Ryan Raut, Presenter: Nothing to Disclose

Veena A. Nair PhD, Abstract Co-Author: Nothing to Disclose

Wolfgang Gaggl PhD, Abstract Co-Author: Researcher, Prism Clinical Imaging, Inc

Brittany Young, Abstract Co-Author: Nothing to Disclose

Christian La, Abstract Co-Author: Nothing to Disclose

Justin Sattin, Abstract Co-Author: Nothing to Disclose

Vivek Prabhakaran MD, PhD, Abstract Co-Author: Nothing to Disclose

A diminished relationship between neural and hemodynamic activity has been observed in various patient groups and has raised some concern regarding the validity of fMRI for these groups. To investigate the extent of neurovascular uncoupling (NVU) in aging and stroke, we compared fMRI activation maps of younger and older healthy subjects, as well as acute stroke patients during a breathhold task.

Anatomical and functional images were collected on a GE 3T MR scanner for 73 subjects: 30 stroke patients (20 male, M = 59 years), 22 old healthy normals (10 male, M = 59 years), and 21 young normals (14 male, M = 22 years). Functional images were acquired during a breathhold task. Not all subjects did all tasks. Group-level analyses compared activation maps using AFNI.

Older normals differed from younger normals in cortical activation in multiple areas, suggesting an increase in the degree of neurovascular uncoupling with age. Stroke patients also differed from younger normals in cortical activation, suggesting that neurovascular uncoupling may indeed be occurring in this population as well. All maps were corrected for multiple comparisons, p < 0.05.

Our results suggest that some NVU may induce changes with age and stroke, though these disparities do not seem severe enough to invalidate fMRI for these groups. Further research is warranted to examine effect of stroke location and to improve understanding of fMRI signal in these groups.

Breathhold mapping can be used to evaluate BOLD fMRI signal in stroke patients. Standard fMRI examinations may result in false negative mapping, leading to erroneous conclusions in this population.

Raut, R, Nair, V, Gaggl, W, Young, B, La, C, Sattin, J, Prabhakaran, V, Altered Functional Activation Maps in Healthy Aging and Stroke due to Neurovascular Uncoupling.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14014517.html