Migraine headache mechanisms

Migraine is characterized by headaches often brought on by stress, emotional change or sleep disturbances, but the mechanism that triggers these episodes remains poorly understood. In February Nature Medicine, Hayrunnisa Bolay and colleagues from Harvard Medical School, Boston, USA show that intrinsic brain activity triggers trigemino-vascular afferents and evokes a series of cortical meningeal and brainstem events consistent with the development of headache.

Bolay et al. used a rat model and found that cortical spreading depression (CSD) of electrical activity — the cause of migraine visual aura — produced long-lasting blood-flow enhancement selectivity within the middle meningeal artery. This effect required both trigeminal and parasympathetic innervation and caused plasma protein leakage within the dura mater in part by a neurokinin-1 receptor mechanism (Nat Med 2002, 8:136-142).

"These data, together with earlier work, point to CSD as a critical event in the mechanism of migraine with...