A first joint AHA and Headache Society grant tests whether migraine weakens brain vessels

Perivascular macrophages wrap cerebral blood vessels and defend them ^[6]. The vessels they sit on run through cycles of constriction, dilation and altered flow during a migraine episode ^[5]. Pelaez's laboratory is testing whether enough of those cycles leave the macrophages hyperactive when there is nothing left to defend against ^[6].

"If migraines happen over and over, these immune cells might stay 'on' for too long. When this happens, they might accidentally make the blood vessels weaker," Pelaez said ^[7]. "If the vessels get weaker, the brain might have a harder time protecting itself from a stroke," she said ^[8]. The project tracks migraine-related neuropeptides as the trigger, and its stated aim is to find targets that quiet the cells or intercept the inflammatory signaling before vessels are damaged ^[9].

The human data cannot settle direction. A population with more strokes and more migraine with aura is consistent with attacks damaging vessels, and equally consistent with vessels that were already different before the first attack ^[10]. A neuropeptide dose that primes macrophages on the bench would be evidence for the first reading. On its own, priming in a dish stops short of showing that primed macrophages are what produces strokes in patients. The announcement describes laboratory work and does not name the species or model system ^[16].

Two hundred thousand dollars over two years is $100,000 a year ^[14]. The figure appears twice in the announcement carrying two meanings: once as the size of the co-funded Innovative Project Award, and once as what the partnership provides together with the three AHA awards, across basic science, clinical trials and population health ^[1][3]. Split four ways, that is $50,000 a project ^[17].

Of the three AHA-only grants, Andrea Harriott's at Massachusetts General Hospital is the one built to catch structural damage as it forms: protein shifts, collateral vessel remodeling and angiogenesis following the cortical spreading depolarizations that underlie aura, to establish whether long-term aura exposure directly damages the brain's vascular architecture ^[11]. Matthew Bender's group at the University of Rochester is building a measurement instead, a non-invasive contrast-free quantitative MRI technique for the glymphatic-hemodynamic axis in idiopathic intracranial hypertension, a raised-pressure disorder that predominantly affects overweight women of childbearing age ^[12]. The fourth award goes to the choroid plexus in obesity-related migraine ^[13].