• Journal of the Korean Society of Physical Medicine
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• v.7 no.1
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• pp.11-20
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• 2012

Purpose : This study is intended to examine the repetitive transcranial magnetic stimulation on cognitive function in the focal ischemic stroke rat model. Methods : This study selected 30 Sprague-Dawley rats of 8 weeks. The groups were divided into two groups and assigned 15 rats to each group. Control group: Non-treatment after injured by focal ischemic stroke; Experimental group: application of repetitive transcranial magnetic stimulation(0.1 Tesla, 25 Hz, 20 min/time, 2 times/day, 5 days/2 week) after injured by focal ischemic stroke. To assess the effect of rTMS, the passive avoidance test, spatial learning and memory ability test were analyzed at the pre, 1 day, $7^{th}$ day, $14^{th}$ day and immunohistochemistric response of BDNF were analyzed in the hippocampal dentate gyrus at $7^{th}$ day, $14^{th}$ day. Results : In passive avoidance test, the outcome of experimental group was different significantly than the control group at the $7^{th}$ day, $14^{th}$ day. In spatial learning and memory ability test, the outcome of experimental group was different significantly than the control group at the $7^{th}$ day, $14^{th}$ day. In immunohistochemistric response of BDNF in the hippocampal dentate gyrus, experimental groups was more increased than control group. Conclusion : These result suggest that improved cognitive function by repetitive transcranial magnetic stimulation after focal ischemic stroke is associated with dynamically altered expression of BDNF in hippocampal dentate gyrus and that is related with synaptic plasticity.

• Journal of information and communication convergence engineering
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• v.8 no.2
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• pp.205-211
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• 2010

In this study, a Magnetic stimulation Pulse Train control technique is introduced and applied to Flyback converter operating in discontinuous conduction mode. In contrast to the conventional pulse width modulation control scheme, the principal idea of a Magnetic stimulation Pulse Train is to achieve output voltage regulation using high and low power pulses. The proposed technique is applicable to any converter operating in discontinuous conduction. However, this work mainly focuses on Flyback topology. In this paper, the main mathematical concept of the new control algorithm is introduced and simulations as well as experimental results are presented.

• The Journal of Korean Physical Therapy
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• v.22 no.1
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• pp.67-73
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• 2010

Purpose: We tested whether repetitive transcranial magnetic stimulation (rTMS) improved recovery following spinal cord injury (SCI) in rats with transplantation of adipose tissue-derived stromal cells (ATSCs). Methods: Twenty Sprague-Dawley rats (200-250 g, female) were used. Moderate spinal cord injury was induced at the T9 level by a New York University (NYU) impactor. The rat ATSCs (approximately $5{\times}10^5$ cells) were injected into the perilesional area at 9 days after SCI. Starting four days after transplantation, rTMS (25 Hz, 0.1 Tesla, pulse width=$370{\mu}s$, on/off time=3 sec/3 sec) was applied daily for 7 weeks. Functional recovery was assessed using the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale as well as pain responses for thermal and cold stimuli. Results: Both groups showed similar, gradual improvement of locomotor function. rTMS stimulation decreased thermal and cold hyperalgesia after 7 weeks, but sham stimulation did not. Conclusion: rTMS after transplantation of ATSCs in an SCI model may reduce thermal hyperalgesia and cold allodynia, and may be an adjuvant therapeutic tool for pain control after stem cell therapy in SCI.

• Korean Journal of Biological Psychiatry
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• v.24 no.4
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• pp.167-174
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• 2017

Based on advances in biotechnology and neuroscience, neuromodulation is poised to gain clinical importance as a treatment modality for psychiatric disorders. In addition to old-established electroconvulsive therapy (ECT), clinicians are expected to understand newer forms of neurostimulation, such as deep brain stimulation (DBS), vagus nerve stimulation (VNS), repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS). Given the growing interest in non-invasive neuromodulation technologies, clinicians may seek sufficient information about neuromodulation to inform their clinical practice. A growing literature suggests that applications of non-invasive neuromodulation have evidence particularly for indications where treatments are currently insufficient, such as drug-resistant depression. However, positive neuromodulation studies require replication, and the precise interactions among stimulation, antidepressant medication, and psychotherapy are unknown. Further studies of long-term safety and the impact on the developing brain are needed. Non-invasive neuromodulatory devices could enable more individualized treatment. However, do-it-yourself (DIY) stimulation kits require a better understanding of the effects of more frequent patterns of stimulation and raise concerns about clinical supervision, regulation, and reimbursement. Wide spread enthusiasm for therapeutic potential of neuromodulation in clinical practice settings should be mitigated by the fact that there are still research gaps and challenges associated with non-invasive neuromodulatory devices.

• Annals of Clinical Neurophysiology
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• v.13 no.1
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• pp.38-43
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• 2011

Background: In the brain, the dominant primary motor cortex (M1) has a greater hand representation area, shows more profuse horizontal connections, and shows a greater reduction in intracortical inhibition after hand exercise than does the non-dominant M1, suggesting a hemispheric asymmetry in M1 plasticity. Methods: We performed a transcranial magnetic stimulation (TMS) study to investigate the hemispheric asymmetry of paired associative stimulation (PAS)-induced M1 plasticity in 9 right-handed volunteers. Motor evoked potentials (MEPs) were measured in the abductor pollicis brevis (APB) muscles of both hands, and MEP recruitment curves were measured at different stimulation intensities, before and after PAS. Results: MEP recruitment curves were significantly enhanced in the dominant, but not the non-dominant M1. Conclusions: These results demonstrate that the dominant M1 has greater PAS-induced plasticity than does the non-dominant M1. This provides neurophysiological evidence for the asymmetrical performance of motor tasks related to handedness.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.2
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• pp.314-319
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• 2008

In this paper, the electric field distribution induced inside the brain during Transcranial Magnetic Stimulation(TMS) has been thoroughly investigated in terms of tissue heterogeneity and anisotropy as well as different head models. To achieve this, first, an elaborate head model consisting of seven major parts of the head has been built based on the Magnetic Resonance(MR) image data. Then the Finite Element Method(FEM) has been used to evaluate the electric field distribution under different head models or three different conductivity conditions when the head model has been exposed to a time varying magnetic field achieved by utilizing the Figure-Of-Eight(FOE) stimulation coil. The results show that the magnitude as well as the distribution of the induced field is significantly affected by the degree of geometrical asymmetry of head models and conductivity conditions with respect to the center of the FOE coil.

• Annals of Clinical Neurophysiology
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• v.16 no.2
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• pp.62-69
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• 2014

Background: Neuromodulation therapy has been used to an adjunctive treatment promoting motor recovery in stroke patients. The objective of the study was to determine the effect of repetitive transcranial magnetic stimulation (rTMS) on neurobehavioral recovery and evoked potentials in rats with middle cerebral artery occlusion. Methods: Seventy Sprague-Daley rats were induced permanent middle cerebral artery occlusion (MCAO) stroke model and successful stroke rats (n=56) assigned to the rTMS (n=28) and sham (n=28) group. The 10 Hz, high frequency rTMS gave on ipsilesional forepaw motor cortex during 2 weeks in rTMS group. The somatosensory evoked potential (SSEP) and motor evoked potential (MEP) were used to evaluate the electrophysiological changes. Behavioral function of the stroke rat was evaluated by the Rota rod and Garcia test. Results: Forty rats ($N_{rTMS}=20;\;N_{sham}=20$) completed all experimental course. The rTMS group showed better performance than sham group in Rota rod test and Garcia test at day 11 (p<0.05) but not day 18 (p>0.05). The amplitude of MEP and SSEP in rTMS group was larger than sham group at day 18 (p<0.05). Conclusions: These data confirm that the high frequency rTMS on ipsilesional cerebral motor cortex can help the early recovery of motor performance in permanent middle cerebral artery stroke model and it may simultaneously associate with changes in neurophysiological activity in brain.

• Clinical Pain
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• v.18 no.1
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• pp.1-7
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• 2019

Objective: To investigate the cortical disinhibition in diabetic patients with neuropathic pain and without pain. In addition, we assessed the cortical disinhibition and pain relief after repetitive transcranial magnetic stimulation (rTMS). Method: We recruited diabetic patients with neuropathic pain (n = 15) and without pain (n = 15). We compared the TMS parameters such as motor evoked potential (MEP) amplitude, cortical silent period (CSP), intracortical inhibition (ICI %) and intracortical facilitation (ICF %) between two groups. Moreover, we evaluated the changes of pain and TMS parameters after five consecutive high frequency (10 Hz) rTMS sessions in diabetic patients with neuropathic pain. The neuropathic pain intensity (visual analog scale) and TMS parameters were assessed on pre-rTMS, post-rTMS 1day, and post-rTMS 5 day. Results: The comparison of the CSP, ICI % revealed significant differences between two groups (p<0.01). After rTMS sessions, the decrease in pain intensity across the three time points revealed a pattern of significant differences (p<0.01). The change of CSP and ICI % across the three test points revealed a pattern of significant differences (p<0.01). The ICI % revealed immediate increase after first rTMS application and significant increase after five rTMS application (p<0.01) in diabetic patients with neuropathic pain. The MEP amplitude and ICF % did not reveal any significant changes. Conclusion: Our findings demonstrate that cortical inhibition was decreased in diabetic patients with neuropathic pain compared with patients without pain. Furthermore, we also identified that five daily rTMS sessions restored the defective intracortical inhibition which related to improvement of neuropathic pain in diabetic patients.

• Annals of Rehabilitation Medicine
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• v.42 no.6
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• pp.777-787
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• 2018

Objective To examine the long-term effects of the low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) combined with task-specific training on paretic hand function following subacute stroke. Methods Sixteen participants were randomly selected and grouped into two: the experimental group (real LF-rTMS) and the control group (sham LF-rTMS). All the 16 participants were then taken through a 1-hour task-specific training of the paretic hand. The corticospinal excitability (motor evoke potential [MEP] amplitude) of the non-lesioned hemisphere, and the paretic hand performance (Wolf Motor Function Test total movement time [WMFT-TMT]) were evaluated at baseline, after the LF-rTMS, immediately after task-specific training, 1 and 2 weeks after the training. Results Groups comparisons showed a significant difference in the MEP after LF-rTMS and after the training. Compared to the baseline, the MEP of the experimental group significantly decreased after LF-rTMS and after the training and that effect was maintained for 2 weeks. Group comparisons showed significant difference in WMFT-TMT after the training. Only in the experimental group, the WMFT-TMT of the can lifting item significantly reduced compared to the baseline and the effect was sustained for 2 weeks. Conclusion The results of this study established that the improvement in paretic hand after task-specific training was enhanced by LF-rTMS and it persisted for at least 2 weeks.

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.104-104
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• 2001

Purpose： In this study, we investigated the possible motor pathways of hemiplegic stroke patients usin combined TMS and BOLD fMRI approach and evaluated the correlation between TMS a fMRI methods. Method： Four subjects, who demonstrated left hemiplegia after stroke, are included. TMS was performed using a Dantec Mag2 stimulator (Dantec Company, USA) in single puls mode with figure eight-shaped coil. Following TMS localization, The BOLD T2＊-weight images were acquired with echo planar imaging sequence (TR = 1.2 sec, TE = 60 msec, and flip angle = 90). Motor activation was studied by means of a repetitive fing flexion-extension task. The stimulation protocol comprised 10 cycles of alternating activati and rest (10 images per cycle). Total 60 cycles were performed and each cycle take abou 1.5 sec. The resulting images were then analyzed with STIMULATE (CMRR, U, o Minnesota) to generate functional maps using a student t-test (p < 0.0005) and cluste analysis.