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Cerebrovascular reactivity, CVR,

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https://www.readbyqxmd.com/read/29282326/neurocognitive-functioning-and-cerebrovascular-reactivity-after-carotid-endarterectomy
#1
Simona Lattanzi, Luciano Carbonari, Gabriele Pagliariccio, Marco Bartolini, Claudia Cagnetti, Giovanna Viticchi, Laura Buratti, Leandro Provinciali, Mauro Silvestrini
OBJECTIVE: To evaluate in patients with TIA and ipsilateral high-grade internal carotid artery (ICA) stenosis whether changes in cognitive performance and cerebral hemodynamics occurred after carotid endarterectomy (CEA) and to explore their relationship. METHODS: Participants were patients who underwent CEA, had TIA within the last 6 months, and had an ipsilateral severe ICA stenosis. Coloured Progressive Matrices (CPM) plus Complex Figure Copy Test (CFCT) and phonemic (ph) plus categorical (ca) Verbal Fluency (VF) tests were performed to assess right and left hemisphere cognitive functions, respectively...
December 27, 2017: Neurology
https://www.readbyqxmd.com/read/29217405/a-novel-perspective-to-calibrate-temporal-delays-in-cerebrovascular-reactivity-using-hypercapnic-and-hyperoxic-respiratory-challenges
#2
Allen A Champagne, Alex A Bhogal, Nicole S Coverdale, Clarisse I Mark, Douglas J Cook
Redistribution of blood flow across different brain regions, arising from the vasoactive nature of hypercapnia, can introduce errors when examining cerebrovascular reactivity (CVR) response delays. In this study, we propose a novel analysis method to characterize hemodynamic delays in the blood oxygen level dependent (BOLD) response to hypercapnia, and hyperoxia, as a way to provide insight into transient differences in vascular reactivity between cortical regions, and across tissue depths. A pseudo-continuous arterial spin labeling sequence was used to acquire BOLD and cerebral blood flow simultaneously in 19 healthy adults (12 F; 20 ± 2 years) during boxcar CO2 and O2 gas inhalation paradigms...
December 4, 2017: NeuroImage
https://www.readbyqxmd.com/read/29214780/mismatch-between-tof-mr-angiography-and-ct-angiography-of-the-middle-cerebral-artery-may-be-a-critical-sign-in-cerebrovascular-dynamics
#3
Keiji Igase, Michiya Igase, Ichiro Matsubara, Kazuhiko Sadamoto
PURPOSE: Although time-of-flight (TOF)-magnetic resonance angiography (MRA) can clearly depict intracranial arteries, the arterial flow of middle cerebral artery (MCA) is occasionally not detected. We evaluated this phenomenon with reference to cerebrovascular dynamics. MATERIALS AND METHODS: Seventeen patients with suspected occlusion of MCA or internal carotid artery on TOF-MRA were enrolled. All patients underwent CT angiography (CTA) and quantitative cerebral blood flow (CBF) examination for measurement of resting CBF and cerebrovascular reactivity (CVR)...
January 2018: Yonsei Medical Journal
https://www.readbyqxmd.com/read/29158356/cerebrovascular-reactivity-and-vascular-activation-in-postmenopausal-women-with-histories-of-preeclampsia
#4
Jill N Barnes, Ronée E Harvey, Kathleen B Miller, Muthuvel Jayachandran, Katherine R Malterer, Brian D Lahr, Kent R Bailey, Michael J Joyner, Virginia M Miller
Cerebrovascular reactivity (CVR) is reduced in patients with cognitive decline. Women with a history of preeclampsia are at increased risk for cognitive decline. This study examined an association between pregnancy history and CVR using a subgroup of 40 age- and parity-matched pairs of women having histories of preeclampsia (n=27) or normotensive pregnancy (n=29) and the association of activated blood elements with CVR. Middle cerebral artery velocity was measured by Doppler ultrasound before and during hypercapnia to assess CVR...
November 20, 2017: Hypertension
https://www.readbyqxmd.com/read/29156413/anterior-posterior-gradient-differences-in-lobar-and-cingulate-cortex-cerebral-blood-flow-in-late-life-depression
#5
Margarita Abi Zeid Daou, Brian D Boyd, Manus J Donahue, Kimberly Albert, Warren D Taylor
Vascular pathology is common in late-life depression, contributing to changes in cerebral function. We examined whether late-life depression was associated with differences in cerebral blood flow (CBF) and whether such differences were related to vascular risk and cerebrovascular pathology, specifically white matter hyperintensity (WMH) volumes. Twenty-three depressed elders and 20 age- and sex-matched elders with no psychiatric history completed cranial 3T MRI. MRI procedures included a pseudo-continuous Arterial Spin Labeling (pcASL) acquisition obtained while on room air and during a hypercapnia challenge allowing for calculation of cerebrovascular reactivity (CVR)...
November 11, 2017: Journal of Psychiatric Research
https://www.readbyqxmd.com/read/29148891/hyperventilation-and-breath-holding-test-with-indocyanine-green-kinetics-predicts-cerebral-hyperperfusion-after-carotid-artery-stenting
#6
Ichiro Nakagawa, Shohei Yokoyama, Daisuke Wajima, Fumihiko Nishimura, Shuichi Yamada, Hiroshi Yokota, Yasushi Motoyama, Young Su Park, Takeshi Wada, Kimihiko Kichikawa, Hiroyuki Nakase
Cerebral hyperperfusion syndrome (CHS) is a serious complication following carotid artery stenting (CAS), but definitive early prediction of CHS has not been established. Here, we evaluated whether indocyanine green kinetics and near-infrared spectroscopy (ICG-NIRS) with hyperventilation (HV) and the breath-holding (BH) test can predict hyperperfusion phenomenon after CAS. The blood flow index (BFI) ratio during HV and BH was prospectively monitored using ICG-NIRS in 66 patients scheduled to undergo CAS. Preoperative cerebrovascular reactivity (CVR) and the postoperative asymmetry index (AI) were also assessed with single-photon emission computed tomography before and after CAS and the correlation with the BFI HV/rest ratio, BFI BH/rest ratio was evaluated...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/29117962/lower-cardiac-index-levels-relate-to-lower-cerebral-blood-flow-in-older-adults
#7
Angela L Jefferson, Dandan Liu, Deepak K Gupta, Kimberly R Pechman, Jennifer M Watchmaker, Elizabeth A Gordon, Swati Rane, Susan P Bell, Lisa A Mendes, L Taylor Davis, Katherine A Gifford, Timothy J Hohman, Thomas J Wang, Manus J Donahue
OBJECTIVE: To assess cross-sectionally whether lower cardiac index relates to lower resting cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) among older adults. METHODS: Vanderbilt Memory & Aging Project participants free of stroke, dementia, and heart failure were studied (n = 314, age 73 ± 7 years, 59% male, 39% with mild cognitive impairment). Cardiac index (liters per minute per meter squared) was quantified from echocardiography. Resting CBF (milliliters per 100 grams per minute) and hypercapnia-induced CVR were quantified from pseudo-continuous arterial spin-labeling MRI...
December 5, 2017: Neurology
https://www.readbyqxmd.com/read/29084064/new-insights-into-cerebral-small-vessel-disease-and-vascular-cognitive-impairment-from-mri
#8
Eric E Smith, Andrew E Beaudin
PURPOSE OF REVIEW: We review recent MRI research that addresses two important challenges in cerebral small vessel disease (SVD) research: early diagnosis, and linking SVD with cognitive impairment. First, we review studies of MRI measurements of blood flow and blood-brain barrier integrity. Second, we review MRI studies identifying neuroimaging correlates of SVD-related cognitive dysfunction, focusing on brain connectivity and white matter microarchitecture. This research is placed in context through discussion of recent recommendations for management of incidentally discovered SVD, and neuroimaging biomarker use in clinical trials...
February 2018: Current Opinion in Neurology
https://www.readbyqxmd.com/read/29066902/effects-of-sevoflurane-versus-propofol-on-cerebrovascular-reactivity-to-carbon-dioxide-during-laparoscopic-surgery
#9
Chunyi Wang, Cheng Ni, Gang Li, Yan Li, Liyuan Tao, Nan Li, Jun Wang, Xiangyang Guo
PURPOSE: Cerebrovascular reactivity to carbon dioxide (CVR-CO2) reflects cerebrovascular reserve capacity, which is important in many brain disorders, including cerebrovascular and Alzheimer's diseases. Meanwhile, there is a relationship between CVR-CO2 and cognitive function. Therefore, the study is aimed at investigating the effects of sevoflurane versus propofol on CVR-CO2 during laparoscopic surgery, as well as the role of CVR-CO2 on cognitive function during perioperative period...
2017: Therapeutics and Clinical Risk Management
https://www.readbyqxmd.com/read/29065769/imaging-of-cerebrovascular-function-in-chronic-traumatic-brain-injury
#10
Franck Amyot, Kimbra Kenney, Carol Moore, Maraglit Harber, L Christine Turtzo, Christian N Shenouda, Erika Silverman, Yunhua Gong, Bao-Xi Qu, Leah Harburg, Hangzang Lu, Eric Wassermann, Ramon Diaz-Arrastia
Traumatic cerebrovascular injury (TCVI) is a common pathologic mechanism of traumatic brain injury (TBI) and presents an attractive target for intervention. The aims of this study were to assess cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) using magnetic resonance imaging (MRI), to assess their value as biomarkers of TCVI in chronic TBI, characterize the spatial distribution of TCVI, and assess the relationships between each biomarker and neuropsychological and clinical assessments. 42 subjects (27 chronic TBI, 15 age and gender-matched healthy volunteers) were studied cross-sectionally...
October 25, 2017: Journal of Neurotrauma
https://www.readbyqxmd.com/read/29036811/sildenafil-improves-vascular-and-metabolic-function-in-patients-with-alzheimer-s-disease
#11
Min Sheng, Hanzhang Lu, Peiying Liu, Yang Li, Harshan Ravi, Shin-Lei Peng, Ramon Diaz-Arrastia, Michael D Devous, Kyle B Womack
BACKGROUND: Alzheimer's disease (AD) is the leading cause of degenerative dementia in the aging population. Patients with AD have alterations in cerebral hemodynamic function including reduced cerebral blood flow (CBF) and cerebral metabolic rate. Therefore, improved cerebrovascular function may be an attractive goal for pharmaceutical intervention in AD. OBJECTIVE: We wished to observe the acute effects of sildenafil on cerebrovascular function and brain metabolism in patients with AD...
October 7, 2017: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/28986176/diffuse-gliomas-exhibit-whole-brain-impaired-cerebrovascular-reactivity
#12
Jorn Fierstra, Christiaan van Niftrik, Marco Piccirelli, Oliver Bozinov, Athina Pangalu, Niklaus Krayenbühl, Antonios Valavanis, Michael Weller, Luca Regli
PURPOSE: Cerebral diffuse gliomas exhibit perilesional impaired cerebrovascular reactivity (CVR), yet the degree of impairment as well as its full spatial extent in the brain remains unknown. With quantitative fMRI, we studied twelve subjects with untreated brain diffuse glioma and twelve healthy controls to assess CVR impairment and determine its distribution throughout the brain. METHODS: In a prospective case-control study, quantitative CVR measurements were derived from BOLD fMRI volumes during standardized iso-oxic changes in carbon dioxide...
October 3, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28967593/measurement-of-cerebrovascular-reactivity-as-blood-oxygen-level-dependent-magnetic-resonance-imaging-signal-response-to-a-hypercapnic-stimulus-in-mechanically-ventilated-patients
#13
Lashmi Venkatraghavan, Julien Poublanc, Jay S Han, Olivia Sobczyk, Casey Rozen, Kevin Sam, James Duffin, David J Mikulis, Joseph A Fisher
BACKGROUND: Impaired cerebrovascular reactivity (CVR) is an important prognostic marker of stroke. Most measures of CVR lack (1) a reproducible vasoactive stimulus and (2) a high time and spatial resolution measure of cerebral blood flow (CBF), particularly for mechanically ventilated patients. The aim of our study was to investigate the feasibility of measuring CVR using sequential gas delivery circuit and gas blender for precise targeting of end-tidal PCO2 (PetCO2), and blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) signal as a surrogate of CBF, in mechanically ventilated patients...
September 26, 2017: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
https://www.readbyqxmd.com/read/28948064/iterative-analysis-of-cerebrovascular-reactivity-dynamic-response-by-temporal-decomposition
#14
Christiaan Hendrik Bas van Niftrik, Marco Piccirelli, Oliver Bozinov, Athina Pangalu, Joseph A Fisher, Antonios Valavanis, Andreas R Luft, Michael Weller, Luca Regli, Jorn Fierstra
OBJECTIVE: To improve quantitative cerebrovascular reactivity (CVR) measurements and CO 2 arrival times, we present an iterative analysis capable of decomposing different temporal components of the dynamic carbon dioxide- Blood Oxygen-Level Dependent (CO 2-BOLD) relationship. EXPERIMENTAL DESIGN: Decomposition of the dynamic parameters included a redefinition of the voxel-wise CO 2 arrival time, and a separation from the vascular response to a stepwise increase in CO 2 (Delay to signal Plateau - DTP) and a decrease in CO 2 (Delay to signal Baseline -DTB)...
September 2017: Brain and Behavior
https://www.readbyqxmd.com/read/28943539/leptomeningeal-collaterals-strongly-correlate-with-reduced-cerebrovascular-reactivity-measured-by-acetazolamide-challenged-single-photon-emission-computed-tomography-using-a-stereotactic-extraction-estimation-analysis-in-patients-with-unilateral-internal-carotid
#15
Takenobu Kunieda, Kosuke Miyake, Hiroki Sakamoto, Yuko Iwasaki, Shin Iida, Satoshi Morise, Kengo Fujita, Masataka Nakamura, Satoshi Kaneko, Hirofumi Kusaka
Objective To assess the correlation between the angiographic appearance of cerebral collateral pathways or the degree of internal carotid artery stenosis (ICAS) and reduced cerebrovascular reactivity (CVR) estimated by single-photon emission computed tomography (SPECT) image analysis in patients with unilateral ICAS. Methods A retrospective analysis was performed in 42 patients with unilateral ICAS who underwent cerebral angiography and acetazolamide-challenged SPECT of the brain. Cerebral blood flow quantitation was performed using the quantitative SPECT/dual-table autoradiography method...
September 25, 2017: Internal Medicine
https://www.readbyqxmd.com/read/28924565/nirs-based-cerebrovascular-regulation-assessment-exercise-and-cerebrovascular-reactivity
#16
Stephanie Miller, Kunal Mitra
Alterations to cerebral blood flow (CBF) have been implicated in diverse neurological conditions. Near-infrared spectroscopy (NIRS)-measured regional cerebral tissue oxygen saturation ([Formula: see text]) provides an estimate of oxygenation of interrogated cerebral volume useful in identifying variations in oxygen supply to cerebral tissue and in monitoring cerebrovascular function. [Formula: see text]-inhalation-based hypercapnic breathing challenges were used to simulate CBF dysregulation, utilizing NIRS to monitor the CBF autoregulatory response...
October 2017: Neurophotonics
https://www.readbyqxmd.com/read/28918088/evaluation-of-cerebrovascular-reactivity-in-subjects-with-and-without-obstructive-sleep-apnea
#17
Clodagh M Ryan, Anne Battisti-Charbonney, Olivia Sobczyk, David J Mikulis, James Duffin, Joseph A Fisher, Lashmi Venkatraghavan
BACKGROUND: Both obstructive sleep apnea (OSA) and altered cerebrovascular reactivity (CVR) are associated with increased stroke risk. Nevertheless, the incidence of abnormal CVR in patients with OSA is uncertain due to the high variability in the way CVR is measured both within and between studies. We hypothesized that a standardized CVR with a consistent vasoactive stimulus and cerebral blood flow (CBF) measure would be reduced in patients with severe OSA compared with healthy controls...
September 13, 2017: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
https://www.readbyqxmd.com/read/28860455/age-differences-in-brain-signal-variability-are-robust-to-multiple-vascular-controls
#18
Douglas D Garrett, Ulman Lindenberger, Richard D Hoge, Claudine J Gauthier
A host of studies support that younger, better performing adults express greater moment-to-moment blood oxygen level-dependent (BOLD) signal variability (SDBOLD) in various cortical regions, supporting an emerging view that the aging brain may undergo a generalized reduction in dynamic range. However, the exact physiological nature of age differences in SDBOLD remains understudied. In a sample of 29 younger and 45 older adults, we examined the contribution of vascular factors to age group differences in fixation-based SDBOLD using (1) a dual-echo BOLD/pseudo-continuous arterial spin labeling (pCASL) sequence, and (2) hypercapnia via a computer-controlled gas delivery system...
August 31, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28756241/rapid-cerebrovascular-reactivity-mapping-enabling-vascular-reactivity-information-to-be-routinely-acquired
#19
Nicholas P Blockley, James W Harkin, Daniel P Bulte
Cerebrovascular reactivity mapping (CVR), using magnetic resonance imaging (MRI) and carbon dioxide as a stimulus, provides useful information on how cerebral blood vessels react under stress. This information has proven to be useful in the study of vascular disorders, dementia and healthy ageing. However, clinical adoption of this form of CVR mapping has been hindered by relatively long scan durations of 7-12 min. By replacing the conventional block presentation of carbon dioxide enriched air with a sinusoidally modulated stimulus, the aim of this study was to investigate whether more clinically acceptable scan durations are possible...
July 26, 2017: NeuroImage
https://www.readbyqxmd.com/read/28724339/influence-of-cerebrovascular-reactivity-on-outcome-of-the-patients-with-%C3%A2-50-symptomatic-unilateral-middle-cerebral-artery-stenosis
#20
Weiqing Zhang, Yanwei Yin, Yingqian Zhang, Fen Yang, Wenqian Shi, Dawei Chen, Chen Song, Huiping Shi, Xuanzhu Zhao, Jin Shi
Purpose/aim of the study: Cerebrovascular reactivity (CVR) reflects the vasodilatory reserve of cerebral resistance vessels, which is an important marker for assessing cerebrovascular disease. The present study is to investigate whether CVR impairment increases adverse long-term outcome risk of patients with ≥ 50% symptomatic unilateral middle cerebral artery (MCA) stenosis (ischemic stroke (IS) or transient ischemic attack (TIA)). MATERIAL AND METHODS: Digital subtraction angiography (DSA) was used to assess the degree of stenosis, and perfusion CT and 5% CO2 inhalation were adopted to evaluate CVR...
August 23, 2017: International Journal of Neuroscience
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