• Title/Summary/Keyword: Motor cortex

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Disturbed Functional Asymmetry of Sensorimotor Cortex in Schizophrenia: A Study with Functional Magnetic Resonance Imaging (정신분열증에서 감각운동피질의 기능적 비대칭성의 장애: 기능적 자기공명영상을 이용한 연구)

  • Ahn, Kook-Jin;Chae, Jeong-Ho;Kim, Tae;Kim, Euy-Neyng;Lee, Jee-Mun;Choi, Kyu-Ho;Hahn, Seong-Tai
    • 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.

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Unsuspected Plasticity of Single Neurons after Connection of the Corticospinal Tract with Peripheral Nerves in Spinal Cord Lesions

  • Brunelli, Giorgio;Wild, Klaus von
    • Journal of Korean Neurosurgical Society
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    • v.46 no.1
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    • pp.1-4
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    • 2009
  • Objective: To report an unsuspected adaptive plasticity of single upper motor neurons and of primary motor cortex found after microsurgical connection of the spinal cord with peripheral nerve via grafts in paraplegics and focussed discussion of the reviewed literature. Methods: The research aimed at making paraplegics walk again, after 20 years of experimental surgery in animals. Amongst other things, animal experiments demonstrated the alteration of the motor endplates receptors from cholinergic to glutamatergic induced by connection with upper motor neurons. The same paradigm was successfully performed in paraplegic humans. The nerve grafts were put into the ventral-lateral spinal tract randomly, with out possibility of choosing the axons coming from different areas of the motor cortex. Results: The patient became able to selectively activate the re-innervated muscles she wanted without concurrent activities of other muscles connected with the same cortical areas. Conclusion: Authors believe that unlike in nerve or tendon transfers, where the whole cortical area corresponding to the transfer changes its function a phenomenon that we call "brain plasticity by areas". in our paradigm due to the direct connection of upper motor neurons with different peripheral nerves and muscles via nerve grafts motor learning occurs based on adaptive neuronal plasticity so that simultaneous contractions of other muscles are prevented. We propose to call it adaptive functional "plasticity by single neurons". We speculate that this phenomenon is due to the simultaneous activation of neurons spread in different cortical areas for a given specific movement, whilst the other neurons of the same areas connected with peripheral nerves of different muscles are not activated at the same time. Why different neurons of the same area fire at different times according to different voluntary demands remains to be discovered. We are committed to solve this enigma hereafter.

Acupuncture stimulation for motor cortex activities: Evidence from 3T functional MRI study

  • 최보영;전신수;유승식;최기순;박상동;임은철;정성택;이형구;서태석
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2003.09a
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    • pp.75-75
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    • 2003
  • Purpose: To investigate whether or not acupuncture of GB34 produces a significant response of the modulation of somatomotor areas by functional magnetic resonance imaging (fMRI) study. Methods: The acupoint, GB34, located in the back of the knee, is known to be effective in recovering motor function after stroke. Using 3T MRI scanner, functional MR imaging of the whole brain was performed in 12 normal healthy subjects during two stimulation paradigms; acupuncture manipulation on GB 34 and sham points. This study investigates the activation of the motor cortex elicited by a soft and an intensified stimulation of GB 34. Three different paradigms were carried out to detect any possible modulation of the Blood Oxygenation Level Dependent (BOLD) response in the somatomortor area to motor stimulation through acupuncture. Results: Group analysis from seven individuals showed that bilateral sensorimotor areas (BA 3,4,6 and 7) showed stimulation related BOLD signal contrast of approximately 6% whereas very few areas were activated when sham stimulation is given. Conclusions: The present study shows that acupuncture fMRI study can be safely conducted in 3T MRI environment, and acupuncture stimulation in GB34 modulates the cortical activities of the soma- to motor area in human. The present findings may shed light on the CNS mechanism of motor function by acupuncture and form a basis for future investigations of motor modulation circuits in the stroke patients. Acknowledgement: This study was supported by a grant of the Mid and Long Term Nuclear RID Plan Program, Ministry of Science and Technology, Republic of Korea.

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Comparison of Cortical Activation between Concentric and Eccentric Exercise: A Pilot fMRI Study (기능적 자기공명영상을 이용한 구심성 및 원심성 근 수축에 따른 뇌 활성도 분석)

  • Kim, Chung-Sun;Kim, Joong-Hwi;Park, Min-Kyu;Park, Ji-Won
    • 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.

Targeting motor and cognitive networks with multichannel transcranial direct current stimulation along with peripheral stimulation in a subacute stroke survivor: single case study

  • Midha, Divya;Arumugam, Narkeesh
    • Physical Therapy Rehabilitation Science
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    • v.9 no.4
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    • pp.318-323
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    • 2020
  • Objective: Reacquisition of motor functions following stroke depends on interhemispheric neural connections. The intervention highlighted in the present case is an insight for augmenting motor recovery by stimulating the lesioned area and adjacent areas governing the motor behaviour of an individual. The purpose of this study was to determine the changes in the motor and cognitive outcomes through multi target stimulation of cortical areas by application of multichannel transcranial direct current stimulation (M-tDCS) in a stroke survivor. Design: A case report. Methods: The patient was a participant of a trial registered with the clinical trial registry of India (CTRI/2020/01/022998). The patient was intervened with M-tDCS over the left primary motor cortex i.e. C3 point and left dorsolateral prefrontal cortex i.e. F3 point with 0.5-2 mA intensity for the period of 20 minutes. SaeboFlex-assisted task-oriented training, functional electrical stimulation over the lower extremity (LE) to elicit dorsiflexion at the ankle and eversion of the foot, and conventional physiotherapy rehabilitation including a tailored exercise program were performed. Outcome assessment was done using the Fugl-Meyer assessment scale (FMA) for the upper and lower extremity (UE and LE), Montreal Cognitive Assessment (MOCA), Wisconsin Gait Scale (WGS) and the Stroke Specific Quality of Life (SSQOL) measures. Assessment was taken at Day 0, 15 and 30 post intervention. Results: Improvement was observed in all the outcome measures i.e FMA (UE and LE), MOCA, SSQOL and WGS across the span of 4 weeks. Conclusions: M-tDCS induced improvement in motor functions of the UE and LE, gait parameters and cognitive functions of the patient.

Emotion Evaluation algorithm of Brain Information System using Dynamic Genitive Maps (동적인지 맵을 이용한 뇌 정보 처리 시스템의 감정 평가 알고리즘)

  • 홍인택;김성주;서재용;김용택;전홍태
    • Proceedings of the IEEK Conference
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    • 2003.07d
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    • pp.1243-1246
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    • 2003
  • It is known that structure of Human's brain information system is controlled by cerebral cortex mainly. Cerebral cortex is divided by sensory area, motor area and associated area largely. Sensory area takes part in information from environment and motor area is actuation by decision as associated area determined. It is possible to copy brain information system by input-output pattern. but there is difficulty in modeling of memorizing new information. Such action is performed by Limbic Lobe and Papez circuit which is controlled by intrinsic emotion. So we need of definition of emotion's role in decision. In this paper, we define roles of emotion in intrinsic decision using Dynamic Cognitive Maps(DCMs). The emotion is evaluated by outside information then intrinsic decision performed as how much emotion variated. The dynamic cognitive maps take part in emotion evaluating process.

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Partial Least Squares-discriminant Analysis for the Prediction of Hemodynamic Changes Using Near Infrared Spectroscopy

  • Seo, Youngwook;Lee, Seungduk;Koh, Dalkwon;Kim, Beop-Min
    • Journal of the Optical Society of Korea
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    • v.16 no.1
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    • pp.57-62
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    • 2012
  • Using continuous wave near-infrared spectroscopy, we measured time-resolved concentration changes of oxy-hemoglobin and deoxy-hemoglobin from the primary motor cortex following finger tapping tasks. These data were processed using partial least squares-discriminant analysis (PLS-DA) to develop a prediction model for a brain-computer interface. The tasks were composed of a series of finger tapping for 15 sec and relaxation for 45 sec. The location of the motor cortex was confirmed by the anti-phasic behavior of the oxy- and deoxy-hemoglobin changes. The results were compared with those obtained using the hidden Markov model (HMM) which has been known to produce the best prediction model. Our data imply that PLS-DA makes better judgments in determining the onset of the events than HMM.

A Real time Internet Game Played with a Brain-Computer Interfaced Animal (뇌-기계접속 된 동물과 사람사이의 실시간 인터넷게임)

  • Lee, H.J.;Kim, D.H.;Lang, Y.R.;Han, S.H.;Kim, Y.B.;Lee, G.S.;Lee, E.J.;Song, C.G.;Shin, H.C.
    • 한국HCI학회:학술대회논문집
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    • 2007.02a
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    • pp.780-783
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    • 2007
  • A Many studies have been made on the prediction of human voluntary movement intention in real-time based on invasive or non-invasive methods to help severely motor-disabled persons by offering some abilities of motor controls and communications. In the present study, we have developed an internet game driven by and/or linked to a brain-computer interface (BCI) system. Activities of two single neuronal units recorded from either hippocampus or prefrontal cortex of SD rats were used in real time to control two-dimensional movements of a robot, or a game object.

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Rebound excitability mediates motor abnormalities in Parkinson's disease

  • Kim, Jeongjin;Kim, Daesoo
    • BMB Reports
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    • v.51 no.1
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    • pp.3-4
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    • 2018
  • Parkinson's disease (PD) is a debilitating disorder resulting from loss of dopamine neurons. In dopamine deficient state, the basal ganglia increases inhibitory synaptic outputs to the thalamus. This increased inhibition by the basal ganglia output is known to reduce firing rate of thalamic neurons that relay motor signals to the motor cortex. This 'rate model' suggests that the reduced excitability of thalamic neurons is the key for inducing motor abnormalities in PD patients. We reveal that in response to inhibition, thalamic neurons generate rebound firing at the end of inhibition. This rebound firing increases motor cortical activity and induces muscular responses that triggers Parkinsonian motor dysfunction. Genetic and optogenetic intervention of the rebound firing prevent motor dysfunction in a mouse model of PD. Our results suggest that inhibitory synaptic mechanism mediates motor dysfunction by generating rebound excitability in the thalamocortical pathway.