Multiple Sclerosis Centers of Excellence
Seizures and Multiple Sclerosis
Marissa Kellogg, MD, MPH, FAES
Seizures and epilepsy occur in a small minority of people with MS. Recent studies using large national databases in different countries show a cumulative incidence of 3-5% of people with MS develop epilepsy. An additional 1-2% of people with MS will experience a single lifetime seizure, but they do not develop epilepsy (i.e., recurrent seizures). In other words, approximately 1/20 people with MS will develop epilepsy and 1/50 will experience a single lifetime seizure but not develop epilepsy. The more physical disability a person has from MS (as assessed using the EDSS disability scale for MS), the more likely they are to develop seizures. Also, the longer duration someone has MS, the more likely they are to develop seizures.
A seizure is a sudden, uncontrolled electrical disturbance in the brain. It can cause changes in behavior, movements or feelings, and changes in levels of consciousness or alertness. There are many different types of seizures, which range in symptoms and severity. They typically last 30 seconds to 2 minutes. A seizure that lasts longer than 5 minutes is either 1) a medical emergency, or 2) a different condition that looks like a seizure but is in fact something else. When someone carries a diagnosis of epilepsy, that means they have had at least two seizures in their lifetime and are at higher risk for ongoing seizures without treatment.
Different types of brain injury or structural brain abnormalities can cause seizures and epilepsy. Common causes include stroke, traumatic brain injury, tumor, brain infection, or MS. However, many times the cause is unknown. Additionally, most people with MS, stroke, or brain injury do NOT develop epilepsy – so we don't completely understand why some people with similar brain conditions develop seizures while others do not. Possible reasons for increased seizure risk include a genetic predisposition, prior infectious or toxic exposure, or increased brain inflammation.
Fortunately, we have very effective anti-seizure medications (ASMs) to prevent recurrent seizures in people with epilepsy. 60-70% of people with epilepsy will achieve seizure-freedom on medications alone – usually by taking just a single medication. Side effects are highly variable between individuals and different medication options – but they can negatively affect quality of life. Some ASMs may interact with MS medications, but fortunately most ASMs do not. It is important to discuss these factors with a prescribing provider and pharmacist to come up with an optimal treatment plan. For the remaining 30-40% of people with epilepsy whose seizures are not controlled with medications alone, there are multiple surgical treatment options, some of which are potentially curative. If you have further questions about seizures or epilepsy, talk to your healthcare provider. They can refer you to a VA seizure specialist if needed.
