Levels of Sodium and Zinc Concentration in Febrile Convulsion

Cho, Woo Jae; Son, Byeong Hee; Kim, Sung Won

Abstract

PURPOSE: A febrile convulsion is a common event during childhood, its pathogenesis is not clear. But there are some hypotheses including electrolyte imbalance, neurotransmitter and metabolic change. Hyponatremia has been thought to decrease the threshold for febrile convulsion and low cerebrospinal zinc level induced by fever or infections causes low cerebrospinal gamma-aminobutyric acid(GABA) which is a major inhibitory neurotransmitter. We therefore carried out a prospective study to investigate whether there is an association with serum sodium levels, CSF zinc concentration and febrile convulsions.
METHODS
Blood and CSF samples for sodium and zinc were taken from 37 children at Pusan Saint Benedict Hospital due to febrile illness from March 1998 to December 1998. They were divided into three groups: 11 with fever but without convulsions(Group I), 15 with aseptic(viral) meningitis(Group II), and 11 with febrile convulsions(Group III). The results were analyzed by Wilcoxon 2 Sample Test.
RESULTS
The means of serum sodium, Zn level and CSF Na, Zn level in the febrile convulsion group were not significantly lower than in other groups(for serum Na : group I 143.09+/-2.84mmol/L, group II 141.60+/-2.49mmol/L, group III 142.54+/-1.80mmol/L; for CSF Na : group I 138.72+/-5.53mmol/L, group II 139.64+/-4.64mmol/L, group III 138.82+/-2.25mmol/L; for serum Zn : group I 90.38+/-9.09micro gram/L, group II 90.28+/-13.64micro gram/L, group III 97.16+/-14.54micro gram/L; for CSF Zn : group I 41.61+/-13.30micro gram/L, group II 45.80+/-12.66micro gram/L, group III 41.04+/-11.17micro gram/L). There was no statistically significant difference in serum sodium and CSF zinc between the three groups of children.
CONCLUSION
There is no evidence in this study, that hyponatremia may increase the susceptability to febrile convulsion or that zinc deprivation may play a role in the pathogenesis of febrile convulsion in previous study. So, more study of pathophysiology of febrile convulsion is needed.