scholarly journals Association of cerebral blood flow with myelin content in cognitively unimpaired adults

2020 ◽  
Vol 2 (1) ◽  
pp. e000053 ◽  
Author(s):  
Mustapha Bouhrara ◽  
Joseph S R Alisch ◽  
Nikkita Khattar ◽  
Richard W Kim ◽  
Abinand C Rejimon ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Blood Supply ◽  
Normal Subjects ◽  
Brain Regions ◽  
Relaxation Rates ◽  
Water Fraction ◽  
Brain White Matter ◽  
Cognitively Normal Subjects ◽  
Age Range

BackgroundMyelin loss and cerebral blood flow (CBF) decline are central features of several neurodegenerative diseases. Myelin maintenance through oligodendrocyte metabolism is an energy-demanding process, so that myelin homeostasis is particularly sensitive to hypoxia, hypoperfusion or ischaemia. However, in spite of its central importance, little is known about the association between blood supply and myelin integrity.ObjectiveTo assess associations between cortical and subcortical CBF, and subcortical myelin content, in critical brain white matter regions.Materials and methodsMRI was performed on a cohort of 67 cognitively unimpaired adults. Using advanced MRI methodology, we measured whole-brain longitudinal and transverse relaxation rates (R1 and R2), sensitive but non-specific markers of myelin content, and myelin water fraction (MWF), a direct surrogate of myelin content, as well as regional CBF, from each of these participants.ResultsAll quantitative relaxometry metrics were positively associated with CBF in all brain regions evaluated. These associations between MWF or R1 and CBF, and, to a lesser extent, between R2 and CBF, were statistically significant in most brain regions examined, indicating that lower regional cortical or subcortical CBF corresponds to a decrease in local subcortical myelin content. Finally, all relaxometry metrics exhibited a quadratic, inverted U-shaped, association with age; this is attributed to the development of myelination from young to middle age, followed by progressive loss of myelin in later years.ConclusionsIn this first study examining the association between local blood supply and myelin integrity, we found that myelin content declines with CBF across a wide age range of cognitively normal subjects.

scholarly journals Cerebral Blood Flow in Posterior Cortical Nodes of the Default Mode Network Decreases with Task Engagement but Remains Higher than in Most Brain Regions

2010 ◽  
Vol 21 (1) ◽  
pp. 233-244 ◽  
Author(s):  
A. Pfefferbaum ◽  
S. Chanraud ◽  
A.-L. Pitel ◽  
E. Muller-Oehring ◽  
A. Shankaranarayanan ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Default Mode Network ◽  
Brain Regions ◽  
Task Engagement ◽  
Default Mode

scholarly journals Comparison of the Effects of Intravenous Papaverine Hydrochloride and Oral Pavabid HP Capsulets on Regional Cerebral Blood Flow in Normal Individuals

1983 ◽  
Vol 3 (4) ◽  
pp. 442-447 ◽  
Author(s):  
Lawrence C. McHenry ◽  
David A. Stump ◽  
George Howard ◽  
Thomas T. Novack ◽  
Don H. Bivins ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Normal Subjects ◽  
Normal Male ◽  
Regional Cerebral Blood ◽  
Normal Individuals ◽  
Left And Right ◽  
Male Subjects ◽  
Papaverine Hydrochloride

A single-blind study was conducted in 13 right-handed normal male subjects to compare the effects of oral and i.v. papaverine on regional cerebral blood flow (rCBF). Six xenon-133 inhalation rCBF measurements were performed on each subject; three tests—baseline, placebo, and drug evaluations—were carried out on each of two separate days. The oral and i.v. drugs were randomized for first-day administration. rCBF, measured as flow gray (FG), increased significantly (p ≤ 0.001) from baseline with both drug forms. Increases of 10.53% and 13.94% (left and right hemispheres, respectively) were demonstrated 90 min after a single 600-mg dose of oral papaverine. Increases of 5.09% and 8.69%, respectively, were recorded immediately after a single 100-mg dose of i. v. papaverine. FG also increased significantly (p ≤ 0.001) for both drug forms when compared to that of placebo. Placebo produced only a slight increase (not significant) with both the oral and i.v. groups. The data show that both oral and i.v. papaverine are equally effective in increasing rCBF in normal subjects.

Abstract 196: Sanguinate (PEGylated-carboxyhemoglobin-bovine) Improves Cerebral Blood Flow and Oxygen Extraction to Vulnerable Brain Regions in Patients at Risk for Delayed Cerebral Ischemia After Subarachnoid Hemorrhage

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Rajat Dhar ◽  
Hemant Misra ◽  
Michael Diringer
Keyword(s):  
At Risk ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Subarachnoid Hemorrhage ◽  
Cerebral Ischemia ◽  
Delayed Cerebral Ischemia ◽  
Brain Regions ◽  
Oxygen Extraction ◽  
Patients At Risk ◽  
Higher Doses

Introduction: Sanguinate is a dual-action oxygen transfer and carbon monoxide-releasing agent with efficacy in animal models of focal brain ischemia and established safety in health volunteers. We performed a dose-escalation study in subarachnoid hemorrhage (SAH) patients at risk for delayed cerebral ischemia (DCI) to evaluate tolerability and explore efficacy in improving cerebral blood flow (CBF) and flow-metabolism balance to vulnerable brain regions. Methods: 12 subjects were studied over three dose tiers: 160mg/kg, 240 mg/kg, and 320 mg/kg, with close safety evaluation prior to proceeding to higher doses. After baseline 15 O-PET measurement of global and regional CBF and oxygen extraction fraction (OEF), Sanguinate was infused over two hours; PET was repeated immediately after and again at 24-hours. Vulnerable brain regions were defined as those with baseline OEF ≥ 0.5. Results: Sanguinate infusion resulted in a significant but transient rise in mean arterial pressure (115±15 to 127±13 mm Hg) that was not dose-dependent. No adverse physiologic or clinical effects were observed with infusion at any dose. Global CBF did not rise significantly after Sanguinate (42.6±7 to 45.9±9 ml/100g/min, p=0.18). However, in the 28% of regions classified as vulnerable, Sanguinate resulted in a significant rise in CBF (42.2±11 to 51.2±18) and reduction in OEF (0.6±0.1 to 0.5±0.11, both p<0.001). The increase in regional CBF was only seen with the two higher doses but OEF improved in all tiers. However, response was attenuated at 24-hours. Conclusions: We safely administered a novel oxygen transport and vasodilating agent to a cohort of patients with SAH. Sanguinate infusion appeared to improve CBF and flow-metabolism balance in vulnerable brain regions and warrants further study in those at-risk for DCI. Higher or repeat dosing may be required for sustained efficacy.

Effects of Defibrination on Hemorheology, Cerebral Blood Flow Velocity, and CO 2 Reactivity During Hypocapnia in Normal Subjects

Stroke ◽  
1996 ◽  
Vol 27 (8) ◽  
pp. 1328-1332 ◽  
Author(s):  
Yoshinari Izumi ◽  
Yoshiyasu Tsuda ◽  
Shin-Ichiro Ichihara ◽  
Tsutomu Takahashi ◽  
Hirohide Matsuo
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Cerebral Blood Flow Velocity ◽  
Normal Subjects

Tau PET Distributional Pattern in AD Patients with Visuospatial Dysfunction

2019 ◽  
Vol 16 (11) ◽  
pp. 1055-1062
Author(s):  
Xi Sun ◽  
Binbin Nie ◽  
Shujun Zhao ◽  
Qian Chen ◽  
Panlong Li ◽  
...  
Keyword(s):  
Temporal Cortex ◽  
Cingulate Cortex ◽  
Normal Subjects ◽  
Neural Correlates ◽  
Brain Regions ◽  
Posterior Cingulate Cortex ◽  
Distributional Pattern ◽  
Cognitively Normal ◽  
Posterior Cingulate ◽  
Cognitively Normal Subjects

Background: Visuospatial dysfunction is one predominant symptom in many atypical Alzheimer’s disease (AD) patients, however, until now its neural correlates still remain unclear. For the accumulation of intracellular hyperphosphorylated tau proteins is a major pathogenic factor in neurodegeneration of AD, the distributional pattern of tau could highlight the affected brain regions associated with specific cognitive deficits. Objective: We investigated the brain regions particularly affected by tau accumulation in patients with visuospatial dysfunction to explore its neural correlates. Methods: Using 18F-AV-1451 tau positron emission tomography (PET), voxel-wise two-sample t-tests were performed between AD patients with obvious visuospatial dysfunction (VS-AD) and cognitively normal subjects, AD patients with little-to-no visuospatial dysfunction (non VS-AD) and cognitively normal subjects, respectively. Results: Results showed increased tau accumulations mainly located in occipitoparietal cortex, posterior cingulate cortex, precuneus, inferior and medial temporal cortex in VS-AD patients, while increased tau accumulations mainly occurred in the inferior and medial temporal cortex in non VS-AD patients. Conclusion: These findings suggested that occipitoparietal cortex, posterior cingulate cortex and precuneus, which were particularly affected by increased tau accumulation in VS-AD patients, may associate with visuospatial dysfunction of AD.

Effects of temperature and anoxia on regional cerebral blood flow in turtles

1992 ◽  
Vol 262 (3) ◽  
pp. R538-R541
Author(s):  
P. E. Bickler
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Brain Regions ◽  
Platinum Electrodes ◽  
Regional Cerebral Blood ◽  
Blood Flows ◽  
Effects Of Temperature ◽  
Kinetics Of ◽  
Hydrogen Clearance

Regional cerebral blood flow (CBF) was measured in isoflurane-anesthetized turtles (Pseudemys scripta) by the hydrogen clearance method. Teflon-coated platinum electrodes (25 microns) were implanted in the olfactory bulbs, midcerebral cortex and cerebellum in eight adult turtles. The electrodes were voltage clamped at +0.30 V relative to a Ag-AgCl electrode implanted in the dorsal neck muscles. Washout kinetics of H2 gas administered via controlled ventilation was used to calculate local blood flow for electrodes exhibiting monoexponential washout kinetics of hydrogen (92 of 104 determinations). Data were obtained in animals with body temperatures of 15, 25, and 35 degrees C under normocapnic conditions during ventilation with 21% O2 and during ventilation with 100% N2. During normoxia, mean blood flows were 1.9 +/- 0.8, 5.0 +/- 1.9, and 6.1 +/- 1.3 (+/- SD) ml.100 g-1.min-1 at 15, 25, and 35 degrees C, respectively. There were no differences between CBF values in the different brain regions. During 1-3 h of anoxia, CBF was 3.0 +/- 2.1, 7.0 +/- 3.7, and 6.6 +/- 2.9 ml.100 g-1.min-1 at 15, 25, and 35 degrees C, respectively (normoxia-anoxia difference not statistically different). Hypercarbia (ventilation with 10-20% CO2 in air or N2), or the transition from anoxia to normoxia, increased CBF up to 80% at each of these temperatures. Maintenance of CBF during anoxia likely contributes to the anoxia tolerance of the turtle brain.

Cerebral blood flow and energy metabolism during stress

1990 ◽  
Vol 259 (2) ◽  
pp. H269-H280 ◽  
Author(s):  
R. M. Bryan
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Energy Metabolism ◽  
Adrenergic Receptor ◽  
Conditioned Fear ◽  
Brain Regions ◽  
Stressful Events ◽  
Ethanol Withdrawal ◽  
Adrenergic Mechanism ◽  
The Brain

Many, but not all, stressful events are accompanied by increases in cerebral blood flow and/or energy metabolism. The stressful events include pharmacological paralysis, footshock, conditioned fear, hypotension, hypoglycemia, hypoxia, noise, and ethanol withdrawal. These increases are significant because 1) all brain regions are often affected, i.e., certain stressful events have global effects on cerebral blood flow and energy metabolism; and 2) various stressful events appear to have a common adrenergic mechanism for increasing cerebral blood flow and energy metabolism. The adrenergic mechanism involves beta-adrenergic receptor stimulation by either epinephrine secreted from the adrenal medulla or possibly norepinephrine endogenous to the brain. While adrenergic mechanisms are not the only mechanism controlling flow and metabolism for a given stressful condition, they do appear to be common to many situations. At least part of the increase in cerebral blood flow and energy metabolism during many conditions appears to be the result of the stress response and not directly a result of the condition itself.

Vasopressin and prostanoid mechanisms in control of cerebral blood flow in hypotensive newborn pigs

1990 ◽  
Vol 258 (2) ◽  
pp. H408-H413 ◽  
Author(s):  
W. M. Armstead ◽  
C. W. Leffler ◽  
D. W. Busija ◽  
R. Mirro
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Metabolic Rate ◽  
Vascular Resistance ◽  
Brain Regions ◽  
Cerebral Metabolic Rate ◽  
Cerebral Vasoconstriction ◽  
Newborn Pigs ◽  
Cerebral Vascular Resistance ◽  
Cerebral Vascular

The interaction between vasopressinergic and prostanoid mechanisms in the control of cerebral hemodynamics in the conscious hypotensive newborn pig was investigated. Indomethacin treatment (5 mg/kg) of hypotensive piglets caused a significant decrease in blood flow to all brain regions within 20 min. This decrease in cerebral blood flow resulted from increased cerebral vascular resistances of 52 and 198% 20 and 40 min after treatment, respectively. Cerebral oxygen consumption was reduced from 2.58 +/- 0.32 ml.100 g-1.min-1 to 1.01 +/- 0.12 and 0.29 +/- 0.08 ml.100 g-1.min-1 20 and 40 min after indomethacin, respectively, in hemorrhaged piglets. Treatment with the putative vascular (V1) receptor antagonist [1-(beta-mercapto-beta, beta-cyclopentamethylene propionic acid-2-(O-methyl)tyrosine]arginine vasopressin (MEAVP) had no effect on regional cerebral blood flow, calculated cerebral vascular resistance, or cerebral metabolic rate either before or during hemorrhagic hypotension. However, decreases in cerebral blood flow and metabolic rate and increases in vascular resistance on treatment with indomethacin were blunted markedly in animals treated with MEAVP. These data are consistent with the hypothesis that the prostanoid system contributes to the maintenance of cerebral blood flow and cerebral metabolic rate during hypotension in the newborn pig, as reported previously, and implicate removal of vasopressinergic modulation by prostanoids as a potential mechanism for indomethacin-induced cerebral vasoconstriction in hypotensive newborn piglets.

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