Using real-time phase contrast MRI to understand coughing associated headaches in patients with Chiari malformation

Motivation: How the obstruction of the cranio-cervical junction in patients with Chiari malformation contributes to coughing associated headache is unknown. Goal(s): To characterise differences in cerebrospinal fluid flow (CSF), and cranial morphology that could explain coughing triggered headache in patients with Chiari. Approach: Patients with and without coughing headache, and healthy controls were imaged to CSF flow while coughing, and 3D shape models were used to compare the cranial morphology. Results: CSF flow rates were similar between groups. However, the anterior CSF space was restricted in the patient groups, with CSF velocities ~1.8 times greater than in healthy controls. Impact: In contrast with popular hypotheses, the Chiari patients CSF flow was not reduced following coughs, but CSF velocities were increased. How this alters the shear stresses acting on soft tissues may provide further insight into the causes of headache.