General features:
(1) partial consciousness
(2) sleep/wake cycles present
Criteria - one or more of the following must be present:
(1) can follow simple commands (may be inconsistent)
(2) can respond with gestures or yes/no answers (regardless of accuracy)
(3) intelligible verbalization
(4) purposeful behaviors contingent to environmental stimuli and not as reflexive activity
Purposeful behaviors may include one or more of the following:
(1) contingent smiling or crying: appropriate smiling or crying in response to the linguistic or visual content of emotional but not neutral stimuli
(2) contingent vocalization or gestures: vocalizations or gestures that occur in direct response to the linguistic content of questions
(3) reaching for objects that demonstrates a clear relationship between object location and direction of reach
(4) holds or touches objects in a way that accommodates for size and shape
(5) sustained visual pursuit or sustained visual fixation that occurs in direct response to moving or salient stimuli
Factors which may result in an underestimation of the level of consciousness:
(1) sensory deficit
(2) motor dysfunction
(3) diminished drive
An observer may overestimate the patient's true level of consciousness if reflexive or infrequent movements are interpreted as purposeful.
