Minimally Conscious State vs Persistent Vegetative State: The Case of Terry (Wallis) vs the Case of Terri (Schiavo)

Abstract

© 2006 Mayo Foundation for Medical Education and Research Miraculous awakening from prolonged coma is in the news again. This time it is the story of Terry Wallis. Newspapers and the blogosphere are covering it extensively, using eye-catching titles: “Miracle in Arkansas”; “Comatose man’s brain rewired itself, doctors say. While fibers were severed, nerve cells stayed intact allowing later recovery”; “As man lay in coma-like state, his brain was busy rebuilding.” In this editorial, I place these claims into perspective and review recent knowledge about recovery from prolonged comatose states. It is useful to briefly revisit the categories of outcome in a patient comatose from a structural injury. To produce prolonged coma, insult and injury to the brain or brainstem must be devastating and widespread. Generally speaking, coma due to a structural cause (eg, anoxia-ischemia, traumatic head injury, hemorrhagic stroke, or meningoencephalitis) is associated with a poor outcome, particularly if patients show no improvement in consciousness within the first weeks. Outcome is worse with any episodes of further neurological deterioration (after early clinical presentation) and possibly better with early therapeutic intervention (eg, antimicrobial drugs, placement of ventriculostomy, or control of increased intracranial pressure) in response to identifiable causes of that deterioration. Patients may never regain consciousness and may die if further brain swelling and herniation or systemic complications occur. Advanced directives or prior voiced wishes of the patient to the family to not provide critical care may lead to withdrawal of support. Patients who survive acute brain injury may never regain consciousness but open their eyes, fail to focus or track objects, and typically develop sleep-and-wake cycles, all clinical telltale signs of an emerging persistent vegetative state (PVS). Patients who awake often have a disability, and many display little effective communication and a major physical and cognitive handicap. New in this nosology is the category of minimally conscious state (MCS), the most severe form of neurological disability in a conscious patient. These major categories of outcome are summarized in Figure 1. Other factors that determine outcome from coma are age and multiorgan involvement. For example, traumatic injury Minimally Conscious State vs Persistent Vegetative State: The Case of Terry (Wallis) vs the Case of Terri (Schiavo)