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Sung Ho Jang - One of the best experts on this subject based on the ideXlab platform.
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traumatic axonal injury of the Medial Lemniscus pathway in a patient with traumatic brain injury validation by diffusion tensor tractography
Neural Regeneration Research, 2016Co-Authors: Sung Ho Jang, Hyeok Gyu KwonAbstract:Traumatic brain injury (TBI) is a common disability-causing neurological disorder. For successful rehabilitation of TBI patients, a thorough evaluation of the presence and extent of neural injury is essential for determining the optimal rehabilitation strategy and accurate prognosis. However, it is difficult to determine the status of neural tracts. Diffusion tensor tractography (DTT), derived from diffusion tensor imaging (DTI), enables visualization of neural tracts three-dimensionally (Mori et al., 1999; Yamada et al., 2003; Jang and Seo, 2014). DTT has been used to detect lesions located in various neural tracts including the fornix, cingulum, corticospinal tract, and spinothalamic tract in patients with TBI (Nakayama et al., 2006; Sugiyama et al., 2007; Wang et al., 2008; Choi et al., 2012; Kim et al., 2015). However, few studies have been performed on injury of the Medial Lemniscus and its thalamocortical pathway, which involves the proprioception (Carey et al., 1993). In the current study, we reported a patient with injury of the Medial Lemniscus pathway (ML) following TBI using DTT. A 24-year-old man who was injured in a traffic accident and underwent conservative treatment for contusional hemorrhage in both frontal lobes at the Department of Neurosurgery in Yeungnam University Hospital, Republic of Korea (Figure 1). Figure 1 T2-weighted MR images and DTT images of a 24-year-old male patient with traumatic brain injury. The patient lost consciousness for 14 days after the accident. Brain MRI at 1 month after onset revealed focal encephalomalatic lesions located in both frontal lobes. Mini-Mental State Examination showed 30 points at 1 month and 7 years after onset. The patient complained of proprioceptive impairment of his left extremities since the onset of TBI. The subscales for tactile sensation and kinesthetic sensation of the Nottingham Sensory Assessment (NSA) were used to determine somatosensory function (Carey et al., 1993). The reliability of the NSA is well-established (Lincoln et al., 1998). In right extremities, any impairment of somatosensory function was not observed at 1 month and 7 years after onset. However, regarding the left extremities, at 1 month after onset, his kinesthetic sensation score indicated impairment (17 [shoulder-3, elbow-3, wrist-2, hand-1, hip-3, knee-2, ankle-2, and foot-1] out of a possible 24 points). At 7 years after onset, his kinesthetic sensation score indicated impairment (20 [shoulder-3, elbow-3, wrist-2, hand-2, hip-3, knee-3, ankle-2, and foot-2] out of a possible 24 points). In contrast, the tactile sensation score was normal at 1 month and 7 years after onset. The patient gave signed, informed consent, and the study protocol was approved by institutional review board of Yeungnam University Hospital, Republic of Korea. DTI data were acquired at 7 years after onset using a 1.5T MRI system (Gyroscan Intera; Philips Medical Systems, Best, the Netherlands). Sixty-seven consecussive slices were acquired parallel to the anterior commissure-posterior commissure line with 32 gradients. DTI parameters were as follows: acquisition matrix = 96 × 96, reconstructed to matrix = 192 × 192, field of view = 240 × 240 mm2, repetition time = 10,398 ms, echo time = 72 ms, echo-planar imaging factor = 59, b = 1,000 s/mm2, number of excitations = 1, and a slice thickness of 2.5 mm. The Functional Magnetic Resonance Imaging of the Brain (FMRIB) Software Library (Oxford, UK, FSL; www.fmrib.ox.ac.uk/fsl) was used to analyze DTI data. Eddy current correction was applied. FMRIB Diffusion Software with routine option (0.5 mm step lengths, 5,000 streamline sample, 0.2 curvature thresholds) was used for fiber tracking. Two regions of interest (ROIs) were placed to reconstruct MLPs. Seed ROI was placed in the Medial posterior region of the medullary pyramids (Jang and Kwon, 2013). The target ROI was given at the ventroposterolateral nucleus of the thalamus (Jang and Kwon, 2013). The right MLP in the patient was thinner and discontinued at the level of the corona radiata compared with the left MLP, and the left MLP showed partial tearing at the level of the centrum semiovale. In the current study, the patient showed proprioceptive impairment in the left extremities. On 7-year DTT, discontinuation and narrowing was observed in the right MLP and partial tearing was observed in the left MLP. These findings indicate severe injury of the right MLP and mild injury of the left MLP. Therefore, we believe that injury of the right MLP was ascribed to the proprioceptive impairment of the left extremities and injury of the left MLP did not accompany proprioceptive impairment because the integrity of the left MLP was preserved and injury of the left MLP was only partial tearing at the centrum semiovale level. We consider that diffuse TBI is the most plausible mechanism for right MLP injury because this patient met the diagnostic criteria of diffuse axonal injury (significant acceleration/deceleration injury during a motor vehicle accident, loss of consciousness for 14 days after injury without a lucid interval, and no specific lesion along pathways of both MLPs) (Adams et al., 1982; Parizel et al., 1998). In summary, injury of the MLPs was demonstrated in a patient with proprioceptive impairment following TBI, using DTT. Our experience with this case suggests that DTT is valuable for detection of MLP injury which cannot be detected on conventional brain MRI after TBI. Although a few previous studies reported on stroke patients with MLP injury by DTT (Hong and Jang, 2010; Seo and Jang, 2014), this is the first study to demonstrate MLP injury in a patient with TBI. However, this study is limited because of a single case report. In addition, use of multi-tensor DTT could generate false positive and negative DTT findings due to crossing fibers in a voxel throughout the brain. Further complementary studies involving larger numbers of patients are warranted. This work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, No. 2015R1D1A4A01020385.
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differences of the Medial Lemniscus and spinothalamic tract according to the cortical termination areas a diffusion tensor tractography study
Somatosensory and Motor Research, 2015Co-Authors: Sung Ho JangAbstract:AbstractWe investigated differences of the Medial Lemniscus and its thalamocortical pathway (ML), and the spinothalamic tract and its thalamocortical pathway (STT) according to the cortical termination areas. We found that the ML and STT terminated in the motor cortex and the somatosensory cortex. The ML may be closely related to the motor cortex for motor planning and execution, while the STT may be closely related to the cerebral cortex for somatosensory function and motor execution.
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recovery of an injured Medial Lemniscus pathway in a patient with intracerebral haemorrhage
Journal of Rehabilitation Medicine, 2014Co-Authors: Sung Ho JangAbstract:Objective: We describe here a patient with intracerebral haemorrhage who showed recovery of an injured Medial Lemniscus and its related thalamocortical pathway on followup diffusion tensor tractography. Case report: A 48-year-old man presented with right hemiplegia following a spontaneous intracerebral haemorrhage in the left corona radiata and basal ganglia. He underwent conservative management for intracerebral haemorrhage and comprehensive rehabilitative therapy. Results: The kinesthetic sensation score (maximum score 24 points) of the Nottingham Sensory Assessment improved from 6 points (at 2 weeks after injury) to 10 points (at 6 weeks) and to 18 points (at 12 weeks). For the left thalamocortical pathway, a discontinuation at the left midbrain below the haematoma was observed on the 2-week diffusion tensor tractography. The 6-week diffusion tensor tractography showed that the integrity of the left thalamocortical pathway had been restored to the left primary motor cortex, and the 12-week diffusion tensor tractography showed restoration to the left primary somatosensory cortex. The fibre number of the left thalamocortical pathway showed an increase (470 at 2 weeks after injury, 1,080 at 6 weeks, and 1,626 at 12 weeks). Conclusion: This patient underwent recovery of an injured thalamocortical pathway over a period of 10 weeks after the second week following intracerebral haemorrhage, in terms of restoration of discontinued integrity and increased fibre number in the thalamocortical pathway.
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anatomical location of the Medial Lemniscus and spinothalamic tract at the pons in the human brain a diffusion tensor tractography study
Somatosensory and Motor Research, 2013Co-Authors: Sung Ho Jang, Hyeok Gyu KwonAbstract:AbstractUsing diffusion tensor tractography, we investigated the anatomical location of Medial Lemniscus (ML) and spinothalamic tract (STT) at pons. We recruited 47 healthy volunteers. Evaluation of the anatomical location of ML and STT was performed using the highest probabilistic location at the upper, middle, and lower pons. According to findings, MLs were located around the middle to Medial one-third, between midline and lateral boundary of pons in the pontine tegmentum and STTs were located posterolaterally to ML.
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Motor recovery via aberrant pyramidal tract in a patient with traumatic brain injury: A diffusion tensor tractography study
Neural Regeneration Research, 2013Co-Authors: Sung Ho JangAbstract:The aberrant pyramidal tract is the collateral pathway of the pyramidal tract through the Medial Lemniscus in the brainstem. A 21-year-old man presented with right hemiparesis due to a traumatic intracerebral hemorrhage in the left corona radiata. His motor function recovered almost to the normal state at 10 months after onset. Through diffusion tensor tractography, the pyramidal tract in the affected (left) hemisphere showed discontinuation at the pontine level at 13 months after onset. An aberrant pyramidal tract was observed, which originated from the primary motor cortex and the supplementary motor area and descended through the corona radiata, then through the posterior limb of the internal capsule and the Medial Lemniscus pathway from the midbrain to the pons, finally entered into the pyramidal tract area at the pontomedullary junction. It suggests that the motor functions of the right extremities in this patient had recovered by this aberrant pyramidal tract.
Ji Heon Hong - One of the best experts on this subject based on the ideXlab platform.
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termination differences in the primary sensorimotor cortex between the Medial Lemniscus and spinothalamic pathways in the human brain
Neuroscience Letters, 2012Co-Authors: Sung Ho Jang, Yong Hyun Kwon, Ji Heon HongAbstract:Abstract The Medial Lemniscus (ML) and its thalamocortical pathway is responsible for proprioception, in contrast, the spinothalamic tract (ST) and its thalamocortical pathway is the neural tract for pain and body temperature. Therefore, the ML pathway plays a crucial role in skillful movements and may be more linked to motor function than the ST pathway. We investigated the differences in the distribution of the primary motor cortex (M1) and the primary somatosensory cortex (S1) between the ML and ST pathways. Adults (mean age: 40.4 years, range: 21–61 years) were recruited for this study. The seed masks for the ML and ST pathways were given on the color map of the medulla according to the known anatomy and waypoint masks were placed on the ventro-postero-lateral nucleus of the thalamus. The volume of ML pathway did not show any difference between the M1 (10.94) and S1 (13.02) ( p > 0.05). By contrast, the mean voxel number of the ST pathway in the M1 (18.25) and S1 (27.38) showed significant difference between the M1 and S1 ( p p
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identification of the Medial Lemniscus in the human brain combined study of functional mri and diffusion tensor tractography
Neuroscience Letters, 2009Co-Authors: Dong Seok Yang, Ji Heon Hong, Woo Mok Byun, So Young Kwak, Chang Ho Hwang, Sung Ho JangAbstract:The Medial Lemniscus (ML) plays a critical role in sensory function and skillful movement. Using combined functional MRI (fMRI) and diffusion tensor tractography (DTT), we attempted to identify the ML pathway and quantify the characteristics of the ML compared to the corticospinal tract (CST). Eleven young healthy subjects without any history of neurological disorder were recruited for this study. For tracking of the ML, a seed region of interest (ROI) was determined using the fMRI activation in the primary sensorimotor cortex (SM1) following proprioceptive input, and a target ROI was given in the ML area of the pons. We were able to locate the ML in 9 out of 11 subjects. All ML started from the ML area just posterior to the transpontine fiber in the pons, and ascended to the SM1 posterolaterally to the cerebral peduncle of the midbrain, the posterior limb of the internal capsule (PLIC), and the corona radiata along with the CST. The fractional anisotropy (FA) value of the ML was similar to that of the CST. We could identify the ML pathway in the human brain using the combined fMRI/DTT method. These results and technique will be helpful for research about the ML in the human brain.
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aberrant pyramidal tract in Medial Lemniscus of brainstem in the human brain
Neuroreport, 2009Co-Authors: Ji Heon Hong, Woo Mok Byun, Han Won Jang, Sung Ho JangAbstract:The aberrant pyramidal tract (APT) refers to the collateral pathway of the pyramidal tract through the Medial Lemniscus in the brainstem. We showed the presence of an APT in the normal human brain using diffusion tensor tractography. Diffusion tensor tractography showed that the motor tracts of the 28 hemispheres in 14 healthy normal individuals originated from the primary sensori-motor cortex and descended through the known pathway of the pyramidal tract. However, in five (17.9%) of the 28 hemispheres, we observed that the APT descended through the Medial Lemniscus from the midbrain to the pons, and then entered into the pyramidal tract at the upper medulla, after which it descended through the pyramidal tract to the lower medulla.
Sami H Erbay - One of the best experts on this subject based on the ideXlab platform.
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t2 hyperintensity of Medial Lemniscus higher threshold application to roi measurements is more accurate in predicting small vessel disease
Journal of Neuroimaging, 2013Co-Authors: Michael Hakky, Kaan D Erbay, Edward Brewer, Robert J French, Jennifer B Midle, Sami H ErbayAbstract:BACKGROUND Medial Lemniscus T2 hyperintensity (MLH) has been recently demonstrated as potential imaging marker for small vessel disease (SVD). Our purpose in this study is to improve accuracy of regions of interest (ROI) analysis for this imaging finding. METHODS AND METHODS Two neuroradiologists retrospectively reviewed 103 consecutive outpatient brain MRI. Medial Lemniscus signal in dorsal pons was evaluated; visually on FLAIR and with ROI on T2. Original MRI interpretations were divided into three categories; SVD, multiple sclerosis (MS), and nonspecific WM changes (non). RESULTS Thirty-seven patients had SVD, 14 patients had MS, 52 had Non. Visual MLH was seen exclusively with SVD and was generally bilateral. Patients with visual MLH belonged to advanced SVD by imaging and clinical parameters. Compared to visual data, ROI analyses of MLH has been known to be compounded by false positives and negatives at low threshold (20% of adjacent to normal brainstem signal). With application of higher ROI threshold (25%), false positives were eliminated but false negatives increased. ROI analyses of MLH by experienced neuroradiologist were more reliable. CONCLUSION MLH seen on high threshold ROI analysis is a reliable radiologic marker in predicting SVD. ROI analysis of MLH should be performed by an experienced neuroradiologist.
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visual t2 hyperintensity of Medial Lemniscus predicts presence of small vessel disease
2013Co-Authors: Michael Hakky, Kaan D Erbay, Edward Brewer, Robert J French, Jennifer B Midle, Sami H ErbayAbstract:Poster: "ECR 2013 / C-1460 / Visual T2 Hyperintensity Of Medial Lemniscus Predicts Presence Of Small Vessel Disease " by: "M. Hakky1, K. Erbay1, E. Brewer1, R. French1, J. Midle2, S. Erbay1; 1Burlington, MA/US, 2Boston, MA/US"
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t2 hyperintensity of Medial Lemniscus is an indicator of small vessel disease
American Journal of Roentgenology, 2012Co-Authors: Sami H Erbay, Kaan D Erbay, Edward Brewer, Robert J French, Jennifer B Midle, Rafeeque A BhadeliaAbstract:OBJECTIVE. Small-vessel disease is a common MRI finding that can be difficult to differentiate from other white matter (WM) diseases because of the lack of a specific pattern of brain involvement. The purpose of our study was to evaluate Medial Lemniscus hyperintensity seen on FLAIR images as an imaging marker for small-vessel disease. MATERIALS AND METHODS. Two blinded neuroradiologists retrospectively reviewed 103 consecutive outpatient brain MRI studies. Medial Lemniscus signal in the dorsal pons was evaluated visually on FLAIR images and after placing regions of interest (ROIs) on T2-weighted images. On the basis of the original interpretations, scans were divided into three categories: small-vessel disease, multiple sclerosis (MS), and normal or nonspecific WM changes. Cardiovascular risk factors were recorded. Analysis of variance and Fisher exact tests were used to determine group differences, and kappa statistics was used to determine interrater agreement. RESULTS. Thirty-seven patients had small-...
Rafeeque A Bhadelia - One of the best experts on this subject based on the ideXlab platform.
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t2 hyperintensity of Medial Lemniscus is an indicator of small vessel disease
American Journal of Roentgenology, 2012Co-Authors: Sami H Erbay, Kaan D Erbay, Edward Brewer, Robert J French, Jennifer B Midle, Rafeeque A BhadeliaAbstract:OBJECTIVE. Small-vessel disease is a common MRI finding that can be difficult to differentiate from other white matter (WM) diseases because of the lack of a specific pattern of brain involvement. The purpose of our study was to evaluate Medial Lemniscus hyperintensity seen on FLAIR images as an imaging marker for small-vessel disease. MATERIALS AND METHODS. Two blinded neuroradiologists retrospectively reviewed 103 consecutive outpatient brain MRI studies. Medial Lemniscus signal in the dorsal pons was evaluated visually on FLAIR images and after placing regions of interest (ROIs) on T2-weighted images. On the basis of the original interpretations, scans were divided into three categories: small-vessel disease, multiple sclerosis (MS), and normal or nonspecific WM changes. Cardiovascular risk factors were recorded. Analysis of variance and Fisher exact tests were used to determine group differences, and kappa statistics was used to determine interrater agreement. RESULTS. Thirty-seven patients had small-...
Hyeok Gyu Kwon - One of the best experts on this subject based on the ideXlab platform.
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traumatic axonal injury of the Medial Lemniscus pathway in a patient with traumatic brain injury validation by diffusion tensor tractography
Neural Regeneration Research, 2016Co-Authors: Sung Ho Jang, Hyeok Gyu KwonAbstract:Traumatic brain injury (TBI) is a common disability-causing neurological disorder. For successful rehabilitation of TBI patients, a thorough evaluation of the presence and extent of neural injury is essential for determining the optimal rehabilitation strategy and accurate prognosis. However, it is difficult to determine the status of neural tracts. Diffusion tensor tractography (DTT), derived from diffusion tensor imaging (DTI), enables visualization of neural tracts three-dimensionally (Mori et al., 1999; Yamada et al., 2003; Jang and Seo, 2014). DTT has been used to detect lesions located in various neural tracts including the fornix, cingulum, corticospinal tract, and spinothalamic tract in patients with TBI (Nakayama et al., 2006; Sugiyama et al., 2007; Wang et al., 2008; Choi et al., 2012; Kim et al., 2015). However, few studies have been performed on injury of the Medial Lemniscus and its thalamocortical pathway, which involves the proprioception (Carey et al., 1993). In the current study, we reported a patient with injury of the Medial Lemniscus pathway (ML) following TBI using DTT. A 24-year-old man who was injured in a traffic accident and underwent conservative treatment for contusional hemorrhage in both frontal lobes at the Department of Neurosurgery in Yeungnam University Hospital, Republic of Korea (Figure 1). Figure 1 T2-weighted MR images and DTT images of a 24-year-old male patient with traumatic brain injury. The patient lost consciousness for 14 days after the accident. Brain MRI at 1 month after onset revealed focal encephalomalatic lesions located in both frontal lobes. Mini-Mental State Examination showed 30 points at 1 month and 7 years after onset. The patient complained of proprioceptive impairment of his left extremities since the onset of TBI. The subscales for tactile sensation and kinesthetic sensation of the Nottingham Sensory Assessment (NSA) were used to determine somatosensory function (Carey et al., 1993). The reliability of the NSA is well-established (Lincoln et al., 1998). In right extremities, any impairment of somatosensory function was not observed at 1 month and 7 years after onset. However, regarding the left extremities, at 1 month after onset, his kinesthetic sensation score indicated impairment (17 [shoulder-3, elbow-3, wrist-2, hand-1, hip-3, knee-2, ankle-2, and foot-1] out of a possible 24 points). At 7 years after onset, his kinesthetic sensation score indicated impairment (20 [shoulder-3, elbow-3, wrist-2, hand-2, hip-3, knee-3, ankle-2, and foot-2] out of a possible 24 points). In contrast, the tactile sensation score was normal at 1 month and 7 years after onset. The patient gave signed, informed consent, and the study protocol was approved by institutional review board of Yeungnam University Hospital, Republic of Korea. DTI data were acquired at 7 years after onset using a 1.5T MRI system (Gyroscan Intera; Philips Medical Systems, Best, the Netherlands). Sixty-seven consecussive slices were acquired parallel to the anterior commissure-posterior commissure line with 32 gradients. DTI parameters were as follows: acquisition matrix = 96 × 96, reconstructed to matrix = 192 × 192, field of view = 240 × 240 mm2, repetition time = 10,398 ms, echo time = 72 ms, echo-planar imaging factor = 59, b = 1,000 s/mm2, number of excitations = 1, and a slice thickness of 2.5 mm. The Functional Magnetic Resonance Imaging of the Brain (FMRIB) Software Library (Oxford, UK, FSL; www.fmrib.ox.ac.uk/fsl) was used to analyze DTI data. Eddy current correction was applied. FMRIB Diffusion Software with routine option (0.5 mm step lengths, 5,000 streamline sample, 0.2 curvature thresholds) was used for fiber tracking. Two regions of interest (ROIs) were placed to reconstruct MLPs. Seed ROI was placed in the Medial posterior region of the medullary pyramids (Jang and Kwon, 2013). The target ROI was given at the ventroposterolateral nucleus of the thalamus (Jang and Kwon, 2013). The right MLP in the patient was thinner and discontinued at the level of the corona radiata compared with the left MLP, and the left MLP showed partial tearing at the level of the centrum semiovale. In the current study, the patient showed proprioceptive impairment in the left extremities. On 7-year DTT, discontinuation and narrowing was observed in the right MLP and partial tearing was observed in the left MLP. These findings indicate severe injury of the right MLP and mild injury of the left MLP. Therefore, we believe that injury of the right MLP was ascribed to the proprioceptive impairment of the left extremities and injury of the left MLP did not accompany proprioceptive impairment because the integrity of the left MLP was preserved and injury of the left MLP was only partial tearing at the centrum semiovale level. We consider that diffuse TBI is the most plausible mechanism for right MLP injury because this patient met the diagnostic criteria of diffuse axonal injury (significant acceleration/deceleration injury during a motor vehicle accident, loss of consciousness for 14 days after injury without a lucid interval, and no specific lesion along pathways of both MLPs) (Adams et al., 1982; Parizel et al., 1998). In summary, injury of the MLPs was demonstrated in a patient with proprioceptive impairment following TBI, using DTT. Our experience with this case suggests that DTT is valuable for detection of MLP injury which cannot be detected on conventional brain MRI after TBI. Although a few previous studies reported on stroke patients with MLP injury by DTT (Hong and Jang, 2010; Seo and Jang, 2014), this is the first study to demonstrate MLP injury in a patient with TBI. However, this study is limited because of a single case report. In addition, use of multi-tensor DTT could generate false positive and negative DTT findings due to crossing fibers in a voxel throughout the brain. Further complementary studies involving larger numbers of patients are warranted. This work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, No. 2015R1D1A4A01020385.
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anatomical location of the Medial Lemniscus and spinothalamic tract at the pons in the human brain a diffusion tensor tractography study
Somatosensory and Motor Research, 2013Co-Authors: Sung Ho Jang, Hyeok Gyu KwonAbstract:AbstractUsing diffusion tensor tractography, we investigated the anatomical location of Medial Lemniscus (ML) and spinothalamic tract (STT) at pons. We recruited 47 healthy volunteers. Evaluation of the anatomical location of ML and STT was performed using the highest probabilistic location at the upper, middle, and lower pons. According to findings, MLs were located around the middle to Medial one-third, between midline and lateral boundary of pons in the pontine tegmentum and STTs were located posterolaterally to ML.
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Characteristics of the aberrant pyramidal tract in comparison with the pyramidal tract in the human brain
BMC Neuroscience, 2011Co-Authors: Hyeok Gyu Kwon, Yong Hyun Kwon, Min Cheol Chang, Sung Ho JangAbstract:Background The aberrant pyramidal tract (APT) refers to the collateral pathway of the pyramidal tract (PT) through the Medial Lemniscus in the midbrain and pons. Using diffusion tensor tractography (DTT), we investigated the characteristics of the APT in comparison with the PT in the normal human brain.