Normal variants and artifacts: Importance in EEG interpretation

• DOI: 10.1002/epd2.20040
• Publication Date: 2023-03-20T09:39:50Z
• Authors: Ushtar Amin; Fábio A. Nascimento; Ioannis Karakis; Donald Schomer; Selim R. Benbadis
• Keywords: Artifact (error)

Overinterpretation of EEG is an important contributor to the misdiagnosis epilepsy. For have a high diagnostic value and specificity, it critical recognize waveforms that can be mistaken for abnormal patterns. This article describes artifacts, normal rhythms, patterns are prone being misinterpreted as abnormal. Artifacts potentials generated outside brain. They divided into physiologic extraphysiologic. Physiologic artifacts arise from body include EMG, eyes, various movements, EKG, pulse, sweat. Some useful interpretation such EMG eye movements. Extraphysiologic body, in turn environments (electrodes, equipment, cellphones) devices within (pacemakers neurostimulators). Normal rhythms awake (alpha rhythm its variants, mu rhythm, lambda waves, posterior slow waves youth, HV-induced slowing, photic driving, photomyogenic response) sleep (POSTS, vertex spindles, K complexes, sleep-related hypersynchrony, frontal arousal rhythm). Breach affect both rhythms. variants or uncertain clinical significance may been considered early days but now normal. These wicket spikes (the most common pattern overread epileptiform), small sharp (aka benign epileptiform transients sleep), rhythmic midtemporal theta drowsiness psychomotor variant), Cigánek midline theta), 6 Hz phantom spike-wave, 14 positive spikes, subclinical discharges adults (SREDA), slow-fused transients, occipital blindness, temporal slowing elderly. Correctly identifying help avoid overinterpretation misdiagnosis. educational review paper addressing learning objective International League Against Epilepsy (ILAE) curriculum.