Heterogeneous motor BOLD-fMRI responses in brain areas exhibiting negative BOLD cerebrovascular reactivity indicate that steal phenomenon does not always result from exhausted cerebrovascular reserve capacity

Abstract

Introduction: Brain areas exhibiting negative blood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) responses to carbon dioxide (CO2) are thought to suffer from a completely exhausted autoregulatory cerebrovascular reserve capacity and exhibit vascular steal phenomenon. If this assumption is correct, the presence of vascular steal phenomenon should subsequently result in an equal negative fMRI signal response during a motor-task based BOLD-fMRI study (increase in metabolism without an increase in cerebral blood flow Show more