The effect of persistent foramen ovale closure on migraine remains an enigma.

he report in this issue of JACC: Cardiovascular Intervenions from Vigna et al. (1) raises more questions about a onfusing area of medicine—the role of persistent foramen vale (PFO) closure in migraine. Persistent foramen ovale is associated with a number of iseases including migraine with aura, cryptogenic stroke, nd decompression illness (2–4). Other right-to-left shunts re also associated with these conditions, which suggests hat a right-to-left shunt per se has an etiological role (5). It s postulated that in some people with migraine with aura a rigger substance passes across a shunt, but if this is so the rigger has not been identified. If this postulated mechanism s responsible for some cases, it cannot account for all ecause not all migraine sufferers have a shunt and many eople with a shunt do not have migraine.