What is epilepsy?
Epilepsy, or a chronic seizure disorder, is a general term for a number of different conditions. Epilepsy is the same thing as a ‘seizure disorder’.
Epilepsies are classified by:
- whether seizures are generalized, focal or both
- whether the seizure types and other features can be grouped together as an epilepsy syndrome
- the cause of the epilepsy, when known
Epilepsy types
There are several different types of epilepsy. Most children with epilepsy have either a generalized epilepsy or focal epilepsy, while some children may have both. Each epilepsy type has different characteristics.
Generalized epilepsies
- In a generalized epilepsy, the seizures begin on both sides of the brain at the same time.
- An EEG will show generalized spike and slow wave discharges.
- Generalized epilepsies include seizure types such as absence, myoclonic, atonic, tonic and tonic-clonic seizures.
Focal epilepsies
- In a focal epilepsy, the seizure begins in one part of the brain or several different parts in the brain.
- An EEG will show spike and wave discharges coming from one or more brain regions.
- Focal epilepsies include seizure types such as focal motor seizures with and without impaired awareness and focal non-motor seizures with and without impaired awareness.
Combined generalized and focal epilepsy
- Some children can have both generalized and focal seizures.
- An EEG will show both generalized spike and wave discharges and abnormalities in discrete brain regions.
- Common examples of combined generalized and focal epilepsies are Dravet syndrome and Lennox-Gastaut syndrome.
Epilepsy syndromes
When your child is diagnosed with an epilepsy syndrome, it means that your child’s clinical history, exam and tests are similar to that of a group of other children. These conditions may also have similar responses to treatment and similar outcomes. Some of the common syndromes are childhood absence epilepsy, Dravet syndrome and Lennox-Gastaut syndrome.
Idiopathic generalized epilepsy
Idiopathic means there is no clear underlying cause for seizures and epilepsy. Idiopathic generalized epilepsy refers to epilepsy in which the doctors are unable to identify a structural problem with the brain or a metabolic disorder to explain seizures, and the seizures are generalized. Many, although not all, idiopathic epilepsy syndromes are self-limited which means that the child will eventually grow out of them.
Genetics
Relatives of a child with idiopathic epilepsy may have a history of seizures. Researchers are discovering that many idiopathic epilepsy syndromes have an associated genetic component. For this reason, the term idiopathic generalized epilepsy is sometimes also used to refer to genetic generalized epilepsies.
With a diagnosis of idiopathic generalized epilepsy, your child is more likely to outgrow their seizures.
Some examples of idiopathic generalized epilepsies include:
- childhood and juvenile absence epilepsy
- juvenile myoclonic epilepsy
- generalized tonic-clonic seizures alone
Self-limited focal epilepsies
Self-limited epilepsies typically begin in childhood and then usually go away on their own. Epilepsies that fall under this classification include:
- benign epilepsy with centrotemporal spikes
- occipital epilepsies of childhood with early onset, which are described as Panayiotopoulos
- occipital epilepsies those with late onset, which are described as Gastaut, not to be confused with Lennox-Gastaut syndrome
To read more about each specific syndrome, please see Generalized epilepsy syndromes and Partial epilepsy syndromes.
Epilepsy management
Determining the underlying cause for epilepsy is important to help manage epilepsy. For example, in children who are not responding to medication and have an abnormal structure in the brain, surgery can offer the possibility of seizure freedom. For other genetic epilepsies that are not responsive to medications, diet therapy or vagus nerve stimulation (VNS) may be considered.
Resources
Epilepsy syndromes — International League against Epilepsy