Abstract
OBJECTIVES: Previous research has indicated a low diagnostic yield of initial EEGs in epilepsy diagnosis in children. This study aimed at exploring factors affecting the diagnostic yield of a first EEG in different ages, and factors affecting the choice of EEG method. METHODS: 1097 EEGs performed as first recordings in children with suspected epilepsy were retrospectively analysed and divided into age groups: ≤ 5, 6-11 and 12-17 years. EEGs were classified as wake recordings with or without provocations, and sleep recordings: spontaneous sleep, sleep induced by deprivation or by melatonin premedication. RESULTS: Epileptiform activity was found in 18 % of all patients, most common (30 %) in children 6-11 years old. It was more likely to be detected in melatonin-induced sleep EEGs compared to other types of sleep EEG. Presence of epileptiform discharges were positively associated to age, sleep, neurological and/or intellectual comorbidity in all children. CONCLUSIONS: The prevalence of epileptiform activity varies depending on the child́s age. Sleep EEG is advantageous as first recording, especially in very young children or with neurological comorbidity. SIGNIFICANCE: Melatonin-induced sleep EEG has higher diagnostic yield compared to other types of sleep EEG. Age, seizure semiology and comorbidity affect the choice of EEG method.