What Is Epilepsy? What Causes Seizures?
An overview of the neurologic disorder including symptoms, causes, seizure types, and safety tips.
What is epilepsy?
Epilepsy is a problem in the brain that causes reoccurring seizures that happen without warning. A seizure is like an “electrical storm” in the brain. During a seizure, the normal pattern of activity in the brain is temporarily disturbed and brain cells begin to fire abnormally. Having a single seizure does not mean that a person has epilepsy. Lots of people have a seizure and do not go on to develop epilepsy.
Many people with epilepsy manage the disorder well through medication, diet, or medical treatments, but complications with epilepsy can lead to serious health concerns or death. In the United States, an estimated 3.4 million people have epilepsy.
What causes epilepsy?
Epilepsy does not have a single cause. For many people with epilepsy, no cause is ever found. Some known causes include:
- Development abnormalities in the brain
- Infections that injure the brain
- Lack of oxygen to the brain
- Disturbance in blood circulation to the brain (stroke and other vascular problems)
- Tumors of the brain
- Previous trauma (such as brain injury)
- Genetic causes
What is a seizure?
A seizure is a surge of electrical activity in the brain that causes a person to function abnormally. During a seizure, electrical impulses in the brain become overactive and occur at the same time, which leads to irregular brain activity. This can cause changes in behavior and body functioning. Any factor that disrupts normal brain function can lead to a seizure, but a person is not considered to have epilepsy until they’ve experienced two or more seizures.
What types of seizures are there?
Several different types of seizures can occur with epilepsy. Focal seizures begin with an electrical discharge in one limited area of the brain. Primary generalized seizures usually begin with a widespread electrical discharge that involves both sides of the brain at the same time. Neurologists now characterize seizures in three major categories:
- Focal onset, which starts in a network of cells on one side of the brain
- Generalized onset, which involves networks on both sides of the brain
- Unknown onset, which is used when it’s not clear where the seizure started; as more information is learned over time or through testing, the seizure type may be revised to a generalized or focal-onset seizure
Each of the three categories is characterized further to determine the patient’s level of awareness during a seizure and if the patient had motor symptoms (jerking, stiffness, or loss of muscle tone, among others) and/or non-motor symptoms such as changes in heart rate, breathing, pallor, a blank stare, or problems talking or understanding, which may indicate cognitive changes.
What should you do if someone near you is having a seizure?
If you see someone having a seizure, it is important that you stay calm. Stay with them until the seizure is over, and time the length of the seizure. A longer seizure (3 to 5 minutes) means you need to call 911. Don’t try to restrain the person or stop their movements, put anything in the person’s mouth, or try to perform CPR. Read more about what to do if someone is having a seizure.
How is epilepsy treated?
Epilepsy is different for everyone. Some people have seizures that are easily controlled, and their epilepsy doesn’t have much control over their lives. For about 60 percent of those diagnosed, seizures can be controlled with medications and surgical procedures.
Some drugs are more effective for specific types of seizures. In some patients, special diets may help to control seizures when medications are either not effective or cause serious side effects. Some antiepileptic drugs are linked to birth defect risks in pregnant women, so women of reproductive age should discuss their options with their neurologists before conceiving.
Articles on Epilepsy from Brain & Life
Self-Help Tools for Patients with Epilepsy
Tips for patients on how they can take control of their health to help improve their quality of life with epilepsy
6 Facts You May Not Know about Epilepsy
Many things about epilepsy are misunderstood, despite widespread access to information from the internet. Here are some of the things one neurologist tells patients and their families to help reassure them.
What to Do If Someone Near You Is Having a Seizure
First aid for seizures is essential for family members and others to know. Follow this list of tips for what to do when someone is having a seizure.
¿Qué hacer ante una crisis convulsiva?
Una lista de consejos sobre qué hacer si alguien presenta una crisis convulsiva.
Juggling Act
Caring for a special needs child along with other siblings is challenging. We asked parents and other experts how they manage.
Important Reasons to See an Epilepsy Specialist
A patient explains why the care of an epileptologist helped to understand the full scope of her epilepsy.
I have epilepsy. How do I know if I can still drive?
A neurologist advises on how to assess your seizure risk while behind the wheel.
Marijuana as Medicine
A cannabinoid was recently approved to treat certain types of epilepsy. We review the evidence for its approval and whether it can be used to treat other disorders.
Epilepsy Resources from Brain & Life
Epilepsy: The Basics
A quick-hit guide to the basics facts about epilepsy symptoms and treatments in a printer-friendly format.
Navigating Life with Epilepsy
A practical book for both patients and their families and caregivers about living with epilepsy.
Patient Organizations
Advocacy and support groups for those who have epilepsy.
