Enhancing motor skill learning through multiple sessions of online high-definition transcranial direct current stimulation in healthy adults: insights from EEG power spectrum.

The purpose of this study was to evaluate the influence of high-definition transcranial direct current stimulation (HD-tDCS) on finger motor skill acquisition. Thirty-one healthy adult males were randomly assigned to one of three groups: online HD-tDCS (administered during motor skill learning), offline HD-tDCS (delivered before motor skill learning), and a sham group. Participants engaged in a visual isometric pinch task for three consecutive days. Overall motor skill learning and speed-accuracy tradeoff function were used to evaluate the efficacy of tDCS. Electroencephalography was recorded and power spectral density was calculated. Both online and offline HD-tDCS total motor skill acquisition was significantly higher than the sham group (P < 0.001 and P < 0.05, respectively). Motor skill acquisition in the online group was higher than offline (P = 0.132, Cohen's d = 1.46). Speed-accuracy tradeoff function in the online group was higher than both offline and sham groups in the post-test. The online group exhibited significantly lower electroencephalography activity in the frontal, fronto-central, and centro-parietal alpha band regions compared to the sham (P < 0.05). The findings suggest that HD-tDCS application can boost finger motor skill acquisition, with online HD-tDCS displaying superior facilitation. Furthermore, online HD-tDCS reduces the power of alpha rhythms during motor skill execution, enhancing information processing and skill learning efficiency.

Effect of Neurostimulation on Chronic Pancreatic Pain: A Systematic Review.

BACKGROUND: Chronic pancreatic pain is one of the most severe causes of visceral pain, and treatment response is often limited. Neurostimulation techniques have been investigated for chronic pain syndromes once there are pathophysiological reasons to believe that these methods activate descending pain inhibitory systems. Considering this, we designed this systematic literature review to investigate the evidence on neuromodulation techniques as a treatment for chronic pancreatic pain. MATERIALS AND METHODS: We performed a literature search using the databases MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), and Embase until April 2024. The included studies used neurostimulation techniques in participants with chronic pancreatic pain and reported pain-related outcomes, with a focus on pain scales and opioid intake. Two reviewers screened and extracted data, and a third reviewer resolved discrepancies. We assessed the risk of bias using the Jadad scale. The authors then grouped the findings by the target of the neurostimulation, cortex, spinal cord, or peripheral nerves; described the findings qualitatively in the results section, including qualitative data reported by the articles; and calculated effect sizes of pain-related outcomes. RESULTS: A total of 22 studies were included (7 randomized clinical trials [RCTs], 14 case series, and 1 survey), including a total of 257 clinical trial participants. The two outcomes most commonly reported were pain, measured by the visual analogue scale (VAS), numeric rating scale (NRS), and pressure pain threshold scores, and opioid intake. Two RCTs investigated repetitive transcranial magnetic stimulation (rTMS), showing a reduction of 36% (±16) (d = 2.25; 95% CI, 0.66-3.83) and 27.2% (±24.5%) (d = 2.594; 95% CI, 1.303-3.885) in VAS pain scale. In another clinical trial, transcranial direct-current stimulation (tDCS) and transcranial pulsed current stimulation were not observed to effect a significant reduction in VAS pain (χ2 = 5.87; p = 0.12). However, a complete remission was reported in one tDCS case. Spinal cord stimulation (SCS) and dorsal root ganglion stimulation were performed in a survey and 11 case series, showing major pain decrease and diminished opioid use in 90% of participants after successful implantation; most studies had follow-up periods of months to years. Two noninvasive vagal nerve stimulation (VNS) RCTs showed no significant pain reduction in pain thresholds or VAS (d = 0.916; 95% CI, -0.005 to 1.838; and d = 0.17; -0.86 to 1.20; p = 0.72; respectively). Splanchnic nerve stimulation in one case report showed complete pain reduction accompanied by discontinuation of oral morphine and fentanyl lozenges and a 95% decrease in fentanyl patch use. Two RCTs investigated transcutaneous electrical nerve stimulation (TENS). One found a significant pain reduction effect with the NRS (d = 1.481; 95% CI, 1.82-1.143), and decreased opioid use, while the other RCT did not show significant benefit. Additionally, one case report with TENS showed pain improvement that was not quantitatively measured. DISCUSSION: The neuromodulation techniques of rTMS and SCS showed the most consistent potential as a treatment method for chronic pancreatic pain. However, the studies have notable limitations, and SCS has had no clinical trials. For VNS, we have two RCTs that showed a non-statistically significant improvement; we believe that both studies had a lack of power issue and suggest a gap in the literature for new RCTs exploring this modality. Additionally, tDCS and TENS showed mixed results. Another important insight was that opioid intake decrease is a common trend among most studies included and that adverse effects were rarely reported. To further elucidate the potential of these neurostimulation techniques, we suggest the development of new clinical trials with larger samples and adequate sham controls.

Investigations of motor performance with neuromodulation and exoskeleton using leader-follower modality: a tDCS study.

This study investigates how the combination of robot-mediated haptic interaction and cerebellar neuromodulation can improve task performance and promote motor skill development in healthy individuals using a robotic exoskeleton worn on the index finger. The authors propose a leader-follower type of mirror game where participants can follow a leader in a two-dimensional virtual reality environment while the exoskeleton tracks the index finger motion using an admittance filter. The game requires two primary learning phases: the initial phase focuses on mastering the pinching interface, while the second phase centers on predicting the leader's movements. Cerebral transcranial direct current stimulation (tDCS) with anodal polarity is applied to the subjects during the game. It is shown that the subjects' performance improves as they play the game. The combination of tDCS with finger exoskeleton significantly enhances task performance. Our research indicates that modulation of the cerebellum during the mirror game improves the motor skills of healthy individuals. The results also indicate potential uses for motor neurorehabilitation in hemiplegia patients.

Effects of transcranial direct current stimulation combined with concurrent dual-task walking on mobility, gait and cognitive outcomes: A systematic review.

INTRODUCTION: Successful execution of normal activities in various populations warrants the performance of dual tasks (DTs). DTs involve motor and cognitive tasking with the involvement of various brain areas. Transcranial direct current stimulation (tDCS) has been used for regulating the excitability of brain cortical regions. The purpose of this review was to evaluate the available scientific evidence on the effects of tDCS combined with concurrent DT walking on mobility, gait and cognition in older adults (OAs) with and without Parkinson's disease (PD). METHODS: The PubMed, PEDro, Cochrane Library, Embase and Web databases of Science were searched for relevant articles published from their beginning until date. Randomized controlled trials were retrieved, and their methodological quality and risk of bias were evaluated using the PEDro scale and the Cochrane risk-of-bias tool respectively. Qualitative and quantitative synthesis were used to analyze the data. RESULTS: Five studies were included in the review. The results revealed that in individuals with PD, active tDCS with concurrent DT walking has more potential to significantly improve DT cost to gait speed (p < 0.05), and the proportion of correct responses during DT time up and go test (TUG)count (p = 0.004). DT walking with concurrent tDCS has potential to significantly improve DT [gait speed count (p = 0.03), cadence (p = 0.0005), double limb support time (DBST) (p < 0.0001), and single-task (ST) cadence (p = 0.008)]. Significant improvements were observed in the DT costs for stride time (p < 0.0001), DBST (p = 0.03), stride time variability (p < 0.00001), and swing time variability (p = 0.002) with the active tDCS combined with concurrent DT training in OAs. CONCLUSIONS: The effects of tDCS combined with concurrent DT walking or training on cognitive, gait and mobility outcomes in OAs with or without PD can be better explained by the DTW training itself. However, tDCS could produce some specific effects in particular outcomes and scenarios.

Repeated prefrontal tDCS for improving mental health and cognitive deficits in multiple sclerosis: a randomized, double-blind, parallel-group study.

BACKGROUND: Multiple Sclerosis (MS) is an autoimmune disease associated with physical disability, psychological impairment, and cognitive dysfunctions. Consequently, the disease burden is substantial, and treatment choices are limited. In this randomized, double-blind study, we conducted repeated prefrontal electrical stimulation in 40 patients with MS to evaluate mental health variables (quality of life, sleep difficulties, psychological distress) and cognitive dysfunctions (psychomotor speed, working memory, attention/vigilance), marking it as the third largest sample size tDCS research conducted in MS to date. METHODS: The patients were randomly assigned (block randomization method) to two groups of sham (n = 20), or 1.5-mA (n = 20) transcranial direct current stimulation (tDCS) targeting the left dorsolateral prefrontal cortex (F3) and right frontopolar cortex (Fp2) with anodal and cathodal stimulation respectively (electrode size: 25 cm2). The treatment included 10 sessions of 20 min of stimulation delivered every other day. Outcome measures were MS quality of life, sleep quality, psychological distress, and performance on a neuropsychological test battery dedicated to cognitive dysfunctions in MS (psychomotor speed, working memory, and attention). All outcome measures were evaluated at the pre-intervention and post-intervention assessments. Both patients and technicians delivering the stimulation were unaware of the type of stimulation being used. RESULTS: Repeated prefrontal real tDCS significantly improved quality of life and reduced sleep difficulties and psychological distress compared to the sham group. It, furthermore, improved psychomotor speed, attention, and vigilance compared to the sham protocol. Improvement in mental health outcome variables and cognitive outperformance were interrelated and could predict each other. CONCLUSIONS: Repeated prefrontal and frontopolar tDCS ameliorates secondary clinical symptoms related to mental health and results in beneficial cognitive effects in patients with MS. These results support applying prefrontal tDCS in larger trials for improving mental health and cognitive dysfunctions in MS. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT06401928.

Transcranial direct current stimulation enhances the protective effect of isoflurane preconditioning on cerebral ischemia/reperfusion injury: A new mechanism associated with the nuclear protein Akirin2.

AIMS: Ischemic stroke is a major cause of disability and mortality worldwide. Transcranial direct current stimulation (tDCS) and isoflurane (ISO) preconditioning exhibit neuroprotective properties. However, it remains unclear whether tDCS enhances the protective effect of ISO preconditioning on ischemic stroke, and the underlying mechanisms are yet to be clarified. METHOD: A model of middle cerebral artery occlusion (MCAO), a rat ischemia-reperfusion (I/R) injury model, and an in vitro oxygen-glucose deprivation/re-oxygenation (O/R) model of ischemic injury were developed. ISO preconditioning and tDCS were administered daily for 7 days before MCAO modeling. Triphenyltetrazolium chloride staining, modified neurological severity score, and hanging-wire test were conducted to assess infarct volume and neurological outcomes. Untargeted metabolomic experiments, adeno-associated virus, lentiviral vectors, and small interfering RNA techniques were used to explore the underlying mechanisms. RESULTS: tDCS/DCS enhanced the protective effects of ISO pretreatment on I/R injury-induced brain damage. This was evidenced by reduced infarct volume and improved neurological outcomes in rats with MCAO, as well as decreased cortical neuronal death after O/R injury. Untargeted metabolomic experiments identified oxidative phosphorylation (OXPHOS) as a critical pathological process for ISO-mediated neuroprotection from I/R injury. The combination of tDCS/DCS with ISO preconditioning significantly inhibited I/R injury-induced OXPHOS. Mechanistically, Akirin2, a small nuclear protein that regulates cell proliferation and differentiation, was found to decrease in the cortex of rats with MCAO and in cortical primary neurons subjected to O/R injury. Akirin2 functions upstream of phosphatase and tensin homolog deleted on chromosome 10 (PTEN). tDCS/DCS was able to further upregulate Akirin2 levels and activate the Akirin2/PTEN signaling pathway in vivo and in vitro, compared with ISO pretreatment alone, thereby contributing to the improvement of cerebral I/R injury. CONCLUSION: tDCS treatment enhances the neuroprotective effects of ISO preconditioning on ischemic stroke by inhibiting oxidative stress and activating Akirin2-PTEN signaling pathway, highlighting potential of combination therapy in ischemic stroke.

The effect of computerized cognitive training and transcranial direct current stimulation on working memory among post-stroke individuals: a systematic review with meta-analysis and meta-regression.

BACKGROUND: Working memory (WM) impairment is a common phenomenon after stroke; however, its management in rehabilitation is less researched. This systematic review and meta-analysis aimed to provide a quantitative synthesis of the impact of computerised cognitive training (CCT) and transcranial direct current stimulation (tDCS) on WM span in post-stroke individuals. METHODS: The literature search in PubMed, Embase, Scopus, and Cochrane Library focused on randomized controlled trials testing the effect of CCT and tDCS on treated stroke patients as compared to untreated controls. Neuropsychological instruments such as Digit Span Forward/Backward and Visual Span Forward Tests defined the outcome of WM span. After extracting study characteristics and quality assessment using the Cochrane Risk of Bias Tool, we conducted a meta-analysis and meta-regression using standardised mean differences. RESULTS: The search yielded 4142 articles, nine of which (N = 461) fulfilled the inclusion criteria. In the case of CCT, we found significant improvement in Digit Span Backward Test (Z = 2.65, P = 0.008; 95% CI [0.10, 0.67]) and Visual Span Forward Test performance (Z = 3.05, P = 0.002; 95% CI [0.15, 0.69]), while for tDCS, we could not find a sufficient number of studies for the analysis. Furthermore, no significant moderating factor was found in the meta-regression. CONCLUSIONS: In conclusion, CCT appears to be a suitable choice to enhance WM span performance after stroke. However, further research is needed to investigate the effect of tDCS due to the limited number of studies. TRIAL REGISTRATION: The meta-analysis was conducted according to PRISMA (Preferred Reporting of Systematic Reviews and Meta-Analyses) standards with a PROSPERO registration protocol (ID: CRD42023387182).

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.

INTRODUCTION: 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. AIM: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: TT combined with active tDCS significantly improves some gait/mobility outcomes and corticomotor excitability in stroke survivors.

Effect of non-invasive brain stimulation in children with acquired brain injury-a scoping review.

Background: Children and young people (CYP) with acquired brain injury (ABI) require early and effective neurorehabilitation to improve long-term functional outcomes. Non-invasive brain stimulation (NIBS), including transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), have been used to improve motor and sensory skills for children with cerebral palsy. However, there is limited evidence supporting its use in CYP with ABI. Objective: To systematically review the TMS and tDCS intervention effects on motor, sensory and other functional issues in CYP with ABI as reported in the literature. Methods: A comprehensive online bibliographic databases search was performed in various databases using keywords related to NIBS and CYP with ABI. Studies that examine the effect of NIBS intervention on motor function and other functional difficulties either as a primary or secondary objective were included in this review. Results: Fourteen studies (10 single case reports, one retrospective analysis, one case series, one randomised and one quasi-randomised controlled trial) published between 2006 and 2023 were identified. These studies examined the use of NIBS to manage motor disorders, hearing, vision, headaches, speech and language and memory issues. Seventy-six children with mild to severe ABI had received NIBS. The session frequency (3-20), duration (10-45 min) was variable, and NIBS delivered between 3 and 28 days. Conclusion: The literature describing NIBS interventions in CYP with ABI is scarce. An insufficient number of studies, inadequate information reported in them, and small sample sizes limit the ability to conclude how effective NIBS is in improving motor function and other functional issues in this cohort. Further studies are therefore necessary to examine the therapeutic effects of NIBS to manage various functional problems in the CYP with ABI.

Transcranial direct stimulation over left inferior frontal gyrus improves language production and comprehension in post-stroke aphasia: A double-blind randomized controlled study.

Transcranial direct current stimulation (tDCS) targeting Broca's area has shown promise for augmenting language production in post-stroke aphasia (PSA). However, previous research has been limited by small sample sizes and inconsistent outcomes. This study employed a double-blind, parallel, randomized, controlled design to evaluate the efficacy of anodal Broca's tDCS, paired with 20-minute speech and language therapy (SLT) focused primarily on expressive language, across 5 daily sessions in 45 chronic PSA patients. Utilizing the Western Aphasia Battery-Revised, which assesses a spectrum of linguistic abilities, we measured changes in both expressive and receptive language skills before and after intervention. The tDCS group demonstrated significant improvements over sham in aphasia quotient, auditory verbal comprehension, and spontaneous speech. Notably, tDCS improved both expressive and receptive domains, whereas sham only benefited expression. These results underscore the broader linguistic benefits of Broca's area stimulation and support the integration of tDCS with SLT to advance aphasia rehabilitation.

Transcranial direct current stimulation as a potential remyelinating therapy: Visual evoked potentials recovery in cuprizone demyelination.

AIMS: Non-invasive neuromodulation by transcranial direct current stimulation (tDCS), owing to its reported beneficial effects on neuronal plasticity, has been proposed as a treatment to promote functional recovery in several neurological conditions, including demyelinating diseases like multiple sclerosis. Less information is available on the effects of tDCS in major pathological mechanisms of multiple sclerosis, such as demyelination and inflammation. To learn more about the latter effects, we applied multi-session anodal tDCS in mice exposed to long-term cuprizone (CPZ) diet, known to induce chronic demyelination. METHODS: Visual evoked potentials (VEP) and motor performance (beam test) were employed for longitudinal monitoring of visual and motor pathways in 28 mice undergoing CPZ diet, compared with 12 control (H) mice. After randomization, anodal tDCS was applied for 5 days in awake, freely-moving surviving animals: 12 CPZ-anodal, 10 CPZ-sham, 5H-anodal, 5 h-sham. At the end of the experiment, histological analysis was performed on the optic nerves and corpus callosum for myelin, axons and microglia/macrophages. KEY FINDINGS: CPZ diet was associated with significantly delayed VEPs starting at 4 weeks compared with their baseline, significant compared with controls at 8 weeks. After 5-day tDCS, VEPs latency significantly recovered in the active group compared with the sham group. Similar findings were observed in the time to cross on the beam test Optic nerve histology revealed higher myelin content and lower microglia/macrophage counts in the CPZ-Anodal group compared with CPZ-Sham. SIGNIFICANCE: Multiple sessions of anodal transcranial direct current stimulation (tDCS) in freely moving mice induced recovery of visual nervous conduction and significant beneficial effects in myelin content and inflammatory cells in the cuprizone model of demyelination. Altogether, these promising findings prompt further exploration of tDCS as a potential therapeutic approach for remyelination.

Is Transcranial Direct Current Stimulation Effective for Cognitive Dysfunction in Substance Use Disorders? A Systematic Review.

Patients with substance use disorders (SUDs) often suffer from cognitive dysfunction (CD), affecting their quality of life and daily functioning. Current treatments, including pharmacotherapy and psychotherapy, have limited efficacy and notable side effects. Transcranial direct current stimulation (tDCS), a non-invasive technique that modulates cortical activity, shows promise in improving cognitive function with minimal side effects and low cost, and could potentially serve as a valuable adjunct to existing therapies. This systematic review aims to evaluate the literature on the effectiveness of tDCS for CD in SUD patients to inform clinical practice and future research. Following PRISMA guidelines, the review includes studies that used tDCS for SUD-related CD. The criteria for inclusion encompassed participants aged 18 and older with a diagnosis of SUD, the use of tDCS (either conventional or high-definition), control groups receiving sham stimulation or no intervention, and cognitive outcome measures for substance-related cognitive function using validated tools. Databases searched were Ovid MEDLINE, PubMed, Web of Science, Embase, Scopus, and PsycINFO, with specific keywords. Twenty-two studies met the criteria, suggesting tDCS can improve cognitive functions in SUD patients, though results varied. Effectiveness may depend on the brain area targeted, stimulation parameters, task requirements, and individual differences. tDCS shows potential in treating SUD-related CD, but further research is needed to optimize stimulation protocols and address study variability. Future studies should use functional magnetic resonance imaging to explore the brain mechanisms by which tDCS improves cognitive function in SUDs and focus on larger, long-term trials to confirm efficacy and refine tDCS treatment parameters.

Early Boost of Linguistic Skills? Individualized Non-Invasive Brain Stimulation in Early Postacute Aphasia.

Non-invasive brain stimulation, such as transcranial direct current stimulation (tDCS), has been shown to increase the outcome of speech and language therapy (SLT) in chronic aphasia. Only a few studies have investigated the effect of add-on tDCS on SLT in the early stage of aphasia; this may be due to methodological reasons, in particular the influence of spontaneous remission and the difficulty of establishing stimulation protocols in clinical routines. Thirty-seven participants with subacute aphasia (PwA) after stroke (23 men, 14 women; mean age 62 ± 12 years; mean duration 49 ± 28 days) were included in two consecutive periods of treatment lasting two weeks each. During the first period (P1) the participants received 10 sessions of SLT, during the second period (P2) the aphasia therapy was supplemented by anodal left hemispheric 2 mA tDCS over the left hemisphere. Severity-specific language tests (Aachen Aphasia Test (AAT), n = 27 and Bielefeld Aphasia Screening-Reha (BIAS-R), n = 10) were administered before P1, between P1 and P2, and after P2. Where information was available, the results were corrected for spontaneous remission (AAT sample), and the therapy outcomes of P1 and P2 were compared. Participants' overall language abilities improved significantly during P1 and P2. However, improvement-as measured by the AAT profile level or the BIAS-R mean percentage value-during P2 (with tDCS) was significantly higher than during P1 (p < 0.001; AAT sample and p = 0.005; BIAS-R sample). Thus, tDCS protocols can be implemented in early aphasia rehabilitation. Despite the limitations of the research design, which are also discussed from an implementation science perspective, this is preliminary evidence that an individually tailored anodal tDCS can have a significant add-on effect on the outcome of behavioral aphasia therapy in subacute aphasia.

Eight sessions of transcranial electrical stimulation for postural response in people with Parkinson's disease: A randomized trial.

BACKGROUND: Impairments in postural responses to perturbation are common in people with Parkinson's disease (PwPD) and lack effective treatment. We recently showed that a single session of transcranial direct current stimulation (tDCS) promotes acute improvement of postural response to perturbation in PwPD. However, the effects of multiple tDCS sessions remain unclear. RESEARCH QUESTION: What is the efficacy of eight sessions of anodal tDCS on postural responses to external perturbation in PwPD? METHODS: Twenty-two PwPD participated in this randomized, double-blind, parallel-arm, and sham-controlled study. Participants were randomly distributed into active (a-tDCS; n=11) or sham stimulation (s-tDCS; n=11). Eight tDCS sessions were applied over the primary motor cortex (M1), with the a-tDCS group receiving 2 mA for 20 minutes. Postural responses to external perturbations were assessed before, 48 hours after, and one month after (follow-up) the completion of tDCS sessions. Primary outcome measures included the onset latency of medial gastrocnemius (MG) muscle and range of center of pressure. Secondary outcomes included electromyography and CoP parameters, and prefrontal cortex (PFC) activity. RESULTS: ANOVA revealed a trend for Group*Moment interaction for MG onset latency (p=0.058). a-tDCS tended to have shorter MG onset latency at post-test (p=0.040; SRM = -0.63) compared to pre-test. For the secondary outcomes, only a-tDCS decreased the time taken to recover balance after the perturbation at post-test and follow-up compared to pre-test (both p<0.001; SRM=-1.42 and -1.53, respectively). Also, only a-tDCS demonstrated lower PFC activity at post-test compared to pre-test (p=0.017; SRM = -0.82) and follow-up (p=0.001). SIGNIFICANCE: Eight sessions of tDCS over M1 improved postural response to perturbation in PwPD. Some benefits lasted for at least a month. Neuromuscular and behavioral changes observed after the intervention were accompanied by decreased PFC activity (executive-attentional control), suggesting that tDCS applied over M1 can improve movement automaticity.

Effectiveness and tolerability of adjunctive transcranial direct current stimulation (tDCS) in management of treatment-resistant depression: A retrospective chart review.

Background: There is a limited number of studies from India investigating the role of transcranial direct current stimulation (tDCS) in treatment-resistant depression (TRD). This clinic-based study reports on the effectiveness of tDCS as an add-on treatment in individuals suffering from TRD. Materials and Methods: Twenty-six right-handed individuals suffering from major depressive disorder who failed to respond to adequate trials of at least two antidepressant drugs in the current episode received tDCS as an augmenting treatment. Twice daily sessions of conventional tDCS were given providing anodal stimulation at the left dorsolateral prefrontal cortex (DLPFC) and cathodal placement at the right DLPFC. A total of 20 sessions were given over 2 weeks. The outcome was assessed based on changes in scores of the Hamilton Rating Scale for Depression (HAMD) and Montgomery-Asberg Depression Rating Scale (MADRS). Results: There was a significant reduction in outcome assessment after tDCS intervention as compared to baseline, with more than 50% of the participants showing response in both scales, which increased further to approximately 77% by the end of 1 month of the follow-up period. Conclusion: Twice daily tDCS sessions with anodal stimulation of left DLPFC and cathodal stimulation of right DLPFC is an effective add-on treatment strategy in individuals with TRD.