Background: Febrile seizures are the most common seizures in children. Their incidence is 2-5 % or 4.8/1000 person-years. To date, the pathophysiology of febrile seizures is unknown. But several hypotheses have
been purposed that it may relate with plasma iron level. Such low incidence in thalassemic patients whose plasma iron level is high could give some clues to this hypothesis.
Patients and Method: Four hundred and thirty thalassemic patients from the hematology clinic at two hospitals in Northeastern Thailand were consecutively enrolled between Febuary 2003 and January2004. The authors reviewed all the medical records of the patients and interviewed their parents for occurrence of febrile seizures.
Results: The patients included 208 males and 222 females with an age ranged of 6 months to 10 years (mean = 6.36 years). Twenty patients (4.7%) had siblings who had febrile seizures. There were 3 episodes out of 2,734 person-years. The incidence was 1.10 per 1,000 person-years (95% CI: 0.23 to 3.20). This was statistically lower than that of the general population (p-value = 0.002). Therefore, the rate in thalassemic patients was 4.4 times less than that of the general population (95% confidence interval: 1.4 to 22.6).
Conclusions: The incidence of febrile seizures in thalassemic patients was very low compared to that of the
general children population. Thus, iron overload may be a major factor involving the brain metabolism that prevents febrile seizures.

Keywords: Febrile seizures, Thalassemia, Brain metabolism