RT Journal Article
SR Electronic
T1 Modulation of the spontaneous hemodynamic response function across levels of consciousness
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 401547
DO 10.1101/401547
A1 Guo-Rong Wu
A1 Carol Di Perri
A1 Vanessa Charland-Verville
A1 Charlotte Martial
A1 Steven Laureys
A1 Daniele Marinazzo
YR 2018
UL http://biorxiv.org/content/early/2018/08/27/401547.abstract
AB Functional imaging research has already contributed with several results to the study of neural correlates of consciousness. Apart from task-related activation derived in fMRI, PET based glucose metabolism rate or cerebral blood flow account for a considerable proportion of the study of brain activity under different levels of consciousness. Resting state functional connectivity MRI is playing a crucial role to explore the consciousness related functional integration, successfully complementing PET, another widely used neuroimaging technique. Here, spontaneous hemodynamic response is introduced to characterize resting state brain activity giving information on the local metabolism (neurovascular coupling), and useful to improve the time-resolved activity and connectivity measures based on BOLD fMRI. This voxel-wise measure is then used to investigate the loss of consciousness under Propofol anesthesia and unresponsive wakefulness syndrome. The dysfunction of hemodynamic response in precuneus and posterior cingulate is found to be a common principle underlying loss of consciousness in both conditions. The thalamus appears to be less obviously modulated by Propofol, compared with frontoparietal regions. However, a significant increase in spontaneous thalamic hemodynamic response was found in patients in unresponsive wakefulness syndrome compared with healthy control. Our results ultimately show that anesthesia- or pathology-induced neurovascular coupling could be tracked by modulated spontaneous hemodynamic response derived from resting state fMRI.