29 research outputs found

    Longitudinal regression analysis of spatial–temporal growth patterns of geometrical diffusion measures in early postnatal brain development with diffusion tensor imaging

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    Although diffusion tensor imaging (DTI) has provided substantial insights into early brain development, most DTI studies based on fractional anisotropy (FA) and mean diffusivity (MD) may not capitalize on the information derived from the three principal diffusivities (e.g. eigenvalues). In this study, we explored the spatial and temporal evolution of white matter structures during early brain development using two geometrical diffusion measures, namely, linear (Cl) and planar (Cp) diffusion anisotropies, from 71 longitudinal datasets acquired from 29 healthy, full-term pediatric subjects. The growth trajectories were estimated with generalized estimating equations (GEE) using linear fitting with logarithm of age (days). The presence of the white matter structures in Cl and Cp was observed in neonates, suggesting that both the cylindrical and fanning or crossing structures in various white matter regions may already have been formed at birth. Moreover, we found that both Cl and Cp evolved in a temporally nonlinear and spatially inhomogeneous manner. The growth velocities of Cl in central white matter were significantly higher when compared to peripheral, or more laterally located, white matter: central growth velocity Cl = 0.0465±0.0273/log(days), versus peripheral growth velocity Cl=0.0198±0.0127/log(days), p−6. In contrast, the growth velocities of Cp in central white matter were significantly lower than that in peripheral white matter: central growth velocity Cp= 0.0014±0.0058/log(days), versus peripheral growth velocity Cp = 0.0289±0.0101/log(days), p−6. Depending on the underlying white matter site which is analyzed, our findings suggest that ongoing physiologic and microstructural changes in the developing brain may exert different effects on the temporal evolution of these two geometrical diffusion measures. Thus, future studies utilizing DTI with correlative histological analysis in the study of early brain development are warranted

    A 19-year-old man with sickle cell disease presenting with spinal infarction: a case report

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    Abstract Introduction Vasculopathy of the large vessels commonly occurs in sickle cell disease, and as a result cerebral infarction is a well characterized complication of this condition. However, spinal infarction appears to be rare. Spinal infarct is infrequent in the non-sickle cell population as well, and accounts for only about 1 percent of all central nervous system infarcts. Case presentation In the present work, we report the case of a 19-year-old African-American man with sickle cell disease who experienced an anterior spinal infarct and subsequent quadriplegia. He was incidentally noted to be a heterozygote for factor V Leiden. We also reviewed the literature and found two previous cases of spinal cord infarction and sickle hemoglobin. Our literature search did not demonstrate that heterozygocity for factor V Leiden plays an important role in spinal cord infarction. Conclusions The paucity of cases associated with sickle hemoglobin does not allow us to postulate any particular risk factors with sickle cell disease that might predispose patients to spinal cord infarction. Our patient’s case raises the question as to whether spinal cord infarction is being missed in individuals with sickle cell disease and neurologic symptoms

    Diffusion tensor imaging based network analysis detects alterations of neuroconnectivity in patients with clinically early relapsing-remitting multiple sclerosis: Network Analysis Detects Neuroconnectivity Alterations in Early Relapsing Remitting MS

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    Although it is inarguable that conventional MRI (cMRI) has greatly contributed to the diagnosis and assessment of Multiple Sclerosis (MS), cMRI does not show close correlation with clinical findings or pathologic features, and is unable to predict prognosis or stratify disease severity. To this end, diffusion tensor imaging (DTI) with tractography and neuroconnectivity analysis may assist disease assessment in MS. We therefore attempted this pilot study for initial assessment of early relapsing remitting (RR) MS. Neuroconnectivity analysis was employed for evaluation of 24 early RRMS patients within two years of presentation, and compared to the network measures of a group of 30 age-and-gender-matched normal control subjects. To account for the situation that the connections between two adjacent regions may be disrupted by an MS lesion, a new metric, network communicability, was adopted to measure both direct and indirect connections. For each anatomical area, the brain network communicability and average path length (APL) were computed and compared to characterize the network changes in efficiencies. Statistically significant (p < 0.05) loss of communicability was revealed in our RRMS cohort, particularly in the frontal and hippocampal/parahippocampal regions as well as the motor strip and occipital lobes. Correlation with the 25 foot walk test with communicability measures in the left superior frontal (r = -0.71) as well as the left superior temporal gyrus (r = -0.43) and left postcentral gyrus (r = -0.41) were identified. Additionally identified were increased communicability between the deep gray matter (GM) structures (left thalamus and putamen) with the major inter-hemispheric and intra-hemispheric white matter tracts, the corpus callosum and cingulum respectively. These foci of increased communicability are thought to represent compensatory changes. The proposed DTI based neuroconnectivity analysis demonstrated quantifiable, structurally relevant alterations of fiber tract connections in early relapsing remitting MS and paves the way for longitudinal studies in larger patient groups

    Fatal Pediatric COVID-19 Case With Seizures and Fulminant Cerebral Edema

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    The novel coronavirus, SARS-CoV-2, can present with a wide range of neurological manifestations, in both adult and pediatric populations. We describe here the case of a previously healthy 8-year-old girl who presented with seizures, encephalopathy, and rapidly progressive, diffuse, and ultimately fatal cerebral edema in the setting of acute COVID-19 infection. CSF analysis, microbiological testing, and neuropathology yielded no evidence of infection or acute inflammation within the central nervous system. Acute fulminant cerebral edema (AFCE) is an often fatal pediatric clinical entity consisting of fever, encephalopathy, and new-onset seizures followed by rapid, diffuse, and medically-refractory cerebral edema. AFCE occurs as a rare complication of a variety of common pediatric infections and a CNS pathogen is identified in only a minority of cases, suggesting a para-infectious mechanism of edema. This report suggests that COVID-19 infection can precipitate AFCE, and highlights the need for high suspicion and early recognition thereof

    Head and neck imaging, 2 Volumes, 4th Ed.

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    Imaging of the Larynx

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    Triple pathological findings in a surgically amenable patient with mesial temporal lobe epilepsy

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    Mesial temporal sclerosis (MTS) is a well-recognized cause of intractable epilepsy; however, coexistence with focal cortical dysplasia (FCD) is less common. Middle fossa epidermoid cysts are rare and may involve the temporal lobe. Most epidermoids are clinically silent, slow-growing, and seldom associated with overt symptomatology, including seizures. We describe a patient with multiple comorbidities including left MTS and a large epidermoid cyst involving the left quadrigeminal plate cistern compressing upon the cerebellar vermis and tail of the left hippocampus, resulting in refractory left temporal lobe epilepsy. The patient underwent left anterior temporal lobectomy. The surgical pathology demonstrated a third pathological finding of left temporal FCD type Ia. The patient has been seizure-free since the surgery. This case provides additional information with regard to the understanding of epileptogenicity and surgical planning in patients with MTS and epidermoid cysts

    Understanding the Radiologist\u27s Role in Evaluating Multiple Sclerosis: A Review of the Tip of the Iceberg.

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    Radiologists add value in the setting of clinically suspected multiple sclerosis (MS) predominantly through knowledge of typical and atypical imaging findings, thus aiding the neurologist in differentiating multiple disease processes with similar clinical presentations which may mimic MS. This paper is meant as a guide to deepen understanding for the radiologist, enabling them to be a helpful member of the care team for MS patients
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