Articles: brain-pathology.
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The neuropathologic sequelae of carbon monoxide (CO) toxicity have been well described in postmortem examinations. Globus pallidus damage as well as diffuse white matter lesions and encephalopathic changes occur. Brain CT has provided imaging correlates to the premortem changes. ⋯ Cerebral edema changes may occur early with subsequent demonstration of globus pallidus lesions and white matter changes. Globus pallidus lesions in many cases do not correlate directly to clinical status and outcome; however, the presence of diffuse white matter disease is a more reliable index of both. These changes are seen in patients in both accidental exposures to CO and in suicide attempts.
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Experimental neurology · Jul 1999
Hypothermia ameliorates ischemic brain damage and suppresses the release of extracellular amino acids in both normo- and hyperglycemic subjects.
It has previously been shown that hypothermia markedly reduces cellular release of the excitatory amino acid glutamate and ameliorates ischemic damage. Based on extensive data showing that preischemic hyperglycemia exaggerates brain damage due to transient forebrain ischemia we posed the question whether glutamate release during ischemia in hyperglycemic rats is attenuated or prevented by induced hypothermia, and if such attenuation/prevention correlates with amelioration of the characteristic brain damage observed in hyperglycemic subjects. The experiments were performed in rats subjected to a 15-min period of forebrain ischemia, plasma glucose concentration being maintained at approximately 5 mM (control) or approximately 20 mM (hyperglycemia) prior to ischemia. ⋯ The concentration of glutamate was further increased in normothermic-hyperglycemic animals. Hypothermia inhibited the rise in glutamate concentrations, as well as in the concentrations of other excitatory and inhibitory amino acids. It is discussed whether hypothermia reduces the hyperglycemia-mediated damage by inhibiting extracellular glutamate release during an ischemic transient.
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AJNR Am J Neuroradiol · Jun 1999
Comparative StudyDiffusion-weighted MR imaging of global cerebral anoxia.
Diffuse cerebral anoxia is a devastating event, and its acute findings, as revealed by conventional MR imaging and CT scanning, may be subtle. We analyzed diffusion-weighted and conventional MR images of patients with diffuse cerebral anoxia to determine their usefulness in establishing the diagnosis during the acute period and in determining the age of insult. ⋯ During the acute period, high-strength diffusion-weighted images showed the abnormal basal ganglia, cerebellum, and cortex to a better extent than did conventional MR images. During the early subacute period, gray matter abnormalities were seen on diffusion-weighted images. During the late subacute period, diffusion-weighted images showed mostly white matter abnormalities. During the chronic stage, the results of diffusion-weighted imaging were normal. Our findings suggest that diffusion-weighted images are helpful for evaluating and dating diffuse cerebral anoxia, and therefore aid in the determination of prognosis and management of these patients.
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Infective endocarditis (IE) is an elusive systemic disorder that is often associated with neurologic complications. The contribution of brain magnetic resonance imaging (MRI) to the diagnosis of IE and the spectrum of such findings has been only sparsely described previously. The authors report cranial MRI findings in 12 patients with IE. ⋯ Most patients studied with gadolinium showed enhancement of lesions (n = 5/8). The authors conclude that cranial MRI may be a valuable tool in the evaluation of patients with IE. The presence of characteristic cranial MRI lesions, especially of multiple types, may prompt early diagnosis and treatment.
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Despite a hundred years' research, the neuropathology of schizophrenia remains obscure. However, neither can the null hypothesis be sustained--that it is a 'functional' psychosis, a disorder with no structural basis. A number of abnormalities have been identified and confirmed by meta-analysis, including ventricular enlargement and decreased cerebral (cortical and hippocampal) volume. ⋯ Functional imaging data indicate that the pathophysiology of schizophrenia reflects aberrant activity in, and integration of, the components of distributed circuits involving the prefrontal cortex, hippocampus and certain subcortical structures. It is hypothesized that the neuropathological features represent the anatomical substrate of these functional abnormalities in neural connectivity. Investigation of this proposal is a goal of current neuropathological studies, which must also seek (i) to establish which of the recent histological findings are robust and cardinal, and (ii) to define the relationship of the pathological phenotype with the clinical syndrome, its neurochemistry and its pathogenesis.