ABSTRACT
Introduction: While migraine with aura is a complex neurological syndrome with a well-characterized clinical phenotype, its pathophysiology still has grey areas which could be partially clarified by microstructural and functional neuroimaging investigations.
Areas covered: This article, summarizing the most significant findings from advanced neuroimaging studies, aims to achieve a unifying pathophysiological model of the migraine aura. A comprehensive review has been conducted of PubMed citations by entering the key word ‘neuroimaging’ combined with ‘migraine with aura’ AND/OR ‘MRI.’ Other keywords included ‘grey matter’ OR ‘white matter’, ‘structural’ OR ‘functional’.
Expert opinion: Converging evidence from advanced neuroimaging investigations underlined the critical role of the extrastriate visual cortex, and in particular the lingual gyrus, in the genesis of the aura phenomenon. However, the relationship between the aura and the headache phase of migraine attacks has not been completely clarified, to date, and underlying pathophysiological mechanisms need to be further elucidated.
Article highlights
Despite the CSD is widely considered the pathophysiological mechanism underlying the aura phenomenon, there are still poor evidences to draw a direct link between hyperemia and oligemia CSD-induced and migraine aura.
Microstructural and functional investigations converged in underlining the critical role of the extrastriate visual cortex, and in particular the lingual gyrus, in the genesis of the aura phenomenon.
Different aura symptoms (e.g. positive or negative manifestations) are subtended peculiar changes in BOLD signal reactivity, reflecting specific cerebral changes for each aura symptoms.
The generation of the pain associated with migraine is associated to trigemino-vascular system activation, putatively through a complex cascade of events, induced by CSD-induced pannexin channels opening, leading to astrocytic and microglia activation and so to neuroinflammation.
Pathophysiological integration between visual and trigeminal pain pathways has been invoked in mechanism subtending MwA, likely due to the involvement of functional pathways or neuroinflammatory processes.
New classification algorithms, using learning machine approaches in combination with multiparametric fMRI measures, are able to discriminate MwA phenotype and this approach could have a diagnostic role in the future clinical practice.
Declaration of interest
G Tedeschi has received speaker honoraria from Sanofi-Aventis, Merck Serono, Bayer Schering Pharma, Novartis, Biogen-Dompe´ AG. has also received funding for travel from Bayer Schering Pharma, Biogen-Dompe´ AG, Merck Serono, Novartis, and Sanofi Aventis; and serve as an associate editor of Neurological Sciences. A Russo has received speaker honoraria from Allergan, Novartis, Teva, and Lilly. They also serve as an associate editor of Frontiers in Neurology (section on Headache Medicine and Facial Pain). A Tessitore has received speaker honoraria from Novartis, Schwarz Pharma/UCB, Lundbeck, Abbvie and GlaxoSmithKline. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or conflict with the subject matter or materials discussed in this manuscript apart from those disclosed.
Reviewer disclosures
Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.