• Directory
  • Search
  • All results
  • Journals
  • Definitions
Images:
  • Wikimedia
  • Wikimedia
  • Wikimedia
  • Wikimedia
  • Wikimedia
  • Wikimedia
  • Wikimedia
  • Merck
  • Merck
Videos:
View video
01:05
Neurosurgeons using electrodes to...
Encyclopedia Britannica
View video
9:12
Epilepsy (generalized, focal):...
Osmosis
View video
8:43
Epilepsy
Medical Centric
Related terms:
akinetic mutism
amblyopia
brain abscess
brain death
brain disorder
brain neoplasm
cerebellar disease
cerebrovascular disorder
encephalitis
Disease or Syndrome
epilepsy Audio
ep·i·lep·sy [ ep-uh-lep-see ]
Subclass of:
Brain Diseases
Etymology:
Greek epilepsia = a seizure; from epi = upon + lepsis = a seizure
The disease was known to the ancients under a variety of names, including epilepsia, and this word appeared in English about 1580.
Definitions related to epilepsy:
  • A disorder characterized by recurrent episodes of paroxysmal brain dysfunction due to a sudden, disorderly, and excessive neuronal discharge. Epilepsy classification systems are generally based upon: (1) clinical features of the seizure episodes (e.g., motor seizure), (2) etiology (e.g., post-traumatic), (3) anatomic site of seizure origin (e.g., frontal lobe seizure), (4) tendency to spread to other structures in the brain, and (5) temporal patterns (e.g., nocturnal epilepsy). (From Adams et al., Principles of Neurology, 6th ed, p313)
    NLM Medical Subject Headings
    U.S. National Library of Medicine, 2025
  • A group of disorders marked by problems in the normal functioning of the brain. These problems can produce seizures, unusual body movements, a loss of consciousness or changes in consciousness, as well as mental problems or problems with the senses.
    NCI Dictionary of Cancer Terms
    U.S. National Cancer Institute, 2021
  • A neurological disorder characterized by recurring seizures.
    NICHD Pediatric Terminology
    U.S. National Cancer Institute, 2021
  • Brain disorder characterized by recurring excessive neuronal discharge, exhibited by transient episodes of motor, sensory, or psychic dysfunction, with or without unconsciousness or convulsive movements.
    CRISP Thesaurus
    National Institutes of Health, 2006
  • Epilepsy caused or apparently caused by device. Do not use when epilepsy is a pre-existing condition.
    U.S. FDA Glossary
    U.S. Food & Drug Administration, 2021
  • Epilepsy is a brain disorder that causes people to have recurring seizures. The seizures happen when clusters of nerve cells, or neurons, in the brain send out the wrong signals. People may have strange sensations and emotions or behave strangely. They may have violent muscle spasms or lose consciousness. Epilepsy has many possible causes, including illness, brain injury, and abnormal brain development. In many cases, the cause is unknown. Doctors use brain scans and other tests to diagnose epilepsy. It is important to start treatment right away. There is no cure for epilepsy, but medicines can control seizures for most people. When medicines are not working well, surgery or implanted devices such as vagus nerve stimulators may help. Special diets can help some children with epilepsy. NIH: National Institute of Neurological Disorders and Stroke
    MedlinePlus
    U.S. National Library of Medicine, 2025
  • (seizure disorder) A brain disorder characterized by episodes of abnormally increased neuronal discharge resulting in transient episodes of sensory or motor neurological dysfunction, or psychic dysfunction. These episodes may or may not be associated with loss of consciousness or convulsions.
    NCI
    U.S. National Cancer Institute, 2021
  • A seizure is an abnormal, unregulated electrical discharge that occurs within the brain�s cortical gray matter and transiently interrupts normal brain function. A seizure typically causes altered awareness, abnormal sensations, focal involuntary movements, or convulsions (widespread violent involuntary contraction of voluntary muscles)....
    Merck Manuals
    Merck & Co., Inc., 2025
  • Epilepsy is a central nervous system (neurological) disorder in which brain activity becomes abnormal, causing seizures or periods of unusual behavior, sensations, and sometimes loss of awareness.
    Mayo Clinic
    Mayo Foundation for Medical Education and Research, 2025
  • 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...
    Encyclopedia Britannica
    Encyclopedia Britannica, Inc., 2025
Return to OpenMD Medical Dictionary > E
Try this search on: Farlex, Merriam-Webster, Oxford Dictionary, or Wordnik

This content should not be used in place of medically-reviewed decision support reference material or professional medical advice. Some terms may have alternate or updated definitions not reflected in this set. The definitions on this page should not be considered complete or up to date.

  • About
  • Feedback
  • Guides
  • Terms
© 2026 OpenMD
The content on this site is NOT a substitute for professional medical advice or diagnosis. Always seek the advice of your doctor or health care provider.