Transcranial Direct Current Stimulation for the Treatment of Refractory Symptoms of Schizophrenia. Current Evidence and Future Directions

Objective: To examine the effectss of transcranial direct current stimulation (tDCS) on objective and subjective indexes of exercise performance.Design: Systematic review and meta-analysis.Data Sources: A systematic literature search of electronic databases (PubMed, Web of Science, Scopus, Google Scholar) and reference lists of included articles up to June 2018.Eligibility Criteria: Published articles in journals or in repositories with raw data available, randomized sham-controlled trial comparing anodal stimulation with a sham condition providing data on objective (e.g. time to exhaustion or time-trial performance) or subjective (e.g. rate of perceived exertion) indexes of exercise performance.Results: The initial search provided 420 articles of which 31 were assessed for eligibility. Finally, the analysis of effect sizes comprised 24 studies with 386 participants. The analysis indicated that anodal tDCS had a small but positive effect on performance g = 0.34, 95% CI [0.12, 0.52], z = 3.24, p = 0.0012. Effects were not significantly moderated by type of outcome, electrode placement, muscles involved, number of sessions, or intensity and duration of the stimulation. Importantly, the funnel plot showed that, overall, effect sizes tended to be larger in studies with lower sample size and high standard error. Summary: The results suggest that tDCS may have a positive impact on exercise performance. However, the effect is probably small and most likely biased by low quality studies and the selective publication of significant results. Therefore, the current evidence does not provide strong support to the conclusion that tDCS is an effective means to improve exercise performance.

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Transcranial Direct Current Stimulation to Facilitate Lower Limb Recovery Following Stroke: Current Evidence and Future Directions

Brain Sciences ◽

10.3390/brainsci10050310 ◽

2020 ◽

Vol 10 (5) ◽

pp. 310

Author(s):

Samuel Gowan ◽

Brenton Hordacre

Keyword(s):

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Lower Limb ◽

Cortical Neurons ◽

Brain Activity ◽

Current Evidence ◽

Potential Candidate ◽

Limb Function ◽

Direct Current Stimulation ◽

Lower Limb Function

Stroke remains a global leading cause of disability. Novel treatment approaches are required to alleviate impairment and promote greater functional recovery. One potential candidate is transcranial direct current stimulation (tDCS), which is thought to non-invasively promote neuroplasticity within the human cortex by transiently altering the resting membrane potential of cortical neurons. To date, much work involving tDCS has focused on upper limb recovery following stroke. However, lower limb rehabilitation is important for regaining mobility, balance, and independence and could equally benefit from tDCS. The purpose of this review is to discuss tDCS as a technique to modulate brain activity and promote recovery of lower limb function following stroke. Preliminary evidence from both healthy adults and stroke survivors indicates that tDCS is a promising intervention to support recovery of lower limb function. Studies provide some indication of both behavioral and physiological changes in brain activity following tDCS. However, much work still remains to be performed to demonstrate the clinical potential of this neuromodulatory intervention. Future studies should consider treatment targets based on individual lesion characteristics, stage of recovery (acute vs. chronic), and residual white matter integrity while accounting for known determinants and biomarkers of tDCS response.

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Transcranial Direct Current Stimulation and Cognition in Neuropsychiatric Disorders: Systematic Review of the Evidence and Future Directions

The Neuroscientist ◽

10.1177/1073858420936167 ◽

2020 ◽

pp. 107385842093616

Author(s):

Valentina Ciullo ◽

Gianfranco Spalletta ◽

Carlo Caltagirone ◽

Nerisa Banaj ◽

Daniela Vecchio ◽

...

Keyword(s):

Systematic Review ◽

Cognitive Impairment ◽

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Neuropsychiatric Disorders ◽

Schizophrenia Spectrum Disorders ◽

Future Directions ◽

Direct Current Stimulation ◽

Schizophrenia Spectrum ◽

Spectrum Disorders

Transcranial direct current stimulation (tDCS) has been implemented in neuropsychiatric disorders characterized by cognitive impairment. However, methodological heterogeneity challenges conclusive remarks. Through a critical analysis of previous conflicting findings and in the light of current neurobiological models of pathophysiology, we qualitatively assessed the effects of tDCS in neuropsychiatric disorders that share neurobiological underpinnings, as to evaluate whether stimulation can improve cognitive deficits in patients’ cohorts. We performed a systematic review of tDCS studies targeting cognitive functions in mental disorders and pathological cognitive aging. Data from 41 studies, comprising patients with diagnosis of mood disorders, schizophrenia-spectrum disorders, Alzheimer’s disease (AD), and mild cognitive impairment (MCI), were included. Results indicate that tDCS has the capacity to enhance processing speed, working memory, and executive functions in patients with mood and schizophrenia-spectrum disorders. The evidence of a positive effect on general cognitive functioning and memory is either inconclusive in AD, or weak in MCI. Future directions are discussed for developing standardized stimulation protocols and for translating the technique therapeutic potential into effective clinical practice.

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Transcranial Direct Current Stimulation in the Management of Refractory Symptoms of Parkinson’s Disease: A Systematic Review

10.5327/1516-3180.221 ◽

2021 ◽

Author(s):

Caio de Almeida Lellis ◽

Marco Alejandro Menacho Herbas ◽

Glaucia Borges Dantas ◽

Leonardo Rizier Galvão

Keyword(s):

Systematic Review ◽

Parkinson’S Disease ◽

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Motor Performance ◽

Fine Motor ◽

Review Of The Literature ◽

Direct Current Stimulation ◽

Refractory Symptoms ◽

Fine Motor Performance

Introduction: Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique increasingly used in neurology. Objectives: To evaluate the safety and efficacy of tDCS in refractory symptoms of Parkinson’s disease (PD). Design and setting: A systematic review of the literature conducted at the Pontifical Catholic University of Goiás. Methods: A systematic review of the literature was conducted in the MedLine and Lilacs databases, with the following search strategy: “(Parkinson Disease) AND (Transcranial Direct Current Stimulation OR TDCS)”. Randomized clinical trials (10 years) were included. Results: One of the studies concluded that simultaneous tDCS of the primary motor cortex (M1) and dorsolateral prefrontal cortex (DLPC) Also, two other articles evaluated the motor response after stimulation of the left DLPC for 20 minutes, with the first realizing improved fine motor performance and attenuation of common oscillatory cortical activity in PD patients, while the second finding an improvement in balance and functional mobility when compared to placebo. Regarding cognitive and mood changes, one of the studies pointed out that a single session of tDCS on the left DLPC is insufficient to improve working memory and inhibition control. Conclusion: tDCS was shown to be a safe and effective therapeutic option in reducing gait freezing and mood disorders, as well as improving fine motor performance and cognition. It is emphasized that further studies on the subject with a larger sample are needed.

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Systematic Review on the Safety and Tolerability of Transcranial Direct Current Stimulation in Children and Adolescents

Brain Sciences ◽

10.3390/brainsci11020212 ◽

2021 ◽

Vol 11 (2) ◽

pp. 212

Author(s):

Derrick Matthew Buchanan ◽

Thomas Bogdanowicz ◽

Neha Khanna ◽

Guillaume Lockman-Dufour ◽

Philippe Robaey ◽

...

Keyword(s):

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Current Evidence ◽

Limited Evidence ◽

Direct Current Stimulation ◽

Current State ◽

Objective Evidence ◽

Safety Studies ◽

Safety Considerations ◽

Objective Side

Background: Transcranial direct current stimulation (tDCS) is a safe, tolerable, and acceptable technique in adults. However, there is limited evidence for its safety in youth. Although limited, there are a handful of important empirical articles that have evaluated safety and tolerability outcomes in youth. However, a synthesis of pediatric safety studies is not currently available. Objective: To synthesize objective evidence regarding the safety and tolerability of pediatric tDCS based on the current state of the literature. Methods: Our search and report used PRISMA guidelines. Our method systematically examined investigations purposefully designed to evaluate the safety, tolerability, and acceptability of tDCS in healthy and atypical youth that were submitted to three databases, from the beginning of the database to November 2019. Safety considerations were evaluated by studies utilizing neuroimaging, physiological changes, performance on tasks, and by analyzing reported and objective side effects; tolerability via rate of adverse events; and acceptability via rate of dropouts. Results: We report on 203 sham sessions, 864 active sessions up to 2 mA, and 303 active hours of stimulation in 156 children. A total of 4.4% of the active sessions were in neurotypical controls, with the other 95.6% in clinical subjects. Conclusion: In spite of the fact that the current evidence is sporadic and scarce, the presently reviewed literature provides support for the safety, tolerability, and acceptability, of tDCS in youth for 1–20 sessions of 20 min up to 2 mA. Future pediatric tDCS research is encouraged.

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