Brain Tumors and Seizures

What is a seizure?

A seizure is caused by a sudden change in electrical activity in the brain. It can cause a few different things to happen, depending on the type of seizure and where it happens in the brain.

It is not known exactly how brain tumors cause a seizure. A few reasons thought to increase your risk are the tumor itself causing changes in the brain, the tumor causing electrolyte changes in your body, less oxygen getting to the brain, and changes to your nerves and neurotransmitters.

The way a brain tumor and seizures affect a person varies greatly. A person may have a seizure that leads to a diagnosis of a brain tumor, but never have another seizure again. Some people have many seizures over the course of their illness. Some people have a warning that a seizure is coming, called an “aura.” An aura can be a headache, a sensory change (smelling a certain smell), or a change in mood.

What are the types of seizures?

The types of seizures are:

• Focal onset aware seizure.
• Focal onset impaired awareness seizure.
• Generalized onset absence seizure.
• Generalized onset motor seizure.
• Unknown onset motor seizure.
• Unknown onset absence seizure.

Each type is named for:

• Where it starts.
• If you are aware during the seizure.
• If and how your body moves during the seizure.
  • Focal onset. The seizure starts in and only affects one part of the brain. This is determined by someone reporting what happened during the seizure. This type is most common if you have a brain tumor.
  • Focal to bilateral. The seizure starts in one part of the brain and spreads to other areas.
  • Generalized onset. The seizure starts in and affects both sides of the brain at the same time. These often start without a warning (no aura).
  • Unknown onset. This term may be used if the seizure was not witnessed, or if you were asleep.
  • Focal aware. Only a small part of the brain is affected, and you are fully aware, even if you can’t speak. You can remember the seizure afterward, even if you cannot describe it.
  • Focal impaired awareness. The seizure is still affecting only one side of the brain, but a little more of the brain is affected. You are confused or unaware of what is happening. You most likely will not remember the seizure afterward. You may feel tired after the seizure.
  • Generalized seizures. Both sides of the brain are affected. You are likely unaware of what is happening. This type is not often related to brain tumors.
  • Motor seizures. You have movement during the seizure. This can look like jerking or twitching movements, lip-smacking, picking at something, or muscles becoming very tense or suddenly weak.
  • Non-motor or absence seizures. There is often no movement during the seizure. It can cause a change in heart rate or breathing, staring, and problems talking or understanding. You can still have sensory effects, such as visual hallucinations (seeing things that are not there), and smelling, feeling, or hearing something that isn’t there. One exception is that you can have small twitches in a certain part of the body, such as the eyelids twitching.

Two people can have the same type of seizure but have very different things happen during the seizure. This is because the actual things a person does during a seizure are based on what area of the brain is affected and what that area controls.

What can raise my risk of having a seizure?

If you have had seizures before, there are some things that can raise your risk of having another seizure. These are:

• Not getting enough sleep.
• Missing doses of medications that help prevent seizures.
• Drugs or alcohol.
• Infections or illnesses.
• Stress – both good and bad stressors.
• Hormonal changes.

How are seizures that are caused by a brain tumor treated?

Your care team may prescribe an antiepileptic or antiseizure medication to prevent seizures. In some cases, a steroid medication is given to reduce swelling in the brain that may be causing the seizures.

How can I help my provider manage my seizures?

• Wear a medical alert bracelet showing that you have seizures.
• If you have an aura or warning sign, move to a safe place to lower your risk of injury.
• If you have seizures regularly, it can be helpful to keep a journal.
  • Record when the seizure happens, how long it lasts, and what happens during the seizure. This may help your provider adjust medications to better control the seizures.
• Talk to your provider about when you should call them and what to do if a seizure happens at night or on a weekend.

How can I help someone with a brain tumor who is having a seizure?

The main goal is to keep them safe. A seizure can last for a few seconds to a few minutes.

• Stay calm, stay with the person, and wait for the seizure to pass.
• Try to move anything sharp or dangerous from the area, place pillows to prevent injury if they fall, or lower them to the ground to avoid a fall. Do not forcibly hold them down.
• Do not place anything in their mouth. If they are lying down, turn their head to the side.
• Make note of how long the seizure lasts and how long it is before they return to normal.
• You do not need to call 911 for most seizures related to a brain tumor. However, you should call 911 for help if the seizure lasts more than 5 minutes, if more than one seizure happens back-to-back, if the person is having trouble breathing, is injured, or if the seizure happens in water. If the seizure is related to a brain tumor, remind the person to call their provider to tell them.

Being a Caregiver for Someone with a Brain Tumor

Being the caregiver of a person with a brain tumor is hard, and the added side effect of seizures can make it even harder. Seizures can be scary, and you may not be sure what to expect each time it happens. Try your best to stay calm and focus on the safety of your loved one during the seizure. Make sure to ask for help or talk with the care team about your concerns. OncoLink has articles to support caregivers and to help during this challenging time.