Severely brain damaged patients represent major ethical and legal challenges in end-of-life care. In particular, the vegetative state has featured significantly in the origins and evolution of the "right to die" movement. The first significant end-of-life case was Quinlan, where the New Jersey Supreme Court, citing Quinlan's constitutional right to privacy, permitted her father to withdraw her ventilator. The right to die movement reached its apex in 1990, when in Cruzan, the United States Supreme Court assumed (without deciding) that an incompetent person had a constitutionally protected liberty interest in refusing life-prolonging treatment. The politically contentious Schiavo case engendered a national discussion about the appropriateness of withdrawing artificial nutrition and hydration at the end of life. These three seminal cases featured young women in a "persistent" vegetative state and defined the boundaries of the right to withhold or withdraw treatment from those with severely impaired consciousness.

The Quinlan case, in particular, marked a turning point, as it allowed physicians, courts, legislatures, and the public to view the vegetative state as a meaningless, bleak existence of irreversible unconsciousness, justifying the decision to forego life-sustaining treatment. Recently, however, sophisticated neuroimaging studies have challenged the decades-old assumption that all vegetative patients lack capacity for conscious thought. The evolving science has promise to transform the evaluation and treatment of patients in a vegetative state and its related disorder of consciousness--the minimally conscious state.