Normal Awake, Drowsy, and Sleep EEG Patterns That Might Be Overinterpreted as Abnormal.

Knowledge of normal patterns is essential for correct EEG interpretation. The overinterpretation of EEG (i.e., ascribing abnormality to EEG patterns that are not associated with disease) is a common problem and can contribute to misdiagnosis and mismanagement. Here, the authors concisely review normal patterns that might be improperly interpreted as abnormal. These include posterior slow waves of youth, central theta, K complexes, asymmetric sleep spindles, hypnagogic and hypnopompic hypersynchrony, arousal patterns, rhythmic midtemporal theta of drowsiness, and the wicket rhythm. Recognition of these patterns will lead to greater accuracy in EEG interpretation and help avoid incorrect management.