Epilepsy

epilepsy, chronic neurological disorder characterized by sudden and recurrent seizures which are caused by an absence or excess of signaling of nerve cells in the brain. Seizures may include convulsions, lapses of consciousness, strange movements or sensations in parts of the body, odd behaviours, and emotional disturbances. Epileptic seizures typically last one to two minutes but can be followed by weakness, confusion, or unresponsiveness. Epilepsy is a relatively common disorder affecting about 40 million to 50 million people worldwide; it is slightly more common in males than females. Causes of the disorder include brain defects, head trauma, infectious diseases, stroke, brain tumours, or genetic or developmental abnormalities. Several types of epileptic disorders are hereditary. Cysticercosis, a parasitic infection of the brain, is a common cause of epilepsy in the developing world. About half of epileptic seizures have an unknown cause and are called idiopathic.

In 1981 the International League Against Epilepsy developed a classification scheme for seizures based on their mode of onset. This work resulted in the formation of two major classes: partial-onset seizures and generalized-onset seizures.