However, Amirsalari and co-workers did not find a significant difference in serum ferritin, hemoglobin, and MCH levels between 9 months to 5-year-old patients with
first seizure and the control group [10]. Moreover, in another study comparing the plasma ferritin levels in 90 children with febrile convulsion (case group) and 90 febrile children without seizure (control group), the researchers did not find a significant relation between plasma ferritin and TIBC levels between the case and control groups [11].
In addition, Momen and colleagues found a positive asso- ciation between iron deficiency and the first febrile convulsion in children in a case–control study [6]. In contrast, a study comparing 100 febrile patients with 100 febrile patients without seizure showed no association between anemia and the incidence of febrile convulsion [9]. We have no definite explanation for these discrepancies between studies but different methodology of studies may explain different results.
Although our study and some other studies indicate the preventive effect of serum iron levels on the occurrence of febrile convulsion in children; other controversial reports from studies with different study design, patients' status, serum ferritin and zinc levels, and different physiological conditions have led to inconsistent findings. Therefore, further complementary studies need to be performed in order to accurately determine the role of serum iron in preventing seizures.
Our study had some limitations. The sample size was less than the desired amount because the number of patients with thalassemia major receiving blood transfusion across Ahvaz was less than the determined number in our sample size calculation. The other major limit of our study was that its design was retrospective and therefore we could not measure the serum iron level at the seizure time to demonstrate increased or decreased serum iron levels at the seizure occurrence.