Association of White Matter Integrity and Age on Cognitive Performance in U-2 Pilots (340)

Objective: To assess whether fractional anisotropy (FA) values within white matter tracts or age had a significant factor in U-2 pilot neurocognitive performance. Background: Previous research has demonstrated U-2 pilots have decreased whole brain average FA values, increased white matter hyperintensity (WMH) burden, and differences in neurocognitive function compared to other military personnel. FA is a relevant imaging biomarker that can more sensitively track white matter changes in neurological diseases and normal aging prior to development of WMH lesions. This analysis assessed whether FA values within white matter tracts or age had significant effect in U-2 neurocognitive performance. Design/Methods: MRI and neurocognitive data were obtained from 103 U-2 pilots prior to implementation of the CARE program. FA values within multiple white matter tracts were acquired from diffusion tensor imaging (n=103). Neurocognitive data was attained through MicroCog evaluation (n=101). A generalized linear model was utilized to investigate independent effects of FA value and age on MicroCog metrics. Results: Higher FA values of the corpus callosum body, internal capsule, corona radiata, external capsule, and fronto-occipital tracts were independently associated with higher MicroCog Spatial Processing scores when controlling for age. Fronto-occipital tract FA values were significantly negatively associated with Reaction Time. Age was positively associated with Reaction Time across all tracts. Conclusions: In our U2 pilot subgroup, this study demonstrated that both age and FA values independently influence certain micro-cognitive metrics with positive correlation to spatial processing when controlling for age in numerous tracts. Increasing age correlates positively with reaction time independent of FA values for all tracts. This study provides further insight that numerous white matter tracts are important in visual spatial integrity enhancing the concept that cortical function is emblematic of a diffuse network between brain regions than a discrete anatomical site. Disclosure: Dr. Cacic has nothing to disclose. Dr. Cerqueira has nothing to disclose. Dr. Sladky has nothing to disclose.