Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Magnetic resonance imaging (MRI) findings in a group of 60 ambulatory elderly individuals (average age, 75.8 yr) were characterized as normal (grade 0), periventricular changes only (grade 1 ). small punctate lesions (grade 2), and confluent or large (> 2 mm) punctate lesions (grade 3). Patients were characterized by stroke risk factors, cardiolipin antibodies, coagulation factors (fibrinogen and plasminogen activator inhibitor-1 ). and Doppler ultrasound findings in the carotid and middle cerebral arteries. ⋯ There was no significant association between variables and MRI grade. These findings suggest that ischemia is not a major cause of MRI signal abnormalities in neurologically asymptomatic elderly individuals.
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Tha pathophysiology of brain injury in patients undergoing cardiopulmonary bypass remains unclear despite several decades of inquiry. The advent of noninvasive high-resolution brain and cerebrovascular imaging by magnetic resonance, computed tomography, and pulsed Doppler ultrasonography now permits in vivo assessment of pathophysiological mechanisms. Neuroradiographic and carotid duplex studies were performed in patients who developed neurological deficits following cardiopulmonary bypass. ⋯ Watershed injury was the predominant finding in a single patient, while findings consistent with global anoxia were present in another patient. Carotid atheroemboli were excluded as a possible source of embolism in 11 patients whose carotid duplex studies were unremarkable preoperatively as well as in 3 further patients whose neuroradiographic findings did not correspond with their moderate carotid disease. It is concluded that infarction due to noncarotid embolism is the primary pathophysiology of neurological deterioration following cardiopulmonary bypass.