It has been noted rather appropriately that “Prion diseases . . . have stumped scientists for decades with a complex ‘whodunnit’ complete with many suspects and a missing murder weapon.” Basically, the brain is killed by clogging with clumps of prion proteins, which have been changed into a rare, abnormally folded state called prions. The classical histopathological features of prion diseases include the formation of “holes” or vacuoles in brain tissue that result in a spongy architecture (hence the name spongiform, resembling a sponge in appearance, encephalopathy, involving alterations of brain structure). Also occurring are a loss of neurons and an increase in astrocytes. For these reasons, when the characteristic signs and symptoms of prion diseases appear, the condition is always fatal.
