Creutzfeldt-Jakob disease, also called Jakob-Creutzfeldt disease or CJD, is a prion [pree-ahn] disease caused by a misshapen protein, called a "prion," building up in the brain. It is a rare brain disorder that is fatal, usually within 6 months of diagnosis and a year of the first symptom. In the United States, there are about 300 new cases per year. While CJD is not "mad cow disease" in humans, both diseases are caused by prions.

A good relationship and clear communication with your doctor will result in the best care for your loved one. Read up on CJD before your appointment so that you can go in prepared to discuss your symptoms, possible tests, and maybe even joining a treatment trial. It helps to write down your questions and concerns ahead of time to be sure you cover everything.

In 1982, Dr. Stanley B. Prusiner at UCSF identified an infectious agent uniquely made of protein and named it the "prion", a combination of "protein" and "infectious". Dr. Prusiner received the Nobel Prize in Physiology or Medicine in 1997 for his radical discovery of a new agent that enables prion disease to be spontaneous, genetic and infectious.