While medical students suspect that every headache is a brain tumor and that every chest pain is a heart attack, experienced physicians know diseases along a spectrum of horror-the ones they dread the most. Among these are cancer, Alzheimer's, stroke, diabetes, and ALS (Lou Gehrig's disease). As the list continues, we come upon locked-in syndrome, a neurologic disease where a victim is awake and alert, but cannot move or communicate due to paralysis...