Resumen de The state of consciousness in patients in the vegetative and minimally conscious states
Edward B Ziff, Elisabete Castelon Konkiewitz
Brain-injured patients may, with the assistance of life support, continue to perform basic bodily functions, but yet be deficient in wakefulness, awareness, decision making or other overt manifestations of consciousness. Here, we review two neurological states observed in brain injured patients with different degrees of brain impairment, the vegetative state (VS) and the minimally conscious state (MCS), and we discuss how these states are diagnosed through assessing patient behavioral responses during clinical examination. We consider how functional neuroimaging has revealed preserved cognitive capacities in patients that were supposed to be in the VS and has introduced a new diagnosis, cognitive motor dissociation. We review the GW Theory proposal that consciousness arises from functional connectivity (FC) of widely separated brain regions. We discuss how such high FC underlies the Default Mode Network (DMN), a group of neural circuits that are active when an individual is not involved with external tasks and engages in introspective thinking. Finally, we discuss the finding that the level of FC of the DMN is diminished in brain injured patients and the proposal that the level of residual DMN FC in brain injured patients is an index of their consciousness.
