Serum Sodium Level in Febrile Seizure - Does It Predict Seizure Recurrence within 24 Hours?

Background: Febrile seizure is the most common convulsive event in children younger than 60 months and often recurs within the first twenty four hours. It has been observed that children with recurrent febrile seizure have lower serum sodium levels. Objective: To ascertain the role of serum sodium level as a predictor of seizure recurrence within the same febrile illness. Materials & Methods: 60 children admitted for febrile seizure between 6 months to 60 months were included in the study. An age and sex matched group of 60 children with fever but no convulsions were the controls. Serum sodium levels were evaluated in all children. Children with seizures were further divided in two groups based on serum sodium level into Group A with serum sodium level 135 mEq/L. Both these group were followed for next 24 hour for recurrence of seizure. Results: Although we did not found any significant difference in the mean serum sodium levels between children with febrile seizures and controls (138.73 + 5.45 mEq/L & 139.73 + 4.65 mEq/L respectively) with p value >0.05 but there were significantly higher mean number of seizures (2.17 + 0.95) in cases having serum sodium level less than 135 mEq/L than cases having serum sodium level more than 135 mEq/l (1.45+ 0.82) within the case group with p value <0.01. Conclusion: Serum sodium level can assist in predicting the risk of recurrence within the same febrile episode although there appear to be no significant association of low serum sodium level and its predisposition to occurrence of initial febrile seizure episode.