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. Author manuscript; available in PMC: 2013 Apr 1.
Published in final edited form as: Anesthesiology. 2012 Apr;116(4):946–959. doi: 10.1097/ALN.0b013e318249d0a7

Figure 1.

Figure 1

Electroencephalogram changes during non-rapid eye movement (NREM) to rapid eye movement-like (REM) transitions during sleep and general anesthesia. (A) During sleep, the change from NREM like activity to REM-like activity is accompanied by the loss of spindles and delta waves and a shift to higher frequency activity. (B) Midway through an operation REM-like activity was noted by loss of spindles and delta waves and a shift to higher frequency activity, in this snapshot, beta activity. (C) On emergence from anesthesia, the patient transitioned through both theta and gamma activity prior to waking, seemingly waking from a REM-like state (upper panel). This started at approximately 0.4 MAC of anesthesia, about 5 minutes from becoming responsive (lower panel). SWS = slow wave sleep. MAC = minimum alveolar concentration. SE = state entropy.