Epilepsy

An epileptic seizure is a brief event caused by excessive or unusually synchronized activity in networks of brain cells. Epilepsy describes an enduring predisposition to have such seizures, rather than one particular seizure or a single disease with one cause. The International League Against Epilepsy's practical clinical definition recognizes three routes to diagnosis: at least two unprovoked (or reflex) seizures more than 24 hours apart; one unprovoked or reflex seizure with a high likelihood of recurrence—at least 60% over the following 10 years; or diagnosis of an epilepsy syndrome. A seizure associated with a temporary cause does not by itself establish epilepsy, and deciding whether an event was epileptic and whether criteria are met requires clinical assessment.

Seizures differ in where abnormal activity begins, how it spreads, and which brain functions are involved. Focal seizures start in one part of the brain; generalized seizures involve networks on both sides from the outset. A person's experience may include jerking or other movements, brief lapses of awareness, changes in sensation or emotion, or altered behavior. Some seizures involve convulsions and loss of consciousness, while others are subtle and easily mistaken for another condition. The categories include many seizure types, and the signs and duration can vary even among people with epilepsy.

Epilepsy can arise from genetic factors, developmental differences in the brain, infections, injury, stroke, tumors, or other conditions that affect brain function. In many cases, no specific cause is identified. Evaluation usually begins with a detailed account of the event and medical history; clinicians may use an electroencephalogram (EEG), brain imaging, or other tests to help characterize seizures or investigate a possible cause. Because some fainting spells and other events can resemble seizures, assessment is also used to distinguish them. Test results inform a diagnosis but must be interpreted in the context of the person's history and symptoms.

Antiseizure medicines are the most common treatment and can control seizures for many people. If seizures continue or medicines are unsuitable, options for selected patients can include epilepsy surgery, implanted devices, or medically supervised dietary approaches. Choice of care depends on seizure type, cause, health circumstances, likely benefits, and possible side effects; a treatment decision is distinct from the formal diagnosis. Epilepsy has varied effects, but it does not prevent everyone from studying, working, or participating in daily activities. The World Health Organization notes that misunderstanding and stigma continue to affect people with epilepsy in many places, making access to accurate information and appropriate care important parts of the public-health response.

The World Health Organization estimates that epilepsy affects around 50 million people worldwide. Access to diagnosis and treatment is uneven, and seizure-related injuries and social exclusion can add to its effects. Public-health programs therefore address both clinical care and barriers such as stigma, while education about seizure first aid can help people respond safely when an event occurs. These population-level concerns coexist with substantial differences in the experiences and needs of individual people.