Iron Deficiency Anemia: The Possible Risk Factor of Complex Febrile Seizure and Recurrence of Febrile Seizure
Annals of Child Neurology
Purpose: A relationship between Febrile seizure (FS) and iron deficiency anemia (IDA) has been found in several studies. However, few studies have focused on the role of IDA in complex febrile seizures (CFS) and simple febrile seizures (SFS) and there is no report on whether IDA is a risk factor for recurrence. The aim of this study was to investigate the role of IDA in SFS and CFS and to examine the effect of IDA on recurrence. Methods: Patients (n=166) who had been diagnosed with FS were
... led in our study. Subjects were divided into the following groups for analysis: the SFS and CFS groups, recurrence and non-recurrence groups. The onset age was compared in each group of patients and laboratory test results based on IDA were compared. Results: Between the SFS and the CFS groups, there was no significant difference in laboratory test results based on IDA. There was a significant difference in onset age between the two groups and the onset age tended to be lower in the CFS group (24.00 vs. 16.49 months) (P=0.004). Comparing recurrence and non-recurrence groups, the mean corpuscular volume was significantly different (P=0.043) with the recurrence group having a lower mean corpuscular volume level (78.92 vs. 77.48). The onset age in the recurrence group was lower (26.02 vs. 19.68 months). Conclusion: This study suggests that onset age could be a risk factor for CFS, and IDA may not contribute to elevating the risk of CFS. However, IDA may play an important role in the recurrence of FS. fects the quality of life in a family 3) . There are many studies which have identified the risk factors of FS. The known provoking factors include fever, genetics, intrau J Korean Child Neurol Soc 2018;26(4):210-214 https://doi.org/10.26815/jkcns.2018.26.4.210 pISSN 1226-6884•eISSN 2383-8973 J Korean Child Neurol Soc 2018;26(4):210-214 211 http://www.cns.or.kr terine risk factors (maternal nicotine and alcohol intake). Other studies have found an association between FS and vaccination. Furthermore, recent studies have also shown an association with iron deficiency anemia (IDA) 1) . The risk of recurrent FS is 15 to 70 percent and recurrence risk factors are age under 18 months, duration of fever, and fever temperature 4,5) . Although some studies have shown that IDA does not play a role in pediatric febrile seizure or even raise seizure threshold 6, 7) , many studies have reported that there is a significantly high number of FS patients with IDA 812) . However, few studies have focused on the role of IDA in complex febrile seizures (CFS) and simple febrile seizures (SFS) 13) . Additionally, to the best of our knowledge, there is no report on whether anemia is a risk factor for recurrence of FS. Therefore, the current study was designed to compare the prevalence of IDA between patients with SFS and those with CFS, and determine whether IDA is a risk factor for FS recurrence. 3.420 (95% CI 1.196-9.775). No significant differences were found between other factors such as low Hb and Hct levels, and low MCV. IDA is the most common micronutrient deficiency worldwide, occurring in 9-40% of children from 6-24 months of age 17) . Be cause iron in the hemoglobin structure plays an important role in transporting oxygen to the brain, some researchers believe that iron may reduce seizure threshold 8) . Additionally, iron is essential for many enzymes involved in the synthesis of neurotransmitters 18) . In iron deficiency, unusual behaviors, fatigue, mental retarda tion, attention deficit disturbance, arousal, decreased learning ability, cognitive impairment, and central nervous system symp toms can occur 1922) . Many studies have investigated the role of IDA in febrile seizures and have found that IDA is a major risk factor in the aggravation of febrile seizures 812,23) . However, few studies have investigated the role of IDA in SFS and CFS. According to Ozaydin et al., Hb, Hct, MCV, platelet, RDW, and MPV levels were significantly lower in patients with CFS compared to patients with SFS 13) . On the contrary, in a study which compared anemia in SFS and CFS patients, Jun et al. showed that the anemia ratio was higher in the CFS group but not statistically significant, and there was no statistically signifi cant difference between the two groups in Hb, MCV, and Hct levels 17) . Ozaydin et al. also studied the risk factors of CFS and found that a family history of epilepsy and febrile seizures, pre maturity, and low birth weight could be risk factors 13) . In our study, we conclude that there is no statistically significant difference in Hb, Hct, and MCV levels between SFS patients and CFS patients, as in the study by Jun et al. Therefore, the results of this study suggest that IDA is just risk factor of febrile seizure and may not be a risk factor for CFS. Febrile seizures have a high recurrence rate, ranging from 15 to 70 percent, depending on the risk factors involved 4,5) . The risk factors identified in previous studies were onset age under 18 months, duration of fever, and fever temperature 4) . To the best of our knowledge, there is no study yet on whether IDA is a risk factor for recurrence of febrile seizures. Similarly, in our study, the onset age was significantly lower in the recurrence group and the odds ratio for onset age under 18 months was 3.689 (95% CI 1.909-7.131), which was significant. The MCV was significantly lower in the recurrence group and the odds ratio was 2.329 (95 % CI 1.951-2.779) after analysis to confirm an association with anemia. There were no significant differences in RBC, Hb, Hct, MCHC, platelet, RDW, and MPV levels between the recurrence and the nonrecurrence groups.