Schedule of Events | Symposia

Neural Correlates of Cognitive Functions in Veterans with Gulf War Illness

Poster Session E - Monday, March 31, 2025, 2:30 – 4:30 pm EDT, Back Bay Ballroom/Republic Ballroom

Yu Zhang¹ (yu.zhang@va.gov), G. Marina Veltkamp¹, Maxine Krengel¹, Peter Bayley¹, Ansgar Furst^1,2; ¹War Related Illness and Injury Study Center, VA Palo Alto Health Care System, ²Stanford University

Background: Impaired cognition is a core symptom of Gulf War Illness (GWI), a complex multifactorial condition affecting veterans of the 1990-91 Gulf War. Little is known about the neural correlates of this condition in mid-aged veterans with GWI, and this study examined the relationship between regional brain volumes (which we previously demonstrated to be potentially reduced in GWI) and measures of neurocognitive performance. Methods: Structural magnetic resonance imaging (MRI) and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) data were collected from 158 veterans (Age=48±6, 87% Male) with GWI. Volumes of bilateral subcortical and brainstem regions were measured using FreeSurfer. A cognitively impaired group (CI-GWI, N=133, age= 47±9) and a cognitively normal group (CN-GWI, N=25, Age=49±6) were defined based on a cutoff value (1 SD below the mean) of the RBANS total index. Group differences and correlations were tested after adjusting for age, sex, education, severity of PTSD, depression and traumatic brain injury. Results: Volumes of the whole brainstem, pons, and nucleus accumbens were substantially smaller (p≤.01), and the hippocampus was marginally smaller (p=.03), in CI-GWI compared to CN-GWI. Linear regression showed that a smaller pons was associated with impaired delayed-memory recall (p=.02); smaller nucleus accumbens was associated primarily with more severe depression (p<.01), and secondarily with lower immediate-memory recall (p=.01); smaller hippocampus was associated with increasing age (p<.01). Conclusion: Cognitive impairment in GWI is associated with damage to the brainstem and other deep brain structures, which may be related to comorbid conditions and specific military environmental exposures.

Topic Area: NEUROANATOMY