Creutzfeldt-Jakob disease (CJD) is a rare, degenerative, fatal brain disorder. Onset of symptoms typically occurs at about age 60. There are three major categories of CJD: sporadic (the most common form, in which people do not have any known risk factors for the disease); hereditary (in which the person has a family member with the disease and tests positive for a genetic mutation associated with CJD), and acquired (in which the disease is transmitted by exposure to brain and nervous system tissue, usually through certain medical procedures). A form called variant CJD can be acquired by eating meat from cattle affected by a disease similar to CJD, called bovine spongiform encephalopathy (commonly called “mad cow” disease). CJD cannot be transmitted through the air or through touching or most other forms of casual contact. Initial symptoms of CJD include problems with muscle coordination, personality changes including progressive and impaired thinking and judgment, vision problems that may lead to blindness, and involuntary muscle jerks called myoclonus. People eventually lose the ability to move and speak, and enter a coma. Tests that help in the diagnosis of CJD include electroencephalography (which records the brain's electrical pattern), detection of certain proteins in the fluid that surrounds the brain and spinal cord, and magnetic resonance imaging. The only way to confirm a diagnosis of CJD is by brain biopsy or autopsy. A brain biopsy is discouraged unless it is need to rule out a treatable disorder. CJD belongs to a family of diseases known as prion diseases--derived from "protein" and "infectious."
There is no treatment that can cure or control CJD, although studies of a variety of drugs are now in progress. Current treatment is aimed at alleviating symptoms and making the person as comfortable as possible. Opiate drugs can help relieve pain, and the drugs clonazepam and sodium valproate may help relieve involuntary muscle jerks. Intravenous fluids and artificial feeding may be needed in later stages of the disease.
CJD is rapidly progressive. About 70 percent of individuals die within one year. In the early stages of disease, people may have failing memory, behavioral changes, lack of coordination and visual disturbances. As the illness progresses, mental deterioration becomes pronounced and people may develop involuntary movements, blindness, and weakness of extremities. People eventually lose the ability to move and speak, and enter a coma.
CJD is believed to be caused by an abnormal form of normal cellular proteins called prions. The normal harmless prion protein is found throughout the body but is most abundant in the nervous system. The infectious form of the prion protein changes shape and clumps together, which may lead to the nerve cell loss and other brain damage seen in CJD. Researchers are examining prions associated with CJD and other prion diseases, and trying to discover factors that influence prion infectivity and transmission. Other projects are examining how abnormal prions cross the protective blood-brain barrier and spread through the central nervous system. Findings may identify new therapies to treat prion diseases. Information from the National Library of Medicine’s MedlinePlus Creutzfeldt-Jakob Disease