Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Cerebral vasculitis is an unusual disorder with many causes. Infectious causes of cerebral vasculitis are predominantly bacterial or viral in nature. Purulent bacterial vasculitis is most often a complication of severe bacterial meningitis. ⋯ Shortly thereafter, an MRI examination revealed diffuse leptomeningeal enhancement and abscess and a right parietal subdural empyema. Infectious vasculitis secondary to purulent meningitis has a rapidly progressive course and presents with cranial nerve palsy with involvement of the cavernous sinus. Although the association of this disease with pregnancy has not been established, it should be recognized that the early imaging studies may be negative or discordant and follow-up imaging might be necessary.
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A patient with mitochondrial encephalomyopathy, lactic acidosis, and strokelike episode (MELAS) syndrome underwent serial measurement of cerebral blood flow with xenon computed tomography (Xe-CBF) while presenting with strokelike episodes accompanied by a cerebral lesion. He underwent positron emission tomography (PET) measurement of the regional cerebral blood flow (PET-CBF), metabolic rate of oxygen (CMRO2), and glucose (CMRGlu) after his symptoms and lesion disappeared. ⋯ In the PET study, decreased CMRO2 and increased PET-CBF and CMRGlu were noted in the entire brain. The strokelike episodes of patients with MELAS are more likely attributed to the failure of oxygen metabolism than to a vascular accident.
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Case Reports
Intraosseous sacral myxopapillary ependymoma and the differential diagnosis of sacral tumors.
Although involvement of other regions of the spinal cord and brain stem is seen, myxopapillary ependymoma is most commonly found at the filum terminale or cauda equina. Less commonly, myxopapillary ependymoma may occur outside the central nervous system from direct metastatic extension of an intrathecal tumor, and rarely it may present as a primary tumor outside the thecal sac. ⋯ They then discuss the magnetic resonance imaging findings of this and other sacral tumors. Myxopapillary ependymoma should be considered in the differential diagnosis for a primary expansile sacral mass along with other lesions such as chordoma, aneurysmal bone cyst, and giant cell tumor.
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The effect of temporal lobe transection area, volume of postoperative gliosis, and surgical technique on patients' seizure-free outcome is unknown. The authors studied the effects of these variables on patients' seizure-free outcome. ⋯ The authors found no clear association between postoperative outcome and residual temporal lobe gliosis, the surgical technique, or the total area of temporal lobe transected by the scalpel.
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Evidence suggests that adenosine (ADN) is a potent vasodilator of cerebral vessels. However, the feasibility of manipulating human cerebral vascular resistance with ADN has not been assessed by means of TCD. The purpose of this study was to quantitatively estimate the change in middle cerebral artery cerebral blood flow velocity (CBFV) in response to intravenous ADN infusion in humans. ⋯ The authors hypothesize that any direct vasodilatory effect of ADN on the distal cerebral peripheral vasculature may be negated by an effect of ADN on depth of respiration resulting in hypocapnia and secondary distal vasoconstriction.