Recently Occluded Intracranial and Extracranial Carotid Arteries

Abstract

Background and Purpose-It is now widely accepted that thrombotic coronary artery occlusion usually follows rupture of an unstable atherosclerotic plaque. The significance of such instability in arteries supplying the brain is less well appreciated. We therefore describe the clinical and pathological features of recent, symptomatic internal carotid artery occlusion to examine the pathogenetic role of plaque instability at both extracranial and intracranial sites. Methods-Cases were selected from a consecutive series of 188 adult neuropathology autopsies. In 90 of these, the principal neuropathological abnormality was cerebral infarction, in 14 cases due to recent occlusion of 1 or more segments of the internal carotid artery. In each case, a full systemic, cardiovascular, and neuropathological autopsy was performed. Plaque instability was assessed by the presence or absence of a large, necrotic, lipid core; a thin, fibrous cap; and superficial inflammation. Results-Of the 14 cases, 3 showed extracranial (carotid sinus), 7 intracranial, and 4 both extracranial and intracranial carotid artery occlusion. In 6 of the 7 occluded carotid sinuses, thrombus overlay an ulcerated, unstable, atherosclerotic plaque. In 1 extracranial and all 11 intracranial occlusions, there was either no atheroma or a mildly stenotic, stable, fibrous plaque, and in these cases, the cause of occlusion was embolism (8 cases), giant-cell arteritis (1 case), and unknown (3 cases). Conclusions-Coronary-type rupture of an unstable atherosclerotic plaque is the usual cause of fatal occlusion of the carotid sinus, but other causes usually underlie intracranial carotid occlusion. The nature and consequences of intracranial atherosclerosis require further study. (Stroke. 1999;30:1319-1325.)

Evaluation of early dynamic changes of intracranial arterial occlusion is useful for stroke etiology diagnosis

“…Lesion patterns related to intrinsic MCA atherosclerosis have been reported previously [7]. We also observed that 30% of our patients with intrinsic MCA atherosclerosis showed partial recanalization with remaining residual stenosis, suggesting that the rupture of unstable atherosclerotic plaques may be relevant to this condition, similar to findings in patients with acute coronary syndrome [17].…”

Evaluation of early dynamic changes of intracranial arterial occlusion is useful for stroke etiology diagnosis

“…Lesion patterns related to intrinsic MCA atherosclerosis have been reported previously [7]. We also observed that 30% of our patients with intrinsic MCA atherosclerosis showed partial recanalization with remaining residual stenosis, suggesting that the rupture of unstable atherosclerotic plaques may be relevant to this condition, similar to findings in patients with acute coronary syndrome [17].…”

Critical Cap Thickness and Rupture in Symptomatic Carotid Plaques

“…One previous study reported pathological features of fatally ruptured carotid plaques (nϭ14) but cap thicknesses were not apparently measured. 3 Our findings lend support to some recently proposed mechanisms of plaque instability. First, thin fibrous cap was positively associated with inflammation of the plaque and of the cap, potentially supporting a link between matrix metalloproteinases and cap thinning.…”

Intracranial atherosclerotic stroke: Specific focus on the metabolic syndrome and inflammation

“…This indicates that a different pathogenesis may underlie extracranial versus intracranial atherosclerosis. All such findings are in line with a previous report based on autopsy data showing that, in contrast to extracranial arterial stenosis, intracranial plaques are usually stable and fibrous and do not represent embolic foci [13,14].…”

Evaluation of early dynamic changes of intracranial arterial occlusion is useful for stroke etiology diagnosis

“…Lesion patterns related to intrinsic MCA atherosclerosis have been reported previously [7]. We also observed that 30% of our patients with intrinsic MCA atherosclerosis showed partial recanalization with remaining residual stenosis, suggesting that the rupture of unstable atherosclerotic plaques may be relevant to this condition, similar to findings in patients with acute coronary syndrome [17].…”

Critical Cap Thickness and Rupture in Symptomatic Carotid Plaques

“…One previous study reported pathological features of fatally ruptured carotid plaques (nϭ14) but cap thicknesses were not apparently measured. 3 Our findings lend support to some recently proposed mechanisms of plaque instability. First, thin fibrous cap was positively associated with inflammation of the plaque and of the cap, potentially supporting a link between matrix metalloproteinases and cap thinning.…”

Intracranial atherosclerotic stroke: Specific focus on the metabolic syndrome and inflammation

“…This indicates that a different pathogenesis may underlie extracranial versus intracranial atherosclerosis. All such findings are in line with a previous report based on autopsy data showing that, in contrast to extracranial arterial stenosis, intracranial plaques are usually stable and fibrous and do not represent embolic foci [13,14].…”

Evaluation of early dynamic changes of intracranial arterial occlusion is useful for stroke etiology diagnosis

“…Lesion patterns related to intrinsic MCA atherosclerosis have been reported previously [7]. We also observed that 30% of our patients with intrinsic MCA atherosclerosis showed partial recanalization with remaining residual stenosis, suggesting that the rupture of unstable atherosclerotic plaques may be relevant to this condition, similar to findings in patients with acute coronary syndrome [17].…”

Critical Cap Thickness and Rupture in Symptomatic Carotid Plaques

“…One previous study reported pathological features of fatally ruptured carotid plaques (nϭ14) but cap thicknesses were not apparently measured. 3 Our findings lend support to some recently proposed mechanisms of plaque instability. First, thin fibrous cap was positively associated with inflammation of the plaque and of the cap, potentially supporting a link between matrix metalloproteinases and cap thinning.…”

Intracranial atherosclerotic stroke: Specific focus on the metabolic syndrome and inflammation

“…This indicates that a different pathogenesis may underlie extracranial versus intracranial atherosclerosis. All such findings are in line with a previous report based on autopsy data showing that, in contrast to extracranial arterial stenosis, intracranial plaques are usually stable and fibrous and do not represent embolic foci [13,14].…”