Chronic disorders of consciousness comprise a tragic group of conditions for which determining prognosis is a prerequisite for clinical decision-making. The Vegetative State (VS) and the Minimally Conscious State (MCS) are syndromes, encompassing a spectrum of severity with various etiologies, most commonly traumatic brain injury or hypoxic-ischemic or hemorrhagic neuronal injury. They can be a transient stage during recovery from an acute brain insult or can be chronic and stable, usually after a variable period of coma. Recent advances in neuroimaging are providing new insights into cerebral activity in patients with severe brain damage. The mapping of cognitive processes (mostly by measuring regional changes in blood flow, initially by PET and currently by fMRI, and by measuring regional metabolic changes by MRSI) is providing insight into the functional neuroanatomy and metabolic assessment of consciousness. However, differential diagnosis of SV and MCS is still difficult and their complex management involves many different and skilled healthcare professionals. This book is aimed at examining the pathophysiology of consciousness disorders with their multifaceted assessment and treatment, including new diagnostic tools and novel prognostic markers, and the important bioethical issues concerning "the end of life" and the "dignity of the person".