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

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

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

Although they usually originate from peripheral problems, foot drop is caused by lesions affecting the neural pathway related to dorsiflexor muscles, whether of central or peripheral origin. We present a patient with sudden isolated foot drop caused by a small infarct in the primary motor cortex mimicking a peripheral origin. This report indicates that patients presenting isolated foot drop should be managed carefully and the possibility of both central and peripheral causes should be considered. To our knowledge, this is the first report of sudden isolated foot drop caused by a cortical infarction mimicking lumbar radiculopathy.
Cerebral Infarction* ; Foot* ; Humans ; Infarction ; Motor Cortex ; Muscles ; Neural Pathways ; Paresis ; Pyramidal Tracts ; Radiculopathy*

PURPOSE: The purpose of this study was to analyze the characteristic MR findings of childhood metachromatic leukodystrophy. MATERIALS AND METHODS: Five female patients (10--29 months old;mean age, 21.8 months) of biochemically confirmed metachromatic leukodystrophy 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 presence or absence of the enhancement. Result.' All 5 cases showed high signal intensity in periventricular deep white matter and centrum semiovale which were bilateral, symmetric and confluent. Posterior predominace, sparing of subcortical U fibers and immediate periventricular white matter, and the involvement of splenium of corpus callosum were also noted in all cases. There were other manifestations, such as 'tigroid pattern' in centrum semiovale (n=4), the involvement of genu of corpus callosum(n=4), posterior limb of internal capsule(n=4), descending pyramidal tracts (n=3), deep cerebellar white matter(n=1), claustrum(n=2), and diffuse brain atrophy(n=1). In three cases with Gd-infusion, contrast enhancement of the lesion was not seen. CONCLUSION: In childhood metachromatic leukodystrophy, MRI can clearly demonstrate the chracteristic extent of the white matter lesion and other associated findings, facilitating the differential diagnosis from other similar leukodystrophies.
Brain ; Corpus Callosum ; Diagnosis, Differential ; Extremities ; Female ; Humans ; Leukodystrophy, Metachromatic* ; Magnetic Resonance Imaging* ; Pyramidal Tracts