@article{ref1,
title="Multi-parametric analysis reveals metabolic and vascular effects driving differences in BOLD-based cerebrovascular reactivity associated with a history of sport concussion",
journal="Brain injury",
year="2019",
author="Champagne, Allen A. and Coverdale, Nicole S. and Germuska, Michael and Cook, Douglas J.",
volume="33",
number="11",
pages="1479-1489",
abstract="<b>Objective</b>: Identify alterations in cerebrovascular reactivity (CVR) based on the history of sport-related concussion (SRC). Further explore possible mechanisms underlying differences in vascular physiology using hemodynamic parameters modeled using calibrated magnetic resonance imaging (MRI). <b>Method</b>: End-tidal targeting and dual-echo MRI were combined to probe hypercapnic and hyperoxic challenges in athletes with (n = 32) and without (n = 31) a history of SRC. Concurrent blood oxygenation level dependent (BOLD) and arterial spin labeling (ASL) data were used to compute BOLD-CVR, ASL-CVR, and other physiological parameters including resting oxygen extraction fraction (OEF<sub>0</sub>) and cerebral blood volume (CBV<sub>0</sub>). Multiple linear and logistic regressions were then used to identify dominant parameters driving group-differences in BOLD-CVR. <b>Results</b>: Robust evidence for elevated BOLD-CVR were found in athletes with SRC history spreading over parts of the cortical hemispheres. Follow-up analyses showed co-localized differences in ASL-CVR (representing modulation of cerebral blood flow) and hemodynamic factors representing static vascular (i.e., CBV<sub>0</sub>) and metabolic (i.e., OEF<sub>0</sub>) effects suggesting that group-based differences in BOLD-CVR may be driven by a mixed effect from factors with vascular <i>and</i> metabolic origins. <b>Conclusion</b>: These results emphasize that while BOLD-CVR offers promises as a surrogate non-specific biomarker for cerebrovascular health following SRC, multiple hemodynamic parameters can affect its relative measurements. <b>Abbreviations</b>: [dHb]: concentration of deoxyhemoglobin; AFNI: Analysis of Functional NeuroImages ( https://afni.nimh.nih.gov ); ASL: arterial spin labeling; BIG: position group: defensive and offensive linemen; BIG-SKILL: position group: full backs, linebackers, running backs, tight-ends; BOLD: blood oxygen level dependent; CBF: cerebral blood flow; CMRO2: cerebral metabolic rate of oxygen consumption; CTL: group of control subjects; CVR: cerebrovascular reactivity; fMRI: functional magnetic resonance imaging; FSL: FMRIB software library ( https://fsl.fmrib.ox.ac.uk/fsl/fslwiki/ ); HC: hypercapnia; HO: hyperoxia; HX: group with history of concussion; M: maximal theoretical BOLD signal upon complete removal of venous dHb; pCASL: pseudo-continuous arterial spin labeling; P<sub>ET</sub>CO<sub>2</sub>: end-tidal carbon dioxide; P<sub>ET</sub>O<sub>2</sub>: end-tidal oxygen; SCAT: sport-concussion assessment tool; SKILL: position group: defensive backs, kickers, quarterbacks, safeties, wide-receivers; SRC: sport-related concussion.<p /> <p>Language: en</p>",
language="en",
issn="0269-9052",
doi="10.1080/02699052.2019.1644375",
url="http://dx.doi.org/10.1080/02699052.2019.1644375"
}