Last reviewed: 25 Sep 2021
Last updated: 16 Oct 2020



History and exam

Key diagnostic factors

  • persistent or repetitive tonic-clonic seizures with altered level of consciousness (generalized convulsive SE)
  • altered awareness/confusion (nonconvulsive SE)

Other diagnostic factors

  • prolonged focal motor activity, or sensory or autonomic symptoms with intact consciousness (focal aware SE)
  • low oxygen saturation

Risk factors

  • nonadherence to anticonvulsant drugs
  • chronic alcoholism
  • refractory epilepsy
  • toxic or metabolic causes
  • processes leading to direct cortical structural damage
  • drug use

Diagnostic investigations

1st investigations to order

  • anticonvulsant drug blood level
  • toxicology screen
  • comprehensive metabolic panel
  • CBC
  • ECG
  • electroencephalography (EEG)

Treatment algorithm



Emily L. Johnson, MD

Assistant Professor of Neurology

Johns Hopkins Medical Institutions




ELJ has been reimbursed by New England Journal of Medicine Knowledge+ and Univadis MD for developing educational materials.


Dr Emily L. Johnson would like to gratefully acknowledge Dr Ronald P. Lesser, Dr Mohammad Koubeissi, and Dr Nabil Azar, previous contributors to this topic.


RPL or his wife have stock in the following companies, which sell health care products: Abbott Labs, Apple, Avanos, Celgene, Express Scripts, Johnson and Johnson, and Pfizer. NJA declares that he has no competing interests. MZK declares that he has no competing interests.

Peer reviewers

Yvonne Hart, MBBS

Consultant Neurologist

John Radcliffe Hospital




YH has been reimbursed by UCB Pharma Ltd, Janssen-Cilag Ltd, Pfizer Ltd, and Eisai Ltd for attending conferences; has taught at meetings sponsored by the above companies and by GlaxoSmithKline Services Unlimited; and has received payment for advisory board work from UCB Pharma Ltd, Janssen-Cilag Ltd, Eisai Ltd, and GlaxoSmithKline Services Unlimited.

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