Types of epilepsy
Epilepsy is the occurrence of sporadic electrical storms in the brain. These storms cause behavioural manifestations (such as staring) and/or involuntary movements (such as grand mal seizures).
There are several types of epilepsy, each with different causes, symptoms, and treatments.
When making a diagnosis of epilepsy, your doctor may use one of the following terms: idiopathic, cryptogenic, symptomatic, generalised, focal or partial.
- Idiopathic: no apparent cause can be found.
- Cryptogenic: no damage to the brain has been identified but other factors suggest the brain has been damaged.
- Symptomatic: symptoms are due to identified brain damage or disruption of brain function.
- Generalised: the seizures involve the whole brain at once.
- Focal or partial: the electrical storm starts from one area of the brain. One type of partial seizure is called Jacksonian epilepsy.
Major types of epilepsy
|Generalised epilepsy || Partial epilepsy|
|Childhood absence epilepsy|
Juvenile myoclonic epilepsy
Epilepsy with grand-mal
seizures on awakening
|Benign focal epilepsy|
| Temporal lobe|
Frontal lobe epilepsy
Type 1: Idiopathic generalised epilepsy
In idiopathic generalised epilepsy there is often, but not always, a family history of epilepsy. Idiopathic generalised epilepsy tends to appear during childhood or adolescence, although it may not be diagnosed until adulthood. In this type of epilepsy, no nervous system (brain or spinal cord) abnormalities other than the seizures have so far been identified. The brain is structurally normal on magnetic resonance imaging (MRI) of the brain.
People with idiopathic generalised epilepsy have normal intelligence and the results of the neurological examination and MRI are usually normal. The results of the electroencephalogram (EEG - a test that measures electrical impulses in the brain) may show epileptic discharges affecting the entire brain (so called generalised discharges).
The types of seizures affecting patients with idiopathic generalised epilepsy may include:
- Myoclonic seizures (sudden and very short duration jerking of the extremities)
- Absence seizures (staring spells - also known as petit mal)
- Generalised tonic-clonic seizures (grand mal seizures)
Idiopathic generalised epilepsy is usually treated with various medications. Some forms of this condition may be outgrown, as is the case with childhood absence epilepsy and a large number of patients with juvenile myoclonic epilepsy.
Type 2: Idiopathic partial epilepsies
Idiopathic partial epilepsy begins in childhood (between ages five and eight) and there may be a family history. Also known as benign focal epilepsy of childhood (BFEC), this is considered one of the mildest types of epilepsy. It is almost always outgrown by puberty and is never diagnosed in adults.
Seizures tend to occur during sleep and are most often simple partial motor seizures that involve the face, and secondarily generalised (grand mal) seizures. The results of the EEG are typically diagnostic, as patients with BFEC exhibit very specific EEG brain wave patterns.