 [4.61], and sham tDCS + sham rTMS: 10.77 [5.67]; F3,236 = 35.79; η2 = 0.31 [95% CI, 0.21-0.39]; P < .001). This trial found that tDCS + rTMS was a more effective and safe treatment option than either the tDCS or rTMS intervention alone for patients with MDD. China Clinical Trial Registry Identifier ChiCTR2100052122.

Efficacy and safety of transcranial direct current stimulation (tDCS) in treatment of refractory epilepsy: an updated systematic review and meta-analysis of randomized sham-controlled trials.

Despite the currently available treatment, one-third of epilepsy patients continue to experience seizures. Transcranial direct current stimulation (tDCS) has emerged as a potential neuromodulation approach for the non-invasive treatment of refractory epilepsy. This study aims to provide a comprehensive investigation of the efficacy and safety of tDCS in patients with drug-resistant epilepsy. The following databases were searched from inception until June 2023; PubMed, Scopus, Embase, WOS, EBSCO, Cochrane Central, and Ovid MEDLINE. Pooled mean difference was calculated for change in seizure frequency (SF), and number of Interictal epileptiform discharges (IEDs) at different follow-up intervals. We included nine parallel randomized sham-controlled trials with a total of 267 patients. Active tDCS patients had a significantly lower SF per month at 4 and 8 weeks (MD = -4.06, 95% CI [-6.01 to -2.12], p < 0.0001), and (MD = -2.66, 95% CI [-5.09 to -0.23], p = 0.03), respectively. However, weekly SF showed no statistically significant results at 4 weeks of follow-up. The IEDs were observed to significantly decline at 2, 4, and 8 weeks of follow-up. The reported adverse events were mild including mild itching and erythematous rash that resolved spontaneously. In conclusion, tDCS significantly reduced monthly SF and the number of IEDs. Future large RCTs with standard clear informed parameters are still required.

Modulation of neural networks and symptom correlated in fibromyalgia: A randomized double-blind multi-group explanatory clinical trial of home-based transcranial direct current stimulation.

Transcranial direct current stimulation (tDCS) might modulate neural activity and promote neural plasticity in patients with fibromyalgia (FM). This multi-group randomized clinical trial compared home-based active tDCS (HB-a-tDCS) on the left dorsolateral prefrontal cortex (l-DLPFC) or home-based sham tDCS (HB-s-tDCS), and HB-a-tDCS or HB-s-tDCS on the primary motor cortex (M1) in the connectivity analyses in eight regions of interest (ROIs) across eight resting-state electroencephalography (EEG) frequencies. We included 48 women with FM, aged 30 to 65, randomly assigned to 2:1:2:1 to receive 20 sessions during 20 minutes of HB-a-tDCS 2mA or HB-s-tDCS, over l-DLPFC or M1, respectively. EEG recordings were obtained before and after treatment with eyes open (EO) and eyes closed (EC). In the EC condition, comparing pre to post-treatment, the HB-a-tDCS on l-DLPFC decreased the lagged coherence connectivity in the delta frequency band between the right insula and left anterior cingulate cortex (ACC) (t = -3.542, p = .048). The l-DLPFC HB-a-tDCS compared to HB-s-tDCS decreased the lagged coherence connectivity in the delta frequency band between the right insula and left ACC (t = -4.000, p = .017). In the EO condition, the l-DLPFC HB-a-tDCS compared to M1 HB-s-tDCS increased the lagged coherence connectivity between the l-DLPFC and left ACC in the theta band (t = -4.059, p = .048). Regression analysis demonstrated that the HB-a-tDCS effect on the l-DLPFC was positively correlated with sleep quality. On the other hand, the HB-a-tDCS on l-DLPFC and HB-s-tDCS on M1 were positively correlated with pain catastrophizing. These results show that HB-a-tDCS affects the neural connectivity between parts of the brain that control pain's emotional and attentional aspects, which are most noticeable at lower EEG frequencies in a rest state. This effect on neural oscillations could serve as a neural marker associated with its efficacy in alleviating fibromyalgia symptoms. identifier [NCT03843203].

Transcranial direct current stimulation for Parkinson's disease: systematic review and meta-analysis of motor and cognitive effects.

Transcranial direct current stimulation (tDCS) is a promising noninvasive intervention for Parkinson's disease (PD). However, studies of its motor and cognitive effect have produced mixed results. We conducted a systematic review including 38 studies and meta-analysis of 12 randomized sham-controlled trials with 263 PD patients. No significant differences were found between active and sham tDCS in motor function (UPDRS-III: SMD = -0.14, p = 0.74), gait (SMD = 0.10, p = 0.513), attention and working memory (SMD = 0.24, p = 0.13), executive function (SMD = 0.03, p = 0.854), and memory and learning (SMD: -0.07, p = 0.758). The prediction intervals indicated substantial heterogeneity among studies. Meta-regression showed small positive effects in younger PD patients with milder symptoms. These findings are preliminary but suggest tDCS may benefit some PD patients while being neutral or harmful to others.

Combining Transcranial Direct Current Stimulation with Exercise to Improve Mobility, Stability, and Tremor Management in 25 Individuals with Parkinson’s Disease

Background/Objectives: Parkinson’s disease (PD) is a neurodegenerative disorder characterized by tremors, balance impairments, and mobility limitations. Innovative approaches like combining transcranial direct current stimulation (tDCS) with exercise show promise in addressing these symptoms. This study investigates the effects of exercise combined with tDCS on mobility and tremor management in PD patients. Methods: Twenty-five individuals aged 60−75 (66.6 ± 7.33), diagnosed with PD (Hoehn and Yahr stage 2−3), were assigned to three groups in a randomized controlled design: exercise with active tDCS (n = 8), exercise with sham tDCS (n = 8), and a control group (n = 9). Dual-task training sessions focusing on walking speed, balance, and force control were conducted over ten sessions. Results: No significant differences were detected across the groups for grip strength or force control measures (p &gt; 0.05). Significant improvements were observed in the intervention group: the Timed Up and Go (TUG) test showed a significant reduction in time (mean difference = 2.498 s, p &lt; 0.001, ηp2 = 0.331); anterior–posterior displacement significantly increased (mean difference = 21.375 mm, p = 0.0269, ηp2 = 0.303); and force-tremor decoupling improved, with coherence in the 1−4 Hz band significantly decreasing (p = 0.0067). Finally, changes in TUG from post- to pre-treatment values were significantly positively correlated with the changes in coherence (R = 0.468, p = 0.018). Conclusions: Combining tDCS with exercise enhances mobility and tremor management in PD patients. These findings support the potential for such interventions to improve functional outcomes and quality of life for individuals with PD.

Home-based transcranial direct current stimulation treatment for major depressive disorder: a fully remote phase 2 randomized sham-controlled trial.

Transcranial direct current stimulation (tDCS) has been proposed as a new treatment in major depressive disorder (MDD). This is a fully remote, multisite, double-blind, placebo-controlled, randomized superiority trial of 10-week home-based tDCS in MDD. Participants were 18 years or older, with MDD in current depressive episode of at least moderate severity as measured using the Hamilton Depression Rating Scale (mean = 19.07 ± 2.73). A total of 174 participants (120 women, 54 men) were randomized to active (n = 87, mean age = 37.09 ± 11.14 years) or sham (n = 87, mean age = 38.32 ± 10.92 years) treatment. tDCS consisted of five sessions per week for 3 weeks then three sessions per week for 7 weeks in a 10-week trial, followed by a 10-week open-label phase. Each session lasted 30 min; the anode was placed over the left dorsolateral prefrontal cortex and the cathode over the right dorsolateral prefrontal cortex (active tDCS 2 mA and sham tDCS 0 mA, with brief ramp up and down to mimic active stimulation). As the primary outcome, depressive symptoms showed significant improvement when measured using the Hamilton Depression Rating Scale: active 9.41 ± 6.25 point improvement (10-week mean = 9.58 ± 6.02) and sham 7.14 ± 6.10 point improvement (10-week mean = 11.66 ± 5.96) (95% confidence interval = 0.51-4.01, P = 0.012). There were no differences in discontinuation rates. In summary, a 10-week home-based tDCS treatment with remote supervision in MDD showed high efficacy, acceptability and safety. ClinicalTrials.gov registration: NCT05202119.

Combined Transcranial Direct Current Stimulation and Pain Neuroscience Education for Chronic Low Back Pain: A Randomized Controlled Trial.

Priming the neural circuity likely targeted by pain neuroscience education (PNE), using transcranial direct current stimulation (tDCS) may enhance the efficacy of PNE. The aim of this study was to compare the effects of active tDCS + PNE to sham tDCS + PNE on measures of pain, pain behaviors, and cognitive function in participants with chronic low back pain (CLBP) and high pain catastrophizing. 20 participants were recruited and randomly allocated into the active tDCS + PNE (n = 10) or sham tDCS + PNE (n = 10) groups. All participants received five sessions of their assigned interventions over a 2-week period. The active tDCS + PNE group received 20 minutes of 2 mA, anodal current applied to the left dorsolateral prefrontal cortex. Within groups, both interventions demonstrated significant improvement in NPRS, PCS, and TSK. The active tDCS + PNE group also demonstrated significant improvement on the SCWT, CTMT2-Inhibitory, and CTMT2-Set Shifting. Between groups, the active tDCS + PNE group showed significantly greater improvement on the PCS, SCWT, and CTMT2-Inhibitory. The results of this pilot study suggest that active tDCS + PNE appeared to provide greater improvement than sham tDCS + PNE on levels of pain catastrophizing and attentional interference in participants with CLBP and high pain catastrophizing, consistent with both interventions targeting brain regions involved in those processes. Considering the differences between groups, tDCS appears to provide a priming effect on PNE.

Effects of osteopathic manipulative treatment associated with transcranial direct current stimulation in individuals with chronic low back pain: A double-blind, randomised placebo-controlled trial

Objective To evaluate the effectiveness of osteopathic manipulative treatment (OMT) associated with transcranial direct current stimulation (tDCS) in reducing pain, disability, and improving quality of life in participants with non-specific chronic low back pain. Design A randomised double-blind clinical trial. Setting Clinical outpatient unit. Subjects 72 participants with non-specific chronic low back pain were randomised into three groups: active tDCS + OMT (n = 24), sham tDCS + sham OMT (n = 24), and sham tDCS + OMT (n = 24). Interventions Evaluations were performed before, after the intervention, and one month post-intervention. tDCS consisted of ten 20-minute sessions over two weeks (five sessions per week). OMT was administered once per week, with two sessions conducted before the first and sixth tDCS sessions. Main measures Pain, disability, and quality of life were assessed at baseline, after two weeks, and at one month of follow-up. Results The visual analogue scale showed a significant decrease in all groups (p < 0.001). However, tDCS + OMT and sham tDCS + OMT demonstrated a clinically significant reduction compared to the sham combination (effect size n² = 0.315). Roland-Morris scores decreased across all groups without specific group effects. EuroQoL 5-Dimension 3-Level improvement was observed only in the tDCS + OMT and sham tDCS + OMT groups (significant difference between T2 and T0, p = 0.002). Conclusion The combination of OMT and tDCS did not provide clinically significant improvement over OMT alone in participants with non-specific chronic low back pain.

Efficacy and Safety of Transcranial Direct Current Stimulation as an Add-On Trial Treatment for Acute Bipolar Depression Patients With Suicidal Ideation.

Bipolar depression poses an overwhelming suicide risk. We aimed to examine the efficacy and safety of transcranial direct current stimulation (tDCS) combined with quetiapine in bipolar patients as a suicidal intervention. In a single-center, double-blind, treatment-naive bipolar depression patients with suicidal ideation were randomly assigned to quetiapine in combination with either active (n = 16) or sham (n = 15) tDCS over the left dorsolateral prefrontal cortex for three consecutive weeks. The 30-min, 2-mA tDCS was conducted twice a day on the weekday of the first week and then once a day on the weekdays of the two following weeks. Primary efficacy outcome measure was the change in the Beck Scale for Suicidal Ideation (BSSI). Secondary outcomes included changes on the 17-item Hamilton Depression Rating Scale (HDRS-17) and Montgomery-Asberg Depression Rating Scale (MADRS). Outcome was evaluated on Day 3 and weekend. Safety outcome was based on the reported adverse reactions. Active tDCS was superior to sham tDCS on the BSSI at Day 3 and tended to sustain every weekend during the treatment process, compared to baseline. However, no difference between active and sham in HDRS-17 and MADRS was found. Response and remission rate also supported the antisuicide effect of tDCS, with higher response and remission rate in BSSI, but no antidepressant effect, compared to sham, over time. Regarding safety, active tDCS was well tolerated and all the adverse reactions reported were mild and limited to transient scalp discomfort. The tDCS was effective as an antisuicide treatment for acute bipolar depression patients with suicidal ideation, with minimal side effects reported.

Effects of treadmill training combined with transcranial direct current stimulation on mobility, motor performance, balance function, and other brain-related outcomes in stroke survivors: a systematic review and meta-analysis.

Treadmill training (TT) is a gait training technique that has commonly been used in neurorehabilitation, and has positive effects on gait, mobility, and related outcomes in stroke survivors. Transcranial direct current stimulation (tDCS) is a non-invasive approach for modulating brain cortex excitability. To evaluate the available scientific evidence on the effects of TT combined with tDCS on mobility, motor performance, balance function, and brain-related outcomes in stroke survivors. Five databases namely the Cochrane library, PEDro, Web of Science, PubMed, and EMBASE, were searched for relevant studies from inception to March, 2024. Only randomized controlled trials were included, and their methodological quality and risk of bias (ROB) were evaluated using the PEDro scale and Cochrane ROB assessment tool respectively. Qualitative and quantitative syntheses (using fixed effects meta-analysis) were employed to analyze the data. The results revealed that TT combined with active tDCS had significant beneficial effects on some mobility parameters, some gait spatiotemporal parameters, some gait kinematic parameters, gait endurance, gait ability, and corticomotor excitability in stroke survivors, but no significant difference on gait speed (P > 0.05), functional mobility (P > 0.05), motor performance (P > 0.05), or some balance functions (P > 0.05), compared with the control conditions. TT combined with active tDCS significantly improves some gait/mobility outcomes and corticomotor excitability in stroke survivors.

Effectiveness of Transcranial Direct Current Stimulation (tDCS) during a Virtual Reality Task in Women with Fibromyalgia-A Randomized Clinical Study.

Fibromyalgia (FM) is a chronic condition characterized by widespread musculoskeletal pain, fatigue, and impaired motor performance. This study aimed to investigate the effects of transcranial direct current stimulation (tDCS) during virtual reality (VR) tasks on the motor performance of women with FM. Participants were divided into two groups: Group A received active tDCS for 10 days followed by sham tDCS for 10 days, while Group B received the opposite sequence. Both groups performed VR tasks using MoveHero software (v. 2.4) during the tDCS sessions. Motor performance was assessed by the number of hits (movement with correct timing to reach the targets) and absolute (accuracy measure) and variable (precision measure) errors during VR tasks. Participants were 21 women, aged 30-50 years, and diagnosed with FM. Group A, which received active tDCS first, presented significant improvements in motor performance (number of hits and absolute and variable errors). The benefits of active tDCS persisted into the sham phase, suggesting a lasting neuroplastic effect. tDCS during VR tasks significantly improved motor performance in women with FM, particularly in complex, extensive movements. These findings indicate that tDCS enhances neuroplasticity, leading to sustained motor improvements, making it a promising therapeutic tool in FM rehabilitation.

Cognitive potency and safety of tDCS treatment for major depressive disorder: a systematic review and meta-analysis.

The benefits of transcranial direct current stimulation (tDCS) for patients with major depression disorders are well-established, however, there is a notable research gap concerning its comprehensive effects on both depressive symptoms and cognitive functions. Existing research is inconclusive regarding the cognitive enhancement effects of tDCS specifically in MDD patients. The present study aims to fill this knowledge gap by scrutinizing the most updated evidence on the effectiveness of tDCS in anti-depressive treatment and its influence on cognitive function. A systematic review was performed from the first date available in PubMed, EMBASE, Cochrane Library, and additional sources published in English from 1 January 2001 to 31 May 2023. We examined cognitive outcomes from randomized, sham-controlled trials of tDCS treatment for major depression. The evaluation process strictly followed the Cochrane bias risk assessment tool into the literature, and meta-analysis was performed according to the Cochrane System Reviewer's Manual. In this quantitative synthesis, we incorporated data from a total of 371 patients across 12 studies. Results showed significant benefits following active tDCS compared to sham for the antidepressant effect [SMD: -0.77 (-1.44, -0.11)]. Furthermore, active relative to sham tDCS treatment was associated with increased performance gains on a measure of verbal memory [SMD: 0.30 (-0.02, 0.62)]. These results did not indicate any cognitive enhancement after active tDCS relative to sham for global cognitive function, whereas there was a noticeable trend toward statistical significance specifically in the effect of verbal memory. Our study offers crucial evidence-based medical support for tDCS in antidepressant and dimension-specific cognitive benefits. Further well-designed, large-scale randomized sham-controlled trials are warranted to further validate these findings. https://inplasy.com/, identifier: INPLASY202360008.

Hand functioning in progressive multiple sclerosis improves with tDCS added to daily exercises: A home-based randomized, double-blinded, sham-controlled clinical trial

Background: Many individuals with progressive multiple sclerosis (PMS) are challenged by reduced manual dexterity and limited rehabilitation options. Transcranial direct current stimulation (tDCS) during motor training can improve rehabilitation outcomes. We developed a protocol for remotely supervising tDCS to deliver sessions of stimulation paired with training at home. Objective: This study evaluated the effectiveness of at-home tDCS paired with manual dexterity training for individuals with PMS. Methods: Sixty-five right-hand dominant participants with PMS and hand impairment were randomized to receive either active or sham M1-SO tDCS paired with manual dexterity training over 4 weeks. Clinical outcomes were measured by the changes in Nine-Hole Peg Test (9-HPT) and Dellon-Modified-Moberg-Pick-Up Test (DMMPUT). Results: The intervention had high rates of adherence and completion (98% of participants completed at least 18 of 20 sessions). The active tDCS group demonstrated significant improvement for the left hand compared with baseline in 9-HPT (−5.85 ± 6.19 vs −4.23 ± 4.34, p = 0.049) and DMMPUT (−10.62 ± 8.46 vs −8.97 ± 6.18, p = 0.049). The active tDCS group reported improvements in multiple sclerosis (MS)-related quality of life (mean increase: 5.93 ± 13.04 vs −0.05 ± −8.27; p = 0.04). Conclusion: At-home tDCS paired with manual dexterity training is effective for individuals with PMS, with M1-SO tDCS enhancing training outcomes and offering a promising intervention for improving and preserving hand dexterity.

Online stimulation of the prefrontal cortex during practice increases motor variability and modulates later cognitive transfer: a randomized, double-blinded and sham-controlled tDCS study

The benefits of learning a motor skill extend to improved task-specific cognitive abilities. The mechanistic underpinnings of this motor-cognition relationship potentially rely on overlapping neural resources involved in both processes, an assumption lacking causal evidence. We hypothesize that interfering with prefrontal networks would inhibit concurrent motor skill performance, long-term learning and associated cognitive functions dependent on similar networks (transfer). We conducted a randomised, double-blinded, sham-controlled brain stimulation study using transcranial direct current stimulation (tDCS) in young adults spanning over three weeks to assess the role of the prefrontal regions in learning a complex balance task and long-term cognitive performance. Balance training combined with active tDCS led to higher performance variability in the trained task as compared to the sham group, impacting the process of learning a complex task without affecting the learning rate. Furthermore, active tDCS also positively influenced performance in untrained motor and cognitive tasks. The findings of this study help ascertaining the networks directly involved in learning a complex motor task and its implications on cognitive function. Hence, opening up the possibility of harnessing the observed frontal networks involved in resource mobilization in instances of aging, brain lesion/injury or dysfunction.

Enhancing response inhibition behavior through tDCS intervention in college students with smartphone addiction

Smartphone addiction, emerging from excessive use of smartphones, poses a challenge to inhibitory control functions within society. This research employed transcranial direct current stimulation (tDCS) as an intervention alongside the stop signal task (SST) to explore behavioral distinctions between individuals with smartphone addiction and a non-addicted control group, focusing on the efficacy of tDCS intervention. The participant cohort comprised 80 individuals, divided into an addiction group (39 participants, with 19 receiving active tDCS and 20 receiving sham tDCS) and a control group (41 participants, with 20 receiving active tDCS and 21 receiving sham tDCS), with anodal stimulation applied over the right dorsolateral prefrontal cortex (dlPFC) and cathodal placement over the left arm. The findings indicate that university students struggling with smartphone addiction exhibit reduced inhibitory control compared to their non-addicted peers, while maintaining similar levels of general cognitive control. Remarkably, tDCS interventions were observed to enhance inhibitory control in both groups. Although the improvement in the addiction group appeared more pronounced numerically than in the control group, no significant interaction with group was noted. However, a higher percentage of participants in the smartphone addiction (SA) group exhibited enhanced response inhibition under active tDCS. This study demonstrates the inhibitory control deficits in individuals addicted to smartphones and underscores the potential of tDCS in enhancing response inhibition. It provides a valuable reference for future tDCS research targeting smartphone addiction and highlights the importance of developing healthier smartphone usage habits.

Meta-analysis of variance in tDCS effects on response inhibition

Deficiencies in response inhibition are associated with numerous mental health conditions, warranting innovative treatments. Transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique, modulates cortical excitability and has shown promise in improving response inhibition. However, tDCS effects on response inhibition often yield contradictory findings. Previous research emphasized the importance of inter-individual factors that are mostly ignored in conventional meta-analyses of mean effects. We aimed to fill this gap and promote the complementary use of the coefficient of variation ratio and standardized mean effects. The systematic literature search included single-session and sham-controlled tDCS studies utilizing stop-signal task or Go-NoGo tasks, analyzing 88 effect sizes from 53 studies. Considering the impact of inter-individual factors, we hypothesized that variances increase in the active versus sham tDCS. However, the results showed that variances between both groups did not differ. Additionally, analyzing standardized mean effects supported previous research showing an improvement in the stop-signal task but not in the Go-NoGo task following active tDCS. These findings suggest that inter-individual differences do not increase variances in response inhibition, implying that the heterogeneity cannot be attributed to higher variance in response inhibition during and after active tDCS. Furthermore, methodological considerations are crucial for tDCS efficacy.

Transcranial Direct Current Stimulation in the Treatment of Chronic Knee Pain: A Scoping Review

Background: Chronic knee pain in older adults is a prevalent condition that significantly impacts quality of life. Transcranial Direct Current Stimulation (tDCS) has emerged as a potential non-invasive treatment option. This scoping review aims to evaluate the efficacy of tDCS in treating chronic knee pain among older adults. Methods: A comprehensive search of peer-reviewed articles was conducted, focusing on randomized controlled trials and pilot studies. Studies were included if they met specific Population, Concept, and Context (PCC) criteria. The primary outcomes assessed were pain reduction and functional improvement. Results: Eleven studies met the inclusion criteria, with a total of 779 participants. However, the results varied across studies, with some showing minimal differences between active tDCS and sham treatments. Advanced neuroimaging techniques, such as functional near-infrared spectroscopy (fNIRS), provided insights into the neuromodulatory effects of tDCS, revealing changes in brain activity related to pain perception. Conclusions: Transcranial Direct Current Stimulation (tDCS) presents a promising avenue for treating chronic knee pain in elderly individuals. However, the current body of research offers mixed results, emphasizing the need for more extensive and standardized studies. Future research should focus on understanding the underlying mechanisms, optimizing treatment protocols, and exploring the long-term effects and safety of tDCS.

Transcranial Direct Current Stimulation as Adjuvant to Gamified Rehabilitation for Upper Limb Function in Paediatric Brain Damage (CHILDBOOST Project): A Study Protocol for a Triple-Blind Randomised Controlled Trial

(1) Background and objectives: Paediatric brain injuries can lead to motor and cognitive deficits. Effective rehabilitation is critical for enhancing independence. While virtual reality (VR) and transcranial direct current stimulation (tDCS) have independently demonstrated beneficial effects on motor and cognitive functions, their combined efficacy and its cognitive effects remain to be explored in this population. We aim to investigate the effects of integrating tDCS with VR training on upper limb (UL) functionality and cognitive outcomes through a triple-blind randomised trial. (2) Methods: Twenty-eight children with hemiparesis secondary to non-progressive brain damage will be randomly allocated into two groups: active anodal tDCS (2 mA) plus UL VR training, and sham tDCS with identical VR training. The tDCS will target M1 of the affected or most affected hemisphere for 20 min, simultaneous to VR training. The following four assessments will be carried out: pre-intervention, post-intervention, and three- and six-months follow-up. (3) Results: This study will explore motor and cognitive outcomes of a motor-based intervention in paediatric brain damage. We hypothesise that the experimental group will show significant improvements in UL function and cognition, enhancing their functional recovery. (4) Conclusions: We propose a multidisciplinary therapeutic approach combining neuromodulation and VR to potentiate functional recovery through enhancing motor and cognitive performance in paediatric brain damage.