A progressive, degenerative disease of brain tissue due to an infection
- More common over the age of 50
- Sometimes runs in families
- Lifestyle as a risk factor depends on the cause
- Gender is not a significant factor
Creutzfeldt–Jacob disease (CJD) is an extremely rare condition in which brain tissue is progressively destroyed by an unusual infectious agent. The disorder leads to a general decline in all areas of mental and physical ability and ultimately to death. CJD affects about one person in a million each year worldwide.
What is the cause?
CJD is caused by an infectious agent known as a prion, which replicates in the brain and causes brain damage. One type of CJD, accounting for 15 in 100 cases, has been found to run in families.
Most people who develop CJD are over the age of 50. Usually, the source of the infection is unknown, but in about 1 in 20 people it can be traced to earlier treatment with products derived from human tissue. Before the use of artificial growth hormones, human growth hormone was one source of infection.
In the mid 1990s, a new, rare variant of CJD (known as vCJD) was discovered in the UK. By the end of 2009, about 170 people had been diagnosed with vCJD, of whom 166 had died. This variant is believed to be linked with eating contaminated meat from cattle with a disease called bovine spongiform encephalopathy (BSE).
What are the symptoms?
It is thought that CJD is present for 2–15 years before symptoms begin to develop gradually. They may include:
Unsteadiness and poor coordination.
Other symptoms develop as the condition progresses and include:
Sudden muscle contractions.
Weakness or paralysis on one side of the body.
In the later stages of CJD, a person may be unable to move and talk.
What might be done?
CJD is usually diagnosed from a person’s symptoms because no specific test is yet available. Anyone suspected of having CJD will have extensive tests, such as MRI and lumbar puncture, and EEG to look for characteristic changes in electrical activity in the brain. A brain or tonsil biopsy, in which a small piece of tissue is surgically removed for examination, may be performed.
There is no cure for CJD, but drugs can relieve some symptoms. For example, symptoms of depression may be treated with antidepressant drugs, and muscle contractions may be controlled by muscle relaxant drugs. However, the disorder is usually fatal within 3 years.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
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