One of the biggest topics of discussion amongst Migraineurs today is that of PFO, "the hole in the heart" that may contribute to Migraines. Migraineurs are asking their doctors to test them to see if they have this condition. Many of those who do want to have the hole repaired -- immediately. However, questions remain and the closure procedure is not yet being performed on the basis of Migraine disease because it has not yet been proven effective. Trials are underway to determine the efficacy of PFO closure for Migraine disease.

What Is PFO:
PFO stands for patent foramen ovale. A PFO is a hole in the wall (septum) that divides the right and left atrium (chambers) of the heart. We all have a PFO during fetal development, but it usually closes before birth. The right side of the heart receives blood and pumps it to the lungs for oxygenation. The blood then goes through the left side of the heart to be pumped to the brain and other organs. A PFO can allow blood that hasn't been oxygenated by the lungs to get into the left side of the heart, thus being pumped to the brain and other organs. If this happens, the body doesn't get enough oxygen. It's also possible that blood clots can pass through the PFO and cause a stroke. PFO is diagnosed with a TEE (transesophageal echocardiogram), which is performed by passing an ultrasound probe down the esophagus, near the heart to get better results than the traditional echocardiogram, which is performed with a standard ultrasound wand outside the chest.

PFO and Migraine:
Research has shown a higher prevalence of PFO among Migraineurs than among people without Migraine.³ Small observational and case-control studies indicate that patients with cryptogenic (of unknown origin) stroke have a higher incidence of patent foramen ovale.⁴ It's still under investigation whether patent foramen ovale closure prevents recurrent strokes. It is thought to be possible that blood without enough oxygen may trigger a Migraine when it reaches the brain. In the April, 2004, issue of Neurology, two groups of researchers from Belgium (Post, et al) and Switzerland (Schwerzmann, et al) studied whether percutaneous closure (closing the PFO by a technique that does not require a major surgical procedure) would lead to fewer Migraines.

The Belgian group gave a questionnaire about Migraines to people after they had the PFO closure.² The Swiss group gave a questionnaire assessing the headache frequency and characteristics for the year before and after the PFO closure.³ There was no appreciable affect on the non-Migraine headache patients. In both studies, the PFO closure was done because doctors suspected that a blood clot passing through the PFO might have caused a stroke. The frequency of Migraine was decreased in both studies after PFO closure. Only the Swiss study evaluated both Migraine and non-Migraine headaches. More information about the effectiveness of PFO closure and headaches from these two studies can be found in the table below.

The implications of these Studies:

• These two studies add to the growing body of evidence of an association between a PFO and Migraine.

  • The number of people who had Migraine with aura in both studies was higher than in the general population.

  • PFO closure was associated with reduction of Migraine symptoms in patients having Migraine both with and without aura.

  • In the second study, non-Migraine headaches were not affected by PFO closure.

• These studies are important since if PFO closure proves effective for Migraine prevention, that makes PFO a potentially correctable trigger of Migraine.

• However, these studies do not support PFO closure as a treatment for Migraine due to two major limitations:

  • The studies were retrospective (they asked patients for information about their headaches that occurred in the past)

  • The studies included only stroke patients. To obtain more conclusive results, a study is needed to  evaluate otherwise healthy Migraineurs and collect data in real time (prospectively).

In discussing these studies of PFO and Migraine completed to date, Diener et al summarize the current situation with Migraine and PFO closure quite succinctly, "These studies, however, have major methodological limitations. Therefore patent foramen ovale closure cannot be recommended for the prevention of Migraine with aura. SUMMARY: At present routine percutaneous closure of isolated patent foramen ovale cannot be recommended for patients with cryptogenic stroke. Patent foramen ovale closure should not be used for the prevention of Migraine."⁴
 

New trials underway:
Clinical trials are now underway to compare Migraine patients who have the PFO closure with Migraine patients who do not. The MIST trial is underway in England, and results are expected in the spring of 2006. MIST stands for Migraine Intervention with STARFlex® Technology. The STARFlex® Septal Repair implant is a small Medical device made of specially developed knitted mesh and flexible metal frame used to close holes in the heart. The MIST II trial for the United States has been granted one step in the FDA approval process and is moving through the final approval process now. Enrollment for MIST II is expected to begin early in 2006.

 

For a copy of the American Academy of Neurology Patient Page about PFO and Migraine, click HERE.

Resources:

¹ Kondapaneni, MD, MPH, Pranathi. "Does the percutaneous closure of patent foramen ovale help
the migraine sufferer?" American Academy of Neurology Patient Page.

² Post, Martjin C.; Thijs, Vincent; Herroelen, Luc; Budts, Werner I.H.L. "Closure of a patent foramen ovale is associated with a decrease in prevalence of migraine." Neurology April, 2004:62:1439–1440.

³ Schwerzmann M, Wiher S, Nedeltchev K, et al. "Percutaneous closure of patent foramen ovale reduces the frequency of migraine attacks." Neurology 2004:62:1399–1401.

⁴ Diener, H.C;, Weimar, C.; Katsarava, Z. "Patent foramen ovale: paradoxical connection to migraine and stroke." Current Opinion in Neurology 2005 Jun;18(3):299-304.
 

Published November 25, 2005.