Seizure Types & Classification

There are many different types of seizures.

Seizures can be divided into two major groups: partial seizures and generalised seizures.

1. Partial seizures
   About 60% of people with epilepsy have partial seizures, also known as focal seizures. These seizures can often be subtle or unusual, and may go unnoticed or be mistaken for anything from intoxication to daydreaming. Seizure activity starts in one area of the brain and may spread to other regions of the brain.

   Types of partial seizures are:

   • Simple Partial (no loss of awareness)
   • Complex Partial (change in awareness and behaviour)
   • Secondarily Generalised Tonic-Clonic* (see note below)
      
2. Generalised seizures
   Generalised seizures are the result of abnormal activity in the whole brain simultaneously. Because of this, consciousness is lost at the onset of the seizure. There are many types of generalised seizures.
   • Generalised Tonic-Clonic
   • Absence
   • Myoclonic
   • Tonic
   • Atonic

*Note: Sometimes a seizure starts as a partial seizure and then becomes a generalised seizure - almost always a tonic-clonic seizure. When this occurs, the seizure is called secondarily generalised.

Most people will only have one or two seizure type(s), which may vary in severity. A person with severe epilepsy or significant damage to the brain may experience several different seizure types.

Here is a simple diagram showing how seizures are classified:

Next >