Can a seizure increase a patient's Creatine Kinase (CK) and Creatine Kinase-MB (CKMB) levels?

Seizures Can Significantly Elevate CK and CK-MB Levels

Yes, seizures can significantly raise both Creatine Kinase (CK) and Creatine Kinase-MB (CK-MB) levels due to intense muscular activity during convulsions. This elevation is primarily from skeletal muscle damage, though it can sometimes be misinterpreted as cardiac injury 1, 2.

Mechanism and Patterns of CK Elevation After Seizures

• Seizures, particularly generalized tonic-clonic seizures, cause intense muscle contractions that lead to muscle fiber damage and subsequent enzyme release 2
• CK elevations typically:
  • Begin within 4-6 hours after seizure activity 3
  • Peak on the 3rd or 4th day post-seizure 4
  • Can reach extremely high levels (>5000 U/L) in some cases 1
  • Are predominantly skeletal muscle in origin (CK-MM isoform) 2

Diagnostic Significance

• CK elevations after seizures can be profound, with studies showing levels up to 39,300 U/L 1
• Sequential CK measurements can help differentiate seizures from other conditions:
  • An increase of >15 mU/ml between first and second day measurements has 69% sensitivity and 94% specificity for distinguishing generalized tonic-clonic seizures from vasovagal syncope 5
  • CK levels >200 mU/ml at 24 hours are highly specific (100%) for seizures versus syncope 5

Clinical Implications and Potential Confusion with Cardiac Events

• CK-MB may also be elevated after seizures, potentially causing diagnostic confusion with myocardial injury 3
• Important distinctions when evaluating elevated CK/CK-MB:
  • Troponin measurements are more specific for cardiac injury than CK-MB 3
  • In seizure patients without cardiac symptoms, CK-MB elevation is likely due to skeletal muscle release rather than cardiac injury
  • The pattern of elevation (rapid rise after seizure) differs from typical MI patterns

Management Recommendations for Elevated CK After Seizures

• Serial assessment of CK, myoglobin, eGFR, and electrolytes should be performed in patients following seizures 1
• When CK levels are significantly elevated after seizures:
  • Implement fluid resuscitation to prevent renal complications
  • Consider urine alkalization
  • Monitor renal function closely, as patients may have reduced eGFR 1
  • Administer diuretic agents if indicated

Important Considerations and Pitfalls

• Not all seizures cause CK elevation - studies show that while 82% of generalized tonic-clonic seizures may cause elevated CK, other seizure types (complex partial, focal motor, absence) typically do not 6
• CK elevation correlates with seizure intensity and muscular activity - patients with alcohol-related seizures tend to have higher elevations 2
• Regular anti-epileptic treatment is associated with lower post-ictal CK elevations 4
• Avoid misdiagnosing cardiac injury based solely on CK-MB elevation in a patient with recent seizure activity

By understanding these patterns of enzyme elevation after seizures, clinicians can avoid unnecessary cardiac workups while still appropriately monitoring for potential complications from significant muscle damage.