J Korean Child Neurol Soc.  1998 May;5(2):265-270.

The Influence of Low Serum Sodium Levels on the Risk of the Recurrence of Febrile Convulsions

• Park HJ

Abstract

PURPOSE: Fever plays an important role in causing disturbances in fluid and electrolyte balance. Hyponatremia has been thought to enhance the susceptibility to febrile convulsions in childhood and to increase a risk of repeat convulsion during same febrile illness. I therefore carried out a study in attempt to investigate how high the serum sodium level is in children with febrile convulsions, and whether there is an association between the recurrence of febrile convulsions and hyponatremia
METHODS
Blood samples for serum sodium measurement were taken from 136 children visited to the Seoul Red Cross Hospital due to an acute febrile convulsion during the period between 1994 and 1996(patient group). I also checked serum sodium in a group of age-matched controls(control group I: no fever, no convulsion, control group II: fever only, control group In non-febrile convulsions). The patient group was divided into two groups, recurrent and non-recurrent groups. The results were analyzed by Student's t-test.
RESULTS
The mean serum sodium level(134.99+/-3.59mmol/L) was significantly lower as compared to all control groups(control group I : 137.92+/-2.19mmol/L, control group II : 137.49+/-2.94mmo1/L, control group III : 137.73+/-2.52mmo1/L, p<0.001). The mean serum sodium levels were not different between each other control groups(p>0.05). Thirty-two of the 136 children(23.5%) with a febrile convulsion developed a repeat convulsion. The mean serum sodium level in the group with repeat convulsions(133.00 +/-3.21mmo1/L) was significantly lower than the mean in the group without repeat convulsions(135.85+/-3.28 mmol/L) The risk of a repeat convulsion approaches 60% In cases with serum sodium levels of 130 mmol/L and gradually decreases to less than 10% in cases with serum sodium levels of 140mmo1/L.
CONCLUSION
Hyponatremia may increase the susceptibility to the febrile convulsions. The lower the serum sodium level, the higher the probability of a repeat convulsion This may be of practical value in deciding whether to admit the child and in advising parents or carers of the risk of a repeat convulsion.

MeSH Terms

Caregivers
Child
Fever
Humans
Hyponatremia
Parents
Recurrence*
Red Cross
Seizures
Seizures, Febrile*
Seoul
Sodium*
Water-Electrolyte Balance
Sodium