What is Creutzfeldt-Jakob disease (CJD)?

Creutzfeldt-Jakob disease (CJD) is a rare, degenerative, fatal disease of the brain.

Early symptoms may include:

• Confusion
• Depression
• Forgetfulness
• Difficulty sleeping
• Behavior changes
• Impaired vision
• Abnormal physical sensations
• Difficulty with voluntary coordination

Once a person begins showing signs or symptoms of CJD, the disease advances quickly over 2 to 12 months.

More advanced symptoms include:

• Balance problems
• Difficulty with speech and movement
• Increased risk of pneumonia
• Dementia
• Coma and eventual death

CJD is very rare, but approximately 40 to 90 people living in Canada die from it each year. CJD can be found in every country around the world.

What causes CJD?

CJD is caused by an abnormal prion – a protein found on the surface of cells. The abnormal prion attaches to other brain cell proteins and bends them out of shape. They attack the brain, killing cells and creating gaps in tissue or sponge-like patches. Once these abnormal CJD prions appear in a person, it can take up to 30 years before symptoms begin.

How does a person get CJD?

Most cases of CJD, about 93 percent, occur without a known reason. 6 percent of cases run in families. Less than one percent of the time, CJD is passed to a person by instruments or transplanted tissue used in eye, brain or spine surgery. CJD is not contagious.

How is CJD diagnosed?

A tentative diagnosis of CJD is made based on:

• Symptoms
• Tests on the fluid surrounding the spinal cord
• Brain images using MRI scans
• Recordings of the brain’s electrical activity using EEG

The diagnosis can only be confirmed through an autopsy.

How do you treat CJD?

There is currently no cure for CJD. Treatment involves physical and occupational therapies. A person with CJD eventually becomes confined to bed and must be fed by a tube.

Is CJD related to variant CJD (vCJD)?

CJD and vCJD are not the same disease. They are part of a group of diseases caused by abnormal prions. The symptoms are similar, although vCJD usually occurs before the age of 30. vCJD is sometimes called human mad cow disease, or human Bovine Spongiform Encephalopathy (BSE). It is thought to be passed to humans from eating cow parts infected with BSE prions.

For more information

For more information on vCJD, visit HealthLinkBC File #55b Variant Creutzfeldt-Jakob disease (vCJD).

For more information on CJD, please visit the Canadian Alzheimer Society web page on Creutzfeldt-Jakob disease at https://alzheimer.ca/en/about-dementia/other-types-dementia/rare-types-dementia/creutzfeldt-jakob-disease.