Category: RespirAct

The Dynamics of Cerebrovascular Reactivity Shown with Transfer Function Analysis

J Duffin, O Sobczyk, A P Crawley, J Poublanc, D J Mikulis, J A Fisher. Neuroimage. 2015 Jul 1;114:207-16. doi: 10.1016/j.neuroimage.2015.04.029. Epub 2015 Apr 16.
Cerebrovascular reactivity (CVR) is often defined as the increase in cerebral blood flow (CBF) produced by an increase in carbon dioxide (CO2) and may be used clinically to assess the health of the cerebrovasculature. When CBF is estimated using blood oxygen level dependent (BOLD) magnetic resonance imaging, CVR values for each voxel can be displayed using a color scale mapped onto the corresponding anatomical scan.

Identifying Significant Changes in Cerebrovascular Reactivity to Carbon Dioxide

O Sobczyk, A P Crawley, J Poublanc, K Sam, D M Mandell, D J Mikulis, J Duffin, J A Fisher. AJNR Am J Neuroradiol. 2016 May;37(5):818-24.
doi: 10.3174/ajnr.A4679. Epub 2016 Feb 4.
Background and purpose: Changes in cerebrovascular reactivity can be used to assess disease progression and response to therapy but require discrimination of pathology from normal test-to-test variability. Such variability is due to variations in methodology, technology, and physiology with time. With uniform test conditions, our aim was to determine the test-to-test variability of cerebrovascular reactivity in healthy subjects and in patients with known cerebrovascular disease.

Development of White Matter Hyperintensity is Preceded by Reduced Cerebrovascular Reactivity

Kevin Sam, Adrian P Crawley, John Conklin, Julien Poublanc, Olivia Sobczyk, Daniel M Mandell, Lakshmikumar Venkatraghavan, James Duffin, Joseph A Fisher, Sandra E Black, David J Mikulis. Ann Neurol. 2016 Aug;80(2):277-85. doi: 10.1002/ana.24712.
Objective: White matter hyperintensities (WMH) observed on neuroimaging of elderly individuals are associated with cognitive decline and disability. However, the pathogenesis of WMH remains poorly understood. We observed that regions of reduced cerebrovascular reactivity (CVR) in the white matter of young individuals correspond to the regions most susceptible to WMH in the elderly. This finding prompted us to consider that reduced CVR may play a role in the pathogenesis of WMH. We hypothesized that reduced CVR precedes development of WMH.