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Acute Ischemic Lesions (acute + ischemic_lesion)

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Medical Sciences100%

Selected Abstracts

Delirium due to Brain Microembolism: Diagnostic Value of Diffusion-Weighted MRI

JOURNAL OF NEUROIMAGING, Issue 2 2007
Pablo Irimia MD
ABSTRACT Delirum is a common complication in hospitalized patients and it is characterized by acute disturbances of consciousness, attention, cognition, and perception. Despite the frequency with which it is observed, ischemic stroke is generally considered as an unusual cause of delirium. A subtype of brain embolism is characterized by multiple small emboli in different vascular territories, a condition known as "brain microembolism." Given the high contrast of acute ischemic lesions in diffusion weighted imaging (DWI) this technique is particularly helpful to detect these small infarctions. We present here a patient with pulmonary metastases who was treated with bronchial artery embolization and who subsequently developed delirium due to brain microembolism. The embolic material crossed through pulmonary arteriovenous fistulas, producing multiple areas of cerebral ischemia. The ischemic lesions could be visualized only on DWI, and they affected the periventricular region, caudate nucleus, thalamus, and cerebellum. [source]

Bilateral Internal Carotid Artery Dissection Mimicking Inflammatory Demyelinating Disease

JOURNAL OF NEUROIMAGING, Issue 4 2003
C. Lie MD
ABSTRACT Background and Purpose. Internal carotid artery (ICA) dissection (ICAD) may be extremely difficult to diagnose only on the basis of historical information and clinical signs, and even standard brain imaging (computed tomography [CT], T2-weighted magnetic resonance imaging [MRI]) may not be sufficient to delineate the underlying pathology clearly, as shown in this case. Methods. The clinical presentation and parenchymal lesion pattern on CT were suggestive of inflammatory demyelinating disease, and additional multiparametric MRI was per-formed. Results. Diffusion-weighted MRI, magnetic resonance angiography, and perfusion-weighted MRI revealed acute ischemic lesions, bilateral ICA obstruction, and bilateral hypoperfusion in the middle cerebral artery territories. Bilateral ICAD was confirmed by Doppler and duplex ultrasound, and anticoagulation therapy was initiated. A follow-up examination showed recanalization of the obstructed ICAs and the normalization of cerebral perfusion. Conclusion. This case illustrates the importance of demonstrating the pathology and the value of multiparametric MRI techniques for the diagnosis and monitoring of ICAD and its hemodynamic consequences. [source]

Moyamoya-disease-related ischemic stroke in the postpartum period

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 5 2009
Kei Miyakoshi
Abstract Stroke during pregnancy or the puerperium is an extremely rare yet serious cause of perinatal morbidity and mortality. Moyamoya disease, a cerebrovascular occlusive pathology with a female predominance, may become symptomatic for the first time in association with pregnancy. A 36-year-old woman with postpartum pre-eclampsia suddenly developed hemiparesis in the left arm with dysarthria after the initiation of antihypertensive measures. Cranial magnetic resonance imaging and angiography revealed acute ischemic lesions in the right hemisphere along with the steno-occlusive lesions of bilateral terminal portions of the internal carotid artery, indicating Moyamoya disease. With anti-platelet medication, the patient recovered gradually and was diagnosed as having Moyamoya disease using conventional angiography 3 months postpartum. In this case, the fluctuations in blood pressure in association with pre-eclampsia appear to have exacerbated the clinical symptoms of Moyamoya disease. As such, Moyamoya disease should be considered as an underlying disease of ischemic stroke associated with pregnancy. [source]

Negative fluid-attenuated inversion recovery imaging identifies acute ischemic stroke at 3 hours or less,

ANNALS OF NEUROLOGY, Issue 6 2009
Götz Thomalla MD
Objective o evaluate the use of fluid-attenuated inversion recovery (FLAIR) imaging as surrogate marker of lesion age within the first 6 hours of ischemic stroke. Methods e analyzed FLAIR and diffusion-weighted imaging (DWI) sequences performed within 6 hours of symptom onset in 120 consecutive patients with ischemic stroke with known symptom onset. The visibility of acute ischemic lesions on FLAIR images was judged in two steps (on FLAIR alone and with knowledge of DWI) and compared with DWI. Results egative FLAIR in the case of positive DWI allocated ischemic lesions to a time window 3 hours or less with a high specificity (0.93) and a high positive predictive value (0.94), whereas sensitivity (0.48) and negative predictive value (0.43) were low. Lesion visibility on FLAIR images alone (35.6%) and with knowledge of DWI (62.5%) was lower than on DWI (97.1%). The sensitivity of FLAIR increased with increasing time from symptom onset from 27.0/50.0% , 3 hours to 56.7/93.3% after 3 to 6 hours (FLAIR alone/with knowledge of DWI). Multivariate regression analysis spotted longer time from symptom onset and larger size of the ischemic lesion as independent predictors of lesion visibility on FLAIR images. Interpretation "mismatch" between positive DWI and negative FLAIR allows the identification of patients that are highly likely to be within the 3-hour time window. Within the first 6 hours of stroke, the sensitivity of FLAIR sequences for acute ischemic lesions increases with time from symptom onset elapsing, approximating 100% after 3 to 6 hours. Ann Neurol 2009;65:724,732 [source]