About creutzfeldt-jakob disease

What is creutzfeldt-jakob disease?

Creutzfeldt-Jakob disease (CJD) is a rare, degenerative, invariably fatal brain disorder. It affects about one person in every one million people per year worldwide; in the United States there are about 200 cases per year. CJD usually appears in later life and runs a rapid course. Typically, onset of symptoms occurs about age 60, and about 90 percent of individuals die within 1 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 involuntary movements, blindness, weakness of extremities, and coma may occur.

There are three major categories of CJD:

  • In sporadic CJD, the disease appears even though the person has no known risk factors for the disease. This is by far the most common type of CJD and accounts for at least 85 percent of cases.
  • In hereditary CJD, the person has a family history of the disease and/or tests positive for a genetic mutation associated with CJD. About 5 to 10 percent of cases of CJD in the United States are hereditary.
  • In acquired CJD, the disease is transmitted by exposure to brain or nervous system tissue, usually through certain medical procedures. There is no evidence that CJD is contagious through casual contact with a CJD patient. Since CJD was first described in 1920, fewer than 1 percent of cases have been acquired CJD.

CJD belongs to a family of human and animal diseases known as the transmissible spongiform encephalopathies (TSEs). Spongiform refers to the characteristic appearance of infected brains, which become filled with holes until they resemble sponges under a microscope. CJD is the most common of the known human TSEs. Other human TSEs include kuru, fatal familial insomnia (FFI), and Gerstmann-Straussler-Scheinker disease (GSS). Kuru was identified in people of an isolated tribe in Papua New Guinea and has now almost disappeared. FFI and GSS are extremely rare hereditary diseases, found in just a few families around the world. Other TSEs are found in specific kinds of animals. These include bovine spongiform encephalopathy (BSE), which is found in cows and is often referred to as “mad cow” disease; scrapie, which affects sheep and goats; mink encephalopathy; and feline encephalopathy. Similar diseases have occurred in elk, deer, and exotic zoo animals.

What are the symptoms for creutzfeldt-jakob disease?

Creutzfeldt-Jakob disease is marked by rapid mental deterioration, usually within a few months. Initial signs and symptoms typically include:

  • Personality changes
  • Anxiety
  • Depression
  • Memory loss
  • Impaired thinking
  • Blurred vision or blindness
  • Insomnia
  • Difficulty speaking
  • Difficulty swallowing
  • Sudden, jerky movements

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 — 12 to 14 months.

What are the causes for creutzfeldt-jakob disease?

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.

How CJD is transmitted

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:

  • Sporadically. Most people with classic CJD develop the disease for no apparent reason. Termed spontaneous CJD or sporadic CJD, this type accounts for the majority of cases.
  • By inheritance. In the United States, about 5 to 10 percent of people with CJD have a family history of the disease or test positive for a genetic mutation associated with CJD. This type is referred to as familial CJD.
  • By contamination. A small number of people have developed CJD after being exposed to infected human tissue during a medical procedure, such as a cornea or skin transplant. Also, because standard sterilization methods do not destroy abnormal prions, a few people have developed CJD after undergoing brain surgery with contaminated instruments.

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).

What are the treatments for creutzfeldt-jakob disease?

No effective treatment exists for Creutzfeldt-Jakob disease or any of its variants. Many drugs have been tested and haven't shown benefits. For that reason, doctors focus on relieving pain and other symptoms and on making people with these diseases as comfortable as possible.

What are the risk factors for creutzfeldt-jakob disease?

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.

  • Age. Sporadic CJD tends to develop later in life, usually around age 60. Onset of familial CJD occurs slightly earlier and vCJD has affected people at a much younger age, usually in their late 20s.
  • Genetics. People with familial CJD have a genetic mutation that causes the disease. The disease is inherited in an autosomal dominant fashion, which means you need to inherit only one copy of the mutated gene, from either parent, to develop the disease. If you have the mutation, the chance of passing it on to your children is 50 percent.

    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 nonexistent.

Is there a cure/medications for creutzfeldt-jakob disease?

This degenerative brain disorder that leads to dementia and, ultimately, death. Creutzfeldt-Jakob disease symptoms can be similar to those of other dementia-like brain disorders, such as Alzheimer's disease. But Creutzfeldt-Jakob disease usually progresses much more rapidly.

Video related to creutzfeldt-jakob disease