Non-existent or imperceptible EEG activity.
D000328:Adult; D001926:Brain Death; D003643:Death; D004569:Electroencephalography; D004576:Electromyography; D004585:Electrooculography; D004827:Epilepsy / Q000150:complications; D005260:Female; D006801:Humans; D009103:Multiple Sclerosis / Q000150:complications