Creutzfeldt-Jakob disease

Creutzfeldt-Jakob 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 to treat growth disorders, human growth hormone injections were one source of infection.


In the mid 1990s, a new, rare variant of CJD that affects people in their teens or 20s was discovered in the UK. By the year 2000, about 50 cases had been reported. 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 is present for 2-15 years before symptoms begin to develop gradually. They may include:

- Depression.
- Poor memory.
- Unsteadiness and poor coordination.

Other symptoms develop as the condition progresses and include:

- Sudden muscle contractions.
- Seizures.
- Weakness or paralysis on one side of the body.
- Progressive dementia.
- Impaired vision.

In the later stages CJD, a person may be unable to move and talk. Those who are confined to bed are prone to serious lung infections.

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, to exclude other treatable causes, and EEG to look for characteristic changes in electrical activity in the brain. A brain 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.