Within 30 days of undergoing surgery, those who suffer from migraines are likelier than those who do not to be readmitted to the hospital and are at increased risk of stroke. That’s according to a January 2017 BMJ study, “Migraine and risk of perioperative ischemic stroke and hospital readmission.”
Of 124,558 surgery patients studied, 8.2 percent (10,179) had migraine diagnoses, and 12.6 percent (1,278) of the latter group had migraines with aura, meaning they experienced visual impairments before getting migraines. Those with migraines were at higher risk (1.75) of stroke following surgery, the study found, noting a difference in the odds ratio between those with aura (2.61) and those without (1.62). Patients should tell their physicians if they suffer from migraines, but they shouldn’t let the study results scare them, according to study author Matthias Eikermann. “The total risk is still low, but it is important for their physicians to know about it,” says Dr. Eikermann, associate professor of anaesthesia at Harvard Medical School and clinical director of Massachusetts General Hospital’s Critical Care Division.
Dr. Eikermann himself suffers from migraines with aura. “I would have a 160 percent increase for stroke,” he says. “That is significant if you look at the total numbers.” Having helped run a pain clinic at a German university hospital prior to moving to Boston, Dr. Eikermann has seen many patients with migraines. “I’m interested in finding out if my work in the operating room in an intensive care unit, which is now my daily bread, interferes with the experiences that I had early on with patients with migraines,” he says.
There has been prior research connecting migraines and strokes, including a 2006 JAMA study by Dr. Eikermann’s co-author Tobias Kurth titled “Migraine and Risk of Cardiovascular Disease in Women,” but the studies have examined longer periods of time. “We know if you look at 20 years, there’s the association,” Dr. Eikermann says. Migraine patients have hyper-excitable brains. “The neurons do funny things. You can get a migraine, and all of a sudden you have some impairment of the ability to see regularly. And then later on you get this headache,” Dr. Eikermann says. “In parallel, the brain consumes more oxygen, and that makes the brain more vulnerable to a stroke.”
Strokes involve critical reductions in oxygen delivered to the brain, which can be triggered by migraine attacks, which consume extra oxygen. “That is probably the mechanism why there’s an increased vulnerability to stroke in those patients,” Dr. Eikermann says. While other studies looked at cohorts over decades, Dr. Eikermann and his colleagues chose to focus on the short span of 30 days post-surgery. During surgery, patients are already vulnerable to stroke, due to decreases in blood pressure as a result of anesthesia or bleeding, and there is inflammation and increased blood coagulation.
“We were thinking since the risk of stroke is so much higher after surgery than during the normal day in the life, that would probably be a scenario where migraine patients with a baseline increase in their stroke risk would be particularly vulnerable,” he says. And of course the stress leading up to surgery and the pain can further increase oxygen consumption. Of course, further research must be conducted, notes Dr. Eikermann, who already has several in the pipeline. “There is not a super high level of evidence at this point, but based on just good clinical judgment, there are a variety of different things that physicians can do to modify the stroke risk in patients,” he says. Those include giving aspirin to patients who are at high-risk for stroke, and anesthesiologists administering medications to control blood pressure.
But there is still a cultural challenge that needs to be overcome, according to Dr. Eikermann. “Migraines still aren’t considered a real disease,” he says, noting the term is often misconceived with gendered stereotypes. “But there is more and more literature clearly showing it’s absolutely a relevant and debilitating disease. This study adds additional information to that conclusion.” And as hospitals are increasingly trying to mitigate the financial risks they have to assume when patients are readmitted within a month, this research can carry wife economic implications. “Who knows what is going to happen with healthcare reform now,” Dr. Eikermann admits. But one thing is clear. “All hospitals are super keen on making sure patients don’t get back to the hospital within 30 days,” he says. “Migraines are independent risks of hospital readmission.”