Re-evaluation of the relationship between migraine and persistent foramen ovale and other right-to-left shunts

Right-to-left shunts (usually persistent foramen ovale) are responsible for a large proportion of cases of decompression illness [1,2]. Previously, we reported in Clinical Science [3] a review of the medical records of 200 consecutive individuals investigated for the cause of their decompression illness that showed that those with a large right-to-left shunt had a considerably increased prevalence of migraine with aura in daily life unconnected with diving, but not of migraine without aura. They also had an increased incidence of migraine aura after dives that liberate venous bubbles [3]. Transcatheter closure of persistent foramen ovale and atrial septal defects usually reduces the severity and frequency of attacks of migraine with aura [4]. Atrial shunts are dominantly inherited and this inheritance is closely associated with the inheritance of familial migraine with aura [5]. However, a significant role for right-to-left...