Iron Insufficiency as a Risk Factor for Febrile Seizures

Abstract

Source: Daoud AS, Batieha A, Abu-Ekteish F, et al. Iron status: a possible risk factor for the first febrile seizure. Epilepsia. 2002;43:740–743.The significance of iron status as a possible risk factor for a first febrile seizure (FFS) was investigated at Jordan University and King Hussein Medical Center, Irbid, Jordan. Children admitted with a FFS between January and December 2000 were compared to a reference group of children hospitalized for a febrile illness (eg, upper and lower respiratory tract infection, gastroenteritis) without seizures. The 2 study groups were comparable in all areas. The mean ferritin level of 75 children with FFS was 29.5 +/− 21.3 mcg/L as compared to 53.3 +/− 37.6 mcg/L in 75 matched controls (P=.0001). A plasma ferritin (PF) level of <30 mcg/L was significantly more prevalent among children with FFS than controls (65% vs 32%, P=.000). Mean levels of hemoglobin concentration (Hgb), mean corpuscular volume (MCV ), and mean corpuscular hemoglobin (MCH) were lower in FFS cases than in controls, and a higher proportion of FFS cases had a Hgb <110g/L, MCV <72 fl, and MCH <24 pg (differences not significant). The mean levels of Hgb (97.2), MCV (70.7), MCH (22.9), and PF (22.2) that were seen in children with complex seizures were lower than those seen in children with simple febrile seizures and differences were statistically significant for Hgb (P=.016) and MCH (P=.03). Mean peak temperature on admission and types of febrile illness were not different between cases and controls. Family histories of epilepsy and febrile convulsions were higher among cases, but the differences between cases and controls were not significant. The findings suggest a possible role for iron insufficiency in FFS.Plasma ferritin (PF), an iron containing protein, is used as a measure of iron deficiency and total body iron status. These authors found low PF levels in children admitted for a first febrile seizure (FFS). Previous studies have shown conflicting results. One report suggests that iron-deficiency anemia may raise, not lower, the threshold for febrile seizures, and that ferritin levels increase in response to any febrile illness.1 Another finds a significantly higher rate of iron-deficiency anemia among children with FFS than in controls.2 Lead poisoning, another possible cause of iron-deficiency anemia and febrile convulsions,3 was considered very unlikely in the study population because of preliminary, unpublished data on a similar population which showed this to be a very rare cause. The reason for the decreased levels of PF in children with FFS was undetermined.Other neurologic disorders in which iron-deficiency anemia may play a role include breath-holding spells,4 developmental delay,5 and behavior and cognitive disorders.6 Treatment with iron may reverse developmental delay in iron-deficiency anemia.7 Testing for iron-deficiency anemia is suggested in infants who have experienced febrile seizures, but further studies are needed to confirm a possible role of iron status in FFS.There is still much to be ironed out in trying to understand the pathophysiology underlying this interesting association between low ferritin levels and febrile seizures. A follow-up study of patients found to be iron-deficient at the time of a first febrile seizure to determine the incidence of subsequent febrile seizures after treatment for iron deficiency would be of great interest.