J Neuroradiology
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Comparative Study
[Histologic characteristics of posterior lumbar epidural fatty tissue].
The aim of this study was to describe the histological specificities of posterior lumbar epidural fat (PLEF) considered a "semi-fluid" tissue. We performed axial histological sections of posterior lumbar epidural fat through the abdomen of two foetuses, as well as histological sections on several planes in 11 adults. For comparison, we simultaneously cut sections in subcutaneous fat of adults (SCF). ⋯ PLEF, therefore, is not a simple filling tissue. Its histological features (homogeneity, scarcity of connective tissue and oriented slits) explain the "semi-fluid" characteristic and confirm the specialization of this fat tissue. Its location at the level of the mobile segment of the lumbar spine suggests that it plays a role of sliding structure between the posterior surface of the thecal sac and the anterior surface of the vertebral arch.
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To assess the value of MRI for meningioma of the posterior cerebral fossa, in correlation with surgical and pathological findings, we retrospectively reviewed 31 cases. The patients (24 females and 6 males ranging in age from 25 to 79 years) were preoperatively studies on a 1,5 T MR imager (GEMS Signa) between july 1989 and november 1993. The protocol included: 1. ⋯ It was affirmed when the tumor extended on the opposing surface of the tentorium and when focal hypersignal existed through the usual tentorial hyposignal on T2-weighted images and T1-weighted images after gadolinium. On the other hand, tentorial linear dural enhancement adjacent to the tumor was not a reliable sign (error in 15.8% of the predicted cases). The meningothelial (syncitial) type was noted in 67.7% of the cases. (ABSTRACT TRUNCATED AT 450 WORDS)
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CT and MRI are not consistently able to differentiate central nervous system (CNS) lymphoma from focal cerebral infection such as toxoplasmosis in the human immunodeficiency virus (HIV) involvement. In this study thallium 201 (and/or technetium-MIBI) SPECT was performed in 6 patients suffering from AIDS and CNS lesions. ⋯ On the other hand one markedly necrotic lymphoma and all infectious lesions did not take up thallium. This suggests a role for thallium 201 brain SPECT in the workup of focal CNS lesions in AIDS.
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The role played by the epidural fat has been reported in lipomatosis induced by exogenous glucocorticoids and in severe obesity with lipomatosis. The role played by the "normal" posterior epidural fat (PEF) in lumbar canal stenosis (LCS) is less well known. The purpose of this study was to determine the part taken by PEF in LCS patients without endocrine disease, corticosteroid therapy or obesity. ⋯ Most patients were suffering from lumbar pain, radiculopathy and/or neurogenic intermittent claudication. The data measured were: antero-posterior (AP) diameter of the dural sac, AP diameter of the bony lumbar canal (BLC), interligamentous distance (ILD) opposite the articular facets, and surface of PEF. The soft elements present on the midline--anterior epidural space (AES) and posterior epidural (PEF)--were expressed as percentage of the AP diameter of the bony lumbar canal.(ABSTRACT TRUNCATED AT 250 WORDS)
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Review Case Reports
[Intracranial dural fistula with spinal cord venous drainage. Apropos of 2 cases].
The authors report 2 new cases of intracranial dural fistula draining into spinal veins. Comparisons with 19 other published cases showed that dural fistulae of the spine share common features with intracranial fistulae. The first case concerned a 78-year old woman presenting with a thoraco-lumbar myelopathy which proceeded by increasingly severe bouts and ended within 6 months in a flaccid sensorimotor paraplegia with urinary incontinence. ⋯ These two cases, compared with those of the literature, shared a number of features with spinal dural arteriovenous fistulae: they occur in middle-aged and predominantly male patients, and the clinical signs of ascending myelopathy are caused by the same physiopathological mechanism of spinal vein hyperpressure. Lesions of the medulla oblongata or the cervical spinal cord are found only in intracranial arteriovenous fistulae draining into spinal veins. Diagnosis is based on data provided by myelography (impressions of dilated and sinous vessels) and MRI (low-intensity perispinal signals, widening of the conus medullaris with high-intensity centrospinal signal); spinal cord angiography only shows a lack of venous return of Adamkiewicz artery without any other abnormality, whereas cerebral arteriography confirmed the diagnosis of intracranial dural arteriovenous fistula draining into spinal veins.