"Low perfusion hyperemia" following middle cerebral arterial occlusion in cats of different age groups.

Tomita, M; Gotoh, Fumio; Amano, Takahiro; Tanahashi, N; Tanaka, Kortaro

doi:10.1161/01.str.11.6.629

Cited by 55 publications

(26 citation statements)

References 16 publications

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“…17 In their study, a raised CBV measured within 6 to 48 hours of stroke onset did not contribute to maintaining metabolic activity in the peri-infarct regions. Tomita et al 34 found "low-perfusion hyperemia" in the ischemia model of cat brain, which followed the initial CBV decrease immediately after MCA occlusion and disappeared within several hours. The low-perfusion hyperemia did not have a protective effect on ischemic lesion evolution.…”

Section: Discussionmentioning

confidence: 99%

Cerebral Blood Volume in Acute Brain Infarction

Hatazawa

Shimosegawa

Toyoshima

et al. 1999

Stroke

102

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Background and Purpose-The aim of this study was to correlate the abnormality in cerebral blood volume (CBV) measured by dynamic susceptibility contrast-enhanced MRI with that in cerebral blood flow (CBF) estimated by single-photon emission CT with [ 99m Tc]hexamethylpropylenamine-oxime in patients with acute ischemic stroke. Methods-Nine patients with unilateral occlusion of either the middle cerebral artery or the internal carotid artery (4 men and 5 women; meanϮSD age, 74.4Ϯ11.6 years) were studied within 6 hours after stroke onset. The relative CBV (relCBV) and CBF (relCBF) in the lesions were defined relative to the contralateral mirror regions. Results-In the brain regions with mild (relCBF Ն0.60), moderate (0.40ՅrelCBFϽ0.60), and severe (relCBF Ͻ0.40) hypoperfusion, the mean relCBV values were 1.29Ϯ0.31, 0.94Ϯ0.49, and 0.30Ϯ0.22, respectively. The relCBV was significantly elevated in the brain areas with mild hypoperfusion (PϽ0.001) and significantly reduced in the brain areas with severe hypoperfusion (PϽ0.001). The relCBF was significantly better than the relCBV in predicting the evolution of infarction (PϽ0.02). The probability of evolving infarction for the hypervolemic (relCBV Ͼ1.0) regions was significantly lower than that for hypovolemic (relCBV Ͻ1.0) regions in the relCBF range between 0.40 and 0.50 (PϽ0.02). Conclusions-In acute ischemic stroke within 6 hours of onset the CBV can be either increased, normal, or decreased, depending on the severity of hypoperfusion. The increased CBV has a protective effect on evolving infarction. Although the CBF is a better predictor of tissue outcome, the CBV measurement may help detect potentially salvageable brain tissue in the penumbra with compromised blood flow. (Stroke. 1999;30:800-806.)

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Section: Discussionmentioning

confidence: 99%

Cerebral Blood Volume in Acute Brain Infarction

Hatazawa

Shimosegawa

Toyoshima

et al. 1999

Stroke

102

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“…From a therapeutic standpoint, robust collaterals are a potent predictor of arterial recanalization, preserved tissue fate, and good clinical outcomes in acute stroke. Although much emphasis has been placed on specific arterial collateral routes that bypass flow around occlusions, the capacity of other elements such as the venous system to maintain cerebral blood volume remains essential (Tomita et al, 1980). Even when seemingly equivalent cases of proximal middle cerebral artery (MCA) occlusion are compared, the underlying etiology or mechanism such as atherosclerotic plaque or thromboembolism culminating in occlusion has a striking effect on ischemic severity (Kim et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Collateral Circulation in Symptomatic Intracranial Atherosclerosis

Liebeskind

Cotsonis

Saver

et al. 2010

J Cereb Blood Flow Metab

109

107

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Collateral circulation in intracranial atherosclerosis has never been systematically characterized. We investigated collaterals in a multicenter trial of symptomatic intracranial atherosclerotic disease. Baseline angiography was reviewed for information on collaterals in stenoses of the internal carotid, middle cerebral, vertebral, and basilar arteries. A battery of angiographic scales was utilized to evaluate lesion site, arterial patency, antegrade flow, downstream territorial perfusion, and collateral circulation, blinded to all other data. Collateral circulation was adequately available for analysis in 287/569 (50%) subjects with proximal arterial stenoses ranging from 50% to 99%. Extent of collaterals was absent or none in 69%, slow or minimal in 10%, more rapid, yet incomplete perfusion of territory in 7%, complete but delayed perfusion in 11%, and rapid, complete collateral perfusion in 4%. Extent of collateral flow correlated with percentage of stenosis (P < 0.0001), with more severe stenoses exhibiting greater compensation via collaterals. Overall, collateral grade increased with diminished antegrade flow across the lesion (thrombolysis in myocardial ischemia) and resultant downstream perfusion (thrombolysis in cerebral infarction) (both P < 0.001). Our findings provide the initial detailed description of collaterals across a variety of stenoses, suggesting that collateral perfusion is a pivotal component in pathophysiology of intracranial atherosclerosis and implicating the need for further evaluation in ongoing studies.

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“…Global and focal models have suggested that volume-flow mismatch (ie, high or preserved CBV with low CBF) may be a feature of early ischemia 16 -19 and represent tissue at risk of infarction. 16,20,21 Such regions have been observed in humans and tend to progress to infarction without intervention. 20,22 Steady-state susceptibility contrast MRI measurements of relative regional CBV provide a unique combination of high sensitivity, accuracy for measurement of CBV changes, and high temporal resolution for in vivo studies.…”

mentioning

confidence: 99%

Cerebrovascular Dynamics of Autoregulation and Hypoperfusion

Zaharchuk

Mandeville

Bogdanov

et al. 1999

Stroke

118

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Background and Purpose-To determine how cerebral blood flow (CBF), total and microvascular cerebral blood volume (CBV), and blood oxygenation level-dependent (BOLD) contrast change during autoregulation and hypotension using hemodynamic MRI. Methods-Using arterial spin labeling and steady-state susceptibility contrast, we measured CBF and changes in both total and microvascular CBV during hemorrhagic hypotension in the rat (nϭ9). Results-We observed CBF autoregulation for mean arterial blood pressure (MABP) between 50 and 140 mm Hg, at which average CBF was 1.27Ϯ0.44 mL ⅐ g Ϫ1 ⅐ min Ϫ1 (meanϮSD). During autoregulation, total and microvascular CBV changes were small and not significantly different from CBF changes. Consistent with this, no significant BOLD changes were observed. For MABP between 10 and 40 mm Hg, total CBV in the striatum increased slightly (ϩ7Ϯ12%, PϽ0.05) whereas microvascular CBV decreased (Ϫ15Ϯ17%, PϽ0.01); on the cortical surface, total CBV increases were larger (ϩ21Ϯ18%, PϽ0.01) and microvascular CBV was unchanged (3Ϯ22%, PϾ0.05). With severe hypotension, both total and microvascular CBV decreased significantly. Over the entire range of graded global hypoperfusion, there were increases in the CBV/CBF ratio. Conclusions-Parenchymal CBV changes are smaller than those of previous reports but are consistent with the small arteriolar fraction of total blood volume. Such measurements allow a framework for understanding effective compensatory vasodilation during autoregulation and volume-flow relationships during hypoperfusion. (Stroke. 1999;30:2197-2205.)

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"Low perfusion hyperemia" following middle cerebral arterial occlusion in cats of different age groups.

Cited by 55 publications

References 16 publications

Cerebral Blood Volume in Acute Brain Infarction

Cerebral Blood Volume in Acute Brain Infarction

Collateral Circulation in Symptomatic Intracranial Atherosclerosis

Cerebrovascular Dynamics of Autoregulation and Hypoperfusion

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