The Experts below are selected from a list of 189 Experts worldwide ranked by ideXlab platform
Terunori Mitsuma - One of the best experts on this subject based on the ideXlab platform.
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the Lateral Corticospinal Tract and spinal ventral horn in x linked recessive spinal and bulbar muscular atrophy a quantitative study
Acta Neuropathologica, 1996Co-Authors: S Terao, Mei Li, Yoshio Hashizume, Gen Sobue, Fumiaki Tanaka, Terunori MitsumaAbstract:A quantitative study was performed on spinal cord lesions in seven patients with X-linked recessive spinal and bulbar muscular atrophy. The myelinated fiber density of the Lateral Corticospinal Tracts at the T7 cord level was well preserved for both large and small myelinated fibers. On the other hand, neurons in the L4 ventral horn were markedly depleted; marked loss was noted of the large alpha and medium-sized gamma motor neurons located in the Lateral and medial nuclei as well as the small neurons in the intermediate zones of the ventral horn. These results suggest that myelinated fiber density and fiber-size distribution in the Corticospinal Tract are well preserved and that neuronal loss in the ventral horns is not restricted to alpha and gamma motoneurons but also involves small interneurons.
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selective loss of small myelinated fibers in the Lateral Corticospinal Tract due to midbrain infarction
Neurology, 1996Co-Authors: S Terao, Makoto Takahashi, Mei Li, Yoshio Hashizume, Hiroshi Ikeda, Terunori Mitsuma, Gen SobueAbstract:Small myelinated fibers in the Lateral Corticospinal Tract (LCST) were selectively diminished as compared with large myelinated fibers in a patient with an old paramedian midbrain infarct involving the red nuclei, oculomotor nuclei, and inferior olivary pseudohypertrophy.Although the physiologic function of small myelinated fibers in the LCST is unknown in humans, we hypothesize that some of these fibers may include the rubrospinal Tract. NEUROLOGY 1996;47: 588-591
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The Corticospinal Tract lesion of amyotrophic Lateral sclerosis--magnetic resonance imaging of the spinal cord
Rinshō shinkeigaku Clinical neurology, 1994Co-Authors: Shin-ichi Terao, Sobue, T Yasuda, T Kachi, Terunori MitsumaAbstract:Magnetic resonance imaging by gradient echo method demonstrated lesions of the Lateral Corticospinal Tract at cervical cord levels in three ALS patients. Patient 1 was a 43-year-old woman with common form of ALS. She developed right-side predominant pyramidal signs, and right-side predominant prolongation of central motor conduction time. MRI showed hypersignal intensity areas in the dorsal region of the Lateral column at the 4th and 5th cervical segments with right-side predominancy. Patient 2 was a 65-year-old man with pseudopolyneurtic form of ALS, who showed lower motor neuron signs without a pyramidal sign. MRI of the 3rd and 4th cervical cord segments demonstrated biLateral hypersignal intensity areas in the dorsal part of the Lateral column. Patient 3 was a 62-year-old man with common form of ALS, who showed marked biLateral pyramidal signs with Babinski's sign. MRI of the 5th cervical spinal cord segment demonstrated biLateral hypersignal intensity areas in the dorsoLateral column. Thus obtained MR images of the spinal cord corresponded well to the postmortem-confirmed degeneration of the spinal Corticospinal Tract. MRI of the spinal cord performed by gradient echo method would provide additional information on the upper motor neuron involvement in ALS.
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Age-related changes of the myelinated fibers in the human Corticospinal Tract: a quantitative analysis
Acta Neuropathologica, 1994Co-Authors: Shin-ichi Terao, Yoshio Hashizume, Gen Sobue, Noriko Shimada, Terunori MitsumaAbstract:A quantitative analysis was made of the myelinated fibers in the Lateral Corticospinal Tract (LCST) at the levels of the 6th cervical, 7th thoracic and 4th lumbar spinal segments in 20 patients between 19 and 90 years old, and who died of non-neurological diseases. The diameter frequency histograms of myelinated fibers of LCST showed a bimodal pattern with a sharp peak of the small myelinated fibers and broad slope of the large myelinated fibers. The ratio of small fiber to large fiber densities was significantly higher in the 6th cervical ( P
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The Corticospinal Tract of amyotrophic Lateral sclerosis--a morphometric analysis of the myelinated fibers
Rinshō shinkeigaku Clinical neurology, 1992Co-Authors: Shin-ichi Terao, Sobue, Terunori MitsumaAbstract:The myelinated fibers in the Lateral Corticospinal Tract at the C6, T7, L4 levels in amyotrophic Lateral sclerosis (ALS) and control cases were morphometrically examined. ALS cases consisted of 6 males and 2 females with ages ranging between 48 and 85 years, and were all the common or bulbar form in clinical manifestation. As for controls, 10 cases who died of non-neurological diseases, with age ranging 36 to 90 years were served. The population and the diameter profile of the myelinated fibers in the Corticospinal Tract of the C6, T7, L4 levels were measured by the method previously described and expressed as number per mm2. In control subjects, fiber-size histograms of myelinated fibers showed a bimodal pattern with a sharp peak of small fibers (less than 7.28 microns) and a broad peak of large fibers (greater than or equal to 7.28 microns) in all the spinal levels. In ALS cases, large myelinated fibers were predominantly diminished in number, a small myelinated fibers were also decreased in some cases. The degree of fiber loss was extremely variable among cases; well populated in large fibers in some cases. As for the rostral caudal distribution of myelinated fiber loss, a caudally-accentuated fiber loss particularly in large fiber was seen in some of the cases. The topographical distribution of fiber loss in the horizontal plane of the Corticospinal Tract in ALS did not show a distinctive pattern.
Sung Ho Jang - One of the best experts on this subject based on the ideXlab platform.
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the difference of gait pattern according to the state of the Corticospinal Tract in chronic hemiparetic stroke patients
NeuroRehabilitation, 2014Co-Authors: Kyung Hee Do, Gil Su Jung, Sung Ho JangAbstract:OBJECTIVES: The Lateral Corticospinal Tract (CST) is one of the most important neuronal pathways that mediate voluntary movements in the human brain. However, little is known about the role of the Lateral CST on the gait. We attempted to investigate differences in gait pattern using a motion analysis system according to the integrity of the contraLateral CST, which was classified using diffusion tensor Tractography (DTT) in chronic hemiparetic stroke patients. METHODS: We recruited 16 chronic hemiparetic stroke patients and 12 normal subjects for this study. DTT findings of the CST for patients were classified into two groups: group A (eight patients); the integrity of the CST was preserved, group B (eight patients) – the CST was discontinued at or below the stroke lesion. We compared variables of gait between group A, group B, and normal controls using the motion analysis system. RESULTS: Group A and the control group showed a significantly higher peak angle for ankle dorsiflexion, knee internal rotation, and hip flexion, compared with group B (p < 0.05). On the other hand, the peak angle for ankle plantarflexion/external rotation, knee flexion/abduction, and hip extension of group A and group B were significantly lower than those of the control group (p < 0.05). CONCLUSION: We found that severe injury of the contraLateral CST caused decreased movement of ankle dorsiflexion, knee internal rotation, and hip flexion in chronic hemiparetic stroke patients. As a result, the circumduction and abduction gait pattern in stroke patients is closely associated with severe injury of the contraLateral CST.
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A review of diffusion tensor imaging studies on motor recovery mechanisms in stroke patients
NeuroRehabilitation, 2011Co-Authors: Sung Ho JangAbstract:AbsTract For the past decade, diffusion tensor imaging (DTI) has been used in elucidation of the motor recovery mechanisms in stroke patients. In the current study, I reviewed the DTI studies with regard to the motor recovery mechanisms in stroke patients, according to the following classification of motor recovery mechanisms; recovery of a damaged Lateral Corticospinal Tract (CST), subcortical peri-lesional reorganization, ipsiLateral motor pathway from the unaffected motor cortex to the affected extremities, and other motor recovery mechanisms. In addition, I discussed the characteristics of DTI as an evaluation tool for motor recovery mechanisms and future direction. DTI has a unique advantage in identification and estimation of neural Tracts at the subcortical level. Therefore, it could contribute much to research on the motor recovery mechanisms of stroke patients, especially, in terms of recovery of a damaged CST and subcortical peri-lesional reorganization. In spite of the advantages of DTI, fewer DTI studies on this topic have been conducted compared to studies using transcranial magnetic stimulation or functional MRI. Therefore, the total number of DTI studies on this topic should be increased. Moreover, further studies on various topics related to brain plasticity of motor function, as well as the motor recovery mechanism itself, should be encouraged; for example, DTI changes with passage of time, with rehabilitative intervention, or with motor recovery.
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Motor outcome and motor recovery mechanisms in pontine infarct: A review
NeuroRehabilitation, 2010Co-Authors: Sung Ho JangAbstract:AbsTract Characteristics of motor recovery mechanisms are known to be linked with motor outcome in stroke. Detailed knowledge of motor outcome and recovery mechanisms in stroke allow for prediction of prognosis and provide the basis for establishment of scientific rehabilitation strategies. Thirteen previous studies with regard to motor outcome (8 studies) and the motor recovery mechanisms (5 studies) in pontine infarct were reviewed. Several motor recovery mechanisms have been reported in pontine infarct: peri-lesional reorganization, and other possible recovery mechanisms (aberrant pyramidal Tract, ipsiLateral motor pathway, and motor recovery via spared Corticospinal Tract). Previous studies on motor outcome in pontine infarct have reported generally good outcome. This good motor outcome appears to be related to the characteristics of the motor recovery mechanisms recovered by the Lateral Corticospinal Tract. We think that further studies on motor outcome and recovery mechanisms should be performed for clarification of various motor Tracts including non-Corticospinal Tract, which can affect the motor outcome and recovery mechanisms in pontine infarct. In addition, the effect of rehabilitation on these topics should also be elucidated.
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A review of motor recovery mechanisms in patients with stroke
NeuroRehabilitation, 2007Co-Authors: Sung Ho JangAbstract:AbsTract Elucidation of the motor recovery mechanisms in stroke patients is important because such information could provide the scientific basis for stroke rehabilitation. The motor recovery mechanism after stroke, however, has not yet been clearly elucidated, but several suggested mechanisms have been proposed. These include the ipsiLateral motor pathway from the unaffected motor cortex to the affected hand, peri-lesional reorganization, the recovery of a damaged Lateral Corticospinal Tract, and contribution of the secondary motor area. Additionally, little is known about the motor recovery mechanism for patients with intracerebral hemorrhage, for locomotor recovery, and for damage at the subcortical level. Therefore, we suggest that further research should be focused on the elucidation of motor recovery mechanisms in relation to the above topics. In the current study, we tried to review the literatures about the motor recovery mechanisms of the patients with stroke.
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can stroke patients walk after complete Lateral Corticospinal Tract injury of the affected hemisphere
Neuroreport, 2006Co-Authors: Ji Hun Hong, Sung Ho JangAbstract:The Lateral Corticospinal Tract is the major motor pathway in humans. The role of this Tract on walking, however, is uncertain. The development of diffusion tensor Tractography enables Corticospinal Tract status to be visualized at the subcortical level. In the present study, we undertook to demonstrate that some stroke patients can walk despite complete Lateral Corticospinal Tract injury. Ten stroke patients who were able to walk with evidence of complete uniLateral Lateral Corticospinal Tract injury, as determined by clinical course, brain magnetic resonance imaging, and diffusion tensor Tractography, were recruited. We conclude that some stroke patients can walk despite complete Lateral Corticospinal Tract injury of the affected hemisphere.
Yukio Nishimura - One of the best experts on this subject based on the ideXlab platform.
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Plasticity for recovery after partial spinal cord injury – hierarchical organization.
Neuroscience Research, 2020Co-Authors: Yukio NishimuraAbstract:AbsTract To cure the impaired physiological functions after the spinal cord injury, not only development of molecular therapies for axonal regeneration, but also that of therapeutic strategies to induce appropriate rewiring of neural circuits should be necessary. For this purpose, understanding the plastic changes in the central nervous system during spontaneous recovery following the injury would be helpful. In this article, a series of studies conducted in the authors’ laboratory on the reorganization of neural networks in the partial spinal cord injury model using macaque monkeys are reviewed. In this model, after selective lesion of the Lateral Corticospinal Tract at the fifth cervical segment, dexterous digit movements are once impaired, but recover through rehabilitative training in a few weeks to a few months. During the recovery, synaptic transmission and organization of the neural circuits exhibit drastic changes depending on the time after the injury, not only in the spinal cord, but also in hierarchically higher order structures such as motor-related cortical areas and even in limbic structures. It is suggested that on top of the molecular therapies, neurorehabilitative and neuromodulatory therapies targeting such higher order structures should be helpful in inducing appropriate rewiring of the neural circuits.
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Comprehensive analysis of area‐specific and time‐dependent changes in gene expression in the motor cortex of macaque monkeys during recovery from spinal cord injury
The Journal of Comparative Neurology, 2018Co-Authors: Noriyuki Higo, Yukio Nishimura, Yumi Murata, Takao Oishi, Akira Sato, Tatsuya Yamamoto, Hirotaka Onoe, Toshio KojimaAbstract:The present study aimed to assess the molecular bases of cortical compensatory mechanisms following spinal cord injury in primates. To accomplish this, comprehensive changes in gene expression were investigated in the biLateral primary motor cortex (M1), dorsal premotor cortex (PMd), and ventral premotor cortex (PMv) after a uniLateral lesion of the Lateral Corticospinal Tract (l-CST). At 2 weeks after the lesion, a large number of genes exhibited altered expression levels in the contralesional M1, which is directly linked to the lesioned l-CST. Gene ontology and network analyses indicated that these changes in gene expression are involved in the atrophy and plasticity changes observed in neurons. Orchestrated gene expression changes were present when behavioral recovery was attained 3 months after the lesion, particularly among the biLateral premotor areas, and a large number of these genes are involved in plasticity. Moreover, several genes abundantly expressed in M1 of intact monkeys were upregulated in both the PMd and PMv after the l-CST lesion. These area-specific and time-dependent changes in gene expression may underlie the molecular mechanisms of functional recovery following a lesion of the l-CST.
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Effects of early versus late rehabilitative training on manual dexterity after Corticospinal Tract lesion in macaque monkeys
Journal of Neurophysiology, 2013Co-Authors: Yoko Sugiyama, Noriyuki Higo, Yukio Nishimura, Yumi Murata, Kimika Yoshino-saito, Takao OishiAbstract:Dexterous hand movements can be restored with motor rehabilitative training after a lesion of the Lateral Corticospinal Tract (l-CST) in macaque monkeys. To maximize effectiveness, the optimal time to commence such rehabilitative training must be determined. We conducted behavioral analyses and compared the recovery of dexterous hand movements between monkeys in which hand motor training was initiated immediately after the l-CST lesion (early-trained monkeys) and those in which training was initiated 1 mo after the lesion (late-trained monkeys). The performance of dexterous hand movements was evaluated by food retrieval tasks. In early-trained monkeys, performance evaluated by the success rate in a vertical slit task (retrieval of a small piece of food through a narrow vertical slit) recovered to the level of intact monkeys during the first 1–2 mo after the lesion. In late-trained monkeys, the task success rate averaged ∼30% even after 3 mo of rehabilitative training. We also evaluated hand performance wi...
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SPP1 is expressed in Corticospinal neurons of the macaque sensorimotor cortex
The Journal of Comparative Neurology, 2010Co-Authors: Noriyuki Higo, Yukio Nishimura, Yumi Murata, Takao Oishi, Fumiharu Tsuboi, Kimika Yoshino-saito, Akira Sato, Tatsuya Yamamoto, Hirotaka Onoe, Masahito TakahashiAbstract:The cellular distribution of SPP1, which we recently identified as a gene with greater expression in the macaque primary motor cortex than in the premotor or prefrontal cortices, was examined in rhesus macaque, common marmoset, and rat brains. In situ hybridization histochemistry revealed that SPP1 mRNA was expressed specifically in pyramidal neurons in layer V of the sensorimotor cortex of the rhesus macaque. These SPP1 mRNA-positive neurons were most abundant in the primary motor area, followed by Brodmann area 5 and the supplementary motor area, in accordance with the distribution of Corticospinal neurons. In addition, injection of a retrograde neuroanatomical tracer into the Lateral Corticospinal Tract (CST) of the spinal cord caused labeling of SPP1 positive neurons, indicating the expression of SPP1 in Corticospinal neurons. SPP1 was also expressed in the thalamus, brainstem, and spinal ventral horn of the rhesus macaque. Although SPP1 was also detected in the brainstem and spinal cord of the marmoset and the rat, it was not detected in their cerebral cortices. Selective expression in the Corticospinal neurons of the sensorimotor cortex of the rhesus macaque suggests that SPP1 plays a critical role in the functional or structural specialization of highly developed Corticospinal systems in certain primate species. J. Comp. Neurol. 518:2633–2644, 2010. © 2010 Wiley-Liss, Inc.
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increased expression of the growth associated protein 43 gene in the sensorimotor cortex of the macaque monkey after lesioning the Lateral Corticospinal Tract
The Journal of Comparative Neurology, 2009Co-Authors: Noriyuki Higo, Yukio Nishimura, Yumi Murata, Takao Oishi, Kimika Yoshinosaito, Masahito Takahashi, Fumiharu TsuboiAbstract:To investigate the neural basis for functional recovery of the cerebral cortex following spinal cord injury, we measured the expression of growth-associated protein 43 (GAP-43), which is involved in the process of synaptic sprouting. We determined the GAP-43 mRNA expression levels in the sensorimotor cortical areas of macaque monkeys with a uniLateral lesion of the Lateral Corticospinal Tract (l-CST) at the C4/C5 level of the cervical cord and compared them with the levels in the corresponding regions of intact monkeys. Lesioned monkeys recovered finger dexterity during the first months after surgery, and the GAP-43 mRNA levels increased in layers II–III in primary motor areas (M1), biLaterally. Double-labeling analysis of the lesioned monkeys showed that GAP-43 mRNA was expressed strongly in excitatory neurons but only rarely in inhibitory interneurons. Expression also increased in the medium-sized (area, 500–1,000 μm2) and large pyramidal cells (area, >1,000 μm2) in layer V of the biLateral M1. The increased expression of GAP-43 mRNA in the M1 contraLateral to the lesion was more prominent during the early recovery stage than during the late recovery stage. In addition, GAP-43 mRNA increased in layers II–III of both the contralesional ventral premotor area and the primary somatosensory area. These results suggest that GAP-43 is involved in time-dependent and brain region-specific plastic changes after l-CST lesioning. The expression patterns imply that plastic changes occur not only in M1 but also in the broad associative cortical network, including the ventral premotor and primary sensory areas. J. Comp. Neurol. 516:493–506, 2009. © 2009 Wiley-Liss, Inc.
Julien Cohenadad - One of the best experts on this subject based on the ideXlab platform.
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7 t mri of the spinal cord can detect Lateral Corticospinal Tract abnormality in amyotrophic Lateral sclerosis
Muscle & Nerve, 2013Co-Authors: Julien Cohenadad, Wei Zhao, Boris Keil, Evamaria Ratai, Christina Triantafyllou, Robert Lawson, Christina Dheel, Lawrence L WaldAbstract:Introduction: Amyotrophic Lateral sclerosis (ALS) is a progressive neurodegenerative disorder affecting lower and upper motor neurons. Degeneration of the Lateral Corticospinal Tract (CST) is a key finding in ALS cervical spinal cord autopsies. We hypothesized that in vivo ultra-high-field MRI of the cervical spinal cord can detect abnormality in the CST. Methods: A patient with ALS (disease duration 23 months) and a healthy control were scanned at 7-T MRI using a 19-channel coil. Multi-echo T2*-weighted imaging was performed in the spinal cord, covering C2–C6. Cross-sectional resolution was 0.37 × 0.37 mm2. Results: We detected clear signal hyperintensity in both segments of the Lateral CST in the ALS patient, which was significant when compared with the normal control subject (P < 10−7). Conclusion: We believe there are potential benefits of 7-T MRI for increased sensitivity and spatial accuracy in characterizing pathology in the spinal cord. Muscle Nerve 47: 760–762, 2013
S Terao - One of the best experts on this subject based on the ideXlab platform.
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the Lateral Corticospinal Tract and spinal ventral horn in x linked recessive spinal and bulbar muscular atrophy a quantitative study
Acta Neuropathologica, 1996Co-Authors: S Terao, Mei Li, Yoshio Hashizume, Gen Sobue, Fumiaki Tanaka, Terunori MitsumaAbstract:A quantitative study was performed on spinal cord lesions in seven patients with X-linked recessive spinal and bulbar muscular atrophy. The myelinated fiber density of the Lateral Corticospinal Tracts at the T7 cord level was well preserved for both large and small myelinated fibers. On the other hand, neurons in the L4 ventral horn were markedly depleted; marked loss was noted of the large alpha and medium-sized gamma motor neurons located in the Lateral and medial nuclei as well as the small neurons in the intermediate zones of the ventral horn. These results suggest that myelinated fiber density and fiber-size distribution in the Corticospinal Tract are well preserved and that neuronal loss in the ventral horns is not restricted to alpha and gamma motoneurons but also involves small interneurons.
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selective loss of small myelinated fibers in the Lateral Corticospinal Tract due to midbrain infarction
Neurology, 1996Co-Authors: S Terao, Makoto Takahashi, Mei Li, Yoshio Hashizume, Hiroshi Ikeda, Terunori Mitsuma, Gen SobueAbstract:Small myelinated fibers in the Lateral Corticospinal Tract (LCST) were selectively diminished as compared with large myelinated fibers in a patient with an old paramedian midbrain infarct involving the red nuclei, oculomotor nuclei, and inferior olivary pseudohypertrophy.Although the physiologic function of small myelinated fibers in the LCST is unknown in humans, we hypothesize that some of these fibers may include the rubrospinal Tract. NEUROLOGY 1996;47: 588-591
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Magnetic resonance imaging of the Corticospinal Tracts in amyotrophic Lateral sclerosis.
Journal of the neurological sciences, 1995Co-Authors: S Terao, G Sobue, T Yasuda, T Kachi, M Takahashi, T MitsumaAbstract:In 13 patients with amyotrophic Lateral sclerosis (ALS), Corticospinal Tract lesions on spinal cord, brain and brain stem were examined by MR imaging. In 9 patients, areas of high signal intensity located in the dorsoLateral columns coinciding with the Lateral Corticospinal Tracts, were detected on axial T2*-weighted MR imaging of the cervical spinal cord using a gradient echo technique. In two patients, these spinal cord MR abnormalities corresponded well to the postmortem pathological findings of Lateral Corticospinal Tract degeneration. T2-weighted abnormal MR signals along the Corticospinal Tract at the brain and brain stem were detected in 4 patients, all of whom also showed abnormal signals on cervical cord MR imaging. Four of 13 patients did not show any abnormal signals on brain and brain stem or spinal cord MR imaging. Spinal cord MR imaging provides a useful information regarding upper motor neuron lesions in ALS.
