Epileptic Seizures - 3 Major Groups of Seizures - Epilepsy Foundation Texas

Group of girls at summer camp celebrating one year of being seizure free.Epileptic Seizures – 3 Major Groups of Seizures

There are 3 major groups of seizures: generalized onset, focal onset, and unknown onset. You may experience just one or more than one kind of seizure. The type of seizure you have and symptoms you show depend on what part of the brain the seizures come from.

Generalized onset seizures

These seizures affect both sides of the brain or groups of cells on both sides of the brain at the same time. This includes types of seizures like tonic-clonic, absence, and atonic to name a few.


Focal onset seizures

This term helps describe where seizures begin. Focal seizures can start in one area or group of cells in just one side of the brain. Focal seizures are broken down into two groups by how aware a person is of their surroundings.

    1. Focal Onset Aware Seizures: When a person is awake and aware during a seizure, it’s called a focal aware seizure. This used to be called a simple partial seizure.
    2. Focal Onset Impaired Awareness: When a person is confused or their awareness is affected in some way during a focal seizure, it’s called a focal impaired awareness seizure. This used to be called a complex partial seizure.


Unknown onset seizures

When we don’t know where a seizure begins, it is called an unknown onset seizure. A seizure could also be called an unknown onset if it’s not witnessed or seen by anyone. For example, when seizures happen at night or to a person who lives alone. Symptoms can be described as motor (muscles are involved) or non-motor (muscles are not involved). As doctors learn more about your seizures, an unknown onset seizure may later be diagnosed as a focal or generalized seizure.

Risks Associated With Epilepsy

Sudden Unexpected Death in Epilepsy (SUDEP)

SUDEP is the sudden, unexpected death of someone with epilepsy, who was otherwise healthy. In SUDEP cases, no other cause of death is found when an autopsy is done. Each year, more than 1 in 1,000 people with epilepsy die from SUDEP. The best way to prevent SUDEP is to take care of yourself! Talk to your doctor or epileptologist, follow your treatment, and live a healthy lifestyle.

No one knows what causes SUDEP, but people who experience the following may be at a higher risk:

  1. Uncontrolled tonic-clonic seizures
  2. Seizures that happen at night
  3. Not taking epilepsy medication regularly

Learn more about SUDEP

Status Epilepticus

Status epilepticus is when a seizure lasts longer than 5 minutes or when seizures occur close together and the person doesn’t recover between seizures. The longer a seizure is happening, the less likely it is to stop on its own. Status epilepticus is considered an emergency and must be treated by a medical professional.

Learn more about status epilepticus

Nonepileptic Seizures or Events

Events that look like seizures but are not due to epilepsy are called. Psychogenic Nonepileptic Seizures (PNES) are a common disorder and have many different symptoms. Unlike epileptic seizures, nonepileptic seizures do not show any signs of abnormal electrical brain activity.

PNES may look like epileptic seizures, but their cause is psychological. In most cases, these seizures come from a psychological conflict or an underlying psychiatric disorder. There is no known cause for PNES.

The treatment of PNES is focused on addressing the underlying psychological problem. A person with PNES will not respond to treatment with antiseizure medication. Your neurologist may team up with your primary care provider and a behavioral health provider to find a treatment that works for you.