From Creutzfeldt-Jakob disease to the mad cow epidemic.

Hans-Gerhard Creutzfeldt and Alfons Jakob independently authored clinical and pathologic descriptions of a new syndrome in the 1920s. This syndrome, which subsequently came to be named after them, was characterized by dementia, motor and coordination abnormalities, a fatal course, and pathologic findings of diffuse spongiform neuronal degeneration. Although it appeared for many years to be little more than a medical curiosity, Creutzfeldt-Jakob disease attained widespread attention by its pathologic similarity to kuru and bovine spongiform encephalopathy, "mad cow disease." Because there are sporadic, familial, and iatrogenic forms of Creutzfeldt-Jakob disease, it is considered to have both genetic and infectious aspects. Although its causation has for some time been ascribed to "slow viruses," the etiology of Creutzfeldt-Jakob disease is currently thought to be due to prions, small proteinaceous infectious particles that have genetic encoding. The debate regarding whether the appearance of atypical Creutzfeldt-Jakob disease can be linked to the epidemic of "mad cow disease" is currently unresolved.