What You Need to Know About Migraine and Stroke

Migraine attacks are best known for causing painful headaches. Strokes are best known for causing numbness and weakness on one side of the body, as well as slurred speech, confusion, decreased or double vision, dizziness, and loss of balance and coordination, according to the American Stroke Association.

But some migraine attacks also cause numbness, weakness, trouble speaking, visual changes, or dizziness, the American Migraine Foundation notes.

And some strokes cause a sudden, severe headache.

Given the sometimes overlapping symptoms of migraine and stroke, it can be difficult to tell which one you’re having — and whether you should go lie down in a dark, quiet room or go immediately to the emergency room.

To complicate matters further, it’s possible for a person to have both a migraine attack and a stroke at the same time.

So how should you respond to symptoms that could be from one or the other condition? And beyond common symptoms, is there a relationship between migraine and stroke?

How Do I Know if It’s a Stroke or Migraine Attack?

Migraine is a neurological disorder characterized by repeated episodes of symptoms, called attacks, that usually include head pain accompanied by nausea, vomiting, and sensitivity to light, touch, smell, or sound. The chain of events that occurs in the brain as a migraine attack unfolds is complicated and not fully understood.

One theory of migraine attacks, described in The Journal of Neuroscience, is that it involves hyperexcitable neuronal (nerve) networks in the brain that, when triggered, cause the release of a variety of chemicals known as neuropeptides (also known as neurotransmitters). Neuropeptides, in turn, cause the dilation and contraction (widening and narrowing) of blood vessels, leading to the symptoms associated with migraine.

A stroke is an episode of decreased blood flow in part of the brain. A stroke can be caused by a blockage in a blood vessel (called an ischemic stroke) or by bleeding from a blood vessel (called a hemorrhagic stroke). In either case, the part of the brain normally served by that blood vessel is starved of oxygen and nutrients, causing tissue injury or death of that portion of the brain. Stroke can also be fatal, particularly if it affects the part of the brain that controls breathing and other major organs, such as the heart.

Both migraine and stroke can cause focal neurological deficits, or abnormal function in specific locations in the body, says Ava Liberman, MD, an assistant professor of clinical neurology at NewYork Presbyterian–Weill Cornell Medical College in New York City. Focal neurological deficits can include weakness or loss of muscle control, numbness and tingling in an area of the body, and problems with speech, vision, or hearing caused by a problem in the brain or nervous system, according to the MedlinePlus.

As a result, a small number of people who arrive at the emergency department with migraine are treated with clot-busting drugs when doctors believe the person is having a stroke, since how quickly doctors are able to stop a stroke is crucial to the person’s recovery and prognosis, says Dr. Liberman. Usually, this does not harm the person, and once the dust settles, the person is correctly diagnosed with migraine, she says.

Which Migraine Types Can Resemble Stroke?

Migraine with aura is the type of migraine most commonly mistaken for stroke, according to Everyday Health's network site Migraine Again. The “aura” in migraine with aura is a set of visual, sensory, or other nervous system symptoms that usually last between a few minutes and an hour, and usually precede the headache phase of an attack. However, it’s possible to have aura symptoms with no headache.

About 25 percent of people with migraine experience aura, according to the StatPearls.

Common aura symptoms are visual effects such as bright flashing lights or spots or zigzags in a person’s field of vision. Other possible aura symptoms include losing sight for short periods; having tingling and numbness in the face, hands, or other areas of the body; hearing sounds such as buzzing or music; and having speech and language problems such as having difficulty finding words or trouble understanding words. Any of those symptoms could easily be assumed to be a sign of a stroke.

Another migraine type that can cause stroke-like symptoms is a very rare inherited condition called familial hemiplegic migraine, or sporadic hemiplegic migraine if it occurs in only one person in a family. Symptoms of a hemiplegic migraine attack are the same as migraine with aura but also include motor, or muscle, weakness on one side of the body that may persist for days or even weeks, per Migraine Again. Rarely, hemiplegic migraine can cause fever, confusion, loss of consciousness, or even coma.

What if I’m Not Sure if It’s Migraine or Stroke?

“If you have a first-time migraine, and you have abnormal symptoms with it, the experience can be very scary,” says Anum Riaz, MD, an assistant professor of neurology at the University of Toledo in Ohio.

Dr. Riaz notes that it’s always a good idea to be evaluated for stroke if you experience symptoms that could indicate either a stroke or a migraine attack, including confusion; suddenly being unable to move your face, arm, or leg, especially on one side; or having trouble speaking.

Liberman concurs, saying, “People with migraine headaches usually know their symptoms, and they should always act on the red flag warning signs of stroke, which include sudden numbness, vision loss, and weakness.”

As a general rule of thumb, migraine typically causes positive sensations — feeling tingly, prickly, seeing spots — while stroke is linked with the absence of sensations, that is, feeling numb or weak, and having vision loss rather than seeing spots, says Riaz.

Another difference worth noting is that stroke symptoms tend to occur suddenly, while migraine symptoms typically develop gradually over the course of hours.

Migraine With Aura Raises Stroke Risk Slightly

While migraine typically does not cause stroke, having migraine with aura can put people at a slightly higher risk of stroke. Liberman stresses that the increased risk is generally small, and people who have migraine should get to know their symptoms and not live in fear of having a stroke.

When stroke occurs as a complication of migraine with aura, it’s called migrainous stroke or migrainous infarction. Migrainous stroke is an uncommon occurrence. According to an article on the link between migraine and stroke, it accounts for only 0.2 to 0.5 percent of all ischemic strokes. In the United States, that would mean about 1,400 to 3,500 out of the nearly 700,000 ischemic strokes that occur each year, according to Centers for Disease Control and Prevention (CDC) statistics.

While many theories have been put forth about why migraine with aura raises the risk of stroke, ultimately, migraine researchers don’t know why this association exists.

How Can I Lower My Stroke Risk?

“Given that migraine with aura is a vascular risk factor, the best thing people with migraine can do is be extra-engaged in reducing the risk factors for stroke that everyone should pay attention to,” says Liberman.

According to the CDC, the leading causes of stroke are high blood pressure, high cholesterol, smoking, obesity, and diabetes.

You can lower your risk of stroke by following a healthy diet, maintaining a healthy weight, being physically active, quitting smoking if you smoke, and avoiding drinking too much alcohol if you drink. Working with your doctor to control any medical conditions you may have — such as high blood pressure, high cholesterol, obesity, diabetes, or heart disease — will also help to lower your risk of stroke. And your doctor can help you quit smoking.

Women of childbearing age who have migraine will want to discuss their stroke risk with their doctor when choosing a method of contraception. While older formulations of birth control pills with higher amounts of estrogen were known to raise stroke risk, this risk is lower for newer formulations with a lower dose of estrogen.

Still, even among the newer birth control pills, the lower the estrogen, the lower the risk of stroke, as shown in a study that compared pills with 20 micrograms of ethinyl estradiol with those containing 30 to 40 micrograms in women ages 15 to 49.

RELATED: How to Choose Birth Control When You Have Migraine