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.
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.
Generalised seizures
- Generalised seizures – also called “generalised 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.
- 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.
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:
- Generalised motor seizures.
- Generalised nonmotor seizures.
Generalised motor seizures
Generalised motor seizures cause a person to lose awareness and have muscle movements. Muscles may stiffen, relax, jerk, spasm, or shake.
“Tonic-clonic” seizures are a kind of generalised 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.
Generalised motor seizures may make someone:
- Cry out.
- Lose consciousness.
- Fall over or down to the ground.
- Have muscle jerks or spasms.
Generalised nonmotor (absence) seizures
Generalised 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.