Ethical issues of nosology in disorders of consciousness

The current classification scheme for severe disorders of consciousness (DoC) has several shortcomings. First, there is no consensus on how to incorporate patients with covert consciousness. Second, there is a mismatch between the definitions of severe DoC, based on consciousness, and the diagnosis of these same DoC, which is based on observable motoric responsiveness. Third, current categories are grouped into large heterogeneous syndromes which share phenotype, but do not incorporate underlying pathophysiology. Here we discuss several ethical issues pertaining to the current nosology of severe DoC. We conclude by proposing a revised nosology which addresses these shortcomings.