A profound state of unconsciousness associated with depressed cerebral activity from which the individual cannot be aroused. Coma generally occurs when there is dysfunction or injury involving both cerebral hemispheres or the brain stem RETICULAR FORMATION. | Feigned coma or psychogenic coma. These patients appear comatose (i.e., unresponsive, unarousable, or both) but have no structural lesion, metabolic or toxic disorder. [MeSH]
