of the major differences in prognosis described in this study, this makes it crucial that mcs be diagnosed correctly. incorrectly diagnosing mcs as vegetative state may lead to serious repercussions related to clinical management. history prior to the mid-1990s, there was a lack of operational definitions available to clinicians and researchers to guide the differential diagnosis among disorders of consciousness. as a result, patients were lumped together into broad categories often based on the severity of the disability (e.g. moderate, severe, extremely severe). these diagnoses were performed without regard to salient differences in behavioral and pathological characteristics. in a three-year period spanning from 1994 to 1996, three position statements regarding the diagnostic criteria of disorder of consciousness were published. the "medical aspects of the persistent vegetative state" was published by the american academy of neurology (aan) in 1994. in 1995, "recommendations for use of uniform nomenclature pertinent to patients with severe alterations in consciousness" was published by the american congress of rehabilitation medicine (acrm). in 1996 the "international working party on the management of the vegetative state: summary report" was published by a group of international delegates from neurology, rehabilitation, neurosurgery, and neuropsychology. however, because the diagnostic criteria were published independently from one another, the final recommendations differed greatly from one another. the aspen neurobehavioral work-group was convened to explore the underlying causes of these disparities. in the end, the aspen work-group provided a consensus statement regarding definitions and diagnostic criteria disorder of consciousness which include the vegetative state (vs) and the minimally conscious state (mcs). ethical issues one of the major ethical concerns involving patients with severe brain damage is their inability to communicate. by definition, patients who are unconscious or are minimally conscious are incapable of giving informed consent which is required for participation in clinical research. typically, written approval is obtained from family members or legal representatives. the inability to receive informed consent has led to much research being refused grants, ethics committee approval, or research publication. this puts patients in these conditions at risk of being denied therapy that may be life-saving. the right to die the right to die in patients with severe cognitive impairment has developed over time because of their grave neurological state and the perceived futility of continued treatment. such cases have been debated vigorously in the past, as in the case with terri schiavo who was diagnosed with persistent vegetative state. in the case of minimally conscious state patients, they are neither permanently unconscious nor are they necessarily hopelessly damaged. thus, these patients warrant additional evaluation. on one hand, some argue that entertaining the possibility of intervention in some patients may erode the "right to die" moral obligation. conversely, there is also fear that people may associate attitudes with higher-functioning people in minimally conscious state with people in persistent vegetative state, thus minimizing the value of their lives. regulating therapeutic nihilism currently, risk aversion dominates the ethical landscape when research involves those with impaired decision-making abilities. fears of therapeutic adventurism has led to a disproportionate view about the under-appreciation of potential benefits and an overstatement of risks. thus, recognizing this distortion is important in order to calculate the right balance between protecting vulnerable populations that cannot provide autonomous consent and potentially restorative clinical trials. notable examples jackie wilson (june 9, 1934 – january 21, 1984), american soul and rock and roll singer who fell into a coma after collapsing on stage, soon recovered conscious but then quickly regressed to a minimally conscious state for the rest of his life. jan grzebski (1942–2008), a polish railroad worker who fell into a minimally conscious state in 1988 and woke up four years later, but didn't fully recover until 2007. chi cheng (1970-2013), an american musician best known as the original bassist for the band deftones who was involved in a serious automobile accident in 2008 that left him in a minimally conscious state for the rest of his life. terry wallis (1964-2022). this american man was in a coma for nearly a year after a truck accident, then a minimally conscious state for 19 years. martin pistorius (born 1975), a south african man who, because of a mystery illness, spent three years in a vegetative state, four years in a minimally conscious state, and five years unable to move anything other than his eyes (locked-in syndrome). in 1999, he fully awakened, and has since recovered to the point that he was able to become a web designer, developer, and author. in 2011, he wrote a book called ghost boy, in which he describes his many years of being comatose.