Prion diseases occur when normal prion protein, found on the surface of many cells, becomes abnormal and clump in the brain, causing brain damage. This abnormal accumulation of protein in the brain can cause memory impairment, personality changes, and difficulties with movement. Experts still don't know a lot about prion diseases, but unfortunately, these disorders are generally fatal.

Prion diseases are rare. About 300 cases are reported each year in the U.S.

Prion diseases comprise several conditions. A prion is a type of protein that can trigger normal proteins in the brain to fold abnormally. Prion diseases can affect both humans and animals and are sometimes spread to humans by infected meat products. The most common form of prion disease that affects humans is Creutzfeldt-Jakob disease (CJD).

How are prion diseases diagnosed?

Prion diseases are confirmed by taking a sample of brain tissue during a biopsy or after death. Healthcare providers, however, can do a number of tests before to help diagnose prion diseases such as CJD, or to rule out other diseases with similar symptoms. Prion diseases should be considered in all people with rapidly progressive dementia.

The tests include:

MRI (magnetic resonance imaging) scans of the brain

Samples of fluid from the spinal cord (spinal tap, also called lumbar puncture)

Electroencephalogram, which analyzes brain waves; this painless test requires placing electrodes on the scalp

Blood tests

Neurologic and visual exams to check for nerve damage and vision loss

How are prion diseases treated?

Prion diseases can't be cured, but certain medicines may help slow their progress. Medical management focuses on keeping people with these diseases as safe and comfortable as possible, despite progressive and debilitating symptoms.

Can prion diseases be prevented?

Properly cleaning and sterilizing medical equipment may prevent the spread of the disease. If you have or may have CJD, do not donate organs or tissue, including corneal tissue.

Newer regulations that govern the handling and feeding of cows may help prevent the spread of prion diseases.

Living with prion diseases

As prion diseases progress, people with these diseases generally need help taking care of themselves. In some cases they may be able to stay in their homes, but they eventually may need to move to a care facility.

Key points about prion diseases

Prion diseases are very rare.

Symptoms can progress rapidly requiring help with daily needs.

Prion diseases are always fatal.

Next steps

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