Cases reported "Cerebral Infarction"

Filter by keywords:



Filtering documents. Please wait...

1/8. Outcome of acute ischemic lesions evaluated by diffusion and perfusion MR imaging.

    BACKGROUND AND PURPOSE: diffusion and perfusion MR imaging have been reported to be valuable in the diagnosis of acute ischemia. Our purpose was to ascertain the value of these techniques in the prediction of ischemic injury and estimation of infarction size, as determined on follow-up examinations. methods: We studied 18 patients with acute ischemic stroke who underwent echo-planar perfusion and diffusion imaging within 72 hours of symptom onset. Quantitative volume measurements of ischemic lesions were derived from relative mean transit time (rMTT) maps, relative cerebral blood volume (rCBV) maps, and/or apparent diffusion coefficient (ADC) maps. Follow-up examinations were performed to verify clinical suspicion of infarction and to calculate the true infarction size. RESULTS: Twenty-five ischemic lesions were detected during the acute phase, and 14 of these were confirmed as infarcts on follow-up images. Both ADC and rMTT maps had a higher sensitivity (86%) than the rCBV map (79%), and the rCBV map had the highest specificity (91%) for detection of infarction as judged on follow-up images. The rMTT and ADC maps tended to overestimate infarction size (by 282% and 182%, respectively), whereas the rCBV map appeared to be more precise (117%). Significant differences were found between ADC and rMTT maps, and between rCBV and rMTT maps. CONCLUSION: Our data indicate that all three techniques are sensitive in detecting early ischemic injury within 72 hours of symptom onset but tend to overestimate the true infarction size. The best methods for detecting ischemic injury and for estimating infarction size appear to be the ADC map and the rCBV map, respectively, and the diffusion abnormality may indicate early changes of both reversible and irreversible ischemia.
- - - - - - - - - -
ranking = 1
keywords = specificity
(Clic here for more details about this article)

2/8. Preserved visual lexicosemantics in global aphasia: a right-hemisphere contribution?

    Extensive testing of a patient, GP, who encountered large-scale destruction of left-hemisphere (LH) language regions was undertaken in order to address several issues concerning the ability of nonperisylvian areas to extract meaning from printed words. Testing revealed recognition of superordinate boundaries of animals, tools, vegetables, fruit, clothes, and furniture. GP was able to distinguish proper names from other nouns and from nonwords. GP was also able to differentiate words representing living things from those denoting nonliving things. The extent of LH infarct resulting in a global impairment to phonological and syntactic processing suggests LH specificity for these functions but considerable right-hemisphere (RH) participation in visual lexicosemantic processing. The relative preservation of visual lexicosemantic abilities despite severe impairment to all aspects of phonological coding demonstrates the importance of the direct route to the meaning of single printed words.
- - - - - - - - - -
ranking = 1
keywords = specificity
(Clic here for more details about this article)

3/8. diffusion MRI in ischemic stroke compared to pathologically verified infarction.

    BACKGROUND: diffusion MRI abnormality correlates with pathology in animal ischemic stroke models. A combined retrospective and prospective analysis of consecutive patients over a 3-year period who had a clinical diagnosis of probable new ischemic stroke, underwent diffusion MRI, and were later studied at autopsy was performed. methods: Inclusion criteria for the retrospective analysis were 1) symptom onset within 14 days of presentation, 2) diffusion MRI within 28 days of symptom onset, and 3) autopsy within 16 weeks of symptom onset. patients with suspected further infarcts between MRI and autopsy were excluded. The locations of all areas of MRI abnormality were identified by a blinded neuroradiologist, and recent infarcts were identified by review of pathologic records and microscopic slides. RESULTS: Eleven patients were identified who fulfilled inclusion criteria, with 25 discrete pathologic infarcts. diffusion MRI abnormality corresponded to pathologically verified infarction in 23 cases, was present in two locations where no pathologic infarct was identified, and was absent in two locations where an infarct was present at autopsy. In two cases, despite clinical suspicion of acute ischemic stroke, no MRI abnormality or pathologic infarct was found. The sensitivity and specificity of diffusion MRI were 88.5% (95% CI, 69.9% to 97.6%) and 96.6% (95% CI, 91.5% to 99.1%). Accuracy was 95.1% (95% CI, 90.2% to 98%). Three further patients who died during the course of the retrospective analysis were studied prospectively, and are described separately. CONCLUSIONS: These findings suggest high accuracy of diffusion MRI for detection of ischemic infarction compared with pathologic examination.
- - - - - - - - - -
ranking = 1
keywords = specificity
(Clic here for more details about this article)

4/8. diffusion-weighted MR findings in isolated angiitis of the central nervous system (IACNS).

    OBJECTIVES: To describe the diffusion-weighted MR (DWI) findings of isolated angiitis of the central nervous system (IACNS) and narrow the differential diagnosis. methods: The DWI findings of two IACNS patients. Apparent diffusion coefficient (ADC) values were measured in the abnormal lesions, and DWI and T2-weighted MR images were visually inspected. RESULTS: IACNS was diagnosed based on clinical history, MR findings and cerebral angiographic findings. DWI showed hyperintense lesions with heterogeneous ADC values (287-1359 x 10(-6) mm2/s), which indicate the coexistence of cytotoxic and vasogenic oedema. CONCLUSIONS: The findings suggest that the various stages of inflammatory process with ischaemia might exist in IACNS and allow a differentiation from the usual arterial ischaemic infarction. DWI with ADC map can be a useful non-invasive diagnostic test increasing specificity in the diagnosis of IACNS, combined with conventional MRI and cerebral angiography.
- - - - - - - - - -
ranking = 1
keywords = specificity
(Clic here for more details about this article)

5/8. Computerized tomographic diagnosis: pitfalls for neurosurgeons.

    Computerized tomography as a diagnostic procedure is characterized by its high sensitivity but limited specificity. This lack of specificity may result in an erroneous diagnosis and, possibly, in ill-advised therapy unless clinical and objective data are carefully considered in interpreting the study. The most common pitfalls encountered are the phenomena of contrast enhancement of infarcts and mass effect associated with infarcts. Many different pathological processes can have similar enhancement patterns. The evolution of high density, acute hemorrhage to isodense areas in the chronic hematoma can become a serious diagnostic problem unless an appropriate history is available. The authors discuss 30 cases in which misinterpretation of CT scans resulted in erroneous diagnoses. Seventeen of these patients underwent operation.
- - - - - - - - - -
ranking = 2
keywords = specificity
(Clic here for more details about this article)

6/8. The "jerky dystonic unsteady hand": a delayed motor syndrome in posterior thalamic infarctions.

    We report the cases of three patients with a thalamic infarct in the territory of the posterior choroidal artery involving the posterior thalamic nuclei. These patients developed delayed complex hyperkinetic motor syndromes, associating ataxia, tremor, dystonia, myoclonus and chorea, which we call "the jerky dystonic unsteady hand". One patient had a severe myoclonic and ataxic-dystonic choreoathetosis; another showed a so-called rubral tremor (myoclonic ataxia with resting, action, and wing-beating tremor) with dystonia; and the third one had a dystonic and ataxic hand with intermittent mild action myoclonus. All of them had sensory dysfunction; two had also presented with a painful Dejerine-Roussy syndrome. All had CT or MRI-proven infarcts in the territory of the posterior cerebral artery involving the posterior choroidal territory with an abnormal signal in the posterior area of the thalamus (pulvinar nucleus) but sparing the other thalamic, subthalamic and midbrain structures. These delayed myoclonic complex hyperkinetic syndromes have not been reported before, and we did not observe them in other topographic forms of thalamic infarcts. They may thus represent a new entity of movement disorders due to lesions in the posterior thalamic nuclei, with specificity for posterior choroidal artery infarcts.
- - - - - - - - - -
ranking = 1
keywords = specificity
(Clic here for more details about this article)

7/8. Acute stroke in a young female with anti-human beta2-glycoprotein I antibodies.

    We report the case of a woman who, at the age of 27, developed a cerebral arterial occlusion. The laboratory investigations showed an anti-human beta2-glycoprotein I antibody, but no other biological sign of antiphospholipid antibody syndrome or autoimmune disorders. The patient otherwise presented with diabetes and moderate obesity. The species specificity of anti-beta2-glycoprotein I antibodies probably explains the discrepancy between false negative results for antiphospholipid antibodies assayed by clotting and ELISA studies and positivity for anti-human beta2-glycoprotein I. Further studies will be important to evaluate the frequency of such antibodies, as well as their value as a risk factor for venous and arterial thrombosis, and their signification within the antiphospholipid antibody syndrome.
- - - - - - - - - -
ranking = 1
keywords = specificity
(Clic here for more details about this article)

8/8. Cerebral venous infarctions presenting as enhancing space-occupying lesions: MRI findings.

    Cerebral venous thrombosis is an unusual form of cerebrovascular disease that may cause cerebral venous infarction (CVI). magnetic resonance imaging (MRI) of the brain may improve the often elusive diagnosis of CVI. However, the sensitivity, specificity, and full spectrum of such MRI findings are poorly understood. The authors present the cases of three patients with CVI whose MRI scans showed abnormally enhancing tumor-like brain lesions. Two of the CVIs were hemorrhagic and exerted mass effect. One patient showed increasingly nodular and heterogeneous ring-like enhancement progressing from the single-dose to the triple-dose gadolinium contrast images. The CVI of a second patient also showed ring-like enhancement. biopsy was performed on one of these patients and was strongly considered for the other two patients to exclude neoplastic disease. Careful examination of the MRI appearance of venous structures and the use of specialized MRI techniques improved the recognition of CVI for two patients and prevented biopsy. This represents the first description of abnormal triple-dose MRI contrast enhancement in CVI. Consideration of CVI in the care of patients with enhancing tumor-like masses may lead to earlier diagnosis and treatment, preventing unnecessary invasive diagnostic procedures. CVI should be added to the differential diagnosis of supratentorial ring-enhancing masses.
- - - - - - - - - -
ranking = 1
keywords = specificity
(Clic here for more details about this article)


Leave a message about 'Cerebral Infarction'


We do not evaluate or guarantee the accuracy of any content in this site. Click here for the full disclaimer.