is a group of neurological diseases characterized by epileptic seizures. Epileptic seizures are episodes that can vary from brief and nearly undetectable to long periods of vigorous shaking. These episodes can result in physical injuries including occasionally broken bones. In epilepsy, seizures tend to recur, and have no immediate underlying cause. Isolated seizures that are provoked by a specific cause such as poisoning are not deemed to represent epilepsy. People with epilepsy in some areas of the world experience stigma due to the condition.
The cause of most cases of epilepsy is unknown
, although some people develop epilepsy as the result of brain injury, stroke, brain tumors, infections of the brain, and birth defects. Known genetic mutations are directly linked to a small proportion of cases. Epileptic seizures are the result of excessive
and abnormal nerve cell activity in the cortex of the brain. The diagnosis
involves ruling out other conditions that might cause similar symptoms such as fainting and determining if another cause of seizures is present such as alcohol withdrawal
or electrolyte problems. This may be partly done by imaging the brain and performing blood tests
. Epilepsy can often be confirmed with an electroencephalogram (EEG), but a normal test does not rule out the condition.
Epilepsy that occurs as a result of other issues may be preventable. Seizures are controllable with medication in about 70% of cases. Inexpensive options are often available. In those whose seizures do not respond to medication, then surgery, neurostimulation, or dietary changes may be considered. Not all cases of epilepsy are lifelong, and many people improve to the point that treatment is no longer needed.
As of 2013 about 22 million people have epilepsy. Nearly 80% of cases occur in the developing world. In 2013 it resulted in 116,000 deaths up from 112,000 deaths in 1990. Epilepsy is more common in older people. In the developed world, onset of new cases occurs most frequently in babies and the elderly. In the developing world onset is more common in older children and young adults, due to differences in the frequency
of the underlying causes. About 5–10% of people will have an unprovoked seizure
by the age of 80, and the chance
of experiencing a second seizure is between 40 and 50%. In many areas of the world those with epilepsy either have restrictions placed on their ability to drive or are not permitted to drive until they are free of seizures for a specific length of time. The word epilepsy is from Ancient Greek: ἐπιλαμβάνειν
"to seize, possess
, or afflict".