[EEG interictal--sensitivity and specificity of the diagnosis of epilepsy]. / Electroencefalograma interictal--sensibilidade e especificidade no diagnóstico de epilepsia.

EEG is a non invasive, cheap and accessible method, systematically used in the investigation of epilepsy. We present a review of studies regarding the prevalence of epileptiform abnormalities in epileptic and non-epileptic patients, with the objective of drawing conclusions about the specificity and sensitivity of the EEG in the diagnosis of epilepsy. We conclude that the sensitivity of the first EEG is 50-55%, although it can reach 92% with exam repetition and use of sleep records and activation techniques. The specificity of the EEG is influenced by many factors and reaches 96% in some epileptic syndromes.