Acute Stroke Patterns in Patients With Internal Carotid Artery Disease

Abstract

Background and Purpose-Diffusion-weighted (DW) MRI is a sensitive method that facilitates early stroke pattern identification. There are limited data about the influence of stenosis grade on the development of particular stroke patterns in internal carotid artery (ICA) disease. We therefore investigated the lesion patterns on DW MRI in acute stroke patients with ICA disease. Methods-DW MRI was analyzed in 102 consecutive acute stroke patients with different degrees of ipsilateral ICA disease. Patients were assigned to 1 of 5 observed lesion patterns: (1) territorial ischemia, (2) subcortical ischemia without or (3) with embolus fragmentation, (4) disseminated lesions in distal cortical regions, and (5) multiple lesions in hemodynamic risk zones. In addition, perfusion-weighted (PW) MRI and MR angiography information was included in the assessment. Results-All patterns were observed in the different stages of ICA disease. Half of the patients with high-grade or subtotal stenosis had lesions in hemodynamic risk zones. Territorial stroke occurred in 47.6% of patients with ICA occlusion. Statistical analysis showed a significant relationship between the degree of stenosis and the observed stroke pattern (Pϭ0.001). In 77.8% of patients exhibiting high-grade ICA stenosis, subtotal stenosis, or occlusion, the perfusion lesion was larger than the diffusion lesion (PW/DW mismatch). Conclusions-Although in the individual patient any of the infarct patterns may occur, in statistical terms the incidence of a particular stroke pattern is clearly dependent on the degree of stenosis. Key Words: carotid artery diseases Ⅲ magnetic resonance imaging, diffusion-weighted Ⅲ stroke, acute A therosclerotic narrowing of the extracranial vessels is a well-recognized cause of cerebral ischemia. The annual stroke risk for patients with asymptomatic internal carotid artery (ICA) stenosis amounts to approximately 1% to 2%. 1,2 Both embolic and hemodynamic mechanisms are assumed to be the cause of stroke in ICA disease. 3 Neuroimaging studies have been performed in an attempt to improve the understanding of the underlying stroke mechanism as a basis for the identification of patients at high risk and for the best possible therapeutic rationale. Studies based on CT have suggested that hemodynamically significant stenoses or obstructions of the extracranial ICA may cause hemodynamic changes in the distal regions of the hemispheric blood supply, the so-called border zones between major vascular territories, while embolism from ICA stenosis is believed to disproportionately affect the middle cerebral artery (MCA) stem and distal branches producing territorial infarction, often including the deep lenticulostriate territory. 4 The coexistence of hypoperfusion and arterial embolism in patients with border zone stroke and ICA disease has recently been postulated. 5 Since the concept of border zone ischemia as a cause of stroke in patients with severe ICA stenosis has also been challenged, 6,7 uncertainty still remains regarding the occurrence and me...

Brainstem Infarction Presenting with Neurogenic Stuttering

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“…9 Bonati et al showed different DWI lesion patterns in 15 stenotic and 25 occlusive CAD. 6 However, the number of patients was too limited to perform analyses of associations between different degrees of luminal narrowing and DWI lesion presence and patterns.…”

Gender Differences in Acute Ischemic Stroke

“…Stroke patterns on CT or MRI scan were classified in territorial, embolic, and lacunar stroke as well as borderzone infarction (see Figure 1) as implemented earlier. 18 In a subset of patients, those without MRI scan because of contraindications or inconclusive CT findings, stroke localization and pattern were classified as uncertain.…”