Epilepsy is one of the most common central nervous system disorders, affecting about one in 100 people in the U.S. of all ages and ethnicity. Seizures usually first appear between 5 and 20 years of age, but can being at any age. It cannot be cured, but for the great majority of patients, medication and surgery control the seizures. For some people, the condition ends by itself. However, seizures continue in about a quarter of patients despite treatment, known as intractable epilepsy.
Seizures occur when brain cells that control body functions generate abnormal or excessive electrical impulses. That disturbance causes the symptoms associated with a seizure. Seizures may be very mild – called petit mal – characterized by rapid blinking or staring blankly into space for brief periods, or they can be severe causing loss of consciousness and convulsions – known as grand mal. Doctors divide seizures into two main categories: focal seizures that occur in just one area of the brain; and generalized seizures affecting both sides of the brain.
The condition is not related to retardation or mental illness and cannot be transmitted. Most seizures seem to cause no damage to the brain, except in some very severe cases.
Among the various type of epilepsy are:
- absence epilepsy – repeated seizures with temporary loss of consciousness
- temporal lobe epilepsy – the most common form of focal seizures
- neocortical epilepsy – seizures begin in the outer layer of the brain
- Lennox-Gastault syndrome – a severe epilepsy affecting children
- Rasmussen’s encephalitis – progressive epilepsy with inflammation of more than half the brain