Classification

The basic classification of epilepsy has changed in recent years. The new basic seizure classification is based on 3 key features:

• 1. Where seizures begin in the brain
• 2. Level of awareness during a seizure (important as can affect safety during seizure)
• 3. Other features of seizures

Focal seizures

• previously termed “partial seizures”
• these start in a specific area, on one side of the brain
• the level of awareness can vary in focal seizures. The terms focal aware (previously termed 'simple partial'), focal impaired awareness (previously termed 'complex partial') and awareness unknown are used to further describe focal seizures
• further to this, focal seizures can be classified as being motor (e.g. Jacksonian march), non-motor (e.g. dejà vu, jamais vu; ) or having other features such as aura
  • For example, seizures originating from the temporal lobe can lead to hallucinations (auditory, gustatory, olfactory), epigastric rising and in some cases, automatisms.

Generalised

• these engage or involve networks on both sides of the brain at the onset
• consciousness lost immediately. The level of awareness in the above classification is therefore not needed, as all patients lose consciousness
• generalised seizures can be further subdivided into motor (e.g. tonic-clonic) and non-motor (e.g. absence)
• specific types include:
  • tonic-clonic (grand mal)
  • tonic
  • clonic
  • typical absence (petit mal)
  • atonic

Unknown onset

• this termed is reserved for when the origin of the seizure is unknown

Focal to bilateral seizure

• starts on one side of the brain in a specific area before spreading to both lobes