UMEM Educational Pearls

Category: Neurology

Title: Does My Seizure Patient Need An EEG?

Keywords: seizure, status epilepticus, nonconvulsive, electrographic, EEG (PubMed Search)

Posted: 1/27/2021 by WanTsu Wendy Chang, MD (Updated: 8/13/2022)
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  • Most seizures resolve spontaneously, however, seizures that persist >5 minutes or recur without the patient returning to their baseline should be treated expeditiously with benzodiazepines and antiepileptic medications.
  • A subset of patients may continue to have electrographic seizures despite cessation of their convulsive seizure activity.
    • Prior studies described 26-52% of patients develop nonconvulsive seizures after resolution of convulsive status epilepticus.
  • The recent Established Status Epilepticus Treatment Trial (ESETT) compared fosphenytoin, levetiracetam, and valproic acid in aborting seizures and improving responsiveness in patients who did not response to initial treatment with benzodiazepines.
    • EEG was not required for this trial, but 58% (278/478) had an EEG within 24 hours after seizure onset.
      • Of those who had an EEG, 14% (39/278) had electrographic seizures.
    • For patients who had clinical treatment success, 13% (13/102) were found to have electrographic seizures.

Bottom Line: Persistent or recurrent seizures are not uncommon in the first 24 hours after status epilepticus even in patients with resolved clinical seizure activity. Early use of EEG can help identify patients who need further escalation of treatment.



  • Zehtabchi S, Silbergleit R, Chamberlain JM, et al. Electroencephalographic seizures in emergency department patients after treatment for convulsive status epilepticus. J Clin Neurophysiol. 2020 Dec 11 [Online ahead of print].

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