Epilepsy is a condition in which a
person has recurrent seizures. A seizure is defined as an abnormal,
disorderly discharging of the brain's nerve cells, resulting in a
temporary disturbance of motor, sensory, or mental function.
There are many types of seizures, depending primarily on what part of
the brain is involved. The term epilepsy says nothing about the type of
seizure or cause of the seizure, only that the seizures happen again and
again. A stricter definition of the term requires that the seizures have
no known underlying cause. This may also be called primary or idiopathic
epilepsy.
- Episodes of abnormal electrical activity within the brain result in
seizures.
- The specific area of the brain affected by the abnormal electrical
activity may result in a particular type of seizure.
- If all areas of the brain are affected by the abnormal electrical
activity, a generalized seizure may result. This means that
consciousness is lost or impaired. Often all the person's arms and legs
stiffen and then jerk rhythmically.
- One seizure type may evolve into another during the course of the
seizure. For example, a seizure may start as a partial, or focal,
seizure, involving the face or arm. Then the muscular activity spreads
to other areas of the body. In this way, the seizure becomes
generalized.