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Brain death (BD), persistent vegetative state, unresponsive wakefulness syndrome (PVS/UWS), minimally conscious state (MCS), EEG, magnetic resonance imaging (MRI), autonomic nervous system (ANS), heart rate variability (HRV)
We compare and discuss three cases including: a clearly brain-dead patient, a vegetative state/unresponsive wakefulness syndrome (VS/UWS) patient and a patient diagnosed as brain-dead (BD) demonstrating some but not all clinical features of a BD state. Two of the patients demonstrated clear presentation allowing for an effective determination of state of death or consciousness. One patient, in comparison to the other two, presented with a complete absence of brainstem reflexes, absence of spontaneous driving to breath, and required permanent mechanical ventilation. Nonetheless, preservation of intracranial structures, remaining brain function in both brainstem and cerebral hemispheres was evidenced in the third case similar to the reported VS/UWS patient. Moreover, autonomic reactivity to mother’s voice stimulation precluded the diagnosis of a BD in the latter case. This third patient was not comatose. The clinical examination demonstrated complete absence of brainstem reflexes, and no spontaneous driving to breath. This patient did not appear to be a VS/UWS, as she had not shown intermittent wakefulness with measurable sleep-wake cycles, and variably preserved cranial nerve reflexes. Therefore, the possibility of a responsive wakefulness state - minimally conscious state (MCS), or MCS emergence state was also excluded. This third patient in contradistinction to the other two demonstrates features similar to BD states, without being brain-dead, comatose, or VS/UWS or MCS states, and therefore rests somewhere on the spectrum of clinical consciousness. The importance of this paper is in that it highlights some of the difficulties in the clinical classification of states of consciousness, when the evaluation is categorized, showing that one of the patients presented rests somewhere else on the spectrum of clinical consciousness.