Anil Krishna Vasireddi BS, Presenter: Nothing to Disclose

Konstantinos Arfanakis PhD, Abstract Co-Author: Nothing to Disclose

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

Shengwei Zhang BEng, Abstract Co-Author: Nothing to Disclose

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

To investigate the association between frequency of late life cognitive activity and diffusion anisotropy throughout the brain.

This study included 152 elderly participants (mean age: 81±7 years) of the Rush Memory and Aging Project. Participants were without dementia or mild cognitive impairment based on a detailed clinical evaluation. Participants were asked to rate the frequency with which they participated in a list of mentally engaging activities during the last year, on a scale of 1 to 5. The mean value of these ratings was considered as the participant’s late life cognitive activity. All participants underwent brain MRI using a 1.5T scanner within one year of clinical evaluation. T1-weighted anatomical, diffusion tensor imaging (DTI), and fluid-attenuated inversion recovery (FLAIR) data were collected on all participants. The DTI data were corrected, tensors were estimated, and fractional anisotropy (FA) maps were generated using TORTOISE (NIH, Bethesda, MD). White matter hyperintensity (WMH) maps were generated using support vector machine classification based on T1-weighted and FLAIR signals (SBIA, University of Pennsylvania). The tract-based spatial statistics (TBSS) approach was used to project FA values from all participants onto a white matter skeleton. The hypothesis that late life cognitive activity is associated with FA was tested in each voxel of the skeleton controlling for age, sex, level of education, and the presence of WMHs. The null distribution was built using the “randomise” tool in FSL (FMRIB, Oxford, UK) and 1000 permutations. Differences were considered significant at p<0.05, Family Wise Error corrected. The Threshold-Free Cluster Enhancement method was used to define clusters with significant differences.

TBSS analysis revealed significant associations between frequency of late life cognitive activity and FA in the genu and body of the corpus callosum, thalamus, fornix, superior parietal, superior frontal, and precentral white matter bilaterally.

In elderly subjects without cognitive impairment, frequent late life cognitive activity is associated with greater diffusion anisotropy in a number of brain regions.

Among elderly subjects with no cognitive impairment, frequent late life cognitive activity is possibly linked to greater microstructural integrity in certain brain regions. 

Vasireddi, A, Arfanakis, K, Fleischman, D, Zhang, S, Bennett, D, Late Life Cognitive Activity Is Associated with Greater Diffusion Anisotropy in Brain White Matter .  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12027920.html