Evaluation of cerebral blood flow and glymphatic function in acute mountain sickness by MRI ASL and DTI ALPS.

To investigate alterations in glymphatic system function and cerebral blood flow (CBF) in individuals with acute mountain sickness (AMS), and to determine the relationship between these imaging findings and clinical symptom severity using diffusion tensor imaging along the perivascular space (DTI-ALPS) and three-dimensional arterial spin labeling (3D-ASL).Forty-one participants who rapidly ascended to high altitude were prospectively enrolled and divided into an AMS group (n = 21) and a non-AMS group (n = 20). All underwent DTI and 3D-ASL MRI sequences. The ALPS index and CBF values were measured, compared between groups, and correlated with Lake Louise AMS Scores (LLS). No significant difference was found in the ALPS index between the AMS and non-AMS groups (P > 0.05). However, the mean ALPS index showed a significant negative correlation with LLS (r = − 0.523, P < 0.001). In contrast, CBF was significantly higher in the cerebral cortex and white matter of the AMS group compared to the non-AMS group (P < 0.05). A weak but significant positive correlation was found between CBF in the corpus callosum and LLS (r = 0.322, P = 0.046). While glymphatic function, as measured by the ALPS index, correlates with AMS severity, it does not significantly differ between AMS and non-AMS groups. Elevated CBF in white matter and cerebral cortex, particularly in the corpus callosum, may serve as a potential imaging biomarker of AMS, underscoring the value of 3D-ASL for non-invasive assessment of cerebral perfusion changes in high-altitude conditions.