Internal Borderzone Infarction

Lee

et al. 2016

Background and Purpose— Fluid-attenuated inversion recovery vascular hyperintensities (FVHs) are seen in some cases with cerebral hemodynamic impairment and collateral flow. Because the worst outcomes of patients with borderzone infarcts were mainly correlated with impaired hemodynamics, the presence of FVH might provide another clue for predicting the prognosis of patients with borderzone infarcts. Methods— We reviewed 1377 consecutive patients with ischemic stroke. Cortical borderzone (CBZ) and internal borderzone infarcts were selected based on diffusion-weighted imaging. FVHs were defined as tubular- or serpentine-shaped hyperintensities in the subarachnoid space. We investigated the clinical significance of FVHs in borderzone-infarcted patients. Results— Among 87 patients with borderzone infarcts, the presence of FVH was observed in 30 (34.5%). We identified 62 patients with CBZ infarcts and 25 patients with internal borderzone infarcts. In the cases with CBZ infarcts, the initial National Institutes of Health Stroke Scale scores and the portions of nonfavorable outcome at 3 months in the FVH(+) group were significantly higher than in the FVH(−) group ( P <0.05 and P <0.001, respectively). Unlike the cases with CBZ infarcts, there were no significant differences of these clinical features between the FVH(+) group and the FVH(−) group in the patients with internal borderzone infarcts. Conclusions— The findings of FVH are associated with relatively severe clinical presentation and nonfavorable prognosis in patients with CBZ infarcts, but not in patients with internal borderzone infarcts. The presence of FVH may help to identify CBZ-infarcted patients who require close observation and hemodynamic control.

mentioning

confidence: 99%

Clinical Significance of Fluid-Attenuated Inversion Recovery Vascular Hyperintensities in Borderzone Infarcts

Lee

et al. 2016

“…In other studies, small border zone infarcts were seen as marker for high-grade ICA stenosis and occlusion, 25,26 while this association was denied in a larger trial. 6 Multiple acute lesions (pattern 4) have been recognized in recent publications as a new stroke pattern in distal and proximal stenosis, 18 and they are thought to be caused by multiple emboli or the breakup of an embolus.…”

Section: Discussionmentioning

confidence: 87%

Acute Stroke Patterns in Patients With Internal Carotid Artery Disease

Szabo

Kern

Gass

et al. 2001

131

102

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...

“…IB infarcts were defined as hyperintense areas in the vascular IB, where the border between DP and SP divides the infarct into 2 approximately equal sections ( Figure 1B). 6 All IB and SP infarcts were detected by DWI, and other subcortical lesions without signal changes in DWI such as leukoariosis in T2-weighted imaging were excluded. To avoid SP infarcts beyond the boundary of white matter medullary arteries as accurately as possible, we excluded infarcts located within the border-zone area between the middle cerebral artery (MCA) and anterior cerebral artery or the MCA and posterior cerebral artery.…”

Section: Methodsmentioning

confidence: 99%

“…2,3 IB infarcts located in the vascular border zone between territories of DP and SP are a topographically well-defined type of deep cerebral infarcts and morphologically distinguishable on neuroimaging. 4 Previous studies suggested that IB infarcts had been attributed to hemodynamic compromise, 5,6 but embolism was recently found to play an important role in the pathogenesis of IB infarcts. [7][8][9] In SP infarcts, although the pathogenesis remains unresolved, embolic mechanism from either the heart or internal carotid artery has been suggested.…”

mentioning

confidence: 99%

Subcortical White Matter Infarcts

Lee

Bang

et al. 2003

Background and Purpose-Because of difficulty in distinguishing between superficial perforator (SP) and internal border-zone (IB) infarcts, some studies lumped SP and IB infarcts together as so-called subcortical white matter infarcts, which might complicate the classification of infarct type and its pathogenesis. Using diffusion-weighted MRI (DWI), we made comparative analyses of clinical and neuroradiological characteristics between IB and SP infarcts to clarify the difference in underlying pathogenesis. Methods-We selected SP and IB infarcts on DWI using templates for the identification of subcortical vascular territories.Sex