Disorders of consciousness (DOC) represent one of the most complex and crucial challenges for neuroscientists. A precise and reliable assessment of the arousal and awareness of consciousness in patients with severe brain damage would allow for a comprehensible classification of DOC. Intensive care has led to an increase in the number of patients who survive after severe acute brain damage. Most comatose patients who survive begin to awaken and recover gradually within 24 weeks. Although some of these individuals gradually experience complete brain function loss which leads to brain death (BD), oftentimes this state is treated as synonymous with the death of the individual. Nonetheless, other individuals progress to wakeful unawareness, which is defined as a vegetative state (VS). DOC terminology may be useful clinically, but does little to explain the nature of consciousness. While it is not known which portions of the brain are responsible for cognition and consciousness, what little is known points to substantial interconnections among the brainstem, subcortical structures and the neocortex. Thus, the higher brain may well exist only as a metaphorical concept and not in reality.