Abstract T P178: Cerebral Blood Flow and Metabolism Associated with Cerebral Microbleeds in Patients with Non-cardioembolic Stroke Without Major Cerebral Arterial Stenosis

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Tetsuya Hashimoto ◽  
Chiaki Yokota ◽  
Ryo Shimomura ◽  
Kazuhiro Koshino ◽  
Toshiyuki Uehara ◽  
...  

Background and Purpose: Cerebral microbleeds (CMBs) are associated with not only higher age but also extensive white matter lesions (WMLs), indicating that CMBs could be a reflection of microangiopathy. CMBs have not yet been examined in association with cerebral blood flow (CBF) and metabolism. The purpose of this study was to clarify the relationships of CMBs with WMLs volume, and CBF and metabolism in patients with ischemic stroke. Methods: We enrolled 19 patients who had past history of non-cardioembolic stroke without severe stenosis (>50%) in major cerebral arteries (69±7 years, 9 women). We measured WMLs volume and counted the number of CMBs on a 1.5-T magnetic resonance imaging (MRI) scanner. CBF, cerebral blood volume, oxygen extraction fraction and cerebral metabolic rate of oxygen were measured with 15 O-labeled gas positron emission tomography (PET). We set 36 regions of interest (ROIs) in the cortex-subcortex regions, basal ganglia and centra semiovale in each patient on MRI. MRI was superimposed on PET images and 4 parameters of each ROI were calculated. Results: CMBs existed in 14 out of 19 patients (median 5; range 0-39). Patients were divided into 2 groups according to the number of CMBs; less than 5 as the group I (n=9) and 5 or more as the group II (n=10). WMLs volume of the group II was larger than that of the group I (median 38.4 with range of 25.1-91.5 vs. 10.0 with 4.2-73.4 ml, p=0.020). In the centra semiovale, CBF of the group II was significantly lower than that of the group I (12.5±2.5 vs. 15.7±3.5 ml/100g/min, p=0.031). In the other regions, there were no significant differences in all 4 parameters of PET between the 2 groups. Conclusions: We showed that the increases in the number of CMBs could indicate cerebral ischemia in the deep white matter of patients with non-cardioembolic stroke without major cerebral arterial stenosis.

1985 ◽  
Vol 5 (4) ◽  
pp. 600-608 ◽  
Author(s):  
William J. Powers ◽  
Robert L. Grubb ◽  
Danielle Darriet ◽  
Marcus E. Raichle

This study was undertaken to determine the minimum CBF and CMRO2 required by the human brain to maintain normal function and viability for more than a few hours. Positron emission tomography (PET) was used to perform regional measurements in 50 subjects with varying degrees of cerebral ischemia but no evidence of infarction. There were 24 normal subjects, 24 subjects with arteriographic evidence of vascular disease of the carotid system, and two subjects with reversible ischemic neurological deficits due to cerebral vasospasm. Minimum values found in the 48 subjects with normal neurological function were 19 ml/100 g-min for regional cerebral blood flow (rCBF) and 1.3 ml/100 g-min for regional cerebral metabolic rate of oxygen (rCMRO2). Minimum values for all 50 subjects with viable cerebral tissue were 15 ml/100 g-min for rCBF and 1.3 ml/100 g-min for rCMRO2. Comparison of these measurements with values from 20 areas of established cerebral infarction in 10 subjects demonstrated that 80% (16/20) of infarcted regions had rCMRO2 values below the lower normal limit of 1.3 ml/100g-min. Measurements of rCBF, regional cerebral blood volume, and oxygen extraction fraction were less useful for distinguishing viable from infarcted tissue. These data indicate that quantitative regional measurements of rCMRO2 with PET accurately distinguish viable from nonviable cerebral tissue and may be useful in the prospective identification of patients with reversible ischemia.


PEDIATRICS ◽  
1980 ◽  
Vol 66 (6) ◽  
pp. 840-847
Author(s):  
Mamdouha Ahdab-Barmada ◽  
John Moossy ◽  
Michael Painter

Pontosubicular necrosis (PSN) is confined to a short perinatal developmental period and is apparently related to asphyxia at birth. Neuronal necrosis with karyorrhexis and proliferative changes in astrocytes are most prominent in the pontine gray matter and subiculum of the hippocampus. We have observed a striking association of PSN in neonates with high arterial blood oxygen (Po2) levels during the first week of life. All autopsies performed on neonates in 1977 at Magee-Womens Hospital (University Health Center of Pittsburgh) were reviewed, and all 64 neonates who survived long enough to have multiple Po2 determinations were studied. All had severe hypoxia, respiratory distress, and/or apnea. Twenty-seven (group I) did not have Po2 levels higher than 150 torr whereas 37 (group II) had Po2 levels higher than 150 torr for a sustained period. PSN was not seen in group I; it was prominent in group II. PSN was most severe between the gestational ages of 26 to 36 weeks. Hyperoxemia may decrease cerebral blood flow selectively at this critical phase of development or there may be a greater sensitivity to the toxic action of high blood oxygen levels in the presence of acidosis and hypoxia. A combination of these factors seems most probable.


2003 ◽  
Vol 23 (8) ◽  
pp. 911-924 ◽  
Author(s):  
Joseph P Culver ◽  
Turgut Durduran ◽  
Daisuke Furuya ◽  
Cecil Cheung ◽  
Joel H Greenberg ◽  
...  

Diffuse optical tomography (DOT) is an attractive approach for evaluating stroke physiology. It provides hemodynamic and metabolic imaging with unique potential for continuous noninvasive bedside imaging in humans. To date there have been few quantitative spatial-temporal studies of stroke pathophysiology based on diffuse optical signatures. The authors report DOT images of hemodynamic and metabolic contrasts using a rat middle cerebral artery occlusion (MCAO) stroke model. This study used a novel DOT device that concurrently obtains coregistered images of relative cerebral blood volume (rCBV), tissue-averaged hemoglobin oxygen saturation (Sto2), and relative cerebral blood flow (rCBF). The authors demonstrate how these hemodynamic measures can be synthesized to calculate an index of the oxygen extraction fraction (OEF) and the cerebral metabolic rate of oxygen consumption (CMRo2). Temporary (60-minute) MCAO was performed on five rats. Ischemic changes, averaged over the 60 minutes of occlusion, were as follows: rCBF = 0.42 ± 0.04, rCBV = 1.02 ± 0.04, ΔSto2 = −11 ± 2%, rOEF = 1.39 ± 0.06 and rCMRo2 = 0.59 ± 0.07. Although rOEF increased in response to decreased blood flow, rCMRo2 decreased. The sensitivity of this method of DOT analysis is discussed in terms of assumptions about baseline physiology, and the diffuse optical results are compared with positron emission tomography, magnetic resonance imaging, and histology observations in the literature.


2012 ◽  
Vol 32 (11) ◽  
pp. 2066-2075 ◽  
Author(s):  
Yasuyuki Kaku ◽  
Koji Iihara ◽  
Norio Nakajima ◽  
Hiroharu Kataoka ◽  
Kenji Fukuda ◽  
...  

In moyamoya disease (MMD), surgical revascularization may be complicated with postoperative hyperperfusion. We analyzed cerebral perfusion and metabolism using positron emission tomography (PET) or single-photon emission computed tomography (SPECT) before and after bypass surgery on 42 sides of 34 adult patients with MMD. In seven cases (16.7%) with symptomatic hyperperfusion, diagnosed by qualitative 123I-iodoamphetamine (IMP) SPECT, a subsequent PET study during postoperative subacute stages revealed significantly increased cerebral blood flow (CBF) from 34.1 ± 8.2 to 74.3 ± 12.8 mL/100 g per minute ( P < 0.01), a persistent increase in cerebral blood volume (CBV)from 5.77 ± 1.67 to 7.01 ± 1.44 mL/100 g and a significant decrease in oxygen extraction fraction (OEF) from 0.61 ± 0.09 to 0.40 ± 0.08 ( P < 0.01). Mean absolute CBF values during symptomatic hyperperfusion were more than the normal control +2 standard deviations, the predefined criteria of PET. Interestingly, two patients with markedly increased cerebral metabolic rate of oxygen (CMRO2) at hyperperfusion were complicated with postoperative seizure. Among preoperative PET parameters, increased OEF was the only significant risk factor for symptomatic hyperperfusion ( P < 0.05). This study revealed that symptomatic hyperperfusion in MMD is characterized by temporary increases in CBF >100% over preoperative values caused by prolonged recovery of increased CBV.


Blood ◽  
2018 ◽  
Vol 131 (9) ◽  
pp. 1012-1021 ◽  
Author(s):  
Kristin P. Guilliams ◽  
Melanie E. Fields ◽  
Dustin K. Ragan ◽  
Cihat Eldeniz ◽  
Michael M. Binkley ◽  
...  

Key Points Exchange transfusions lower global CBF and OEF in SCA, suggesting transfusions reduce infarct risk by relieving cerebral metabolic stress. In SCA, OEF is highest in the deep white matter, where infarct risk is high; transfusions reduce the volume of tissue with elevated OEF.


Neurosurgery ◽  
2001 ◽  
Vol 48 (2) ◽  
pp. 436-440 ◽  
Author(s):  
Colin P. Derdeyn ◽  
DeWitte T. Cross ◽  
Christopher J. Moran ◽  
Ralph G. Dacey

Abstract OBJECTIVE AND IMPORTANCE The presence of reduced blood flow and increased oxygen extraction fraction (OEF) (misery perfusion) in the hemisphere distal to an occluded carotid artery is a proven risk factor for subsequent stroke. Whether angioplasty of intracranial stenosis is sufficient to reverse this condition has not been documented. CLINICAL PRESENTATION A 67-year-old man exhibited progressive right hemispheric ischemic symptoms despite maximal antiplatelet and antithrombotic therapy. Angiography demonstrated focal 80% stenosis of the supraclinoid segment of the ipsilateral internal carotid artery. TECHNIQUE 15O positron emission tomographic measurements of cerebral blood flow and OEF were made before and after transfemoral percutaneous angioplasty. OEF values measured before angioplasty were elevated in the middle cerebral artery distal to the stenosis. Angioplasty reduced the degree of luminal stenosis to 40% (linear diameter). OEF values measured 36 hours after angioplasty were normal. CONCLUSION Angioplasty of intracranial stenosis can restore normal cerebral blood flow and oxygen extraction, despite mild residual stenosis after the procedure. Hemodynamic measurements may be useful for the identification of patients with the greatest potential to benefit from angioplasty.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Jing Lin ◽  
Dilong Wang ◽  
Linfang Lan ◽  
Yuhua Fan

White matter lesions (WMLs), also known as leukoaraiosis (LA) or white matter hyperintensities (WMHs), are characterized mainly by hyperintensities on T2-weighted or fluid-attenuated inversion recovery (FLAIR) images. With the aging of the population and the development of imaging technology, the morbidity and diagnostic rates of WMLs are increasing annually. WMLs are not a benign process. They clinically manifest as cognitive decline and the subsequent development of dementia. Although WMLs are important, their pathogenesis is still unclear. This review elaborates on the advances in the understanding of the pathogenesis of WMLs, focusing on anatomy, cerebral blood flow autoregulation, venous collagenosis, blood brain barrier disruption, and genetic factors. In particular, the attribution of WMLs to chronic ischemia secondary to venous collagenosis and cerebral blood flow autoregulation disruption seems reasonable. With the development of gene technology, the effect of genetic factors on the pathogenesis of WMLs is gaining gradual attention.


Radiology ◽  
1999 ◽  
Vol 210 (2) ◽  
pp. 519-527 ◽  
Author(s):  
A. Gregory Sorensen ◽  
William A. Copen ◽  
Leif Østergaard ◽  
Ferdinando S. Buonanno ◽  
R. Gilberto Gonzalez ◽  
...  

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