Creutzfeldt-Jakob disease.

Creutzfeldt-Jakob disease (CJD) is a progressive, degenerative, and fatal disease of the central nervous system. It is caused by abnormal accumulation of prion proteins and is characterized mainly by progressive dementia, myoclonus, and cerebellar, pyramidal, and extrapyramidal findings. Psychiatric symptoms may also accompany CJD and are often the first signs of the disease.