The purpose of our study was to define the signal characteristics and clinical circumstances associated with emboli detected in the middle cerebral artery using 2-MHz pulsed transcranial Doppler ultrasound in patients undergoing carotid endarterectomy. Signals designating emboli were transients displaying harmonic qualities the signatures of which were clearly different from those of mechanical...

BACKGROUND AND PURPOSE The use of Doppler ultrasound to detect arterial emboli has major implications for the classification and treatment of stroke. Experimental studies indicate that embolic materials produce different ultrasound signals, depending on their acoustic properties. To examine the possibility of characterizing emboli of different sources in the clinical setting, we compared the em...

BACKGROUND AND PURPOSE Cerebral embolism has been implicated in the development of cognitive and neurological deficits following bypass surgery. This study proposes methodology for estimating cerebral air embolus volume using transcranial Doppler sonography. METHODS Transcranial Doppler audio signals of air bubbles in the middle cerebral artery obtained from in vivo experiments were subjected...

OBJECTIVE To compare the occurrence of spontaneous cerebral emboli and venous to arterial circulation shunts in patients with Alzheimer's disease or vascular dementia and controls without dementia. DESIGN Cross sectional case-control study. SETTING Secondary care old age psychiatry services, Manchester. PARTICIPANTS 170 patients with dementia (85 with Alzheimer's disease, 85 with vascular...

The purpose of the present study was to determine whether cerebral hyperperfusion after revascularization inhibits development of cerebral ischemic lesions due to artery-to-artery emboli during exposure of the carotid arteries in carotid endarterectomy (CEA). In patients undergoing CEA for internal carotid artery stenosis (≥70%), cerebral blood flow (CBF) was measured using single-photon emissi...

Correspondence to: Dr Chambers. How is cardiac stroke diagnosed? Approximately 20% of strokes are caused by cerebral haemorrhage and 80% by infarction.1 Of the infarctions, a proportion are thrombotic and the rest as a result of emboli either from artery to artery within the cerebral circulation or from the heart or aorta. The diagnosis of a cardiac source for emboli is based to some degree on ...

Occlusion of the anterior cerebral artery is a rare condition. A review of CT scans from 413 patients with ischemic infarction confirmed this low relative incidence: only 3% of CT scans evidencing infarction involved the territory of the anterior cerebral artery. Four major mechanisms of anterior cerebral artery occlusion have been identified in this series: Emboli in unusual hemodynamic circum...

BACKGROUND AND PURPOSE This is a study of cardiac diseases associated with the 1,382 cases of first cerebral infarction in residents of Rochester, Minn., during 1960-1984. METHODS This is a population-based study in Rochester, Minn., for which the medical record-linkage system was used to identify cardiac disease among patients with first cerebral infarction. RESULTS There were 318 patients...

BACKGROUND AND PURPOSE Cerebral microembolic signals detected by transcranial Doppler are frequent during carotid angioplasty with stenting and carotid endarterectomy (CEA). Their potential harmful effects on the brain are, however, unclear. The aim of this study was to relate the frequency and type of per-procedural microembolic signals to procedure-related ipsilateral ischemic strokes and new...