554 Abstract. – OBJECTIVE: Most febrile seizures occur outside of hospitals, and in most cases, information about the characteristics of the sei- zures is obtained from the parents. This makes it difficult to differentiate between simple and com- plex seizures. The aim of this study is to evalu- ate the significance of the Neutrophil-Lympho- cyte Ratio (NLR) and the red blood cell (eryth- rocyte) distribution width (RDW) in distinguish- ing between simple and complex febrile seizures. PATIENTS AND METHODS: The files of 142 patients between the ages of 6 months and 5 ye- ars who were admitted to the Emergency Depart- ment with the diagnosis of first febrile seizure were reviewed retrospectively. Complete blood count and C-reactive protein (CRP) parameters obtained from the venous blood samples col- lected from the patients at admission were eva- luated. RESULTS: The average values of NLR for sim- ple and complex seizure groups were 2.38 ± 1.60 and 3.42 ± 1.77 respectively, and the difference was statistically significant (p < 0.001). The aver- age values of RDW for simple and complex sei- zure groups were 16.15 ± 1.37 and 16.27 ± 1.53, respectively; the difference was not significant (p = 0.631). We used receiver operating charac- teristic (ROC) analysis and chose a cutoff value of 2.315 for the NLR, and we found that the sen- sitivity and specificity were 62.7% and 53.8%, respectively (area under the curve [AUC]: 0.665, p = 0.001, confidence interval [CI] 0.573-0.756). CONCLUSIONS: We suggest that NLR may provide clinicians with an insight into differen- tiating between simple and complex febrile sei- zures; however, it does not produce a clear-cut distinction. We found that the RDW ratio is not useful in this differentiation. Key Words Febrile seizure, Children, Neutrophil-lymphocyte ratio, Red blood cell distribution width, Epilepsy, Fe- ver, Convulsion. Introduction Febrile seizures affect children between 6 months and 6 years of age and are seen in 2%- 5% of children 1 . Complex seizures constitute 25%-30% of these seizures 1,2 . Complex seizures are defined as seizures by fever with at least one of the following characteristics: seizure duration longer than 15 minutes, recurrence within 24 hours, and showing focal characteristics of and/ or accompanied by neurological abnormalities 3 . The American Academy of Pediatrics recom- mended that no further diagnostic evaluations are required, except determining the source of fever, in the treatment approach to simple febrile seizu- res 4 . On the other hand, in the etiology, usually a more detailed diagnostic approach is selected for complex febrile seizures because of the higher risk of recurrence and the possible presence of serious pathologies that should be treated immediately. Additionally, Vestergaard et al 5 observed that the sudden and unexpected death rate was doubled within two years after complex febrile seizures when compared to the normal population, whereas this ratio was similar between the simple febrile seizure group and the normal population. Most febrile seizures occur outside of hospitals, and information on the character of the seizures is usually obtained from the parents. Currently, there are no objective parameters to distinguish between these two types of seizures. Hence, objective diag- nostic indicators to determine the type of seizures in non-hospital seizures are needed. Goksugur et al 6 suggested that NLR and RDW may be used to objectively make this distinction. Neutrophil-Lymphocyte Ratio (NLR) is an in- expensive, easily accessible, and easily calculable parameter that has been used for evaluation of European Review for Medical and Pharmacological Sciences 2017; 21: 554-559 Y. YIGIT 1 , S. YILMAZ 2 , A. AKDOGAN 1 , H.C. HALHALLI 1 , A.E. OZBEK 1 , E.G. GENCER 3 1 Department of Emergency Medicine, Derince Education and Research Hospital, Kocaeli, Turkey 2 Department of Emergency Medicine, Medical Faculty, Kocaeli University, Turkey 3 Department of Emergency Medicine, Kartal Dr. Lutfi Kirdar Education and Research Hospital, Istanbul, Turkey Corresponding Author: Yavuz Yigit, MD; e-mail: dryavuzyigit@gmail.com The role of neutrophil-lymphocyte ratio and red blood cell distribution width in the classification of febrile seizures