Back Different types of seizures

Seizures can last from a few seconds to a few minutes and are characterized by a variety of symptoms. These can range from simple blank staring to jerking limb movements, convulsions and a brief loss of consciousness.

An Important Note: 2017 Revised Classification of Seizures.
The International League against Epilepsy (ILAE), the world's main scientific body devoted to the study of epilepsy, has recently revised its classification of seizures. The changes are meant to help facilitate the description of seizure events, diagnosis and treatment.

Since it may take some time for these new terms to be full adopted into practice, it is also important to be aware of the alternative (older) terms. The table below outlines both.

It is important you know the kind of seizures you have so you can seek the best treatment. Here is an overview of different types of seizures:

2017 ILAE Seizure Classification

May also be called:

FOCAL SEIZURES: Seizures that start in a specific location, on one side of the brain.

Focal seizures can be further sub-classified based on AWARENESS and MOVEMENT (see below).

Partial Seizures
  • Focal aware: In this type of focal seizure, the person is fully aware that the event is occurring, even if they are unable to talk or respond.
Simple Partial Seizure
  • Focal impaired awareness: In this type of focal seizure, awareness is impaired at any time during a seizure, or the person appears confused. Even if the person has a vague idea of what happened, it would still be classified as focal impaired awareness.
Complex Partial Seizure
  • Awareness unknown: If no one is there to witness the seizure, the awareness during the seizure may be unknown. In these situations, the awareness term may not be used or it would be described as awareness unknown.
 
  • Focal motor seizure: A focal seizure in which some type of movement occurs during the event e.g. twitching, jerking, or stiffening movements of a body part or automatisms (automatic movements such as licking lips, rubbing hands, walking, or running).
 
  • Focal non-motor seizure: A focal seizure in which there are changes in sensation, emotions, thinking, or experiences (but not movement).
 

GENERALIZED SEIZURES: A seizure that starts in, and affects, both hemispheres of the brain.

Generalized seizures are all presumed to affect a person’s awareness or consciousness in some way. Therefore, they are NOT sub-classified based on AWARENESS. They can, however, be sub-classified based on MOVEMENT (see below).

 
  • Generalized motor seizure: A generalized seizure in which some type of movement occurs during the event e.g. twitching, jerking, or stiffening movements of a body part or automatisms (automatic movements such as licking lips, rubbing hands, walking, or running). Encompasses many sub-classes which are outlined on the right.

Atonic seizure (drop attack): A type of generalized seizure characterized by sudden loss of muscle tone and strength; may cause the head to drop suddenly, objects to fall from the hands, or the legs to lose strength, with falling and potential injury.

Myoclonic seizure: A seizure characterized by sudden jerking of the muscles, similar to the effect of being hit by a jolt of electricity.

Tonic-clonic: An epileptic seizure characterized by a fall to the ground (tonic phase) followed by jerking movements (clonic phase).

Convulsion (grand mal seizure): A seizure characterized by stiffening of the body and jerking, excess salivation (foaming at the mouth), and loss of control of urine, followed by a period of confusion.

  • Generalized non-motor seizure: These seizures involve brief changes in awareness, staring, and some may have automatic or repeated movements like lipsmacking.

Absence seizure

Petit mal seizure

FOCAL TO BILATERAL SEIZURE: A seizure that starts in a specific location on one side of the brain and then spreads, affecting both hemispheres of the brain.

Secondary Generalization

Secondary Generalized Seizure

UNKNOWN ONSET: Term used to describe seizures if the onset is not known. The seizure type can be changed later once it is determined which location in the brain the person’s seizures are beginning.

 

Other definitions and types of seizures:

Aura: A warning that a seizure may begin, often described as a “funny feeling”. An aura is actually a small seizure that may develop into a larger seizure or disappear.

Epilepsia partialis continua: A rare seizure type that consists of repeated jerking lasting for long periods of time. Often seen in Rasmussen’s encephalitis.

Febrile seizure: A seizure caused by a high fever in children under the age of 5. Most of these children do not develop epilepsy.

Pseudoseizure: Clinically resembles an epileptic seizure but without epileptic discharges from the brain. Also called psychogenic or nonepileptic seizure, most often caused by severe psychosocial stress.

Status epilepticus: A condition of recurrent seizures on the same day or prolonged seizures requiring immediate medical attention.

Video: Functional Regions of the Brain

Video: Classification of Epileptic Seizures