Types of Seizures

Overview

Main types of seizures

There are two main types of seizures,1 named based on where the seizure starts in the brain.

Focal seizures

• Focal seizures – also called “focal onset seizures” – begin on one side of the brain. They may cause changes in awareness, behavior, or sensation, or abnormal movements usually on just one side of the body.

• It is possible for this type of seizure to spread to both sides of the brain. When this happens, it can cause a loss of consciousness and movements on both sides of the body.

Generalized seizures

• Generalized seizures – also called “generalized onset seizures” -- begin (or appear to begin) on both sides of the brain at the same time.
• They usually cause a loss of consciousness or awareness and may also cause abnormal movements on both sides of the body.

A person with epilepsy can have more than one type of seizure.

Describing seizures

Health care providers may use these medical terms when talking about the muscle movements made during seizures:

• Tonic: Muscles become stiff.
• Atonic: Sudden, unexpected loss of muscle strength or tone.
• Myoclonic: Short, lightning-quick, jerking movements.
• Clonic: Periods of rhythmic shaking or jerking movements.

About focal seizures

There are two main types of focal seizures. They are distinguished by whether they cause a loss of awareness. These are:

• Focal onset aware seizures.
• Focal impaired awareness seizures.

Focal onset aware seizures

Focal onset aware seizures do not cause a loss of awareness. A person can sometimes talk during these types of seizures and remember them after they happen. These types of seizures used to be called “simple partial seizures.”

These types of seizures may make someone:

• Feel a sense of déjà vu.
• Have a funny feeling in their stomach.
• Have abnormal movements.

Focal impaired awareness seizures

Focal impaired awareness seizures cause a loss of awareness. They may or may not cause abnormal movements. They used to be called "complex partial seizures."

These types of seizures may make someone:

• Confused or dazed.
• Pick at their clothes.
• Smack their lips.
• Unable to respond to questions or directions for a few minutes.

About generalized seizures

There are many types of generalized seizures. They are primarily distinguished by whether they impact a person’s awareness and body movements. Two main types include:

• Generalized motor seizures.
• Generalized nonmotor seizures.

Generalized motor seizures

Generalized motor seizures cause a person to lose awareness and have muscle movements. Muscles may stiffen, relax, jerk, spasm, or shake. People with this type of seizure may also have a combination of these movements.

"Tonic-clonic" seizures are a kind of generalized motor seizure that many people think of when they hear of a seizure. These cause muscle stiffness and rhythmic jerking. They usually last a few minutes and may cause confusion and tiredness afterwards. These used to be called "grand mal" seizures.

Generalized motor seizures may make someone:

• Cry out.
• Lose consciousness.
• Fall over or down to the ground.
• Have muscle jerks or spasms.

Generalized nonmotor (absence) seizures

Generalized nonmotor or "absence" seizures cause short, sudden lapses of consciousness. They often may not even be noticed. They used to be called "petit mal" seizures.

These types of seizures may make someone to:

• Stare into space.
• Blink their eyes quickly.
• Make chewing or hand movements.

Seeking Emergency Help

Seizures don't usually require emergency medical attention. But there are situations when emergency medical care is needed.

Call 911 if these things happen:

• The seizure lasts longer than 5 minutes.
• Another seizure starts soon after the first one.
• The person has trouble breathing or waking up after the seizure.
• The person is injured during the seizure.
• The seizure happens in water.

Important reasons to seek emergency services:

Call 911 if the person having the seizure:

• Has never had a seizure before.
• Has diabetes and loses consciousness.
• Is pregnant.