scholarly journals Cerebral Hemodynamics and Executive Function in Sickle Cell Anemia

Stroke ◽  
2021 ◽  
Author(s):  
Kemar V. Prussien ◽  
Bruce E. Compas ◽  
Rachel E. Siciliano ◽  
Abagail E. Ciriegio ◽  
Chelsea A. Lee ◽  
...  
Keyword(s):  
Working Memory ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Executive Function ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Brain Magnetic Resonance Imaging ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Extraction Fraction

Background and Purpose: Individuals with sickle cell anemia experience cognitive deficits, even in the absence of cerebral infarcts or strokes. This study tested the hypothesis that elevated cerebral blood flow and oxygen extraction fraction are associated with lower executive function in individuals with sickle cell anemia. Methods: Three-Tesla brain magnetic resonance imaging was performed, including anatomic, gray matter cerebral blood flow, and global oxygen extraction fraction imaging. Executive function was measured using the working memory index from an age-appropriate Wechsler battery and tasks from the National Institutes of Health Toolbox Cognition Battery. Bivariate and multivariate models were examined (significance: P <0.05). Results: Fifty-four participants (age range=6–31 years) with sickle cell anemia were enrolled. Hematocrit was positively related to fluid cognition, cerebral blood flow was inversely related to working memory and inhibitory control, and oxygen extraction fraction was inversely related to processing speed. Associations remained significant in multivariate analyses controlling for age, income, and infarcts. Conclusions: Elevated cerebral blood flow and oxygen extraction fraction, markers of hemodynamic impairment, are associated with deficits in executive function in individuals with sickle cell anemia.

scholarly journals Hemodynamic mechanisms underlying elevated oxygen extraction fraction (OEF) in moyamoya and sickle cell anemia patients

2016 ◽  
Vol 38 (9) ◽  
pp. 1618-1630 ◽  
Author(s):  
Jennifer M Watchmaker ◽  
Meher R Juttukonda ◽  
Larry T Davis ◽  
Allison O Scott ◽  
Carlos C Faraco ◽  
...  
Keyword(s):  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Structural Mri ◽  
Interquartile Range ◽  
Cerebrovascular Reactivity ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Vascular Reserve ◽  
Extraction Fraction ◽  
Oxygen Carrying Capacity

Moyamoya is a bilateral, complex cerebrovascular condition characterized by progressive non-atherosclerotic intracranial stenosis and collateral vessel formation. Moyamoya treatment focuses on restoring cerebral blood flow (CBF) through surgical revascularization, however stratifying patients for revascularization requires abilities to quantify how well parenchyma is compensating for arterial steno-occlusion. Globally elevated oxygen extraction fraction (OEF) secondary to CBF reduction may serve as a biomarker for tissue health in moyamoya patients, as suggested in patients with sickle cell anemia (SCA) and reduced oxygen carrying capacity. Here, OEF was measured (TRUST-MRI) to test the hypothesis that OEF is globally elevated in patients with moyamoya (n = 18) and SCA (n = 18) relative to age-matched controls (n = 43). Mechanisms underlying the hypothesized OEF increases were evaluated by performing sequential CBF-weighted, cerebrovascular reactivity (CVR)-weighted, and structural MRI. Patients were stratified by treatment and non-parametric tests applied to compare study variables (significance: two-sided P < 0.05). OEF was significantly elevated in moyamoya participants (interquartile range = 0.38–0.45) compared to controls (interquartile range = 0.29–0.38), similar to participants with SCA (interquartile range = 0.37–0.45). CBF was inversely correlated with OEF in moyamoya participants. Elevated OEF was only weakly related to reductions in CVR, consistent with basal CBF level, rather than vascular reserve capacity, being most closely associated with OEF.

Abstract TMP93: Elevated Oxygen Extraction Fraction Measured With Noninvasive MRI may be Discriminatory for Stroke Risk in Adults With Sickle Cell Anemia

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Lori C Jordan ◽  
Melissa Gindville ◽  
Allison Scott ◽  
Megan K Strother ◽  
Adetola Kassim ◽  
...  
Keyword(s):  
Linear Regression ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Stroke Risk ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Extraction Fraction ◽  
Clinical Impairment ◽  
Mean Differences ◽  
Oxygen Carrying Capacity

Introduction: No screening procedures exist for evaluating stroke risk in adults with sickle cell anemia (SCA). Reduced oxygen carrying capacity is present in SCA, which may initially be compensated for by an increase in cerebral blood flow (CBF) and then by increased oxygen extraction fraction (OEF). Hypothesis: OEF and CBF can be measured noninvasively and reproducibly with MRI using clinically-available equipment in adults with SCA; elevated OEF provides added discriminatory capacity for clinical impairment relative to vasculopathy extent and CBF alone. Methods: Structural, CBF-weighted, and MRA imaging, together with a noninvasive OEF-weighted T 2 -relaxation-under-spin-tagging (TRUST)-MRI method was applied in SCA adults (n=26) and race and age-matched controls (n=11). A Kruskal-Wallis test was applied to evaluate mean differences between SCA and control parameters. Linear regression assessed how elevated OEF correlated with increasing clinical impairment defined by presence of infarct, vasculopathy, or use of regular blood transfusions for SCA. Results: OEF had high reproducibility within the same scan session, n=37 (ICC = 0.989). Whole-brain OEF and CBF were increased in SCA adults (OEF=0.46±0.08; CBF=52.4±8.3 ml/100g/min) versus controls (OEF=0.35±0.06; CBF=43.6±5.1 ml/100g/min). Hematocrit and OEF were inversely correlated (R 2 =0.72; p<0.01). Linear regression revealed a stronger relationship of OEF than CBF with clinical impairment. In SCA adults without impairment (n=12) CBF and OEF have an inverse relationship (R 2 =0.41; p=0.01, Fig. 1A) but with clinical impairment (infarct, vasculopathy or severe pain requiring regular transfusions, n=14) CBF and OEF become uncoupled (R 2 =0.08; p=0.16; Fig. 1B) as CBF may not be able to increase further and may plateau or decline. Conclusion: TRUST-MRI OEF is a rapid, reproducible measure. OEF shows promise as screening tool for hemodynamic impairment and stroke risk in adults with SCA.

scholarly journals Red cell exchange transfusions lower cerebral blood flow and oxygen extraction fraction in pediatric sickle cell anemia

Blood ◽  
2018 ◽  
Vol 131 (9) ◽  
pp. 1012-1021 ◽  
Author(s):  
Kristin P. Guilliams ◽  
Melanie E. Fields ◽  
Dustin K. Ragan ◽  
Cihat Eldeniz ◽  
Michael M. Binkley ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
White Matter ◽  
Sickle Cell Anemia ◽  
Metabolic Stress ◽  
Oxygen Extraction Fraction ◽  
Red Cell ◽  
Deep White Matter ◽  
Extraction Fraction ◽  
Key Points

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.

Reversal of Focal Misery Perfusion after Intracranial Angioplasty: Case Report

Neurosurgery ◽  
2001 ◽  
Vol 48 (2) ◽  
pp. 436-440 ◽  
Author(s):  
Colin P. Derdeyn ◽  
DeWitte T. Cross ◽  
Christopher J. Moran ◽  
Ralph G. Dacey
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Intracranial Stenosis ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Positron Emission ◽  
Misery Perfusion ◽  
Before And After ◽  
Hemodynamic Measurements

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.

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