• The Journal of Korean Physical Therapy
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• v.21 no.4
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• pp.65-71
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• 2009

Purpose: Transcranial direct current stimulation (tDCS) is a useful method for modulating the brain activity. This study compared the effect of continuous and interrupted tDCS using the change in the movement related cortical potential. Methods: Thirty healthy participants (male: 18 and female: 12) were assigned randomly to three groups; sham tDCS, continuous tDCS, which the current continuously flowed for 10 minutes, and interrupted tDCS, which the interrupted current flowed for 10 minutes (repetition: 4sec stimulation and 5sec rest) at an intensity of 1mA with anodal polarity. The effect of tDCS on the right primary motor area was measured from the movement related cortical potential (MRCP) before and after the experiment. MRCP consisted of the bereitshaftspotential (BP) and negative slope potential (NS) at Cz and C4. Results: Continuous and interrupted tDCS showed a significant difference in the changes in the BP, NS at Cz and C4 compared to the sham tDCS. However, there was no significant difference between the continuous tDCS and interrupted tDCS. Conclusion: The change in cortical activity by continuous and interrupted tDCS results from an improvement in the MRCP. An interrupted tDCS may be a safe and useful modality for stimulating the cortical region.

• Korean Journal of Applied Biomechanics
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• v.32 no.4
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• pp.121-127
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• 2022

Objective: The purpose of this study was to investigate potential effects of transcranial direct current stimulation (tDCS) on bimanual force control capabilities in healthy young adults. Method: Eighteen right-handed healthy young adults (10 females and 8 males; age: 23.55 ± 3.56 yrs) participated in this crossover design study. All participants were randomly allocated to both active-tDCS and sham-tDCS conditions, respectively. While receiving 20 min of active- or sham-tDCS interventions, all participants performed bimanual isometric force control tasks at four submaximal targeted force levels (i.e., 5%, 10%, 15, and 20% of maximal voluntary contraction: MVC). To compare bimanual force control capabilities including force accuracy, variability, and regularity between active-tDCS and sham-tDCS conditions, we conducted two-way repeated measures ANOVAs (2 × 4; tDCS condition × Force levels). Results: We found no significant difference in baseline MVC between active-tDCS and sham-tDCS conditions. Moreover, our findings revealed that providing bilateral tDCS including anodal tDCS on left primary motor cortex (M1) and cathodal on right M1 while conducting bimanual force control trials significantly decreased force variability and regularity at 5%MVC. Conclusion: These findings suggest that providing bilateral tDCS on M1 areas may improve bimanual force control capabilities at a relatively low targeted force level.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.445-452
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• 2015

Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers a low-intensity direct current to the cortical areas, thereby facilitating or inhibiting spontaneous neuronal activity. This study was designed to examine the changes in various sensory functions after tDCS. A single-center, single-blinded, randomized trial was conducted to determine the effect of a single session (August 4 to August 29) of tDCS with the current perception threshold (CPT) in 50 healthy volunteers. Nerve conduction studies (NCS) were performed in relation to the median sensory and motor nerves on the dominant hand to discriminate peripheral nerve lesions. The subjects received anodal tDCS with 1mA for 15 minutes under two different conditions, with 25 subjects in each group. The conditions were as follows: tDCS on the dorsolateral prefrontal cortex (DLPFC) and sham tDCS on DLPFC. The parameters of the CPT was recorded with a Neurometer$^{(R)}$ at frequencies of 2000, 250 and 5 Hz in the dominant index finger to assess the tactile sense, fast pain and slow pain, respectively. In the test to measure the CPT values of the DLPFC in the anodal tDCS group, the values increased significantly in all of 250 and 5 Hz. All CPT values decreased for the sham tDCS. These results showed that DLPFC anodal tDCS can modulate the sensory perception and pain thresholds in healthy adult volunteers. This study suggests that tDCS may be a useful strategy for treating central neurogenic pain in rehabilitation medicine.

• Korean Journal of Biological Psychiatry
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• v.25 no.4
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• pp.89-100
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• 2018

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation method that delivers 1-2 mA of current to the scalp. Several clinical studies have been conducted to confirm the therapeutic effect of major depressive disorder (MDD) patients with tDCS. Some studies have shown tDCS's antidepressant effect, while the others showed conflicting results in antidepressant effects. Our aim of this review is to understand the biological bases of tDCS's antidepressant effect and review the results of studies on tDCS's antidepressant effect. For the review and search process of MDD treatment using tDCS, the US National Library of Medicine search engine PubMed was used. In this review, we discuss the biological mechanism of tDCS's antidepressant effect and the existing published literature including meta-analysis, systematic review, control trial, open studies, and case reports of antidepressant effects and cognitive function improvement in patients with MDD are reviewed. We also discuss the appropriate tDCS protocol for MDD patients, factors predictive of response to tDCS treatment, the disadvantages of tDCS in MDD treatment, and side effects.

• IMMUNE NETWORK
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• v.16 no.1
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• pp.13-25
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• 2016

Dendritic cells (DCs) are considered to play major roles during the induction of T cell immune responses as well as the maintenance of T cell tolerance. Naive CD4⁺ T cells have been shown to respond with high plasticity to signals inducing their polarization into effector/helper or regulatory T cells. Data obtained from in vitro generated bone-marrow (BM)-derived DCs as well as genetic mouse models revealed an important but not exclusive role of DCs in shaping CD4⁺ T cell responses. Besides the specialization of some conventional DC subsets for the induction of polarized immunity, also the maturation stage, activation of specialized transcription factors and the cytokine production of DCs have major impact on CD4⁺ T cells. Since in vitro generated BM-DCs show a high diversity to shape CD4⁺ T cells and their high similarity to monocyte-derived DCs in vivo, this review reports data mainly on BM-DCs in this process and only touches the roles of transcription factors or of DC subsets, which have been discussed elsewhere. Here, recent findings on 1) the conversion of naive into anergic and further into Foxp3^- regulatory T cells (Treg) by immature DCs, 2) the role of RelB in steady state migratory DCs (ssmDCs) for conversion of naive T cells into Foxp3⁺ Treg, 3) the DC maturation signature for polarized Th2 cell induction and 4) the DC source of IL-12 for Th1 induction are discussed.

• Journal of The Korean Society of Integrative Medicine
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• v.8 no.2
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• pp.11-20
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• 2020

Purpose : The purpose of this study was to research the effects of dual-hemisphere transcranial direct current stimulation (dual tDCS) and modified constraint-induced movement therapy (mCIMT) to improve upper extremity motor function after stroke. Methods : The study period was from August 2019 to November 2019, and included 24 patients who met the selection criteria. Participants were divided into 2 groups: dual tDCS and mCIMT, and sham dual tDCS and mCIMT group. Dual tDCS and mCIMT group performed mCIMT immediately after applying dual tDCS for 20 minutes, and sham dual tDCS and mCIMT group performed mCIMT immediately after applying sham tDCS for 20 minutes without turning on the power source. Total interventions were conducted 5 times per week for 4 weeks, and mCIMT was conducted for 30 minutes per session for both experimental and control groups. Fugl-Meyer assessment (FMA) and Motor Activity Log scale (MAL) were analyzed before and after 4 weeks of intervention. Results : Both experimental and control groups showed significant changes in FMA, Amount of Use (AOU), and Quality of Movement (QOM) of MAL. When the differences between groups was compared using ANCOVA, the experimental group showed a greater improvement in FMA and AOU of MAL than the control group. Conclusion : In order to enhance the effect of improving upper limb function of stroke patients, dual tDCS could be applied to provide more effective treatment in the clinical setting. Further studies will be needed in larger groups of stroke patients, including long-term follow-up, and multi-group comparisons through the establishment of anodal tDCS and mCIMT, cathodal tDCS, and mCIMT groups to clarify the effects of dual tDCS. In addition, research is needed to establish a protocol for tDCS, and this evidence-based intervention protocol is expected to be used in the clinical setting as an interventional method for various purposes.

• Physical Therapy Korea
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• v.21 no.4
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• pp.1-8
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• 2014

Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers low-intensity direct current to cortical areas, thereby facilitating or inhibiting spontaneous neuronal activity. This study was designed to investigate changes in various sensory functions after tDCS. We conducted a single-center, single-blinded, randomized trial to determine the effect of a single session of tDCS with the current perception threshold (CPT) in 50 healthy volunteers. Nerve conduction studies were performed in relation to the median sensory and motor nerves on the dominant hand to discriminate peripheral nerve lesions. The subjects received anodal tDCS with 1 mA for 15 minutes under two different conditions, with 25 subjects in each groups: the conditions were as follows tDCS on the primary motor cortex (M1) and sham tDCS on M1. We recorded the parameters of the CPT a with Neurometer$^{(R)}$ at frequencies of 2000, 250, and 5 Hz in the dominant index finger to assess the tactile sense, fast pain and slow pain, respectively. In the test to measure CPT values of the M1 in the tDCS group, the values of the distal part of the distal interphalangeal joint of the second finger statistically increased in all of 2000 Hz (p=.000), 250 Hz (p=.002), and 5 Hz (p=.008). However, the values of the sham tDCS group decreased in all of 2000 Hz (p=.285), 250 Hz (p=.552), and 5 Hz (p=.062), and were not statistically significant. These results show that M1 anodal tDCS can modulate sensory perception and pain thresholds in healthy adult volunteers. The study suggests that tDCS may be a useful strategy for treating central neurogenic pain in rehabilitation medicine.

• The Journal of Korean Physical Therapy
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• v.36 no.1
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• pp.39-44
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• 2024

Purpose: Cybersickness is a type of motion sickness induced by virtual reality (VR) or augmented reality (AR) environments that presents symptoms including nausea, dizziness, and headaches. This study aimed to investigate how cathodal transcranial direct current stimulation (tDCS) alleviates motion sickness symptoms and modulates brain activity in individuals experiencing cybersickness after exposure to a VR environment. Methods: This study was performed on two groups of healthy adults with cybersickness symptoms. Subjects were randomly assigned to receive either cathodal tDCS intervention or sham tDCS intervention. Brain activity during VR stimulation was measured by 38-channel functional near-infrared spectroscopy (fNIRS). tDCS was administered to the right temporoparietal junction (TPJ) for 20 minutes at an intensity of 2mA, and the severity of cybersickness was assessed pre- and post-intervention using a simulator sickness questionnaire (SSQ). Result: Following the experiment, cybersickness symptoms in subjects who received cathodal tDCS intervention were reduced based on SSQ scores, whereas those who received sham tDCS showed no significant change. fNIRS analysis revealed that tDCS significantly diminished cortical activity in subjects with high activity in temporal and parietal lobes, whereas high cortical activity was maintained in these regions after intervention in subjects who received sham tDCS. Conclusion: These findings suggest that cathodal tDCS applied to the right TPJ region in young adults experiencing cybersickness effectively reduces motion sickness induced by VR environments.

• The Journal of Korean Physical Therapy
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• v.23 no.6
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• pp.49-53
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• 2011

Purpose: The purpose of this study is to investigate whether dual-hemisphere transcranial direct current stimulation (tDCS) could induce more cortical activity, compared to single-hemisphere, using functional MRI (fMRI). Methods: One right-handed healthy subject was recruited. Three phases of dual-hemisphere tDCS (i.e. anodal tDCS over the left-dominant primary sensoriomotor cortex (SM1) and cathodal tDCS over the right-non dominant SM(1) were consecutively delivered on to a subject, during fMRI scanning. The voxel count and the intensity index in the averaged cortical map were analyzed among the three tDCS phases. Results: Our result showed that cortical activation was observed on all the three phases of the dual-hemisphere tDCS. Voxel count and intensity index were as following; 912 and 4.07 in the first phase, 1102 and 3.90 in the second phase, 1031 and 3.80 in the third phase. Conclusion: This study demonstrated that application of the dual-hemisphere tDCS could induce cortical activity and maintain to recruit cortical neurons. Our findings suggested that application of dual-hemisphere tDCS could produce efficiency of the ongoing tDCS effect to facilitate cortical excitability.

• The Journal of Korean Physical Therapy
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• v.31 no.5
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• pp.328-332
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• 2019

Purpose: This study examined the effects of transcranial direct current stimulation (tDCS) on the static balance ability of patients with back pain. Methods: The subjects comprised of 30 males and females in their 20s, who were divided into two groups with and without tDCS. The balance posture ratio score was calculated to determine the changes in balance ability before and after the application of tDCS using balance equipment. A paired t-test was conducted to determine the changes over time, and an independent t-test was performed to determine the changes between the groups. The significance level was set to ${\alpha}=0.05$. Results: A significant difference in the changes in the static balance ability of CTDCSG between before and after applying tDCS was observed while the subjects' eyes were open (p<0.05). A comparison between the groups after the experiments revealed significantly increased changes in CTDCSG compared to STDCSE (p<0.05). The changes in static balance ability were not significant when the subjects' eyes were closed (p>0.05). Conclusion: The application of tDCS positively changed the static balance ability of patients with back pain. The results of this study showed that tDCS could be used as an intervention to increase the static balance ability of patients with back pain in the clinical field. The study results could be used further as foundational data for future studies on tDCS.