Investigating macrophage-mediated inflammation in migraine using ultrasmall superparamagnetic iron oxide-enhanced 3T magnetic resonance imaging

• Published in: Cephalalgia 2019-10, Vol.39 (11), p.1407-1420
• Main Authors: Khan, Sabrina, Amin, Faisal Mohammad, Fliedner, Frederikke Petrine, Christensen, Casper Emil, Tolnai, Daniel, Younis, Samaira, Olinger, Anne Christine Rye, Birgens, Henrik, Daldrup-Link, Heike, Kjær, Andreas, Larsson, Henrik Bo Wiberg, Lindberg, Ulrich, Ashina, Messoud
• Format: Article
• Language: English
• ISSN: 0333-1024; 1468-2982
• DOI: 10.1177/0333102419848122

Background Initiating mechanisms of migraine headache remain poorly understood and a biomarker of migraine does not exist. Inflammation pertaining to the wall of cerebral arteries and brain parenchyma has been suggested to play a role in migraine pathophysiology. Objective We conducted the first experimental human study to investigate macrophage-mediated inflammation as a possible biomarker of migraine. Methods Using ultrasmall superparamagnetic iron oxide (USPIO)-enhanced 3T magnetic resonance imaging (MRI), we investigated the presence of macrophages in cerebral artery walls and in brain parenchyma of patients with migraine without aura. We used the phosphodiesterase-3-inhibitor cilostazol as an experimental migraine trigger, and investigated both patients who received sumatriptan treatment, and patients who did not. To validate our use of USPIO-enhanced MRI, we included a preclinical mouse model with subcutaneous capsaicin injection in the trigeminal V1 area. The study is registered at ClinicalTrials.gov with the identifier NCT02549898. Results A total of 28 female patients with migraine without aura underwent a baseline MRI scan, ingested cilostazol, developed a migraine-like attack, and underwent an USPIO-enhanced MRI scan > 24 hours after intravenous administration of USPIO. Twelve patients treated their attack with 6 mg s.c. sumatriptan, while the remaining 16 patients received no migraine-specific rescue medication. The preclinical model confirmed that USPIO-enhanced MRI detects macrophage-mediated inflammation. In patients, however, migraine attacks were not associated with increased USPIO signal on the pain side of the head compared to the non-pain side. Conclusion Our findings suggest that migraine without aura is not associated with macrophage-mediated inflammation specific to the head pain side.