Absence seizures

Last reviewed: 28 Aug 2022
Last updated: 24 Jun 2022

Summary

Definition

History and exam

Key diagnostic factors

  • family history of childhood seizures
  • staring episode, lasting 5 to 10 seconds; several times per day with no aura/postictal state
  • childhood onset
  • normal physical examination
  • hyperventilation-induced seizure
More key diagnostic factors

Other diagnostic factors

  • simple automatisms
  • recent decline in school performance
  • complex automatisms
  • early onset (before age 4 years)
Other diagnostic factors

Risk factors

  • family/genetic history of childhood absence epilepsy or juvenile myoclonic epilepsy
  • acquired brain injury: for example, hypoxia-ischaemia, trauma, infection
  • other congenital inborn errors of metabolism, structural defects, chromosomal abnormalities
  • developmental delay or intellectual disability
  • female sex
More risk factors

Diagnostic investigations

1st investigations to order

  • EEG
More 1st investigations to order

Investigations to consider

  • MRI brain
  • testing for metabolic disorders (e.g., serum amino acids, urine organic acids, lactate pyruvate or specific enzymatic tests)
  • cerebrospinal fluid and serum glucose
More investigations to consider

Emerging tests

  • gene testing

Treatment algorithm

ACUTE

typical absence seizures without a history of generalised tonic-clonic seizures (childhood absence epilepsy)

typical absence seizures with a history of generalised tonic-clonic seizures (CAE, JAE, JME)

atypical absence seizures

ONGOING

refractory to treatment

Contributors

Authors

Judith L. Z. Weisenberg, MD

Assistant Professor of Neurology

Washington University Medical School

St. Louis

MO

Disclosures

JLZW states that she has no competing interests.

Acknowledgements

Dr Judith L. Z. Weisenberg would like to gratefully acknowledge Dr Michael Wong, a previous contributor to this topic.

Disclosures

MW declares that he has no competing interests.

Peer reviewers

Anita Devlin, MBBS, MD

Consultant Paediatric Neurologist

Royal Victoria Infirmary

NHS Foundation Trust

Newcastle-upon-Tyne

UK

Disclosures

AD and two epilepsy nurses from her department have been reimbursed by UCB Pharma, the manufacturer of levetiracetum, for attending several conferences. One of the epilepsy nurses received a one-off sponsorship payment from UCB Pharma to cover the initial set-up costs of the adolescent epilepsy support group. One epilepsy nurse has been reimbursed by Cyberonics, the manufacturer of vagal nerve stimulators, for attending one or more conferences.

Cigdem Akman, MD

Division of Pediatric Neurology

Columbia University College of Physicians and Surgeons

New York

NY

Disclosures

CA declares that he has no competing interests.

Angus A. Wilfong, MD

Associate Professor

Pediatrics and Neurology

Baylor College of Medicine

Medical Director

Comprehensive Epilepsy Program

Texas Children's Hospital

Houston

TX

Disclosures

AAW declares that he has no competing interests.

Helen Cross, MB, ChB, PhD, FRCP, FRCPCH

Head of Neurosciences Unit

The Prince of Wales’s Chair of Childhood Epilepsy

National Centre for Young People with Epilepsy

London

UK

Disclosures

HC has received research funds from HAS, Epilepsy Research UK, SHS, and the Milk Development Council. She has received funding for an epilepsy training fellowship from UCB and Eisai. She has also received travel funding from Eisai, UCB, and GlaxoSmithKline.

  • Differentials

    • Daydreaming
    • Attention deficit hyperactivity disorder (ADHD)
    • Complex partial epilepsy of frontal or temporal lobe origin
    More Differentials
  • Guidelines

    • Epilepsies in children, young people and adults
    • Antiseizure medication withdrawal in seizure-free patients: practice advisory update summary
    More Guidelines
  • Patient leaflets

    Absence seizures in children

    More Patient leaflets
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