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Seizures - Introduction

Jessica Mason, MD, Mel Herbert, MD MBBS FAAEM, and Stuart Swadron, MD, FRCPC

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C3 - August - Seizures Summary 537 KB - PDF

An overview of seizures and review of seizure terminology.

C3 - Seizures in Adults

 Jessica Mason MD, Stuart Swadron MD, Mel Herbert MD

* Drug doses are a guide only, always check second source and follow local practice guidelines

Take Home Points

  • Most seizures stop spontaneously - but those patients seizing for more than 5 minutes are unlikely to stop.
  • The initial priority when a patient is actively seizing is to protect them from physical harm and stop the seizure.
  • Benzodiazepines, through any route available, are first line in treatment, followed by a repeat dose and then a stepwise progression to second and third line drugs with endotracheal intubation as necessary.
  • Unless the seizure is typical in a patient with known seizure disorder, serious diagnoses, such as poisoning, brain tumor, and meningitis, must be considered and worked-up as appropriate.
  • In many cases, diagnoses other than seizure must be entertained - notably a cardiac event such as syncope.
  • New onset seizures in patients who are pregnant and with HIV/AIDS may represent a variety of challenging and serious diagnoses - early consultation is advised.



Seizures frighten everybody.  They can be distressing not only for patients but also for their families, public bystanders and even emergency providers.  Because the convulsions associated with seizures can be so dramatic, we tend to lose our ability to think in a logical manner when a patient is actively seizing.  In this episode of C3, we cover the initial approach to the seizing patient, how to manage status epilepticus and how to disposition these patients from the emergency department. 


  • Some important definitions:
    • Seizure - abnormal neurologic function caused by inappropriate electrical discharges in the brain
    • Convulsion - motor activity from seizure
    • Epilepsy - condition of recurrent seizures, not due to a specific structural (e.g. brain tumor) or metabolic (e.g. hypoglycemia) cause 
  • Key Types of Seizures:
    • Tonic-clonic
      • This is what most people think of when they think of seizure
      • Alternating stiffening (tonic) and rhythmic jerking (clonic)
      • 3 typical phases:
        • Tonic - abrupt onset of LOC, rigidity, with apnea and cyanosis, usually urinate and sometimes vomit
        • Clonic - symmetric, rhythmic jerking
        • Post-ictal - somnolence, fatigue, may last hours 
    • Absence
      • Classically in school-aged children
      • Usually resolve as the child grows up
      • Can have up to 100 per day
      • Brief (seconds sometimes), LOC but no loss of postural tone
      • Patients appear confused, detached, withdrawn
      • Stops abruptly with no post-ictal phase
    • Partial
      • Simple partial/focal seizures do not involve LOC
      • Complex partial seizures are the fascinating ones
        • They can appear to cause personality changes, hallucinations
        • Generally present differently than the typical “seizure” patient, more likely altered mental status



Claassen J et al. Emergency Neurological Life Support: Status Epilepticus.  Neurocrit Care (2015) 23:S136–S142.


Falco-Walter JJ, Bleck T.  Treatment of Established Status Epilepticus. J Clin Med. 2016 May; 5(5): 49.


Huff S et al. Clinical Policy: Critical Issues in the Evaluation and Management of Adult Patients Presenting to the Emergency Department With Seizures.  From the American College of Emergency Physicians Clinical Policies Subcommittee.  Ann Emerg Med. 2014;63:437-447.


Khoujah D, Abraham MK. Status Epilepticus: What’s New?  Emerg Med Clin N Am 34 (2016) 759–776.


Krumholz A, et al.  Evidence-based guideline: Management of an unprovoked first seizure in adults: Report of the Guideline Development Subcommittee of the American Academy of Neurology and the American Epilepsy Society. Neurology. 2015 Oct 27;85(17):1526-7.


Webb J, et al.  An Emergency Medicine-Focused Review of Seizure Mimics. J Emerg Med 2017; 52 (5):645-653.



Ryan A. -

Will a Zip file be made available for download?

Tracy G. -

Ryan: You will find the zip file download at the very bottom of the "Downloads" pull-down menu.

Derek I., M.D. -

Great episode as always but I am concerned about some of the doses that you mentioned in your summary. As you alluded to, seizures have a kindling effect: they longer they go on, the more difficulty it is to stop the seizures. Specifically

1) For adults, The initial dose of lorazepam should be 4mg not 2mg as mentioned in the summary or 10mg of midazolam.

2) The correct dose of levetiracetam is not 1g but 60 mg/kg to maximum of 4500mg.

3) The correct dosing of valproic acid in status epilepticus is 40mg/kg to maximum dose of 3000mg.

There is a current multicenter trial examening the optimal 2nd line agent: Levetiracetam v. valproate v. fosphenytoin for status epilepticus

Would be happy to talk to you more about this subject as this is one of my interests.

Derek Isenberg, MD, FAAEM
Temple University

Cody B. -

Other important questions for the new onset seizure in 21 year old female: is she less than 6 weeks post partum? new meds - tramadol? Wellbutrin? Etc..

Tim V. -

I would reconsider not using succinylcholine to intubate status epilepticus patients. I appreciate the risk of hyperkalemia but if you don't readily have access to continuous EEG monitoring (not sure about US, but very common in Canada) any other paralytic will result in you losing your ability to monitor seizure activity.

Daniel L. -

FYI this episode does not appear in the iPhone EMRAP app

Tracy G. -

Daniel L. Please refresh your iPhone app again, and this C3 episode should now be available.

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C3 - Seizures Full episode audio for MD edition 63:53 min - 89 MB - M4AC3 - 2017 - August Seizures - Board Review Answers 190 KB - PDFC3 - 2017 - August Seizures - Board Review Questions 136 KB - PDFC3 - 2017 - August Seizures - Individual MP3 85 MB - ZIPC3 - August - Seizures Summary 537 KB - PDF