Can Migraine and Stroke Cross Paths?

This blog post is written by Dr. Vasileios-Arsenios Lioutas, a staff neurologist at Beth Israel Deaconess Medical Center.

Migraine is a term that is very widely used, and yet rather poorly understood. Many people use the terms ‘migraine’ and ‘headache’ interchangeably. And while it’s true that the most prominent feature of a migraine is indeed a headache, the reality is more complex.

Migraine is common, affecting approximately 15-20% of the people across their lifespan, which makes it the second most common headache type. The first one being tension-type headache. It affects women three times more frequently than men. The pain can be severe. It characteristically affects either the right or left half of the head and is often accompanied by nausea and vomiting. Lights and noises become difficult to tolerate and patients often feel the need to lie down in a quiet, dark room. Those affected find it difficult to carry on with their activities during the attacks, which can last anywhere from a few hours up to three days or even more on rare occasions. For many patients, it can be bothersome, even debilitating sometimes, but essentially nothing more than a form of headache.

However, for a subgroup of migraineurs, things are more complex. Approximately 20-25% of patients with migraine experience additional symptoms, which are known as migrainous ‘aura’. These are most commonly visual. They take the form of zig-zag lines, colorful spots, flashing lights or simply blurring or dimming of vision that usually start as a small spot which gradually builds up in a few minutes, affecting a large part of the visual field. After its peak, it starts to subside gradually and clears up in a matter of another few minutes. Although visual symptoms are by far the most common, patients also experience other focal symptoms, such as pins-and-needles or numbness affecting one side of the body or face, confusion and difficulty finding words, or weakness of one arm or leg. By definition, an aura lasts 60 minutes or less and is then followed by the onset of headache.

By this point many of you will very likely have thought, “Wait a second. Aren’t many of those symptoms very similar to what people with strokes experience?” The answer is yes. Many of the symptoms are similar, or on occasion, identical. And sometimes it is difficult to tell them apart. However, there are some telltale signs: Usually, patients are able to identify their symptoms as migraine aura, simply because they have had it before and they recognize the pattern. 

Migraine auras

• usually don’t last more than 30-45 minutes from the time of appearance to resolution. (There are occasions where they last more than that, but those are rather infrequent).
• have a distinct pattern, in a sense that they tend to build up over minutes, rather than appearing in a lightning fashion, which is the case with stroke.
• are followed or accompanied by a headache. (Again, there are the rare occasions when people experience all the aura symptoms but with no headache, known as ‘migraine without headache’).

 Symptoms that are reason to seek medical attention:

• last much longer than usual,
• have a different quality, or
• appear in a very abrupt fashion as opposed to gradual build up

 This isn’t the only way in which migraine and stroke cross paths. Studies have found that there seems to be an association between migraine with aura and stroke. Those suffering from the condition have twice the risk of stroke compared to the general population. This most certainly creates an uneasy feeling. Those who have migraine with aura might be wondering “So am I going to have a stroke?” The answer is that these findings should be viewed with caution. The fact that there is an association does NOT mean that there is a causative link. In other words, we cannot assume that migraine with aura causes stroke. We have not identified a causative mechanism, so, for the time being, this remains a very interesting observation that we keep investigating further.

The next logical question is probably “So, is there anything I can do to protect myself? What if I take medication to reduce the frequency of migraine attacks? Would that help reduce the risk of stroke too?” The answer to the latter question is likely no, but we don’t know for sure (mainly because the absolute number of strokes in patients with migraine is small, making comparisons and analyses difficult).

There is, however, one very significant fact that applies to young women (those 45 years old and younger). It has been found beyond doubt that using oral contraceptive pills that contain estrogen increases the stroke risk significantly, and if combined with smoking, then it is a really dangerous mix. The stroke risk for those who smoke and use oral contraceptive pills is tenfold. Therefore, young women who have migraine with aura should be cautious regarding oral contraception. That does not exclude it as an option, but it should be explicitly discussed with your doctor.