Epilepsy
What is epilepsy?
Epilepsy (EP-uh-LEP-see) is a brain disorder. It occurs when the electrical signals in the brain are disrupted. This change in the brain leads to a seizure (SEE-zhur). Seizures can cause brief changes in a person's:
- Body movements
- Awareness
- Emotions
- Senses, such as taste, smell, vision, or hearing
Some people may only have a single seizure during their lives. One seizure does not mean that a person has epilepsy. People with epilepsy have repeated seizures.
What are the different types of seizures caused by epilepsy?
There are 2 types of seizures. Each has its own set of symptoms. Partial seizures are the most common type of seizure in adults with epilepsy. They occur when changes in electrical signals begin in one area of the brain. Three kinds of partial seizures are:
Simple partial seizures. This type of seizure affects a small area of the brain. It lasts no more than a few seconds in most cases. Simple partial seizures do not affect consciousness. Sometimes the person just notices unusual feelings.
- Complex partial seizures. These seizures occur through a larger area of the brain. A loss of consciousness occurs. Sometimes the person will stop speaking, act strangely, or have repetitive movements.
- Secondarily generalized seizures. Simple and complex partial seizures that start in one part of the brain can spread through the entire brain. These are known as secondarily generalized seizures. Once the entire brain is affected, there can be a loss of consciousness and shaking of all of the limbs.Generalized seizures occur when the changes in electrical signals spread through the entire brain at once. The most common generalized seizures are:
- Generalized tonic-clonic seizures. This type is also known as grand mal seizures. It causes rapid movements of all limbs for 1 to 2 minutes or more. It also causes a person to become unconscious. Recovery can sometimes take hours.
- Absence seizures. This type, also known as petit mal seizures, occurs mostly in children. It causes staring and changes in the level of consciousness.
What are the causes of epilepsy?
In 70% of people with epilepsy, the cause is unknown. However, in some cases of epilepsy, seizures either run in families or are caused by short-term or lasting scarring or damage to the brain from:
- Head injury
- Serious brain infections, such as meningitis
- Brain tumors
- Brain surgery
- Brain abscess
- Stroke
- Alzheimer's disease or other diseases that change the brain's structure
- Hardening of the arteries or any condition that keeps blood or oxygen from getting to the brain
For a person with epilepsy, certain things can "trigger" a seizure, including:
- Stress
- Lack of sleep
- Infection
- Starvation or dehydration
- Alcohol
- Flashing lights or strobe lights
- Certain medications
- Withdrawing from an addictive drug (including alcohol)
- Fevers (in children)
Who is most likely to have epilepsy?
About 2 million people in the United States have epilepsy. It occurs most often in adults over age 65 and in children, but it may occur at any age. It is not usually possible to predict who is most likely to have epilepsy.