What’s the Connection Between MS and Seizures?

By Marygrace Taylor
Published on May 4, 2026
Medically Reviewed by Michael R. Yochelson, MD, MBA

A seizure can be scary. And when you’re already living with multiple sclerosis (MS), it’s easy to wonder whether the episode could somehow be related — and if you now have a new symptom you’ll need to manage.

Though seizures aren’t a typical MS symptom, they happen in around 5 percent of people with the disease. That’s three to six times higher than the seizure rates for the general population.

[1] Having MS for longer or having secondary progressive multiple sclerosis (SPMS) seems to increase the chances.

[2]

Fortunately, MS-related seizures can be controlled with the right medications. Here’s what you should know about this uncommon symptom and what it may mean for your health.

What a Seizure Looks and Feels Like

A seizure is an abnormal surge of electrical activity in the brain.

[3] There are different types that can cause different types of symptoms.

• Focal seizures start on one side of the brain. They can cause feelings of déjà vu or confusion, cause someone to make abnormal movements (like twitching or jerking), or sensory symptoms (like seeing bright flashing lights). If a focal seizure spreads to both sides of the brain, it can cause a person to briefly lose consciousness.[4]
• Generalized seizures start on both sides of the brain at the same time. They cause people to lose consciousness — either briefly (which can look like the person is spaced out) or for a few minutes while the person has muscle jerks or spasms.[5] When most people picture a seizure, this is what they’re thinking of.

MS can also cause certain movements that may mimic seizures, but that have a different underlying cause.

[6] “Patients can get spasticity that causes their legs to shake. They can also have muscle twitching called paroxysmal dystonia, that can come and go and look a lot like a seizure,” says Michelle Apperson, MD, PhD, the director of the UC Davis Multiple Sclerosis Program in Sacramento, California.

Causes of Seizures in MS

Generally speaking, seizures happen when a sudden, unusual electrical signal fires in the brain.

[3] The firing can stem from genetic factors, brain abnormalities, brain injuries, or infections, as well as things like stress, sleep deprivation, alcohol withdrawal, or the use of certain medications.

[7]

Seizures caused by MS aren’t fully understood, but experts have a few possible theories. During an MS relapse, inflammation from an active lesion could make the brain’s neurotransmitters more excitable, causing electrical misfirings that lead to seizures.

[2] This can happen at any point during the course of MS, and in some cases, it could be the thing that leads a person to their MS diagnosis.

“We’ve had cases where a person’s initial symptom was a seizure, they get an MRI, and it shows an active MS lesion was likely the cause of the seizure,” says Dr. Apperson.

It’s also possible that long-term MS may lead to brain changes that make seizures more likely, research suggests. Over time, lesions can cause brain scarring that may alter the brain’s electrical activity. Having MS for many years may also lower the brain’s concentration of GABA, a neurotransmitter that’s involved in regulating the brain’s electrical impulses.

[2]

All that said, it’s also possible for a person with MS to have a seizure for reasons that aren’t related to their MS at all, says Eric Williamson, MD, an associate professor of neurology at UCLA Health a and member of the UCLA Multiple Sclerosis Program. The best way to figure out what’s driving the seizures is to get evaluated by a neurologist.

Diagnosing Seizures in MS

Understanding what’s causing your seizures is the first step toward managing them. Your care team will rely on a few different diagnostic tools, including:

[8]

• Medical History A history of your seizure symptoms can offer clues about whether the seizures are related to your MS or caused by something else, and whether you’re likely to have more seizures.
• Electroencephalogram (EEG) This noninvasive test uses small metal electrodes applied to the scalp to measure electrical activity in your brain. “We’re looking for areas in the brain that show slowed activity or electrical sparks, which you can continue to see after the seizure has ended,” Apperson says. You may get video monitoring during the EEG, too. If you have more seizure symptoms, your team can look at the EEG to confirm whether electrical changes are happening in your brain at the same time.
• Brain Imaging Tests Magnetic resonance imaging (MRI) can reveal whether an active MS lesion is triggering the seizure, says Apperson.
• Additional Tests, as Needed If the above tests suggest that your seizures aren’t related to your MS, your care team might recommend blood, neurological, or behavioral tests to look for another underlying cause.

Seizures can be a one-off event that are set off by a specific trigger, including an active MS lesion. If you’ve had more than one seizure without a known underlying cause (like an active lesion) more than 24 hours apart, you’ll be diagnosed with epilepsy.

[9]

Treatment for Seizures in MS

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