• The Journal of Korean Physical Therapy
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• v.17 no.3
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• pp.421-428
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• 2005

The tenn 'Brain plasticity' has been identified that our central nervous system is continuously being adapted and modulated according to environmental needs and demands, and has been used to encompass the multifarious mechanisms related to learning, development, and recovery from damage to the nervous system. The purpose of this study was to demonstrate cortical reorganization in a 26-year-old right-handed hemiparetic patient with traumatic primary motor cortex (M1) injury, using functional MRI (fMRI). The unaffected (left) primary sensori-motor cortex centered on the precentral knob was activated during unaffected (right) hand movements. However, the medial area of the injured M1 was activated during affected (left) hand movements. It seems that the motor function of the affected hand in this patient was reorganized into the medial area of the injured precentral knob. These investigations provide a great useful information and clinical evidences with the specialized clinician in stroke physical therapy about patient's prognosis and therapeutic guidelines.

• The Journal of Korean Physical Therapy
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• v.22 no.2
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• pp.25-30
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• 2010

Purpose: Behavior and movement are accomplished by voluntary contractions of skeletal muscles. There are three types of muscle contractions: concentric, isometric and eccentric. The aim of our study was to determine whether there is a difference in the cortical activation pattern between concentric contraction and eccentric contraction of the wrist extensor muscle. Methods: Four healthy right-handed volunteers without any previous history of physical or neurological illness were recruited. fMRI scanning was done during 4 repeated blocks of concentric and eccentric exercise of the wrist joint. Subjects exercised for 12 seconds and then rested for 12 seconds before beginning the second set of exercises. To determine the excitability of cortical neurons during exercise, voxel count and intensity index were analyzed. Results: For right hand movements, when concentric contractions of the right wrist were done, only the left primary motor area was activated. In contrast, during eccentric contraction, both the primary motor area and secondary motor area were activated. For left hand movements, both concentric and eccentric contractions induced only the supplementary motor cortex and the contralateral primary motor cortex. Conclusion: During eccentric contractions, both the primary motor area and secondary motor area are activated in ipsilateral and contralateral brain areas. Thus, eccentric contractions require more complex and difficult movements than concentric contractions do.

• The Journal of Korean Physical Therapy
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• v.15 no.3
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• pp.295-345
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• 2003

This study investigated activation of cerebral cortex in patients with hemiplegia that was caused by neural damage. Key-point control movement therapy of Bobath was performed for 9 weeks in 3 subjects with hemiplegia and fMRI was used to compare and analyze activated degree of cerebral cortex in these subjects. fMRI was conducted using the blood oxygen level-dependent(BOLD) technique at 3.0T MR scanner with a standard head coil. The motor activation task consisted of finger flexion-extension exercise in six cycles(one half-cycles = 8 scans = $3\;sec{\times}\;8\;=\;24\;sec$). Subjects performed this task according to visual stimulus that sign of right hand or left hand twinkled(500ms on, 500ms off). After mapping activation of cerebral motor cortex on hand motor function, below results were obtained. 1. Activation decreased in primary motor area, whereas it increased in supplementary motor area and visual association area(p<.001). 2. Activation was observed in bilateral medial frontal gyrus, middle frontal gyrus of left cerebrum, inferior frontal gyrus, inter-hemispheric, fusiform gyrus of right cerebrum, superior parietal lobule of parietal lobe and precuneus in subjedt 1, parahippocampal gyrus of limbic lobe and cingulate gyrus in subject 2, and inferior frontal gyrus of right frontal lobe, middle frontal gyrus, and inferior parietal lobule of left cerebrum in subject 3 (p<.001). 3. Activation cluster extended in declive of right cellebellum posterior lobe in subject 1, culmen of anterior lobe and declive of posterior lobe in subject 2, and dentate gyrus of anterior lobe, culmen and tuber of posterior lobe in subject 3 (p<.001). In conclusion, these data showed that Key-point control movement therapy of Bobath after stroke affect cerebral cortex activation by increasing efficiency of cortical networks. Therefore mapping of brain neural network activation is useful for plasticity and reorganization of cerebral cortex and cortico-spinal tract of motor recovery mechanisms after stroke.

• 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.

• 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.

• Journal of Yeungnam Medical Science
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• v.22 no.2
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• pp.119-130
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• 2005

Stroke is a leading cause of chronic physical disability. The recent randomized controlled trials have that motor function of chronic stroke survivors could be improved through physical or pharmacologic intervention in the stroke rehabilitation setting. In addition, several functional neuroimaging techniques have recently developed, it is available to study the functional topography of sensorimotor area of the brain. However, the mechanisms involved in motor recovery after stroke, are still poorly understood. Four motor recovery mechanisms have been suggested, such as reorganization into areas adjacent to the injured primary motor cortex (M1), unmasking of the motor pathway from the unaffected motor cortex to the affected hand, attribution of secondary motor areas, and recovery of the damaged contralateral corticospinal tract. Understanding the motor recovery mechanisms would provide neurorehabilitation specialists with more information to allow for precise prognosis and therapeutic strategies based on the scientific evidence; this may help promote recovery of motor function. This review introduces several methodologies for neuroimaging techniques and discusses theoretical issues that impact interpretation of functional imaging studies of motor recovery after stroke. Perspectives, for future research are presented.

• Proceedings of the KSMRM Conference
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• 2004.09a
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• pp.73-74
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• 2004

• Proceedings of the KSMRM Conference
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• 2004.09a
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• pp.71-72
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• 2004

• Journal of the Korean Society of Physical Medicine
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• v.5 no.3
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• pp.467-476
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• 2010

Purpose : This study was performed to understand the relationship between hand and mouth shapes using functional magnetic resonance imaging(fMRI). Methods : Two healthy volunteers without any previous history of physical or neurological illness were recruited. fMRI was done that volunteers was 6 repeated of natural mouth, close mouth and open mouth while power grip and pinch grip movement. Results : Cerebral cortex activation was not well observed for the natural mouth during the power grip exercise. For the closed mouth, the temporal lobe, Broca's area, the prefrontal area related to thinking and judgment, the supplementary motor area, the auditory area and Wernicke's area were activated. For the open mouth, cortical activation was also observed in the temporal lobe, Wernicke's area, the prefrontal area related to thinking and the orbital frontal area related to visual sense. During the pinch grip exercise, cortical activation was observed for the natural mouth in the primary sensory area, Wernicke's area, the primary and supplementary motor area, and the prefrontal area. For the closed mouth, cortical activation was observed in the temporal lobe, Wernicke's area, the prefrontal area related to thinking, the secondary visual area, the primary sensory area and the supplementary motor area. In the case of the open mouth, cortical activation was observed in a few parts in the temporal lobe as well as Wernicke's area, the prefrontal area related to thinking, and other areas related to visual sense such as the primary visual area, the secondary visual area and the visual association area. Conclusion : Brain was more activation for close mouth and open mouth more than natural mouth movement.

• The Journal of Internal Korean Medicine
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• v.22 no.2
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• pp.263-269
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• 2001

Monoplegia is the paralysis of either the upper or lower limb. Monoplegia is commonly caused by an injury to the cerebral cortex; it is rarely caused by an injury to the internal capsule, brain stem, or spinal cord. Most cerebral cortex is derived from the occlusion of a brain cortex blood vessel due to thrombus or embolus. According to motor homunculus, lower limb monoplegia occurs from limited damage to the most upper part of the primary motor area(Brodmann's area 4, located in precentral gyrus). Clinically, lower limb monoplegia due to brain cortical infarction is commonly misunderstood as monoplegia due to spinal injury because the lesion is situated at the most upper part of precentral gyrus. We had many difficulties in finding lesion on brain CT, but we diagnosed two patients correctly by using an MRI, who have lower limb monoplegia due to brain cortical infarction oriental treatment.