Why this association between the two exists is the subject of much research, but so far scientists only have theories.
Similarities
Stroke and migraine are both events that can cause a variety of symptoms, which means that there isn’t one defined trademark symptom that’s a guaranteed indication of either one. Each condition is characterized by a number of features, and usually, not all of these features are present with every stroke or every migraine.
The strong overlap between the symptoms of migraine and those of stroke is due to changes in the brain. Some of the similar symptoms the two conditions can share include the following.
Disorientation: Both conditions can cause a sense of disorientation, although in a stroke, this is generally characterized by confusion, while the disorientation of a migraine is usually caused by extreme pain. Vision changes: The vision loss of a stroke is usually described as an area of blindness from one or both eyes, while the vision changes of migraine are typically described as flashing lights or squiggly lines. A severe migraine can indeed cause true vision loss as well. Vertigo: Both conditions are associated with dizziness or a spinning sensation. A stroke is far more likely to produce physical balance and coordination problems than a migraine. Feeling unwell: Generally, both conditions produce an overall sense of feeling vaguely terrible. People who have migraine headaches are normally able to describe their symptoms in great detail, while people who have a stroke are often unable to describe their symptoms and are sometimes unable to communicate altogether. Abnormal feelings and behavior: Both stroke and migraine may cause you to feel and act like you’re not yourself. And both conditions can feel as if they are continuing to get worse with no end in sight. Pain: Migraines are usually associated with pain, while strokes are not typically associated with pain. However, sometimes strokes, particularly those caused by bleeding in the brain (hemorrhagic strokes) or tearing of the arteries (arterial dissection), do cause pain. The severe pain of a migraine can make it difficult to determine whether the overwhelming head pain is indeed a stroke or a migraine. Often, the head pain of a stroke is sudden and overwhelming, while the pain of a migraine is typically more gradual. Other physical symptoms: Strokes typically cause one-sided weakness, one-sided numbness, partial vision loss, speech difficulties, or a combination of these symptoms. Migraines aren’t usually associated with weakness, numbness, vision loss, or speech difficulties, but on rare occasions, they can cause these physical symptoms. Hypertension: Sudden bouts of extremely high blood pressure can trigger a stroke or a migraine if you’re already predisposed to these conditions.
Differences
A stroke and a migraine may overlap when it comes to some symptoms, but there are also several important distinctions between the two that can help differentiate them. More importantly, the results of a medical evaluation of these conditions are quite different, as is the treatment.
Migraines usually recur: A migraine is often a recurrent event. Most of the time, your first migraine doesn’t produce neurological deficits such as weakness, loss of sensation, or vision loss. However, there are exceptions to this rule and sometimes a person’s first-ever migraine can be associated with neurological deficits. Migraines often have triggers: Migraines tend to be associated with triggers such as food, hormonal changes, stress, lack of sleep, loud noises, and chemical smells. A stroke is not normally associated with such everyday triggers and is more likely to be precipitated by extreme alterations in blood pressure or an irregular heartbeat, both of which are events that you would not expect to feel. Stroke risk increases with age: Strokes are far more likely to affect individuals who are older than age 60 and who have risk factors such as heart problems, hypertension, blood disorders, or high cholesterol. These risk factors are not associated with migraines, which generally start in your 20s or 30s; it’s highly unusual for a person to begin having migraines after the age of 50. Migraines are temporary: One of the important differences between a stroke and a migraine is how long the episode lasts. A stroke is permanent, while a migraine is temporary. A stroke causes permanent brain damage due to a lack of blood supply to your brain, which injures your brain tissue, often leading to permanent disability. A migraine is a temporary event that eventually improves and doesn’t cause brain damage.
What’s Behind the Link
The connection between migraine and stroke is complex and remains something that is not well-understood. But in looking into the reasons behind some shared symptoms, as well as the increased risk of stroke with migraine, scientists have come up with some theories regarding the link:
Cortical spreading depression: This mechanism involves a wave of changes in the brain that spreads along the cerebral cortex, the outermost layer of the brain, leading to reduced blood flow and inflammation. Cortical spreading depression is considered to have a major role in migraine, particularly in migraine with aura, and it may also play a role in strokes. Genes: There are some rare gene mutations that scientists are discovering increase the risk of both stroke and migraine. Migraine medications: Ergotamines like dihydroergotamine (DHE) cause blood vessels to constrict, which could slightly increase the risk of stroke. Triptans like Imitrex (sumatriptan) and Zomig (zolmitriptan) may also create the same problem, but much less evidence has been found with regard to these drugs. Patent foramen ovale (PFO): The association between PFO, a hole in the heart that doesn’t close after birth, and migraine is unknown due to mixed study results, but some experts believe there’s a link between PFO and migraine with aura. As far as its relationship to stroke, PFO has been linked to certain types, as well as to transient ischemic attacks (TIAs or mini-strokes which, unlike true strokes, are reversible).
Stroke During a Migraine
In rare instances, a stroke can occur during a migraine attack, usually in young women who have a history of migraine with aura. This is called a migrainous infarction, and it’s so uncommon that the vast majority of people who have migraines will never experience this rare complication. Scientists are still trying to understand why this happens and what the cause-effect relationship is.
Risk Factors
Migraine and stroke are both associated with a genetic tendency. If you have a family history of stroke, you’re more likely to have a stroke. Similarly, if you have a family history of migraine, you’re much more likely to experience migraines.
Of course, both migraine and stroke are associated with additional risk factors that must be independently considered.
It’s particularly important to also be aware of risk factors that can further increase the inherent risk of stroke in migraineurs:
Having migraine with aura (the risk may be up to twice as high as it is in people who experience migraine without aura) Being under the age of 45 Having frequent migraines Taking birth control pills that contain high levels of estrogen Smoking
The Role of Birth Control Pills
Oral contraceptives slightly increase the risk of stroke for anyone who is taking them, and this risk goes up when you have other risk factors for stroke. If you’re taking birth control pills to help prevent menstrual migraines and/or as a form of birth control, you might be wondering if it’s safe for you to take them when it comes to your stroke risk. Whether or not birth control pills are right for you depends on a number of factors.
There are two types of hormonal oral contraceptives—the combination pill, which contains both estrogen and progestin, and the progestin-only pill, often called the mini pill. Older formulations of birth control pills contained much higher dosages of estrogen than they do now, and studies have shown that it’s these higher doses that have the strongest association with stroke.
As mentioned, if you have migraine with aura, you have a higher risk of stroke than people who don’t experience aura. Taking combination birth control pills that contain 50 µg or more of estrogen may increase this risk even further, though there isn’t sufficient evidence to say if this is true with today’s lower estrogen doses.
If you have migraine without aura, you can probably safely take combination birth control pills with low doses of estrogen as long as you have no other stroke risk factors such as:
Being over the age of 35 (aging is a risk factor for stroke) Smoking Other medical conditions like diabetes, high blood pressure, heart disease, high cholesterol, or sickle cell disease Being obese A family history of stroke under the age of 45
For migraines with aura that are related to your menstrual cycle, your healthcare provider may prescribe you an oral contraceptive with the lowest dose of estrogen possible (as long as you don’t have any other stroke risk factors) since you likely need the hormonal balance to keep your migraines at bay. If you just need contraception, there are a variety of other options available that don’t carry the increased stroke risk with them.
Treatment
Migraines and strokes are managed very differently from each other. Migraines require treatment with medication, which doesn’t prevent or improve a stroke. The medications used for stroke don’t prevent or improve migraines either.
After a stroke, most people have some level of disability and need to participate in physical therapy and rehabilitation.
A Word From Verywell
Since having migraines is associated with a higher risk of stroke, especially if you have migraine with aura, it doesn’t hurt to work on reducing any other potential stroke risk factors that you can control. For instance, if you’re overweight or obese, talk to your healthcare provider about a healthy eating and exercise plan. If you smoke, look into smoking cessation options. If you have other health conditions, make sure to see your healthcare provider for follow-ups and stick to your treatment plan. Staying on top of your health can help you feel better, be more empowered, and could significantly improve your quality of life.