The diagnostic yield of a first EEG in children with suspected epilepsy: A retrospective age-related comparison between awake and sleep recordings.

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.