• Title/Summary/Keyword: Motor cortex

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The Upper Ascending Reticular Activating System between Intralaminar Thalamic Nuclei and Cerebral Cortex in the Human Brain

  • Jang, Sungho;Kwak, Soyoung
    • The Journal of Korean Physical Therapy
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    • v.29 no.3
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    • pp.109-114
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    • 2017
  • Purpose: The ascending reticular activating system (ARAS) is responsible for regulation of consciousness. In this study, using diffusion tensor imaging (DTI), we attempted to reconstruct the thalamocortical projections between the intralaminar thalamic nuclei and the frontoparietal cortex in normal subjects. Methods: DTI data were acquired in 24 healthy subjects and eight kinds of thalamocortical projections were reconstructed: the seed region of interest (ROI) - the intralaminar thalamic nuclei and the eight target ROIs - the medial prefrontal cortex, dorsolateral prefrontal cortex, ventrolateral prefrontal cortex, orbitofrontal cortex, premotor cortex, primary motor cortex, primary somatosensory cortex, and posterior parietal cortex. Results: The eight thalamocortical projections were reconstructed in each hemisphere and the pathways were visualized: projections to the prefrontal cortex ascended through the anterior limb and genu of the internal capsule and anterior corona radiata. Projections to the premotor cortex passed through the genu and posterior limb of the internal capsule and middle corona radiata; in contrast, projections to the primary motor cortex, primary somatosensory cortex, and posterior parietal cortex ascended through the posterior limb of the internal capsule. No significant difference in fractional anisotropy, mean diffusivity, and fiber volume of all reconstructed thalamocortical projections was observed between the right and left hemispheres (p>0.05). Conclusion: We reconstructed the thalamocortical projections between the intralaminar thalamic nuclei and the frontoparietal cortex in normal subjects. We believe that our findings would be useful to clinicians involved in the care of patients with impaired consciousness and for researchers in studies of the ARAS.

Cortical Activation in the Human Brain induced by Transcranial Direct Current Stimulation (경두개 직류전류 자극이 대뇌피질의 뇌 활성도에 미치는 영향)

  • Kwon, Yong-Hyun;Kim, Chung-Sun;Jang, Sung-Ho
    • The Journal of Korean Physical Therapy
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    • v.21 no.4
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    • pp.73-79
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    • 2009
  • Purpose: Recently, neurostimulation studies involving manipulation of cortical excitability of the human brain have been increasingly attempted. We investigated whether transcranial direct current stimulation (tDCS) applied to the underlying cerebral cortex, directly induces cortical activation during fMRI scanning. Methods: We recently recruited five healthy subjects without a neurological or psychiatric history and who were right-handed, as verified by the modified Edinburg Handedness Inventory. fMRI was done while constant anodal tDCS was delivered to the underlying SM1 area?? immediately after the pre-stimulation for eighteen minutes. Results: Group analysis yielded an averaged map that showed that the SM1 area and the superior parietal cortex in the ipsilateral hemisphere were activated. The voxel size and peak intensity were, respectively, 82 and 5.22 in the SM1, and 85 and 5.77 in the superior parietal cortex. Conclusion: Cortical activation can be induced by constant anodal tDCS of the underlying motor cortex. This suggests that tDCS may be an effective therapeutic device for enhancing? physical motor function by modulating neural excitability of the motor cortex.

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Evaluation of the Postoperative Motor Function for Metastatic Brain Tumors Around the Motor Cortex (운동중추 주변에 위치한 전이성 뇌종양의 수술 후 운동 기능에 대한 평가)

  • Kim, Sang Hyo;Jung, Shin;Kang, Sam Suk;Lee, Jung Kil;Kim, Tae Sun;Kim, Jae Hyoo;Kim, Soo Han;Lee, Je Hyuk
    • Journal of Korean Neurosurgical Society
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    • v.30 no.sup1
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    • pp.25-29
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    • 2001
  • Objective : Intracranial metastasis is responsible for nearly 50% of mortalities of systemic cancers. Although its frequency is increasing and there is little doubt that improving the quality and expectancy of life is the final goal, the mode of treatment is still disputed. The authors report the postoperative motor function after surgery in patients with metastatic tumors around the motor cortex. Materials and Methods : We studied 24 patients with metastatic tumors around the central sulcus during the last 22 months. Motor function was assessed pre- and post-operatively as well as its response to corticosteroids. MRI, neuronavigation system and intraoperative ultrasonography were used for tumor localization and functional MRI and cortical stimulator were used to define the motor cortex. Results : Single metastasis was found in 13 cases(54%) and 11 cases(44%) had multiple foci. Thirteen cases were located in precentral, 7 in postcentral, and 4 in superior or middle-frontal lobe. The most common primary focus was the lung(16 cases). There was no difference in postoperative motor function improvement between the steroid responsive group and non-responsive group(92% versus 90%). Ninty-two percent of the patients showed significant improvement of motor function and lived independently but there was worsening in the upper extremity in one and in another no improvement. Whole brain radiation of 3000cGy was given in all cases and 4 patients died of recurrence in primary or intracranial focus during mean follow-up periods of 14 monthes. Conclusion : Surgery may provide substantial improvement of the motor function and quality of life of the patients with metastatic tumors around the motor cortex.

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Neurophysiological Evaluation of the Motor System Using Transcranial Magnetic Stimulation (뇌자기자극을 이용한 운동신경계의 신경생리학적 평가)

  • Shin, Hae-Won;Sohn, Young-H.
    • Annals of Clinical Neurophysiology
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    • v.13 no.1
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    • pp.1-12
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    • 2011
  • Transcranial magnetic stimulation (TMS) is a non-invasive tool used to study aspects of human brain physiology, including motor function and the pathophysiology of various brain disorders. A brief electric current passed through a magnetic coil produces a high-intensity magnetic field, which can excite or inhibit the cerebral cortex. Although various brain regions can be evaluated by TMS, most studies have focused on the motor cortex where motor evoked potentials (MEPs) are produced. Single-pulse and paired-pulse TMS can be used to measure the excitability of the motor cortex via various parameters, while repetitive TMS induces cortical plasticity via long-term potentiation or long-term depression-like mechanisms. Therefore, TMS is useful in the evaluation of physiological mechanisms of various neurological diseases, including movement disorders and epilepsy. In addition, it has diagnostic utility in spinal cord diseases, amyotrophic lateral sclerosis and demyelinating diseases. The therapeutic effects of repetitive TMS on stroke, Parkinson disease and focal hand dystonia are limited since the duration and clinical benefits seem to be temporary. New TMS techniques, which may improve clinical utility, are being developed to enhance clinical utilities in various neurological diseases.

Motor Areas of the Cerebral Cortex-New Vistas

  • Tanji, Jun
    • The Korean Journal of Physiology
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    • v.28 no.1
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    • pp.19-25
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    • 1994
  • On the basis of morphological and functional studies, it is now established that there exist multiple motor representation areas in the frontal lobe of subhuman primates. Recent development of analysis on cerebral critical organization in human subjects, utilizing novel techniques of PET and MRI, provides evidence of corresponding motor areas. Each area has its unique sources of inputs from the thalamus and from other parts of the cerebral cortex. To understand functional roles of these multiple motor areas, it is necessary to study neural activity while subjects are performing a variety of motor tasks. In view of high accuracy in spatial and temporal resolution, the analysis of single cells in relation to specific aspects of motor behavior remains to be a powerful research technique. It is with this technique that a number of novel concepts on functional roles of multiple motor areas have been proposed.

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Effects of the Bee Venom Herbal Acupuncture on the Neurotransmitters of the Rat Brain Cortex

  • Yun, Hyoung-Seok;Lee, Jae-Dong
    • Journal of Pharmacopuncture
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    • v.4 no.1
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    • pp.125-139
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    • 2001
  • In order to study the effects of bee venom herbal acupuncture on the neurotransmitters of the rat brain cortex, herbal acupuncture with the bee venom group and normal saline group was performed bilaterally on the point corresponding to LI 4 of the rat. The average optical density of the neurotransmitters from the cerebral cortex was analyzed 30 minutes after the herbal acupuncture with immunohistochemical methods. The results were as follows: 1. The density of NADPH-diaphorase in the bee venom group was increased significantly at the motor cortex, visual cortex, auditory cortex, cingulate cortex, retrosplenial cortex, and perirhinal cortex, compared to the normal saline group. 2. The average optical density of vasoactive intestinal peptide in the bee venom group had significant changes at the insular cortex, retrosplenial cortex, and perirhinal cortex, compared to the normal saline group. 3. The average optical density of neuropeptide-Y in the bee venom group increased significantly at the visual cortex and cingulate cortex, compared to the normal saline group.

Functional-Magnetic Resonance Imaging and Transcranial Magnetic Stimulation in a Case of Schizencephaly (뇌열 1예의 기능적 자기공명영상과 경두부 자기자극)

  • 변우목;한봉수;이재교;장용민
    • Investigative Magnetic Resonance Imaging
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    • v.4 no.1
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    • pp.14-19
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    • 2000
  • Purpose : This study was to present the functional brain mapping of both functional magnetic resonance imaging(MRI) and transcranial magnetic stimulation(TMS) in a case of schizencephaly. Materials and methods : A 28-year-old man, who had left hemiplegia and schizencephaly in right cerebral hemisphere, was exacted with both functional MRI and TMS. Motor function of left hand was decreased whereas right hand was within normal limit. For functional MRI, gradient-echo echo planar imaging($TR/TE/{\alpha}$=1.2 sec/90 msec/90) was employed. The paradigm of motor task consisted of repetitive self-paseo hand flexion-extension exercises with 1-2 Hz periods. An image set of 10 slices was repetitively acquired with 15 seconds alternating periods of task performance and rest and total 6 cycles (three ON periods and three OFF periods) were performed. In brain mapping, TMS was performed with the round magnetic stimulator (mean diameter; 90mm). The magnetic stimulation was done with 80% of maximal output. The latency and amplitude of motor evoked potential(MEP)s were obtained from both abductor pollicis brevis(APB) muscles. Results : Functional MRI revealed activation of the left primary motor cortex with flexion-extension exercises of healthy right hand. On the other hand, the left primary motor cortex, left supplementary motor cortex, and left promoter areas were activated with flexion-extension exercises of left hand. In TMS, magnetic evoked potentials were induced in no areas of right cerebral hemisphere, but in 5 areas of left corebral hemisphere from both abductor pollicis brevis. Latency, amplitude, and contour of response of the magnetic evoked potentials in both hands were similar. Conclusion : Functional MRI and TMS in a patient with schizencephaly were successfully used to localize cortical motor function. Ipsilateral motor pathway is thought to be secondary to reinforcement of the corticospinal tract of the ipsilateral motor cortex.

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Measurement of Event-related Hemodynamic Responses on Motor Cortex Measured by Near-infrared Spectroscopy (근적외선 분광 분석법을 이용한 운동령에서의 사건 기반 산소 포화도 변화 신호 측정)

  • Lee, Dong-Chul;Shin, Jae-Young;Kim, Ji-Hyun;Jeong, Ji-Chai
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.7
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    • pp.1049-1055
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    • 2012
  • We measure the hemodynamic responses during the 4 kinds of tasks on the motor cortex in the right and left human brain by using near-infrared spectroscopy. The experimental results show that the change of concentration of oxy-hemoglobin is larger than that of deoxy-hemoglobin and the change of concentration of chromophores induced by finger and arm related task show more activations than that of leg.

Medial Reorganization of Primary Motor Cortex in Patient with Traumatic Brain Injury: a fMRI Case Study (외상성 뇌손상 환자에서 대뇌피질의 재조직화: 사례보고)

  • Choi, Jin-Ho;Kwon, Yong-Hyun
    • 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.

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