“There times when a patient experiences an event, and it’s not immediately apparent if they’ve had a seizure or a migraine,” says Lauren Doyle Strauss, DO, a headache specialist and an assistant professor at Wake Forest Baptist Health in Winston Salem, North Carolina. “That’s because there can be an overlap in some of the ways that people describe both of those problems,” Dr. Strauss explains. There is evidence that the two disorders are associated with each other: The prevalence of migraine in children with epilepsy — which causes seizures — is estimated at 8 to 24 percent, which is approximately double the risk found in the general population, according to a paper published in the Journal of Headache and Pain. This type of seizure, which is triggered by a migraine attack with aura, is considered a rare but real complication of migraine, according to the International Headache Society (ICHD-3).

A Seizure Can Be Part of Epilepsy or Migraine

To better understand the connection between migraine and seizures, it’s helpful to understand what a seizure is, says Strauss. “You could describe it as a sudden surge of electrical activity in the brain,” she says. Johns Hopkins Medicine defines a seizure as “a burst of uncontrolled electrical activity between brain cells (also called neurons or nerve cells) that causes temporary abnormalities in muscle tone or movements (stiffness, twitching, or limpness), behaviors, sensations, or states of awareness.” People are diagnosed with epilepsy after they have had two or more unprovoked seizures, according to the Centers for Disease Control and Prevention (CDC). RELATED: Seizures Not Caused by Epilepsy

Seizures Are Different Depending on Where They Occur in the Brain

There are two categories of seizures: generalized seizures, which affect both sides of the brain, and focal seizures (also called partial seizures), which take place is just one part of the brain, according to the CDC. Depending on which part of the brain is affected, that’s the area that will manifest symptoms, explains Strauss. “For example, if the area of the brain that controls your language is affected, then that makes sense that your language may not be normal during the seizure. It could cause you to stutter or have trouble with your words,” she says. Similarly, if someone had a seizure in the area of the brain that controls your vision, that may correlate with visual symptoms, says Strauss. Just because the seizure begins in one part of the brain doesn’t mean it stays there. “A seizure can start in one area of the brain and can quickly spread to other areas or across the entire brain,” she says. People can experience a seizure in a lot of different ways, says Strauss. “You can have a change in your awareness; others may notice that you’re staring. You may have amnesia, where you forget or are unaware there’s been a change in your surroundings, or you don’t even know that a seizure happened,” she says. “Your whole body can shake — that’s called a grand mal seizure, and it’s often what people think about when they when they think of seizure. You can also have shaking in one arm or just one leg,” says Strauss.

Can a Migraine Attack Cause Someone to Have a Seizure?

“We don’t fully understand what provokes a migraine and what provokes a seizure; it could be possible that something provokes both,” says Strauss. Headaches can occur on their own and be unrelated to seizures, or a headache can be a symptom that happens before, during, or after a seizure, says Strauss. “We use the terms ‘preictal,’ which is before the seizure, ‘ictal,’ which is during the seizure, and ‘postictal,’ which is after the seizure,” she says. Preictal and ictal headaches are relatively rare and usually don’t last long, according to the Epilepsy Foundation. Headaches that occur after a seizure are more common. A survey of 372 patients attending an epilepsy clinic found that 45 percent of them had experienced a postictal headache, and more than 1 in 5 always had one.

Is It a Migraine Attack or a Seizure?

“If a person is having migraine symptoms that aren’t responding to migraine therapies, and they have neurologic symptoms associated with the headaches, it’s reasonable to take a step back and say, ‘Are we sure these are migraines?’” says Strauss. If you have a grand mal seizure, it’s usually clear that it’s a seizure, she says. “However, with focal seizures or partial seizures or complex partial seizures, these more subtle seizures where it’s only affecting one part of the brain, it can be difficult to always know: Is this migraine, or is this seizure?” There are some differences between headaches associated with seizures and the headache of a migraine attack that can help a doctor distinguish between the two, says Strauss, including the following:

Prodrome symptoms can occur with either migraine or seizure. The prodrome is the warning that the migraine is going to happen, says Strauss. “In migraine, a person can have nausea, vomiting, weakness, stiff neck, paleness, and yawning, which can occur starting hours or days before the pain portion of the migraine.” In seizures, symptoms such as a “rising” feeling in the stomach, perception of certain smells, feeling of numbness, or a sense of déjà vu may precede motor symptoms.Automatism suggests a seizure. “In seizures, we can have something called an automatism, which is where there can be involuntary movements. This can include things like chewing movements or a movement that looks like you’re picking lint off your clothes — fidgety movements,” Strauss says. There aren’t automatisms with migraine, and so if you experience that, it suggests a seizure-related headache, she says.Visual disturbances may differ between migraine and seizure. You can experience visual disturbances in both seizures and migraine, says Strauss. “When it’s related to seizures, these are usually going to be very short in duration, and patients will describe things like circular colored scribbles that can move horizontally to the other side,” she says. Visual disturbances in migraine emerge more gradually, over minutes to hours, and are most commonly scintillating scotoma, where the disturbance stays in one spot and grows from that point, says Strauss.Memory loss usually suggests a seizure. “Headaches can cause confusion in both cases, but if the person actually can’t remember that the headache happened, we would think it may have been related to seizure,” says Strauss. However, transient global amnesia, or a sudden, temporary episode of memory loss, can occur with migraine.Onset of headache differs between migraine and seizure. “Migraine pain tends to come on gradually, whereas a headache related to seizure can come on very suddenly; it hits you hard and fast,” says Strauss.Unusual tastes or smells suggest a seizure. If a person has a strange smell or a strange taste along with the headache, that would be consistent with seizure and not usually migraine, says Strauss. “People will describe smells like burnt fire or bananas or they taste something metallic. It’s usually something strange and noxious, and no one else around them is smelling it or tasting it,” she says.

Can Hemiplegic Migraine Cause Seizures?

Sporadic hemiplegic migraine is a very rare form of migraine that has different associated genes with it, says Strauss. There have been reports that some people can have alterations in consciousness with this type of migraine, according to the National Organization for Rare Disorders (NORD). It’s not certain how many people have this type of migraine, but studies in a population of Denmark estimated it affects about 1 in 10,000 people in the general population. This type of migraine can have a very long aura phase — lasting anywhere from an hour to as long as a week. The hallmark symptom of hemiplegic migraine is weakness on one side of the body that happens just before or during the headache phase. In severe attacks, hemiplegic migraine can cause confusion, memory loss, personality or behavioral changes, seizures, and even coma, according to MedlinePlus. Patients can sometimes be concerned about whether they have hemiplegic migraine or seizures — there is some interesting overlap, says Strauss. “We have to be careful we’re not missing a diagnosis of seizure; just because you have headache and you have weakness with it, you don’t want to assume that it’s hemiplegic migraine,” she says. For example, people who have focal seizures that affect the motor control center in the brain when the seizure ends can get weakness in their arm, their leg, or both, says Strauss. The best way to distinguish between hemiplegic migraine and seizures is to do an electroencephalogram (EEG).