Skip to Main Content


  • A neurologic condition that causes recurring seizures and abnormal electric activity in the brain
  • Types of seizures include generalized, absence, grand mal, and partial seizures
  • Treatment involves medication or surgery
  • Involves Neurology and Neurosurgery
Related Terms:



About 3 million U.S. adults and 370,000 children live with epilepsy, which are seizures are caused by an interruption to the brain’s normal electrical activity. While these interruptions are sometimes linked to a tumor or brain injury, there's no apparent cause for many cases. Luckily, with proper treatment and prevention, most people with epilepsy can achieve an enjoyable quality of life. Yale Medicine is home to some of the world's leading specialists in the treatment of epilepsy.

What is epilepsy?

Epilepsy is the diagnosis for people who have seizures, which are interruptions in the normal electrical activity in the brain. Sometimes, but not always, seizures bring violent convulsions and loss of consciousness; these are called “grand mal” seizures. But there are several other different types of seizures as well. Not all involved a loss of consciousness.  

Some people are merely struck by a very intense feeling. Others have what are known as "absence seizures," which are lapses of feeling unaware, sometimes described as “staring spells."  Seizures can also manifest themselves as shaking in only one part of the body. All seizures are brief, lasting for only a few minutes.

Patients do not have to simply cope with seizures, says  Lawrence Hirsch, MD, co-director of the Yale Medicine Epilepsy & Seizure Program. “We have come a long way in the treatment of epilepsy, and people should seek treatment at an expert center if they are still having seizures. We can get rid of seizures in the majority of patients.”

How is epilepsy diagnosed?

Sometimes a person experiences a single seizure, with no apparent cause, and never has another. If a person has two or more unprovoked seizures -- or one seizure with a high risk of more in the future -- he or she will be diagnosed with epilepsy. The diagnosis is made after a thorough examination by a neurologist. 

In order to properly diagnose epilepsy, doctors often monitor patients using an electrocardiogram (to measure electrical activity of the heart) and an electroencephalogram (to measure electrical activity of the brain). An accurate diagnosis is very important because other serious ailments can be mistaken for epileptic seizures. For example, spells of suddenly passing out and having some jerking or stiffening could be a sign of a different sort of brain condition or a dangerous heart problem.

What are the different types of seizures?

When most people think of a seizure, they picture a violent fit of convulsions. But seizures come in many forms, and they can all look very different to an observer. There are two broad categories of seizures: generalized and partial.

Generalized seizures: Seizures that involve both sides of the brain.

  • Absence seizures. Characterized by brief, seconds-­long “staring spells,” sometimes with rapid blinking.
  • Grand mal seizures (also called tonic clonic seizures). Characterized by violent, whole­ body muscle spasms, shaking, and loss of consciousness that lasts for about three minutes.

Partial seizures (also called focal seizures): Seizures that involve only one part of the brain.

  • Simple partial seizures. Only affecting a small portion of the brain, this type of seizure is characterized by twitching or strange sensations but no loss of consciousness. 
  • Complex partial seizures. Characterized by confusion and an inability to answer questions or interact. The person will not remember some or all of the episode.
  • Secondary generalized seizures. These begin as partial seizures, but then spread to both sides of the brain and turn into a generalized tonic­ clonic seizure, as described above.

How is epilepsy treated?

Most people with epilepsy can be treated effectively with medication but it can be difficult to predict which drugs will help which patients; fortunately, there are many. A doctor will prescribe a specific medication depending on the type of seizures a patient is experiencing.

For example, a common drug called carbamazepine is used to treat partial and generalized seizures. Ethosuximide, another drug, is typically only used for absence seizures, while lacosamide is typically used to treat partial seizures.

Each medication has its own list of associated side effects. Some of the side effects could be seen as beneficial, such as weight loss, headache prevention, decreasing pain, or helping with depression or anxiety. 

Still, in about one-third of epilepsy patients, medication will not be enough to completely control seizures. For those patients, brain surgery is often helpful.

How is Yale Medicine's approach to epilepsy unique?

Yale Medicine's Epilepsy & Seizure Program is internationally known for its ability to help people with epilepsy, including especially difficult cases.

It is a Level 4 center (the highest level), which means that patients have access to the most extensive and advanced medical and psychological treatments and services. Through their cutting-edge research on medication, surgery, devices, and other aspects of epilepsy care, Yale Medicine’s physicians can guide patients toward the latest treatments. They can also connect them with clinical trials that offer access to the newest tests and therapies for epilepsy.