What is epilepsy?

Many people will have one seizure at some stage in their lives, but this is not necessarily epilepsy because there is a low risk of recurrence. Many children with epilepsy will eventually ‘grow out of it’ by the time they reach adulthood. For some people, the tendency to recurrent seizures may be a lifelong predisposition.

The International League Against Epilepsy (ILAE) classifies epilepsy as a disease of the brain that can be defined by the presence of any of the following conditions:

1. At least two unprovoked (or reflex) seizures occurring more than 24 hours apart.
2. One unprovoked (or reflex) seizure and a probability of further seizures similar to the general recurrence risk (at least 60%) after two unprovoked seizures, occurring over the next 10  years.
3. Diagnosis of an epilepsy syndrome.

Syndromes are identified by the type of seizure/s, the age at onset, the EEG pattern and the pattern the seizures follow. They are sometimes associated with other underlying conditions. Identifying a seizure syndrome may be useful as sometimes this allows the most appropriate medication to be prescribed.

There are many stages in the diagnostic process. It is extremely important to get a correct diagnosis and this may need lots of tests and take considerable time. Questions need to be answered, such as:

• Is it epilepsy or is it something else?
• If it is epilepsy, what sort of epilepsy is it?
• Where does it start in the brain?
• Is there any structural abnormality in the brain?

• A full clinical history and a good description of the seizure/s;
• A physical and neurological examination;
• Investigations that may include an EEG recording and a CT scan or MRI brain scan.