A seizure is a period of excessive activity of cerebral neurons. An epileptic seizure is “a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain” (Fisher et al. 2005). Certain brain regions, including the temporal lobes, have a higher susceptibility to seizures. Seizures may be spontaneous or associated with a precipitating event such as sleep deprivation or alcohol consumption. They occur one or more times per day in some patients but at much longer intervals in others.
The clinical (operational) definition of epilepsy by the ILAE (2014) requires “at least two or more unprovoked (or reflex) seizures occurring more than 24 hours apart” or a significantly increased risk of having a second seizure in a 10-year window following one unprovoked seizure. In addition, ILAE (2014) defines epilepsy to be resolved for those who remain seizure free for 10 years, with no seizure medications for the past 5 years.
- Browne, T. R., & Holmes, G. L. (2008). Handbook of epilepsy (4th ed.). Philadelphia: Lippincott, Williams & Wilkins.Google Scholar
- Scheffer, I. E., Berkovic, S., Capovilla, G., Connolly, M. B., French, J., Guilhoto, L., Hirsch, E., Jain, S., Mathern, G. W., Moshé, S. L., Nordli, D. R., Perucca, E., Tomson, T., Wiebe, S., Zhang, Y.-H., & Zuberi, S. M. (2017). ILAE classification of the epilepsies: Position paper of the ILAE Commission for Classification and Terminology. Epilepsia, 58, 512–521.CrossRefGoogle Scholar
- Engel, J., Jr., & Pedley, T. A. (2008). Epilepsy: A comprehensive textbook (2nd ed.). Philadelphia: Lippincott, Williams & Wilkins.Google Scholar
- Laidlaw, J., Richens, A., & Oxley, J. (Eds.). (1988). A textbook of epilepsy (3rd ed.). Edinburgh: Churchill Livingstone.Google Scholar
- Niedermeyer, E. (1990). The epilepsies: Diagnosis and management. Baltimore: Urban & Schwarzenberg.Google Scholar
- Wyllie, E. (Ed.). (1997). The treatment of epilepsy: Principles and practice (2nd ed.). Baltimore: Williams & Wilkins.Google Scholar