UMEM Educational Pearls

Category: Neurology

Title: First-time Seizures: Labs to Check

Keywords: seizure, first-time seizure, new onset seizure (PubMed Search)

Posted: 8/26/2009 by Aisha Liferidge, MD (Updated: 12/5/2021)
Click here to contact Aisha Liferidge, MD

  • Glucose abnormalities and hyponatremia are the two laboratory findings most frequently associated with triggering first-time seizures in adult patients.
  • Always check an HCG in women who present with their first seizure, as this may reveal the source (i.e. eclampsia) and/or may affect testing, disposition, and initiation of an anti-epileptic drug (AED).
  • Drug abuse screens should be considered in patients with their first seizure, but no prospective studies have demonstrated benefit from routine use.


  • Turnbull, et al. "Utility of laboratory studies in the ED patient with a new onset seizure."  Ann Emerg Med. 1990; 19: 373-77.
  • Eisner, et al. "Efficacy of a standard seizure workup in the ED." Ann Emerg Med. 1986; 15: 33-9.