The Relation Between Simple Febrile Convulsion And Serum Zinc Level In Children

Background: Febrile seizures are the most common seizures of childhood, aged between 6 months to 5 years. Pathophysiology of febrile seizure remains unknown, but reduction in serum and cerebrospinal fluid zinc levels, and low gamma-amino butyric acid (GABA) levels are thought to play a role in the pathogenesis of febrile seizure occurrence or recurrence. Objective: To find out the serum zinc level in children with simple febrile convulsion , and its relationship with age, sex, duration of fever and the causes of febrile illness. Patients and methods: A case-control study was performed on 90 children aged between six months to five years presented at emergency department of Child Central Teaching Hospital over a period of 4 months (from 15 November 2015 to 15 February 2016). Forty five patients had simple febrile seizure which is single attack of generalized convulsion with fever (temperature ≥38℃) occurring once time within 24 hours (as case group) and 45 patients were presented with acute febrile illness without convulsion in same degrees of temperature (as control group). A venous blood samples were obtained from both groups for determination of serum zinc level using colorimetric test kit and measured by Spectrophotometer. Results: A total of 90 patients were included, 45 patients were had febrile convulsion (28 males & 17 females), While the other 45 one had febrile illness with no fit (21 males and 24 females). The Mean temperatures of children in cases and control groups were (39.4±0.4℃ & 38.9±0.4℃ ), respectively. The serum zinc level was low in 28 patients (62.2%) of febrile convulsion group, while only 14 patients (31.1%) of control group had low serum zinc level. Mean serum zinc level was 64.8±4 μg/dl , 74.18±14.9 μg/dl in cases and control group respectively which was significant statically (p<0.001). No significant relationship was observed between serum zinc level and age; patients had low serum zinc level in those aged below one year, 1-3 years & 3-5years, respectively with almost similar distribution in the control group] (p=0.795). Also no significant relationship between serum zinc level and sex among patients in febrile convulsion group and control one (M:F ratio 1.5:1 & 1.25:1 respectively, p=0.738). There was significant positive correlation between duration of fever before the attack and low serum zinc level in febrile convulsion patients. A higher percent of patients with low serum zinc level (78.2%) was seen in cases got longer duration of fever (more than 24 hr) before the fit, while only(45.4%) of patients who got fit in the 1st24 hours of the start of fever(p=0.023). So also the percentage of patients with low serum zinc level was higher in those with febrile convulsion for the first time as compared to patients with recurrent ones (p=0.03) which was statistically significant. No correlation between causes of fever with & low serum zinc level in both groups except gastro-enteritis cause which had high frequency of fit in low serum zinc [14 of patients got GE; 6 of them got low serum zinc level: 5 (83.3%) got fit & 1 (16.6%) had no fit], It is statistically Significant (p=0.001) that might relate to other race elements. Conclusion: Serum zinc level is lower in patients with febrile convulsion and no specific age group or gender is particularly predisposed to develop hypozincemia. Low serum zinc level is more obvious when the fever last more than 24 hours before occurrence of fit and it may play a role in the 1st attack of febrile convulsion. Only gastro-enteritis found to have significant association with low serum zinc level.