• The Journal of Korean Physical Therapy
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• 제25권5호
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• pp.260-265
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• 2013

Purpose: This study was conducted in order to evaluate the quantitative effectiveness of region of interest (ROI) setting in MR-DTI analysis with and without fMRI activation results. Methods: Ten right-handed normal volunteers participated in this study. DTI and fMRI datasets for each subject were obtained using a 1.5T MRI system. For neural fiber tracking, ROIs were drawn using two methods: The drawing points were located in the fMRI activation areas or areas randomly selected by users. In this study, the neural fiber tract targeted the corticospinal tract (CST) Quantitative analyses were performed and compared. The pixel numbers passing through the fiber tract in the individual brain volume were counted. The ratios between the ROI pixel numbers and the extracted fiber pixel numbers, and the ratios between the fiber pixel numbers and the whole-brain pixel numbers were also calculated. Results: According to our results, extracted CST fiber tract in which the ROI was drawn with fMRI activation areas showed higher distribution than drawing the ROI by users' hands. In addition, the quantitatively measured values represented higher pixel distribution: The counted average pixel numbers were 4553.8 and 1943.3. The average ratios of the ROI areas were 33.87 and 22.52. The average percentages of the individual whole-brain volume numbers were 2.06 and 0.87. Conclusion: Results of this study appear to indicate that use of this method can allow for more objectives and significant for study of the recovery of neural fiber mechanisms and brain rehabilitation.

• Investigative Magnetic Resonance Imaging
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• 제24권1호
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• pp.51-54
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• 2020

Superficial siderosis is attributed to hemosiderin deposition in the subpial layers of the nervous system. The clinical features of infratentorial superficial siderosis (ISS) are hearing loss, cerebellar ataxia, and corticospinal tract signs and the most common cause of idiopathic ISS is a dural defect. As magnetic resonance imaging (MRI) has advanced, the diagnosis of infratentorial superficial siderosis can be confirmed by unique radiological findings in MRI. Here, we report on a female patient diagnosed with idiopathic ISS by means of clinical symptoms and radiological findings.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2006년도 제33회 추계학술대회 발표논문집
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• pp.153-153
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• 2006

• 대한의용생체공학회:의공학회지
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• 제28권3호
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• pp.317-324
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• 2007

The application of diffusion tensor imaging (DTI) and fiber tractography to Wallerian degeneration (WD) is important because this technique is a very potent tools for quantitatively evaluating fiber tracts in vivo brain. We analyzed a case and control using tracts of interest (TOI) analysis to quantify WD. We scanned a case of old infarction and an age-matched healthy volunteer. T1 magnetization prepared rapid acquisition gradient echo (MPRAGE), fluid attenuated inversion recovery (FLAIR) and 12-direction diffusion tensor imaging (DTI) were obtained and analyzed using TOI analysis. The value of mean diffusity ($D_{av}$) and fracional anisotrophy (FA) were analyzed statistically by MWU test. A p-value of less than 0.05 was considered to indicate statistical significance. A comparison of the global fiber diffusion characteristics shows WD of both the corpus callosum and the ipsilateral superior longitudinal fasciculus. The corpus callosum in particular showed trans-hemispherical degeneration. Local fiber characteristics along the geodesic paths show WD in the corpus callosum, ipsilateral superior longitudinal fasciculus, ipsilateral corticospinal tract, and ipsilateral corticothalamic tract. We have demonstrated changes in $D_{av}$ and FA values and a clear correspondence with the WD in various tracts. TOI analysis successfully revealed radial WD in white matter tracts from a region of encephalomalacia and primary gliosis, although they were only slightly affected.

• Investigative Magnetic Resonance Imaging
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• 제13권1호
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• pp.40-46
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• 2009

목적 : 기능적 뇌 자기공명영상 (fMRI)과 확산텐서영상(DTI) 합성기법을 이용하여 피질척수로의 여러 부위에서 정량적 특성을 연구하고자 하였다. 대상 및 방법 : 신경학적 이상이 없는 정상인 10명 (남: 8, 여: 2, 평균연령: 30세, 연령분포 : 22 -38세)을 대상으로 하였다. fMRI는 1.5T를 이용하였으며, 손의 쥐기 펴기를 수행하였다. fMRI와 확산텐서섬유로(DTT)의 합성이 가능한 DtiStudio 프로그램을 이용하여 피질척수로를 3차원 영상화하였다. 이때, 시작 관심영역은 2차원 분할 비등방성(fractional anisotropy, FA) 색지도(color map)에서 fMRI의 운동 수행 시 활성부위가 가장 많은 곳으로, 목표 관심영역은 하부 전방 뇌교의 피질척수 부위로 설정하였다. 정량적 분석을 위하여 관심영역을 부채살부터 연수까지 좌우 각각 5곳에 설정하여 분할 비등방성과 현성 확산계수(ADC)를 측정하였다. 결과 : 모든 대상자는 fMRI에서 일차 감각운동 영역이 주로 활성화되었다. 확산텐서 영상에서 피질척수로의 경로는 일차 감각운동 영역부터 연수까지 주행하였다. 피질척수로의 FA 값은 모든 대상자에서 중뇌와 내측 섬유띠의 후지가 타 부위보다 높았다. 결론 : fMRI와 DTT의 합성기법은 피질척수로 상태의 3차원 영상화 및 각 부위에서 FA와 ADC값을 이용한 정량적 분석이 가능하였다. 앞으로, fMRI와 DTT 합성기법은 뇌손상 환자에서 피질척수로의 명확한 상태를 연구하는 데 유용하게 이용될 것으로 사료된다.

• 대한임상검사과학회지
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• 제50권2호
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• pp.211-215
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• 2018

이 연구의 목적은 운동피질 주변의 뇌종양 환자를 대상으로 수술 중 피질척수로를 보존하고 운동 능력을 더 정확하게 평가하기 위함이다. 경두개운동유발전위는 위양성(false positive)과 위음성(false negative)이 혼재하는 검사이기 때문에 수술 중 검사상 파형의 변화가 없었다 할 지라도 검사의 내용을 완전히 신뢰할 수 없다. 보다 자세한 검사를 위해 대뇌피질을 선택적으로 자극할 수 있는 직접피질자극검사를 시행하였다. 직접피질자극 검사를 시행한 2케이스 에서는 수술 중 피질이 담당하는 부위를 찾고 지속적으로 진폭의 변화를 확인하며 검사할 수 있어 운동경로를 보존하며 수술 할 수 있었다. 하지만 직접피질 자극검사를 시행하지 않고 경두개운동유발전위 검사만을 시행한 환자에서는 수술 후 환자의 운동 능력이 감소되는 것을 경험할 수 있었다. 위와 같은 결과를 볼 때 직접피질자극 검사는 매우 유용한 검사이고 뇌종양 수술 시 경두개운동유발전위 검사와 병행하여 환자에게 올 수 있는 후유장애를 줄일 수 있는 방법이다.

• 한방재활의학과학회지
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• 제18권3호
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• pp.19-39
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• 2008

목 적 : 천궁은 중추신경계 신경조직의 손상을 감소시키는 데에 유효한 것으로 보고되었다. 따라서 손상 척수신경에서 천궁에 의한 각각의 신경조직의 반응성을 조사하기 위하여 흰쥐의 손상된 척수 신경에 천궁 추출물을 처리하여 관찰하였다. 방 법 : 흰쥐의 척수조직에 타박손상을 가한 후 천궁을 처리하고 손상부위의 GAP-43과 Cdc2 및 Erk1/2 단백질의 수준, 축삭 및 성상세포의 수, 아교상혼의 정도를 각각 확인하여 손상부위 및 피질척수로의 재성장 여부를 관찰하였다. 결 과 : 천궁처리에 의하여 손상부위에서는 GAP-43과 Cdc2 및 Erk1/2 단백질의 수준이 증가하였다. 손상척수 부위에서 성상세포의 수는 천궁처리에 의하여 비손상대조군에 비해 증가하였다. CSPG 단백질에 의하여 확인된 아교상흔의 정도는 천궁처리에 의하여 감소하였다. Dil에 의한 정방향 염색에 의하여 피질척수로를 확인하였으며, 측방축삭의 싹돌기는 천궁처리에 의하여 손상부위 상단부 및 하단부에 각각 증가하였다. 고분자미세관을 손상척수부위에 이식하여 미세관내부로 축삭 및 비신경세포의 이주양상을 분석한 결과 천궁처리에 의하여 축삭 및 성상교세포의 이주증가를 확인하였다. 결론 : 천궁이 손상척수신경부위에서 비신경세포 특히 성상세포의 활성화에 기여함을 알 수 있었다. 이러한 활성화는 손상 피질척수로 축삭의 재성장 반응을 증가시키는 효과가 있는 것으로 판단된다.

• Journal of Korean Neurosurgical Society
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• 제46권1호
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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.

• Korean Journal of Radiology
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• 제22권7호
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• pp.1142-1151
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• 2021

Objective: To evaluate microstructural damage in high myopia (HM) patients using 3T diffusion kurtosis imaging (DKI). Materials and Methods: This prospective study included 30 HM patients and 33 age- and sex-matched healthy controls (HCs) with DKI. Kurtosis parameters including kurtosis fractional anisotropy (FA), mean kurtosis (MK), axial kurtosis (AK), and radial kurtosis (RK) as well as diffusion metrics including FA, mean diffusivity, axial diffusivity (AD), and radial diffusivity derived from DKI were obtained. Group differences in these metrics were compared using tract-based spatial statistics. Partial correlation analysis was used to evaluate correlations between microstructural changes and disease duration. Results: Compared to HCs, HM patients showed significantly reduced AK, RK, MK, and FA and significantly increased AD, predominately in the bilateral corticospinal tract, right inferior longitudinal fasciculus, superior longitudinal fasciculus, inferior fronto-occipital fasciculus, and left thalamus (all p < 0.05, threshold-free cluster enhancement corrected). In addition, DKI-derived kurtosis parameters (AK, RK, and MK) had negative correlations (r = -0.448 to -0.376, all p < 0.05) and diffusion parameter (AD) had positive correlations (r = 0.372 to 0.409, all p < 0.05) with disease duration. Conclusion: HM patients showed microstructural alterations in the brain regions responsible for motor conduction and vision-related functions. DKI is useful for detecting white matter abnormalities in HM patients, which might be helpful for exploring and monitoring the pathogenesis of the disease.

• BMB Reports
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• 제49권11호
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• pp.635-640
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• 2016

Recent evidence indicates that the ephrin receptors and ephrin ligands (Eph/ephrin) expression modulate axonal reorganization and synaptic plasticity in stroke recovery. To investigate the effect of task-specific training (TST) on Eph/ephrin expression in the corticospinal tract (CST) after stroke, we compared Eph/ephrin expression in the peri-infarct cortex, pyramid, and spinal cord of a photothrombotic stroke model of rat brains treated with or without TST. The TST treatment showed significantly better recovery in the behavioral tests compared with no treatment. The significant upregulation of ephrin-A1 and ephrin-A5 observed in activated astrocytes of the CST at 2 weeks' post-stroke was decreased by TST. At 5 weeks, post-stroke, the elevated ephrin-A5 levels were decreased in the ipsilateral pyramid and spinal cord by TST. Glial fibrillary acidic protein was upregulated concomitantly with the altered ephrin expression after stroke, and the expression of these proteins was attenuated by TST. These data suggest that TST alters the expression of ephrin ligands in the CST after stroke.