Epilepsy is a condition in which people have recurrent seizures. Seizures are sudden attacks of abnormal electrical activity in the brain and can range from mild to severe.

Epilepsy is a family of conditions and its symptoms and effects vary from person to person. Epilepsy can first occur in people of any age, but is most likely to start during childhood or in old age. Many people have at least one seizure over a lifetime. Of these, only about one third will develop epilepsy, while the rest never have the experience again. Overall incidence of epilepsy worldwide is about 50 per 100,000 people.

What causes epilepsy?

Often, the cause is unknown, although experts think that genetics may play a role:

  • When no definite cause can be identified, epilepsy is said to be idiopathic. People with idiopathic epilepsy tend to respond well to medication. If you have idiopathic epilepsy, it should cause minimal disruption to your life.
  • Other causes include brain damage, caused by, for instance, stroke or a tumour, or by diseases such as meningitis or malaria. Such epilepsy is termed symptomatic.
  • Sometimes there is suspected, but not proven, brain damage, as in some people with learning difficulties. This type of epilepsy is classified as cryptogenic.

Epilepsy classification

Five different components are used to classify epilepsy in each person affected.1 This views the condition in terms of:

  • The way the brain reacts during seizure.
  • The type of seizure that is experienced.
  • The syndrome, as defined by the symptoms experienced.
  • The origin of the epilepsy (idiopathic, symptomatic or cryptogenic).
  • The degree of disruption the seizures and symptoms cause to everyday life.

The type of seizure varies and can range from grand mal to petit mal. Grand mal seizures affect the whole brain and lead to loss of consciousness and convulsions. Petit mal seizures affect only part of the brain and may last only a few seconds. They do not lead to loss of consciousness but are associated with aimless behaviour.

Seizures may also be classified as focal onset. These are seizures in which the seizure begins in a region of the brain, but afterwards spreads throughout it. Focal point seizures are associated with unusual feeling, called an ‘aura’, prior to major attack.

Epilepsy triggers

Many things can trigger a seizure, including strobe lighting, stress, tiredness, dehydration, even reading. If you suffer from epilepsy, you should try to identify the triggers that affect you the most.

Epilepsy diagnosis

People are not usually assessed for epilepsy until they have had at least 2 seizures. Beyond this, the National Council of Clinical Excellence (NICE) provides these guidelines:

  • Urgency: diagnosis should be made as soon as possible.
  • Professionalism: diagnosis should be made by a specialist.
  • Electroencephalogram (EEG): this may be used for corroboration in adults, but should generally be used only after the second instance of seizure in children.
  • Magnetic Resonance Imaging (MRI): imaging is important for those who first develop symptoms before the age of 2 or in adulthood, for those who experience focal onset epilepsy, and for those who fail to respond to standard medication. It is not usually appropriate for idiopathic epilepsy.
  • Specific diagnosis: diagnosis should determine type of seizure, syndrome, cause, and any other health conditions, including those unrelated to the epilepsy.

If you have mild seizures, maybe just petit mal, it may not be obvious how frequent these are or exactly how they affect you. Video-telemetry can then be used to fine tune your diagnosis, which involves staying in hospital and perhaps not taking your medication. An EEG is recorded and your movements and facial expressions are also recorded on video so that any signs of a seizure can be compared with your brain activity at the time.