Classification of epileptic seizures updated
The International League Against Epilepsy (ILAE) has updated the operational classification of epileptic seizures, building upon the framework published in 2017 to establish a common language for all health care professionals involved in epilepsy care.
"Updated classification of epileptic seizures: A position paper by the International League Against Epilepsy" is published in the journal Epilepsia.
"The updated classification of epileptic seizures incorporates published evidence and real-world experience to clarify and standardize terms and concepts," said ILAE President J. Helen Cross. "The primary objective is to provide a common language and standardized definitions for clinical practice, regardless of setting."
The classification also offers a clear and robust structure for implementation in research databases and clinical trials. The update emphasizes accessible terms for patients and caregivers.
Classification details
The updated classification comprises four main classes—focal, generalized, unknown, and unclassified—and 21 seizure types, in contrast to 63 seizure types in the 2017 classification.
Six key changes were made:
- "Onset" is removed from the names of the four main seizure classes.
- A distinction is made between classifiers and descriptors. Classifiers reflect biological classes and directly impact clinical management, while descriptors characterize specific features within a seizure type.
- "Consciousness" replaces "awareness" as a classifier. Consciousness is defined by both awareness and responsiveness.
- The motor vs. non-motor dichotomy is replaced by observable manifestations vs. non-observable manifestations.
- Seizures are described by the chronological sequence of signs and symptoms, rather than by relying solely on the first sign.
- Epileptic negative myoclonus is recognized as a seizure type.
"The updates preserve the fundamental framework of seizure classification while enhancing broad clinical applicability across diverse settings," said Sándor Beniczky, who was co-chair of the ILAE Task Force for Seizure Classification with Eugen Trinka.
The update process
A working group of 37 members from all ILAE regions assessed the real-world application of the 2017 seizure classification and recommended adjustments. After conducting a systematic review to assess the strengths and limitations of the 2017 classification, the group proposed updates and utilized a modified Delphi process that required a consensus threshold of two-thirds agreement for any proposal.
After completing a draft revision, a two-month public comment period was opened via the ILAE website. Seven additional members were appointed to the group to address and incorporate issues raised during this period, under the leadership of Elaine Wirrell. The final version was reviewed and approved by the ILAE Executive Committee.
"The update was needed based on the real-world experience with implementation of the 2017 classification," said Trinka. "We believe that the updated version is applicable at all levels of care: from primary care providers to specialized epilepsy surgery centers."
"Special emphasis was placed on ensuring coherence with general medical terminology and internal consistency," said Beniczky.
Seizure types are numbered to ensure consistency across databases and languages.
Translations and other resources
The updated classification also prioritized accurate and clear translation into languages other than English. The update is currently available in Arabic, Chinese, Danish, English, French, German, Hungarian, Italian, Japanese, Korean, Portuguese, Romanian, Russian, Spanish, and Ukrainian. Translations are available in Data supplement 6 of the position paper.
Seizures in neonates are not included in the updated classification; they are addressed in a separate position paper. A commentary paper has also been published.
More information:
Sándor Beniczky et al, Updated classification of epileptic seizures: Position paper of the International League Against Epilepsy, Epilepsia (2025). DOI: 10.1111/epi.18338
Ronit M. Pressler et al, The ILAE classification of seizures and the epilepsies: Modification for seizures in the neonate. Position paper by the ILAE Task Force on Neonatal Seizures, Epilepsia (2021). DOI: 10.1111/epi.16815
Commentary: Sándor Beniczky et al, Updating the ILAE seizure classification, Epilepsia (2025). DOI: 10.1111/epi.18399
Provided by International League Against Epilepsy