better known as creutzfeldt-jakob disease. A dementing disease of the brain. It is believed due to an unconventional (not a bacteria or virus), transmissible agent called a prion. Symptoms of cjd include forgetfulness, nervousness, jerky trembling hand movements, unsteady gait, muscle spasms, chronic dementia, balance disorder, and loss of facial expression. Cjd is classified as a spongiform encephalopathy. most cases occur randomly (sporadically), but inherited forms exist. There is neither treatment nor cure for cjd. Other names for cjd include creutzfeldt-jakob syndrome and jakob-creutzfeldt disease.