Information on prognosis allows decisions to be made on management

Patients in a vegetative state seem to be awake with their eyes open but show no evidence of awareness.1 They do not interact with others and make no purposeful or voluntary responses to visual, auditory, tactile, or noxious stimuli. They are able to breathe spontaneously, and they retain their gag, cough, sucking, and swallowing reflexes. Sleep-wake cycles are preserved, and so are the hypothalamic and brain stem autonomic responses. They are incontinent of urine and faeces, but they may retain their cranial nerve, spinal, and primitive reflexes. Inconsistent non-purposive movements occur, notably facial grimacing and chewing; they make sounds; and they may show inconsistent auditory and oculomotor orienting reflexes to peripheral sounds or movement. The diagnosis of a vegetative state is not tenable if there is any degree of voluntary movement, sustained visual pursuit, consistent and reproducible visual fixation, or response to threatening gestures.2 3

The condition is distinct from coma, in which patients have their eyes closed and lack sleep-wake cycles, and from the “locked-in” syndrome, in which patients are aware of themselves and their environment but have lost motor function and speech, communication being achieved by eye movement or blinks. Akinetic mutism is a rare syndrome in which movement is pathologically slowed or nearly absent and speech is lost but wakefulness and self awareness are variably preserved—though the …