• The Journal of Korean Physical Therapy
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• v.29 no.4
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• pp.164-168
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• 2017

Purpose: Functional electrical stimulation (FES) is a device that activates the sensorimotor cortex through electrodes attached to the surface of the skin. However, it is difficult to expect positive changes if the recipient is not attentive to the motion. To complement the perceived cognitive limitations of FES, we attempted to investigate the changes of sensorimotor cortex activity by simultaneously providing action observation with FES. Methods: Electroencephalogram was measured in 28 healthy volunteers. Relative band power over the sensorimotor cortex was analyzed and compared in three conditions: during rest, during FES alone, during action observation with FES. Results: The results showed significant differences in each relative band power. Relative alpha power and relative beta power were the lowest by application of FES combined with action observation, while the relative gamma power was the highest. Conclusion: These results suggest that combining FES with observation could be more effective than FES alone in neurorehabilitation.

• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.139-147
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• 2007

The aim of this study was to evaluate effects of short-tenn repetitive-bilateral excercise on the activation of motor network using functional magnetic resonance imaging (fMRI). The training program was performed at 1 hr/day, 5 days/week during 6 weeks. Fugl-Meyer Assessments (FMA) were performed every two weeks during the training. We compared cerebral and cerebellar cortical activations in two different tasks before and after the training program: (1) the only unaffected hand movement (Task 1); and (2) passive movements of affected hand by the active movement of unaffected hand (Task 2). fMRI was performed at 3T with wrist flexion-extension movement at 1 Hz during the motor tasks. All patients showed significant improvements of FMA scores in their paretic limbs after training. fMRI studies in Task 1 showed that cortical activations decreased in ipsilateral sensorimotor cortex but increased in contralateral sensorimotor cortex and ipsilateral cerebellum. Task 2 showed cortical reorganizations in bilateral sensorimotor cortex, premotor area, supplemetary motor area and cerebellum. Therefore, this study demonstrated that plastic changes of motor network occurred as a neural basis of the improvement subsequent to repetitive-bilateral excercise using the symmetrical upper-limb ann motion trainer.

• Journal of Korean Neurosurgical Society
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• v.62 no.3
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• pp.265-271
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• 2019

The expansion and folding of the cerebral cortex occur during brain development and are critical factors that influence cognitive ability and sensorimotor skills. The disruption of cortical growth and folding may cause neurological disorders, resulting in severe intellectual disability and intractable epilepsy in humans. Therefore, understanding the mechanism that regulates cortical growth and folding will be crucial in deciphering the key steps of brain development and finding new therapeutic targets for the congenital anomalies of the cerebral cortex. This review will start with a brief introduction describing the anatomy of the brain cortex, followed by a description of our understanding of the proliferation, differentiation, and migration of neural progenitors and important genes and molecules that are involved in these processes. Finally, various types of disorders that develop due to malformation of the cerebral cortex will be discussed.

• The Journal of Korean Physical Therapy
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• v.32 no.5
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• pp.307-311
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• 2020

Purpose: This study examined the effects of changes in the intensity of Functional Electrical Stimulation (FES) on CorticoMuscular Coherence (CMC) during action observation. This paper presents a neurophysiological basis for the effective intensity of FES. Methods: Twenty-seven healthy volunteers were asked to observed a video with FES. The FES was provided with a sensory stimulation level, nerve stimulation level, and motor stimulation level. Simultaneously, an electroencephalogram (EEG) of the sensorimotor cortex and electromyogram (EMG) from the wrist extensor muscle were recorded. The peak CMC and average CMC were analyzed to compare the differences caused by the FES intensity. Results: The peak CMC showed a significant increase in the alpha band during motor stimulation (p<0.05). The average CMC showed a significant increase in the beta band during motor stimulation (p<0.05). Conclusion: The intensity of FES, which causes actual movement, increased the CMC during action observation. These results show that the intensity of the FES can affect the functional connection between the sensorimotor cortex and muscle.

• The Journal of Korean Physical Therapy
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• v.22 no.2
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• pp.7-13
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• 2010

Purpose: This study was designed to determine the correlation between faster response time and functional activities of brain regions during cognitive time management. Methods: Twelve healthy subjects participated in this experiment. Subjects performed the serial reaction time task (SRTT), which was designed by the Superlab program, during fMRI scanning. When the 'asterisk' appeared in the 4 partition spaces on the monitor, the subject had to press the correct response button as soon as possible. Results: fMRI results showed activation of the left primary sensorimotor cortex, both premotor areas, the supplementary motor area, posterior parietal cortex and cerebellum. There were significant correlations, from moderate to strong, between faster reaction time and BOLD signal intensity in activated areas. Conclusion: These results suggest that motor skill learning to be needed cognitive time management is associated with greater activation of large scale sensorimotor networks.

• The Journal of Korean Physical Therapy
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• v.26 no.6
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• pp.386-390
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• 2014

Purpose: We aimed to investigate whether visuomotor function would be modulated, when healthy subjects performed tracking task after tDCS application over the primary sensorimotor cortex (SM1) in the non-dominant hemisphere. Methods: Thirty four right-handed healthy participants were enrolled, who randomly and evenly divided into two groups, real tDCS group and sham control group. Direct current with intensity of 1 mA was delivered over SM1 for 15 minutes. After tDCS, tracking task was measured, and their performance was calculated by an accuracy index (AI). Results: No significant difference in AI at the baseline between the two groups was observed. The AI of the real tDCS group was significantly increased after electrical stimulation, compared to the sham control group. Two way ANOVA with repeated measurement showed a significant finding in a large main effects of time and group-by-repeated test interaction. Conclusion: This study indicated that application of the anodal tDCS over the SM1 could facilitate higher visuomotor coordination, compared to sham tDCS group. These findings suggest possibility that tDCS can be used as adjuvant brain modulator for improvement of motor accuracy in healthy individuals as well as patients with brain injury.

• Journal of Korean Neurosurgical Society
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• v.50 no.3
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• pp.209-215
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• 2011

Objective : The authors investigated the changes of cortical sensorimotor activity in functional MRI (fMRI) and functional recovery in spinal cord injury (SCI) patients who had been treated by bone marrow cell transplantation. Methods : Nineteen patients with SCI were included in this study; ten patients with clinical improvement and nine without. The cortical sensorimotor activations were studied using the proprioceptive stimulation during the fMRI. Results : Diagnostic accuracy of fMRI with neurological improvement was 70.0% and 44.4% for sensitivity and specificity, respectively. Signal activation in the ipsilateral motor cortex in fMRI was commonly observed in the clinically neurological improved group (p-value=0.002). Signal activation in the contralateral temporal lobe and basal ganglia was more commonly found in the neurological unimproved group (p-value<0.001). Signal activation in other locations was not statistically different. Conclusion : In patients with SCI, activation patterns of fMRI between patients with neurologic recovery and those without varied. Such plasticity should be considered in evaluating SCI interventions based on behavioral and neurological measurements.

• The Journal of Korean Physical Therapy
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• v.27 no.3
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• pp.135-139
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• 2015

Purpose: The aim of this study was to compare EEG topographical maps in patients with chronic stroke after action observation physical training. Methods: Ten subjects were recruited from a medical hospital. Participants observed the action of transferring a small block from one box to another for 6 sessions of 1 minute each, and then performed the observed action for 3 minutes, 6 times. An EEG-based brain mapping system with 32 scalp sites was used to determine cortical reorganization in the regions of interest (ROIs) during observation of movement. The EEG-based brain mapping was comparison in within-group before and after training. ROIs included the primary sensorimotor cortex, premotor cortex, superior parietal lobule, inferior parietal lobule, superior temporal lobe, and visual cortex. EEG data were analyzed with an average log ratio in order to control the variability of the absolute mu power. The mu power log ratio was in within-group comparison with paired t-tests. Results: Participants showed activation prior to the intervention in all of the cerebral cortex, whereas the inferior frontal gyrus, superior frontal gyrus, precentral gyrus, and inferior parietal cortex were selectively activated after the training. There were no differences in mu power between each session. Conclusion: These findings suggest that action observation physical training contributes to attaining brain reorganization and improving brain functionality, as part of rehabilitation and intervention programs.

• The Korean Journal of Nuclear Medicine
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• v.35 no.4
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• pp.231-240
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• 2001

Purpose: Normal aging results in detectable changes in the brain structure and function. We evaluated the changes of regional cerebral glucose metabolism in the normal aging process with FDG PET. Materials and Methods: Brain PET images were obtained in 44 healthy volunteers (age range 20-69 'y'; M:F = 29:15) who had no history of neuropsychiatric disorders. On 6 representative transaxial images, ROIs were drawn in the cortical and subcortical areas. Regional FDG uptake was normalized using whole brain uptake to adjust for the injection dose and correct for nonspecific declines of glucose metabolism affecting all brain areas equally. Results: In the prefrontal, temporoparietal and primary sensorimotor cortex, the normalized FDG uptake (NFU) reached a peak in subjects in their 30s. The NFU in the prefrontal and primary sensorimotor cortex declined with age after 30s at a rate of 3.15%/decade and 1.93%/decade, respectively. However, the NFU in the temporoparietal cortex did not change significantly with age after 30s. The anterior (prefrontal) posterior (temporoparietal) gradient peaked in subjects in their 30s and declined with age thereafter at a rate of 2.35%/decade. The NFU in the caudate nucleus was decreased with age after 20s at a rate of 2.39%/decade. On the primary visual cortex, putamen, and thalamus, the NFU values did not change significantly throughout the ages covered. These patterns were not significantly different between right and left cerebral hemispheres. Of interest was that the NFU in the left cerebellar cortex was increased with age after 20s at a rate of 2.86%/decade. Conclusion: These data demonstrate regional variation of the age-related changes in the cerebral glucose metabolism, with the most prominent age-related decline of metabolism in the prefrontal cortex. The increase in the cerebellar metabolism with age might reflect a process of neuronal plasticity associated with aging.

• Investigative Magnetic Resonance Imaging
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• v.4 no.1
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• pp.52-57
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• 2000

Purpose : The purpose of this study was to investigate the pattern of cerebral response to motor tasks in patients with schizophrenia compared with normal subjects using functional MRI. Materials and methods ; Nine right handed-schizophrenic patients and six right-handed normal subjects were included. We used right hand movement as task. Series of 120 consecutive echo-planar images per section were acquired during three cycles of task and rest activations. Lateralization index of cortical response was measured and compared between patients and normal subjects. Results ; Right hand motor task was associated with greater activation in left sensorimotor cortex than the right in normal subjects. Schizophrenia patients showed relatively decreased activation in left cortex and increased activation in right cortex compared with normal subjects. In one patient, reversed lateralization was noted. Conclusion : Normal hemispheric asymmetry of cortical response to motor task was found in different pattern in schizophrenia. Our result is consistent with functional disturbance of motor circuitry in this disorder. Functional MRI will play an important role in diagnosis and research of this disorder.