ABSTRACT To alert clinicians about the occurrence of a subtype of brain infarction, its suspected etiology, and its detection by specific neuroimaging techniques.
The article presents 5 nonconsecutive patients admitted to the stroke services of 2 tertiary care hospitals, who presented with acute or subacute symptoms suspicious, but at times atypical, of brain ischemia.
Each patient had evidence of 3 to > 20 small areas of recent brain infarction detected by diffusion-weighted imaging (DWI). When available, brain computerized tomography images were not helpful for the diagnosis of these recent infarcts. Most lesions were present on magnetic resonance imaging fluid-attenuated inversion recovery sequences, but the diffusion-weighted images allowed the determination of their acuity. Further evaluation revealed a potential source of embolism in each patient. Brain microembolism was suspected in all cases.
Small and multiple areas of acute or subacute brain infarction occasionally present with clinical features atypical for brain embolism. They can be detected by magnetic resonance DWI studies.
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ABSTRACT: Transcranial Doppler can detect microembolic signals which are characterized by unidirectional high intensity increase, short duration, random occurrence, and a "whistling" sound. Microembolic signals have been detected in a number of clinical settings: carotid artery stenosis, aortic arch plaques, atrial fibrillation, myocardial infarction, prosthetic heart valves, patent foramen ovale, valvular stenosis, during invasive procedures (angiography, percutaneous transluminal angioplasty), surgery (carotid, cardiopulmonary bypass, orthopedic), and in certain systemic diseases. Microembolic signals are frequent in large artery disease, less commonly detected in cardioembolic stroke, and infrequent in lacunar stroke. This article provides an overview about the current state of technical and clinical aspects of microembolus detection.Stroke research and treatment. 01/2012; 2012:382361.
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ABSTRACT: Transcranial Doppler can detect microembolic signals, which are characterized by unidirectional high intensity increase, short duration, and random occurrence, producing a "whistling" sound. Microembolic signals have been proven to represent solid or gaseous particles within the blood flow. Microemboli have been detected in a number of clinical cardiovascular settings: carotid artery stenosis, aortic arch plaques, atrial fibrillation, myocardial infarction, prosthetic heart valves, patent foramen ovale, valvular stenosis, during invasive procedures (angiography, percutaneous transluminal angioplasty) and surgery (carotid, cardiopulmonary bypass). Despite numerous studies performed so far, clinical significance of microembolic signals is still unclear. This article provides an overview of the development and current state of technical and clinical aspects of microembolus detection.International Journal of Surgery (London, England) 02/2006; 4(4):232-41. · 1.44 Impact Factor
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ABSTRACT: Much attention in the literature has focused on the relationship between perioperative microemboli during cardiac and vascular surgery and postoperative cognitive decline. Transcranial Doppler ultrasonography (TCD) has been used to measure high-intensity transient signals (HITS), which represent microemboli during cardiac, vascular, and orthopedic surgery. The purpose of this study was to systematically examine the literature with respect to HITS and postoperative cognitive function. Systematic PubMed searches identified articles related to the use of TCD and cognitive function in the surgical setting. The literature remains largely undecided on the role of HITS and cognitive impairment after surgery, with most studies being underpowered to show a relationship. Although the cognitive effects of HITS may be difficult to detect, subclinical microemboli present potential harm, which may be modifiable. TCD represents a tool for intraoperative cerebral monitoring to reduce the number of HITS during surgery.American journal of surgery 09/2008; 197(1):55-63. · 2.36 Impact Factor