They found that there were widespread cerebral atrophy in both patients. The lateral ventricles were increased in size, and the corpus callosum and the periventricular white matter were diminished. The DTI maps showed that there was significant reduction of volume in the medial corpus callosum and other parts of the brain compared to normal subjects. They also found markedly lower diffusion values in white matter and increased cerebral spinal fluid compartments. Cortical injuries at this level provides a particular favorable environment for sprouting of new axons to occur in the intact areas of the cortex, which may explain some of the greater recovery rates in minimally conscious state patients. The axonal regrowth has been correlated with functional motor recovery. The regrowth and rerouting of the axons may explain some of the changes to brain structure. These findings support the efforts to prospectively and longitudinally characterize neuroplasticity in both brain structure and function following severe injuries. Utilizing DTI and other neuroimaging techniques may further shed light on the debates on long-distance cortical rewiring and may lead to better rehabilitation strategies.Some areas of the brain that are correlated with the subjective experience of pain were activated in MCS patients when noxious stimulation was present. Positron emission tomography (PET) scans found increased blood flow to the secondary sensory cortex, posterior parietal cortex, premotor cortex, and the superior temporal cortex. The pattern of activation, however, was with less spatial extent. Some parts of the brain were less activated than normal patients during noxious stimulus processing.
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.