A person in a vegetative state (VS) is
awake but shows no signs of awareness of themselves or their
They will open their eyes and demonstrate sleep-wake cycles
and basic reflexes such as blinking or startling at sudden noises, or
withdrawing a limb at painful stimuli.
They may show smiles, grimaces, shed a tear or make grunting
or groaning sounds.
They may make a range of spontaneous movements including
chewing, teeth grinding, swallowing, roving eye movements and purposeless limb
movements. The grasp reflex may also be present.
They do not display any purposeful response to sensory or
cognitive stimuli, for example, they will not constantly track a moving object
with their eyes or respond to commands.
Duration leads to differing terminology such as persistant of
permanent vegetative state (PVS). The latter is not generally used under a
period of twelve months and even after several years a patient may emerge from
VS and progress to a minimally conscious