Investigating Sea-Level Brain Predictors for Acute Mountain Sickness: A Multimodal MRI Study before and after High-Altitude Exposure

ROC curve analysis of MR imaging features. The prediction performance using different features of multimodal MR imaging as input, measured by the AUC of the ROC curves. fALFF and DC from fMRI were detected as valid predictors, yielding significant AUC values. CT indicates cortical thickness; FD, fractal dimension; GI, gyrification index; GMV, gray matter volume; ReHo, regional homogeneity; SD, sulcus depth; WMV, white matter volume, CSFV, CSF volume. ** P < .01, *** P < .001.

Comparison of functional metrics between AMS and non-AMS groups. A, Sea-level voxelwise differences. Differences between AMS and non-AMS groups are identified using t tests, corrected with the Gaussian random field at P < .05. For both fALFF and DC, AMS showed increased functional metrics in the medial prefrontal cortex, supramarginal gyrus, posterior cingulate cortex, and superior frontal gyrus and decreased functional metrics in the supplementary motor area, postcentral gyrus, paracentral lobule, Rolandic operculum, middle cingulate cortex, and superior temporal gyrus. B, Sea-level network-wise differences. Among 7 typical functional networks at sea level, we detected significant lower fALFF and DC in the SMN in the AMS group (*: P < .05; **: P < .01). The error bars present the standard error of the mean (SEM). C, High-altitude voxelwise differences. At high altitudes, for both fALFF and DC, AMS showed decreased functional metrics in the postcentral gyrus, Rolandic operculum, and superior temporal gyrus. D, High-altitude network-wise differences. Among 7 typical functional networks at high altitude, we detected significant lower fALFF in SMN in the AMS group (*: P < .05). The error bars present SEM. L indicates left; R, right.