Go ahead and peruse wikipedia for "prion diseases" ... it's a fascinating subject with some very scary subtopics. Of particular note: http://en.wikipedia.org/

Go ahead and peruse wikipedia for "prion diseases" ... it's a fascinating subject with some very scary subtopics. Of particular note: http://en.wikipedia.org/wiki/Fatal_familial_insomnia http://en.wikipedia.org/wiki/Fatal_familial_insomnia ... and the account of one patient who valiantly struggled to prolong his life in the face of this disease.