Assessment of Cerebrospinal Fluid Dynamics During Normal Breathing and Valsalva Maneuver using Real-Time MRI

Motivation: Chiari Malformation Type I (CMI) involves cerebellar tonsil herniation that partially obstructs cerebrospinal fluid (CSF) flow, and individuals with this condition often experience Valsalva-induced headaches. Although these headaches resolve quickly, their underlying cause remains unknown. Goal(s): Examining CSF dynamics during the Valsalva maneuver to better understand the mechanisms behind Valsalva-induced headaches. Approach: Using real-time MRI, healthy and CMI subjects performed the Valsalva maneuver to measure CSF flow rate and stroke volume (SV). Results: Flow rate and SV decreased significantly during Valsalva, returning to normal within seconds, showing rapid system recovery post-perturbation, with no observed differences between healthy and CMI groups. Impact: Reduction in CSF flow during Valsalva, followed by rapid recovery, may explain the quick resolution of Valsalva headaches in Chiari Malformation. However, the cause remains unclear, as no differences in CSF flow changes were observed between Chiari and healthy groups.