Measuring vascular reactivity with breath-holds after stroke: a method to aid interpretation of group-level BOLD signal changes in longitudinal fMRI studies
Author(s)
Geranmayeh, F
Wise, RJS
Leech, R
Murphy, K
Type
Journal Article
Abstract
Blood oxygenation level-dependent (BOLD) contrast functional magnetic resonance imaging (fMRI) is a widely used technique to map brain function, and to monitor its recovery after stroke. Since stroke has a vascular etiology, the neurovascular coupling between cerebral blood flow and neural activity may be altered, resulting in uncertainties when interpreting longitudinal BOLD signal changes. The purpose of this study was to demonstrate the feasibility of using a recently validated breath-hold task in patients with stroke, both to assess group level changes in cerebrovascular reactivity (CVR) and to determine if alterations in regional CVR over time will adversely affect interpretation of task-related BOLD signal changes. Three methods of analyzing the breath-hold data were evaluated. The CVR measures were compared over healthy tissue, infarcted tissue and the peri-infarct tissue, both sub-acutely (∼2 weeks) and chronically (∼4 months). In this cohort, a lack of CVR differences in healthy tissue between the patients and controls indicates that any group level BOLD signal change observed in these regions over time is unlikely to be related to vascular alterations. CVR was reduced in the peri-infarct tissue but remained unchanged over time. Therefore, although a lack of activation in this region compared with the controls may be confounded by a reduced CVR, longitudinal group-level BOLD changes may be more confidently attributed to neural activity changes in this cohort. By including this breath-hold-based CVR assessment protocol in future studies of stroke recovery, researchers can be more assured that longitudinal changes in BOLD signal reflect true alterations in neural activity.
Date Issued
2015-02-27
Date Acceptance
2015-01-05
Citation
Human Brain Mapping, 2015, 36 (5), pp.1755-1771
ISSN
1097-0193
Publisher
Wiley
Start Page
1755
End Page
1771
Journal / Book Title
Human Brain Mapping
Volume
36
Issue
5
Copyright Statement
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Subjects
Science & Technology
Life Sciences & Biomedicine
Neurosciences
Neuroimaging
Radiology, Nuclear Medicine & Medical Imaging
Neurosciences & Neurology
vascular reactivity
stroke
fMRI
breath-hold
CEREBRAL-BLOOD-FLOW
CEREBROVASCULAR REACTIVITY
POSTSTROKE APHASIA
RECOVERY
MRI
RESERVE
CO2
NORMALIZATION
OCCLUSION
RESPONSES
Adult
Aged
Brain
Brain Mapping
Breath Holding
Cerebrovascular Circulation
Feasibility Studies
Female
Humans
Longitudinal Studies
Magnetic Resonance Imaging
Male
Middle Aged
Oxygen
Stroke
Experimental Psychology
1109 Neurosciences
1702 Cognitive Science
Publication Status
Published