Prognosis in disorders of consciousness

In patients with prolonged disorders of consciousness (DOC), clinical evolution is determined by several factors closely interacting with each other: etiology, patient's age (likely influencing the physiological process of recovery, e.g., brain plasticity), the duration of DOC (likely related to the severity of brain damage), the structural and functional integrity of neuronal populations (as assessed by neurophysiological and neuroimaging methods), and the presence of clinical complications that could impact care strategies. In the present chapter, we will offer a brief review of the most recent studies on clinical evolution of patients with prolonged DOC and of the longitudinal studies searching for robust prognostic markers in such patients. We will argue that some prognostic indicators for patients in vegetative state can be gathered in the rehabilitative phase, whereas reliable markers to characterize DOC patients who will present late recovery of responsiveness and consciousness have not been identified. Moreover, long-term evolution of patients in minimally conscious state has not been clearly established, and definite prognostic information is not available for these patients. For these reasons, prospective longitudinal systematic investigations of outcome in large groups of individual with prolonged DOC are needed to better clarify the natural recovery of DOC and to define prognostic markers useful to update current positions on medical, ethical, and legal issues connected with management and care of these patients.