Danger Dust

Summary

In military service members with a history of repetitive blast exposure, higher blast exposure correlated with distinct functional MRI connectivity patterns, changes in cortical volume, and clinical neurobehavioral tests scores; a predictive model indicated possible changes in functional connectivity even in the absence of observable anatomical alterations.

Key Results

■ In this analysis of 212 members of special operations forces, participants with higher blast exposure showed altered functional connectivity (FC) in the superior and inferior lateral occipital cortex (LOC), frontal medial cortex, left superior frontal gyrus, and precuneus compared with the the low-exposure group (P value range, .001–.04) and had higher cortical volume in the LOC compared with healthy controls and the low-exposure group (P value range, .01–.04).

■ Clinical scores from the Neurobehavioral Symptom Inventory and Posttraumatic Stress Disorder Checklist for Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) were inversely correlated with FC in the LOC, superior parietal lobule, precuneus, and default mode networks (r = −0.163 to −0.384; P value range, <.001 to .04).

■ Predictive functional MRI modeling classified groups into high or low exposure with 88.00% sensitivity (95% CI: 78.00, 98.00), 67% specificity (95% CI: 53.00, 81.00), and 73% accuracy (95% CI: 60.00, 86.00).