Physical exercise activates intrinsic CSF outflow metrics in healthy humans

Possible two intrinsic CSF egress pathways of dura mater and the lower parasagittal dura (PSD) are observed using non-contrast spin-labeling MRI. Intrinsic CSF outflow metrics increase in the adults with an active lifestyle than adults with sedentary lifestyle. However, after 3 weeks of increased physical activity, the sedentary group showed improved CSF outflow metrics. This improvement was notable at the lower PSD, where outflow metrics were highest among the active group. These quantitative CSF results indicate a new pathway of CSF flow from the lower PSD to the superior sagittal sinus that is most evident in physically active individuals.