Altered cerebrovenous drainage in patients with migraine as assessed by phase-contrast magnetic resonance imaging

Objective: We aimed to assess whether migraine is associated with changes in the distribution of the venous drainage through primary and secondary pathways by using phase-contrast magnetic resonance imaging (MRI). Methods: We examined 26 patients (37.3 ± 13.9 years) with recurring migraine headaches and 26 age-and gender-matched controls with no neurologic disease (37.3 ± 13.7 years) on a 3 Tesla MR scanner. A 2D time-of-flight MR-venography of the upper neck region was performed to visualize the venous vasculature. Cine-phase contrast scans with highvelocity encoding were employed to quantify arterial inflow and flow in the primary venous channels (right and left jugular veins), whereas scans with low-velocity encoding were employed to quantify flow in the secondary venous channels (epidural, vertebral, and deep cervical veins). Results: Patients with migraine showed (i) a higher prevalence of dense secondary extracranial venous networks (15 vs. 2, P = 0.00002) and (ii) a significantly larger percentage of venous outflow through secondary channels (10.5% vs. 5.5%; of total cerebral blood flow, P = 0.02). This mainly included drainage through epidural, vertebral, and deep cervical veins. Conclusion: Migraine patients showed a significantly larger percentage of venous outflow through secondary channels. The mechanism of this alteration remains to be elucidated. Potential mechanisms include repeated release of vasoactive substances or growth factors.