What causes migraines remains poorly understood. (Not my words.) But in some cases, the headache symptoms have been linked to a common hole in the heart called a patent foramen ovale, or PFO. Since 2000, some medical reports have indicated that repairing the hole for other reasons can also bring migraine relief. These are largely anecdotal, although there have since been medical trials.
The PFO is a small hole between the upper chambers of the heart. Before birth this channel is open, allowing blood to bypass the foetal lungs. When lungs become functional at birth, the channel usually closes. However, it fails to close in a significant minority (15%-25%). This can allow a blood clot from one part of the body to travel through the flap and up to the brain, causing a stroke. At some point a possible link was made when some stroke patients who had had their flap closed reported a decrease in their migraines. It was this that made researchers begin to take an interest in migraine and PFOs.
A PFO is typically harmless and requires no treatment. More than 95% of those with a PFO will never know they have it. But if the PFO remains open, it can lead to stroke, migraines, decompression illness in divers and low blood oxygen levels.
When I first read about PFO and its possible link with migraine, I allowed myself a great deal of optimism and wanted to join the MIST trial (Migraine Intervention With STARFlex Technology), the first such investigation of the connection with migraine in the UK. Of course, I was barking at the moon as I live too remotely to take part in trials and travelling is a major trigger.
My GP agreed that an echocardiogram would be a good idea, though he seemed a little amused by my possibly misplaced excitement. The link between migraine and stroke is often made in the press and in the medical literature. So part of me is always half expecting to have one. And were I to have a PFO and be able to get it remedied, it could fix two things in one go.
Alas my heart looked perfectly fine, pumping away efficiently with no sign of a gap. It was a good experience though, as I had never seen it before and I only had to go to Oban Hospital.
The trial began recruiting in 2005 and those selected didn’t know whether they were being repaired or having a sham operation. They had to have had intransigent migraines with aura, which many medications had failed to help significantly. It was a thorough trial and described thus: A Prospective, Multicentre, Double-Blind, Sham-Controlled Trial to Evaluate the Effectiveness of Patent Foramen Ovale Closure With STARFlex Septal Repair Implant to Resolve Refractory Migraine Headache.
In around 2008 the result showed that closing a PFO appears to have had a positive effect on some migraine sufferers—but only some. It also helped researchers understand more about the benefits of cardiac intervention and this will help future trials, of which there have now been three.
For me it means two things:
- migraine research has to be done for its own sake, not because they find something out accidentally;
- this research will not help me or many like me at the moment.
Photo by Cassi Josh on Unsplash
