"In the space of 12 months, Stephen Churchill lost his focus, his memory, then most of his speech, then even the ability to dress, feed, and clean himself. He developed an excessive fear of water and sharp objects and refused to bathe or shave. And before long, with his unsteady gait and his tendency to fall, he spent his days slumped in a wheelchair or confined to a bed. To the staff of the nursing home where Stephen lived, the relentless decline was depressingly familiar - it had all the earmarks of Alzheimer's disease. But something in the picture did not fit. The patient, when he died, was only 19 years old. " "Doctors later discovered that Stephen had succumbed to a new kind of killer, the prion, now known to be the cause of mad cow disease in cattle, chronic wasting disease in American deer and elk, and Creutzfeldt-Jakob disease and fatal insomnia, among other exotic ailments, in humans. Doctors and researchers have been aware of some of these diseases for a century and more, but only in the last two decades have scientists even begun to understand just how the "pathological protein" spreads to new species and invariably kills its victims. " "In this book, Philip Yam describes the history of the scientific effort to track down and understand the prion, and the medical effort, still underway, to devise treatments for those who suffer from its ravages. "--Jacket.