A sponge-like appearance results when nerve cells die.
Symptoms depend on which region of the brain is affected.
A precise diagnosis of a prion disease can only be made upon autopsy. The figures show thin sections of diseased brains. Introduction Prions - novel infectious agents differing from all other known pathogenic agents Prions infect animals and humans From Dr Jekyll to Mr Hyde Different prions affect different regions of the brain Prion disease arise in three different ways These pages are based on material from the 1997 Physiology or Medicine Nobel Poster.