Creutzfeldt-Jakob (KROITS-felt YAH-kobe) disease is a degenerative brain disorder that leads to dementia and, ultimately, death. Symptoms of Creutzfeldt-Jakob disease (CJD) can resemble those of other dementia like brain disorders, such as Alzheimer's. But Creutzfeldt-Jakob disease usually progresses much more rapidly.
CJD captured public attention in the 1990s when some people in the United Kingdom developed a form of the disease, variant CJD (vCJD), after eating meat from diseased cattle. However, "classic" Creutzfeldt-Jakob disease hasn't been linked to contaminated beef.
Although serious, CJD is rare, and vCJD is the least common form. Worldwide, there is an estimated one case of CJD diagnosed per million people each year, most often in older adults.
Creutzfeldt-Jakob disease is marked by rapid mental deterioration, usually within a few months. Initial signs and symptoms typically include:
As the disease progresses, mental symptoms worsen. Most people eventually lapse into a coma. Heart failure, respiratory failure, pneumonia or other infections are generally the cause of death. Death usually occurs within a year.
In people with the rarer vCJD, psychiatric symptoms may be more prominent in the beginning, with dementia, the loss of the ability to think, reason and remember, developing later in the illness. In addition, this variant affects people at a younger age than classic CJD does and appears to have a slightly longer duration of 12 to 14 months.
Creutzfeldt-Jakob disease and its variants belong to a broad group of human and animal diseases known as transmissible spongiform encephalopathies (TSEs). The name derives from the spongy holes, visible under a microscope, that develop in affected brain tissue.
The cause of Creutzfeldt-Jakob disease and other TSEs appears to be abnormal versions of a kind of protein called a prion. Normally these proteins are harmless. But when they're misshapen, they become infectious and can harm normal biological processes.
The risk of CJD is low. The disease can't be transmitted through coughing or sneezing, touching, or sexual contact. The three ways it develops are:
Cases of CJD related to medical procedures are referred to as iatrogenic CJD. Variant CJD is linked primarily to eating beef infected with mad cow disease (bovine spongiform encephalopathy, or BSE).
Most cases of Creutzfeldt-Jakob disease occur for unknown reasons, and no risk factors can be identified. However, a few factors seem to be associated with different kinds of CJD.
Genetic analysis in people with iatrogenic and vCJD suggest that inheriting identical copies of certain variants of the prion gene may increase your risk of developing CJD if you're exposed to contaminated tissue.
Exposure to contaminated tissue - People who've received human growth hormone derived from human pituitary glands or who've had grafts of tissue that covers the brain (dura mater) may be at risk of iatrogenic CJD.
The risk of contracting vCJD from eating contaminated beef is difficult to determine. In general, if countries are effectively implementing public health measures, the risk is virtually non-existent.
Rapid symptom progression is one of the most important clues that a person may have Creutzfeldt-Jakob disease.
There is no single test, or any combination of tests, that can conclusively diagnose sporadic CJD in a living person, but the following tests may help determine whether an individual has CJD: