Normal variants with an epileptiform appearance in electroencephalograms. A literature review and clinical implications

Abstract

Normal epileptiform-like variants or benign epileptiform variants are a diagnostic challenge in the interpretation of electroencephalograms, which require the knowledge and extensive experience of those responsible for the electroencephalographic report. They include a heterogeneous group of findings, some quite uncommon, initially related to epilepsy and various neurological conditions. Most of them are currently considered variants with no pathological significance, and their over-interpretation usually leads to misdiagnosis and the establishment of unnecessary treatments. Prevalence data are variable and usually come from selected populations, so they are difficult to extrapolate to a healthy population. Studies with invasive electrodes and recent series link some of these variants with epilepsy. We aim to review the characteristics and prevalence of the main benign epileptiform variants and to update their clinical significance.