Stephanie Anne Harmon, Abstract Co-Author: Nothing to Disclose

Debra A Fleischman PhD, Abstract Co-Author: Nothing to Disclose

Robert John Dawe BS, Abstract Co-Author: Nothing to Disclose

David A Bennett MD, Abstract Co-Author: Nothing to Disclose

Konstantinos Arfanakis PhD, Presenter: Nothing to Disclose

The purpose of this work was to test the hypothesis that the microstructural integrity of white matter tissue is reduced in elderly subjects with high levels of circulating inflammatory markers.

Serum samples from 320 non-demented elderly participants of the Rush Memory and Aging Project were assayed for C-reactive protein (CRP) and tumor necrosis factor-alpha (TNFα). Subjects were stratified into groups of high and low systemic inflammation based on a composite measure of CRP and TNFα. The first 14 MRI-eligible participants from the upper quartile of inflammation (age=81.2±3.6years) and the first 14 participants from the lower quartile (age=81.2±6.1years) were scanned with diffusion tensor imaging (DTI) on a 1.5T MRI scanner: TE=84.6ms, TR=5.4s, 36 oblique-axial slices, FOV=24cm, slice thickness=3mm, acquisition matrix=128×128, NEX=6, 2 b=0s/mm2 images, 12 diffusion directions at bvalue=900s/mm2, scan time 7min:33s. DTI post-processing was performed using TORTOISE (NIH). Voxelwise t-tests were used to compare fractional anisotropy (FA) and trace values between groups of high and low inflammation using Tract-Based Spatial Statistics (TBSS). Effects of inflammation, volume of white matter hyperintensities, age, sex, education, systolic blood pressure, and body mass index on regions showing significant differences in FA and trace were investigated.

Figure 1 shows significantly lower FA (p<0.05, corrected for multiple comparisons) (Fig.1 Top) and significantly higher trace (Fig.1 Bottom) in white matter regions of the high inflammation group compared to the low inflammation group. These differences were due to higher radial diffusivity in the high inflammation group. There were no regions with significantly lower FA or higher trace in the low inflammation group.

This work demonstrates that in non-demented elderly persons, high levels of systemic inflammation are associated with significantly lower FA and higher trace in white matter.

Our work suggests that high levels of systemic inflammation in the elderly may be a risk factor for reduced microstructural integrity of brain tissue.

Harmon, S, Fleischman, D, Dawe, R, Bennett, D, Arfanakis, K, White Matter of Nondemented Elderly Subjects Shows Reduced Mircrostructural Integrity with Increased Levels of Systemic Inflammation.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11008029.html