Coma and other disorders of consciousness
Michel Jouvet
Coma is classically defined as loss of motility, sensation and consciousness with preservation of autonomic functions. Though not inaccurate, this definition is no longer considered as adequate. If loss of consciousness seems to be a necessary and sutficient symptom to talk of coma (it being understood that we are dealing with a lethargic state very different from sleep, in as much as the subject cannot be roused by strong external stimulation), it follows that loss of voluntary motility and sensation are natural consequences of the loss of consciousness and add no useful precision to the definition.