Prevalence of electroencephalography abnormality in children with complex febrile seizures and multiple episodes of febrile seizures

Introduction: Febrile seizures are the most common seizure disorder in childhood. Although most febrile seizures are benign and self-limited, there are high risk of epilepsy and abnormal electroencephalography findings in patients with complex febrile seizures and multiple episodes of febrile seizure. There has been no prior study about the prevalence of abnormal electroencephalography findings in complex febrile seizures and multiple episodes of febrile seizures in Thailand.
Objective: To study the prevalence of electroencephalography abnormality in children with complex febrile seizures and multiple episodes of febrile seizures.
Methods: This is a cross-sectional study. Patients aged between 6 months to 5 years old who were diagnosed with complex febrile seizures or multiple episodes of febrile seizures were enrolled in this study from July 1, 2017 to June 30, 2018 at Faculty of Medicine Vajira Hospital, Navamindradhiraj University. After initial history taking and physical examination, electroencephalography (EEG) were performed within 1 week. EEG results were interpreted by a pediatric neurologist. The data was recorded and then analyzed.
Results 100 patients (62 males, 38 females) were enrolled in this study. 18 cases were diagnosed with complex febrile seizure, while 82 cases had multiple episodes of febrile seizure. Abnormal EEG findings were seen in 4 cases of complex febrile seizures (22.2%) and 6 cases of multiple episodes of febrile seizures (7.3%). Patients with complex febrile seizures were more likely to have EEG abnormalities than multiple episodes of febrile seizures (OR 8.15, p-value <0.001). At 6-month follow up, 18 patients (18%) in this study were diagnosed with epilepsy.
Conclusions The prevalence of electroencephalography abnormality was 10% in children with complex febrile seizures and multiple febrile seizure. EEG abnormalities were 8.51 times more common in patients with complex febrile seizures than the patients with multiple episodes of febrile seizures. The risk of developing epilepsy at 6 months is 18% in our study.
Keywords Complex febrile seizures, Multiple episodes febrile seizures, electroencephalography, epilepsy, prevalence