Migraine is a primary headache disorder that causes significant suffering in approximately 13 percent of the population of the United States. It accounts for an estimated $23 billion in annual cost to the economy through health-care expenses and lost productivity.
Two major features of migraine are migraine aura (MA) and headache. MA occurs in nearly one-third of migraine patients and consists of one or more focal neurological symptoms that develop gradually over 5-20 minutes and persist for less than 60 minutes. MA typically precedes development of migraine headache.
Several years ago single-center retrospective analyses first reported an apparent association between partial or complete relief of migraine symptoms and transcatheter closure of patent foramen ovale (PFO) for secondary stroke prevention (Reisman M, et al., 2005). The foramen ovale normally serves as a one-way valve in the interatrial septum for physiologic right-to-left shunt in utero. Complete fusion of interatrial septae normally occurs by two years of age. When septae fail to fuse, however, the PFO is a potential tunnel that can be opened by reversal of the interatrial pressure gradient. PFO is the most common form of right-to-left circulatory shunt (RLS).