Utility of laboratory testing for infants with seizures

Area of Science:

• Pediatric Neurology
• Clinical Chemistry
• Emergency Medicine

Background:

• Infants with seizures often undergo laboratory testing to identify underlying causes.
• The utility and yield of these tests in nonfebrile seizures (NFSz) require further investigation.

Purpose of the Study:

• To determine the frequency of laboratory studies in infants with NFSz.
• To assess the proportion of clinically significant abnormal results.
• To identify clinical characteristics associated with abnormal findings.

Main Methods:

• Retrospective cohort study of infants (< or = 12 months) presenting with seizures to a tertiary children's hospital ED.
• Reviewed 2 years of data, classifying serum chemistry results as normal, outside normal range, or clinically significantly abnormal.

Main Results:

• 50% of NFSz infants underwent testing vs. 24% with febrile seizures (FSz).
• 13% of tested NFSz infants had clinically significant abnormalities (hyponatremia, hypocalcemia).
• Infants seizing in the ED (43%), those with hypothermia, and neonates (<1 month) showed higher abnormality rates.

Conclusions:

• Abnormal serum chemistries are a significant factor in NFSz among infants.
• Laboratory testing is recommended for NFSz infants actively seizing in the ED, with hypothermia, or under 1 month old.
• This study highlights the importance of targeted laboratory evaluation in specific infant populations with seizures.