The enigma of the latent period in the development of symptomatic acquired epilepsy - Traditional view versus new concepts

Epilepsy Behav. 2015 Nov;52(Pt A):78-92. doi: 10.1016/j.yebeh.2015.08.037. Epub 2015 Sep 25.


A widely accepted hypothesis holds that there is a seizure-free, pre-epileptic state, termed the "latent period", between a brain insult, such as traumatic brain injury or stroke, and the onset of symptomatic epilepsy, during which a cascade of structural, molecular, and functional alterations gradually mediates the process of epileptogenesis. This review, based on recent data from both animal models and patients with different types of brain injury, proposes that epileptogenesis and often subclinical epilepsy can start immediately after brain injury without any appreciable latent period. Even though the latent period has traditionally been the cornerstone concept representing epileptogenesis, we suggest that the evidence for the existence of a latent period is spotty both for animal models and human epilepsy. Knowing whether a latent period exists or not is important for our understanding of epileptogenesis and for the discovery and the trial design of antiepileptogenic agents. The development of antiepileptogenic treatments to prevent epilepsy in patients at risk from a brain insult is a major unmet clinical need.

Keywords: Animal models; Early and late seizures; Epileptogenesis; Kindling; Temporal lobe epilepsy; Traumatic brain injury.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Brain Injuries / complications
  • Brain Injuries / physiopathology
  • Disease Models, Animal
  • Epilepsy / etiology*
  • Epilepsy / physiopathology
  • Epilepsy / psychology
  • Humans
  • Stroke / complications
  • Stroke / physiopathology