The Multi-Society Task Force developed criteria for the diagnosis of the persistent vegetative state (PVS). These can help evaluate a patient with impaired consciousness. The authors are from the American Academy of Neurology, American Academy of Pediatrics and 3 other neurological societies.


Criteria for the diagnosis of vegetative state:

(1) no evidence of awareness of self or the environment

(2) an inability to interact with others

(3) no evidence of sustained, reproducible, purposeful, or voluntary behavioral responses to visual, auditory, tactile or noxious stimuli

(4) no evidence of language comprehension or expression

(5) intermittent wakefulness manifested by the presence of sleep-wake cycles

(6) sufficiently preserved hypothalamic and brainstem autonomic functions to permit survival with medical and nursing care

(7) bowel and bladder incontinence

(8) variably preserved cranial nerve reflexes (pupillary, oculocephalic, corneal, vestibulo-ocular, gag) and spinal reflexes


Patients usually show some motor activity, but movements are done in a meaningless or reflexive manner. A patient may be misdiagnosed as minimally conscious if these activities are misinterpreted.




PVS present for >= 1 month


irreversible PVS



• No term is offered for PVS lasting < 1 month. I will use "transient" for the implementation.


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