• Journal of Neurogastroenterology and Motility
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• 제24권4호
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• pp.512-527
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• 2018

This review provides a comprehensive overview of brain imaging studies of the brain-gut interaction in functional gastrointestinal disorders (FGIDs). Functional neuroimaging studies during gut stimulation have shown enhanced brain responses in regions related to sensory processing of the homeostatic condition of the gut (homeostatic afferent) and responses to salience stimuli (salience network), as well as increased and decreased brain activity in the emotional response areas and reduced activation in areas associated with the top-down modulation of visceral afferent signals. Altered central regulation of the endocrine and autonomic nervous responses, the key mediators of the brain-gut axis, has been demonstrated. Studies using resting-state functional magnetic resonance imaging reported abnormal local and global connectivity in the areas related to pain processing and the default mode network (a physiological baseline of brain activity at rest associated with self-awareness and memory) in FGIDs. Structural imaging with brain morphometry and diffusion imaging demonstrated altered gray- and white-matter structures in areas that also showed changes in functional imaging studies, although this requires replication. Molecular imaging by magnetic resonance spectroscopy and positron emission tomography in FGIDs remains relatively sparse. Progress using analytical methods such as machine learning algorithms may shift neuroimaging studies from brain mapping to predicting clinical outcomes. Because several factors contribute to the pathophysiology of FGIDs and because its population is quite heterogeneous, a new model is needed in future studies to assess the importance of the factors and brain functions that are responsible for an optimal homeostatic state.

• 한국전문물리치료학회지
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• 제12권2호
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• pp.73-80
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• 2005

We investigated the activation of the cerebral cortex during active movement, passive movement, and functional electrical stimulation (FES), which was provided on wrist extensor muscles. A functional magnetic resonance imaging study was performed on 5 healthy volunteers. Tasks were the extension of right wrist by active movement, passive movement, and FES at the rate of .5 Hz. The regions of interest were measured in primary motor cortex (M1), primary somatosensory cortex (SI), secondary somatosensory cortex (SII), and supplementary motor area (SMA). We found that the contralateral SI and SII were significantly activated by all of three tasks. The additional activation was shown in the areas of ipsilateral S1 (n=2), and contralateral (n=1) or ipsilateral (n=2) SII, and bilateral SMA (n=3) by FES. Ipsilateral M1 (n=1), and contralateral (n=1) or ipsilateral SII (n=1), and contralateral SMA (n=1) were activated by active movement. Also, Contralateral SMA (n=3) was activated by passive movement. The number of activated pixels on SM1 by FES ($12{\pm}4$ pixels) was smaller than that by active movement ($18{\pm}4$ pixels) and nearly the same as that by passive movement ($13{\pm}4$ pixels). Findings reveal that active movement, passive movement, and FES had a direct effect on cerebral cortex. It suggests that above modalities may have the potential to facilitate brain plasticity, if applied with the refined-specific therapeutic intervention for brain-injured patients.

• The Journal of Korean Physical Therapy
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• 제22권5호
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• pp.103-108
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• 2010

Purpose: The aim of this study is to investigate whether motor cortex excitability by transcranial direct current stimulation (tDCS) over primary motor cortex (M1) affects motor performance of serial reaction task. Methods: Cathodal, anodal and sham tDCS (1 mA) are applied over right M1 of 24 subjects for 30 minutes including 11minutes for task period time. We applied two electrodes at the same position to both an experimental group and a sham-controlled group, and we made 2 groups recognize to be applicated of stimulation. Flexion, extension of wrist and thumb flexion are carried out following colors of arrows on the monitor. Serial reaction time task was applied to confirm the difference of the reaction time between 2 groups. Results: Reaction time is decreased in both tDCS-group and Sham-controlled tDCS group, and the degree of reduction is much greater in the post-test than pre-test. Reduction of reaction time between groupsis statistically significant. Conclusion: We consider that anodal tDCS increased the cortical excitability of the underlying motor cortex and it can be helpful to modulate motor performance. It seems that tDCS is an effective modality to modulate brain function, and it will be great help to mediate strategy for the brain injury patients.

• Journal of Korean Neurosurgical Society
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• 제44권4호
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• pp.196-198
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• 2008

Objective : Vagus nerve stimulation (VNS) has been used in epilepsy patients refractory to standard medical treatments and unsuitable candidates for resective or disconnective surgery. In this study, we investigated the efficacy of VNS to patients who had refractory result to epilepsy surgery and patients with post-traumatic epilepsy. Methods : We analyzed the effect of VNS in 11 patients who had undergone previous epilepsy surgery and patients with intractable post-traumatic epilepsy associated with brain injury. All patients underwent VNS implantation between October 2005 and December 2006. Results : We evaluated seizure frequency before and after implantation of VNS and maximum follow up period was 24 months. In the first 6 months, 11 patients showed an average of 74.3% seizure reduction. After 12 months, 10 patients showed 85.2% seizure reduction. Eighteen months after implantation, 9 patients showed 92.4% seizure reduction and 7 patients showed 97.2% seizure reduction after 24 months. Six patients were seizure-free at this time. Conclusion : We conclude that the VNS is a helpful treatment modality in patients with surgically refractory epilepsy and in patients with post-traumatic epilepsy due to severe brain injury.

• 대한의용생체공학회:의공학회지
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• 제36권4호
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• pp.95-102
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• 2015

Epilepsy is a chronic neurological disease which produces repeated seizures. Over 30% of epileptic patients cannot be treated with anti-epileptic drugs, and surgical resection may cause loss of brain functions. Seizure suppression by electrical stimulation is currently being investigated as a new treatment method as clinical evidence has shown that electrical stimulation to brain could suppress seizure activity. In this paper, design of a real-time closed-loop neurostimulation system for epileptic seizure suppression is presented. The system records neural signals, detects seizures and delivers electrical stimulation. The system consists of a 6-channel electrode, front-end amplifiers, a data acquisition board by National Instruments, and a neurostimulator and Generic Osorio-Frei algorithm was applied for seizure detection. The algorithm was verified through simulation using electroencephalogram data, and the operation of whole system was verified through simulation and in- vivo test.

• Annals of Clinical Neurophysiology
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• 제16권2호
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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.

• 한국의학물리학회지:의학물리
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• 제30권1호
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• pp.22-31
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• 2019

Purpose: To develop a new diffusion-based functional MRI (fMRI) sequence to generate apparent diffusion coefficient (ADC) maps in single excitation and evaluate the contribution of b0 signal on neuronal changes. Materials and Methods: A diffusion-based fMRI sequence was designed with single measurement that can acquire images of three directions at a time, obtaining $b=0s/mm^2$ during the first baseline condition (b0_b), followed by 107 diffusion-weighted imaging (DWI) with $b=600s/mm^2$ during the baseline and visual stimulation conditions, and another $b=0s/mm^2$ during the last activation condition (b0_a). ADC was mapped in three different ways: 1) using b0_b (ADC_b) for all time points, 2) using b0_a (ADC_a) for all time points, and 3) using b0_b and b0_a (ADC_ba) for baseline and stimulation scans, respectively. The fMRI studies were conducted on the brains of 16 young healthy volunteers using visual stimulations in a 3T MRI system. In addition, the blood oxygen level dependent (BOLD) fMRI was also acquired to compare it with diffusion-based fMRI. A sample t-test was used to investigate the voxel-wise average between the subjects. Results: The BOLD data consisted of only activated voxels. However, ADC_ba data was observed in both deactivated and activated voxels. There were no statistically significant activated or deactivated voxels for DWI, ADC_b, and ADC_a. Conclusions: With the new sequence, neuronal activations can be mapped with visual stimulation as compared to the baseline condition in several areas in the brain. We showed that ADC should be mapped using both DWI and b0 images acquired with the same conditions.

• 대한의생명과학회지
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• 제29권4호
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• pp.263-273
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• 2023

This study aimed to investigate effect of scalp acupuncture (SA) and repetitive transcranial magnetic stimulation (rTMS) intervention on neuromotor function in photothrombotic cerebral infarction (PCI) rat model. Sixty male SD rats were used. PCI was induced on M1 cortex of right frontal lobe. SA was performed at the Qianding (GV21), Xuanli (GB6) acupoints of ipsilesional M1. Low-frequency rTMS was delivered to contralesional M1. All rats were randomly divided into 4 groups: group A, normal (n, 15); group B, PCI without any stimulation intervention (n, 15); group C, PCI with SA (n, 15); group D, PCI with rTMS (n, 15). Rota-rod test and Ladder rung walking test (LWT) were done weekly for 8 weeks after PCI. SA or rTMS was started from post-PCI 4^th day as protocol for 8 weeks. H/E stain and IHC were done. Western blot and qRT-PCR study were performed for MAP2 and BDNF from ipsilesional M1 peri-infarction tissue. Brain MRI study was conducted to quantify the volume of cerebral infarction. As a result, left forelimb and hindlimb function significantly improved more in group C and D than control group, with expressed more BDNF and MAP2. And brain MRI showed focal infarction of right M1 after PCI, and infarction volume progressively decreased in group C and D than group B from post-PCI 5^th to 8^th week. SA or rTMS was more effective than no intervention group on neuromotor function of PCI rat model. The functional recovery was associated with stimulation intervention-related neurogenesis.

• The Journal of Korean Physical Therapy
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• 제36권1호
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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.

• 의료법학
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• 제21권2호
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• pp.209-244
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• 2020

TMS와 tDCS는 자기와 전류를 통하여 뇌에 자극을 가함으로서 환자나 개별 이용자의 질병을 치료하고, 이외에도 건강을 관리하거나 증진시킬 수 있는 비침습적 기기를 말한다. 이들 기기의 효과와 안전성은 몇몇 질병에서 입증되고 있으나, 아직도 이에 대한 연구는 진행 중이다. 점차 증가하고 있는 이들 기기의 활용도에 비해 TMS와 tDCS를 직접 규율하는 입법례를 찾기는 어렵다. 미국, 독일, 일본의 TMS와 tDCS에 대한 법적 규율을 살펴보면, TMS는 중등도의 위해도를 가진 의료기기로 승인되어 있는 반면, tDCS는 아직 의료기기로 승인된 상태는 아니다. 하지만, 최근 FDA 가이드집이나 유럽 MDR 규정의 변화, 미국의 리콜사례, 독일과 일본의 관련 법 규정, 전문가 그룹의 제언 등을 검토하면, tDCS도 조만간 의료기기로 승인되어 규율될 것으로 보인다. 물론, tDCS를 의료기기가 아닌 일반제품으로 보더라도 다른 법률과 제도를 통하여 제품의 안전성과 효과를 규제할 수는 있다. 그러나 이 기기가 인간의 뇌에 미칠 수 있는 여러 영향을 고려할 때, 이를 독자적으로 규율할 필요성이 크다. 우리도 TMS와 tDCS를 규율하는 명시적 법률은 없으나, 이 두 기기는 식약처 고시에 따라 3등급 의료기기로 판정된다. 그리고 TMS는 가이드 라인에 따라 미국 FDA 지침에 의해 안전성과 성능을 평가하도록 하고 있다. 하지만, tDCS는 아직 이에 대한 구체적 지침은 존재하지 않는다. tDCS 기기가 일부 병원에서, 그리고 개별 구매자를 통하여 가정에서 사용되고 있는 현실을 고려하면, 이러한 규제의 공백은 신속히 보완되어야 한다. 장기적으로는 비침습적 뇌자극기기를 독자적으로 규율할 수 있는 법적 시스템의 정비가 필요하다.