At the center of the debate over Terri Schiavo's fate is the question of her diagnosis: Is she in a persistent vegetative state, or in a milder state of brain damage called minimal consciousness? And in either case, does she have any chance to regain awareness? While a few neurologists say it is possible she has been misdiagnosed, an overwhelming majority say there is little room for disagreement. Patients who have suffered brain damage from oxygen deprivation - like Ms. Schiavo, whose heart briefly stopped in February 1990 - almost never recover if they have remained in a vegetative state...