No abstract available.
Pyramidal Tracts*

Diffusion tensor tractorgraphy which is based on line propagation method with brute force approach is implemented and the vector correlation function is proposed in addition to the conventional fractional anisotrophy value as a criterion to select seed points. For the whole tractography, the proposed method used 41% less seed points than the conventional brute force approach for FA > or =0.3 and most of the fiber tracks in the outer region of white matter were removed. For the corticospinal tract passing through region of interest, the proposed method has produced similar results with 50% less seed points than conventional one.
Diffusion ; Pyramidal Tracts

According to the anatomical pathways of the corticobulbar tract, it is known that the responsible lesion site of central facial palsy is at the level of the midpons or the more rostral portion. In rare cases, central facial palsy is found in medullary lesions. We report two cases of medullary infarctions which presented as central facial palsy. These cases suggested that the hypothesis that part of the pathway of the facial corticobulbar fibers descend ipsilaterally to the lower medulla before decussating and ascending contralaterally to the facial nucleus.
Facial Paralysis* ; Infarction* ; Pyramidal Tracts

No abstract available.
Brain ; Muscle Spasticity ; Paraparesis, Spastic ; Pyramidal Tracts

PURPOSE: Diffusion tensor imaging (DTI) data must be analyzed by an analyzer after data processing. Hence, the analyzed data of DTI might depend on the analyzer, making it a major limitation. This paper reviewed previous DTI studies reporting the repeatability and reproducibility of data from the corticospinal tract (CST), one of the most actively researched neural tracts on this topic. MATERIALS AND METHODS: Relevant studies published between January 1990 and December 2018 were identified by searching PubMed, Google Scholar, and MEDLINE electronic databases using the following keywords: DTI, diffusion tensor tractography, reliability, repeatability, reproducibility, and CST. As a result, 15 studies were selected. RESULTS: Measurements of the CSTs using region of interest methods on 2-dimensional DTI images generally showed excellent repeatability and reproducibility of more than 0.8 but high variability (0.29 to 1.00) between studies. In contrast, measurements of the CST using the 3-dimensional DTT method not only revealed excellent repeatability and reproducibility of more than 0.9 but also low variability (repeatability, 0.88 to 1.00; reproducibility, 0.82 to 0.99) between studies. CONCLUSION: Both 2-dimensional DTI and 3-dimensional DTT methods appeared to be reliable for measuring the CST but the 3-dimensional DTT method appeared to be more reliable.
Diffusion Tensor Imaging ; Diffusion ; Methods ; Pyramidal Tracts

We report the clinical usefulness of elucidating the state of the corticospinal tract (CST) by the use of diffusion tensor image tractography (DTT) in hemiparetic stroke patients. DTT was performed using 1.5 T magnetic resonance imaging. DTT demonstrated that the CST of the affected hemisphere was preserved in the medial portion of the hematoma in patient 1, but was interrupted by a hematoma in patient 2. DTT seems to be useful for elucidating the status of the CST in hemiparetic stroke patients.
Diffusion ; Hematoma ; Humans ; Magnetic Resonance Imaging ; Pyramidal Tracts ; Stroke

No abstract available.
Diffusion ; Leukoencephalopathies ; Pyramidal Tracts ; Sepsis ; Sepsis-Associated Encephalopathy

Opalski syndrome is a rare lateral medullary infarction variant presenting with ipsilateral motor deficits known to be caused by involvement of the post-decussating pyramidal tract. Here, we report two rare cases of Opalski syndrome presenting as ipsilateral sensorimotor deficits in cerebral infarction.
Cerebral Infarction ; Infarction ; Lateral Medullary Syndrome ; Pyramidal Tracts

Computed tomographic findings were analyzed in 46 patients with hypertensive putaminal hemorrhage accompainied by hemiparesis. It has been important prognostic index whether to involve or not to involve posterior limb of internal capsule. To study the reason for this, the relationship between the extent of a hematoma and the level ar which the pyramidal tract was destroyed was investigated. From the consideration of the process of destruction of the pyramidal tract by a hematoma, it seemed that computed tomographic findings at the level of the body of the lateral ventricle rather than at the prognosis of hemiparesis.
Extremities ; Hematoma ; Humans ; Internal Capsule ; Lateral Ventricles ; Paresis ; Prognosis* ; Putaminal Hemorrhage* ; Pyramidal Tracts

PURPOSE: The purpose of this study was to analyze the MR findings of childhood adrenoleukodystrophy regarding the extent of white matter degeneration and the pattern of enhancement, and to correlate these findings with clinical manifestations. MATERIALS AND METHODS: Six male patients (5-13 years old;mean age, 8.7 years) of biochemically confirmed adrenoleukodystrophy were included in this study. We evaluated the extent of white matter degeneration which was shown as high signal intensity on T2-weighted image, and the pattern of enhancement. Also we correlated the MR findings with clinical manifestations of symptoms and the results of evoked potential studies. RESULTS:The most common sites of predominant involvement were occipital deep white matter, optic radiation, and splenium of corpus callosum (n = 4, 66.7%). The other sites of predominant involvement were frontal deep white matter (n = 1, 16.7%) and pyramidal tract with cerebellum (n = 1, 16.7%). After contrast enhancement, there was peripheral rim enhancement surrounding the most severely affected areas in five cases (83. 3%). These findings were consistent with clinical symptoms in five cases (83.3%), but the results of evoked potential studies were consistent with clinical symptoms in only two cases (33.3%). CONCLUSION:In childhood adrenoleukodystrophy, MRI can clearly demonstrate specific tracts of involvement and these findings were well correlated with clinical manifestations.
Adrenoleukodystrophy* ; Cerebellum ; Corpus Callosum ; Evoked Potentials ; Humans ; Magnetic Resonance Imaging* ; Male ; Pyramidal Tracts