Early postictal serum lactate concentrations are superior to serum creatine kinase concentrations in distinguishing generalized tonic–clonic seizures from syncopes


Concentrations of serum creatine kinase (CK) and serum lactate are frequently measured to help differentiate between generalized tonic–clonic seizures (GTCS) and syncope. The aim of this prospective cohort study was to systematically compare these two markers. The primary outcome is the measurement of serum lactate and CK in blood samples drawn within 2 h of the event in patients admitted with either a GTCS (n = 49) or a syncope (n = 36). Furthermore, the specificity and sensitivity of serum lactate and CK are determined as diagnostic markers in distinguishing between GTCS and syncope. GTCS patients have significantly higher serum lactate levels compared to syncope patients (p < 0.001). In contrast, CK does not differ between groups at admission. Regarding the first hour after the seizure, we identify a cut-off for serum lactate of 2.45 mmol/l for diagnosing GTCS as the cause of an impairment of consciousness with a sensitivity of 0.94 and a specificity of 0.93 (AUC: 0.97; 95% CI 0.94–1.0). In the second hour after the event, the ROC analysis yields similar results (AUC: 0.94; 95% CI 0.85–1.0). Serum lactate is a sensitive and specific diagnostic marker to discriminate GTCS from syncope and is superior to CK early after admission to the emergency department.

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  1. 1.

    Chowdhury FA, Nashef L, Elwes RD (2008) Misdiagnosis in epilepsy: a review and recognition of diagnostic uncertainty. Eur J Neurol 15:1034–1042

    CAS  Article  PubMed  Google Scholar 

  2. 2.

    Chesson AL, Kasarskis EJ, Small VW (1983) Postictal elevation of serum creatine kinase level. Arch Neurol 40:315–317

    CAS  Article  PubMed  Google Scholar 

  3. 3.

    Orringer CE, Eustace JC, Wunsch CD et al (1977) Natural history of lactic acidosis after grand-mal seizures. A model for the study of an anion-gap acidosis not associated with hyperkalemia. N Engl J Med 297:796–799

    CAS  Article  PubMed  Google Scholar 

  4. 4.

    Winocour PH, Waise A, Young G et al (1989) Severe, self-limiting lactic acidosis and rhabdomyolysis accompanying convulsions. Postgrad Med J 65:321–322

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  5. 5.

    Matz O, Zdebik C, Zechbauer S et al (2016) Lactate as a diagnostic marker in transient loss of consciousness. Seizure 40:71–75

    CAS  Article  PubMed  Google Scholar 

  6. 6.

    Faul F, Erdfelder E, Lang AG et al (2007) G*Power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav Res Methods 39:175–191

    Article  PubMed  PubMed Central  Google Scholar 

  7. 7.

    Hanley JA, McNeil BJ (1982) The meaning and use of the area under a receiver operating characteristic (ROC) curve. Radiology 143:29–36

    CAS  Article  Google Scholar 

  8. 8.

    Youden WJ (1959) Index for rating diagnostic tests. Cancer 3:32–35

    Article  Google Scholar 

  9. 9.

    Glötzner FL, Planner M, Gaab M (1979) Creatine kinase in serum after grand mal seizures. Eur Neurol 18:399–404

    Article  PubMed  Google Scholar 

  10. 10.

    Neufeld MY, Treves TA, Chistik V et al (1997) Sequential serum creatine kinase determination differentiates vaso-vagal syncope from generalized tonic-clonic seizures. Acta Neurol Scand 95:137–139

    CAS  Article  PubMed  Google Scholar 

  11. 11.

    Mahmoud AT, El Deghady AA (2005) Serum prolactin and creatine kinase levels in epileptic and non epileptic seizures. Alex J Pediatr 19:217–222

    Google Scholar 

  12. 12.

    Libman MD, Potvin L, Coupal L (1991) Seizure vs. syncope: measuring serum creatine kinase in the emergency department. J Gen Intern Med 6:408–412

    CAS  Article  PubMed  Google Scholar 

  13. 13.

    Broder G, Weil MH (1964) Excess lactate: an index of reversibility of shock in human patients. Science 143:1457–1459

    CAS  Article  PubMed  Google Scholar 

  14. 14.

    Attana P, Lazzeri C, Chiostri M et al (2012) Lactate clearance in cardiogenic shock following ST elevation myocardial infarction: a pilot study. Acute card care 14:20–26

    Article  PubMed  Google Scholar 

  15. 15.

    Akkose S, Ozgurer A, Bulut M et al (2007) Relationships between markers of inflammation, severity of injury, and clinical outcomes in hemorrhagic shock. Adv Ther 24:955–962

    CAS  Article  PubMed  Google Scholar 

  16. 16.

    Jeng JC, Jablonski K, Bridgeman A et al (2002) Serum lactate, not base deficit, rapidly predicts survival after major burns. Burns 28:161–166

    Article  PubMed  Google Scholar 

  17. 17.

    Khan FY (2009) Rhabdomyolysis: a review of the literature. Neth J Med 67:272–283

    CAS  PubMed  Google Scholar 

  18. 18.

    Benzon HT, Toleikis JR, Meagher LL et al (1988) Changes in venous blood lactate, venous blood gases, and somatosensory evoked potentials after tourniquet application. Anesthesiology 69:677–682

    CAS  Article  PubMed  Google Scholar 

  19. 19.

    Kaplan LJ, Kellum JA (2004) Initial pH, base deficit, lactate, anion gap, strong ion difference, and strong ion gap predict outcome from major vascular injury. Crit Care Med 32:1120–1124

    CAS  Article  PubMed  Google Scholar 

  20. 20.

    Puskarich MA, Trzeciak S, Shapiro NI et al (2012) Prognostic value and agreement of achieving lactate clearance or central venous oxygen saturation goals during early sepsis resuscitation. Acad Emerg Med 19:252–258

    Article  PubMed  PubMed Central  Google Scholar 

  21. 21.

    Chiolero RL, Revelly JP, Leverve X et al (2000) Effects of cardiogenic shock on lactate and glucose metabolism after heart surgery. Crit Care Med 28:3784–3791

    CAS  Article  PubMed  Google Scholar 

  22. 22.

    Stang M, Wysowski DK, Butler-Jones D (1999) Incidence of lactic acidosis in metformin users. Diabetes Care 22:925–927

    CAS  Article  PubMed  Google Scholar 

  23. 23.

    Record CO, Chase RA, Williams R et al (1981) Disturbances of lactate metabolism in patients with liver damage due to paracetamol overdose. Metabolism 30:638–643

    CAS  Article  PubMed  Google Scholar 

  24. 24.

    Almenoff PL, Leavy J, Weil MH et al (1989) Prolongation of the half-life of lactate after maximal exercise in patients with hepatic dysfunction. Crit Care Med 17:870–873

    CAS  Article  PubMed  Google Scholar 

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We gratefully acknowledge comments from Dr. Laura Hausmann (PhD).

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Correspondence to Oliver Matz.

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All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

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Informed consent was obtained from all individual participants included in the study.

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Matz, O., Heckelmann, J., Zechbauer, S. et al. Early postictal serum lactate concentrations are superior to serum creatine kinase concentrations in distinguishing generalized tonic–clonic seizures from syncopes. Intern Emerg Med 13, 749–755 (2018). https://doi.org/10.1007/s11739-017-1745-2

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  • Lactate
  • Seizure
  • Diagnostic marker
  • Syncope
  • Creatine kinase (CK)