Vessel-wall MRI in primary headaches: The role of neurogenic inflammation

Objective: The purpose of this study was to investigate if vessel-wall magnetic resonance imaging (VW-MRI) could differentiate among primary headaches disorders, such as migraine and cluster headache (CH), and detect the presence of neurogenic inflammation. Background: The pathophysiology of primary headaches disorders is complex and not completely clarified. The activation of nociceptive trigeminal afferents through the release of vasoactive neuropeptides, termed "neurogenic inflammation," has been hypothesized. VW-MRI can identify vessel wall changes, reflecting the inflammatory remodeling of the vessel walls despite different etiologies. Methods: In this case series, we enrolled seven patients with migraine and eight patients with CH. They underwent a VW-MRI study before and after the intravenous administration of contrast medium, during and outside a migraine attack or cluster period. Two expert neuroradiologists analyzed the magnetic resonance imaging (MRI) studies to identify the presence of vessel wall enhancement or other vascular abnormalities. Results: Fourteen out of 15 patients had no enhancement. One out of 15, with migraine, showed a focal parietal enhancement in the intracranial portion of a vertebral artery, unmodified during and outside the attack, thus attributable to atherosclerosis. No contrast enhancement attributable to neurogenic inflammation was observed in VW-MRI, both during and outside the attack/cluster in all patients. Moreover, MRI angiography registered slight diffuse vasoconstriction in one of seven patients with migraine during the attack and in one of eight patients with cluster headache during the cluster period; both patients had taken triptans as symptomatic therapy for pain. Conclusions: These preliminary results suggest that VW-MRI studies are negative in patients with primary headache disorders even during migraine attacks or cluster periods. The VW-MRI studies did not detect signs of neurogenic inflammation in the intracranial intradural vessels of patients with migraine or CH.