Creutzfeldt-Jakob disease (CJD) is a rare and fatal brain disease. CJD is caused by a prion, a type of infectious protein, that trigger normal proteins in the body to misfold. CJD causes dementia and other neurologic problems. Once symptoms begin, it can lead to death in months to a year.

Classic Creutzfeldt-Jakob disease occurs worldwide in older adults, with the average age in the late 60s. Very few cases occur in people who are younger than 30 years old. In the United States, about 500-600 cases have been reported per year.

Causes

There are three main types of CJD infection:

1. Sporadic

The vast majority of all CJD cases reported (about 85%) are called sporadic. These types of cases occur when prion proteins already in the body misfold for some unknown reason. The result is disease that breaks down the brain’s functions. Some cases are fatal within a few months of the first symptoms, and most are fatal within a year.

2. Familial

About 5-15% of CJD cases occur because the person has inherited a mutation in the prion protein gene. A person with CJD with a first-degree relative (parent, sibling, or child) who also has the disease would have familial CJD.

3. Iatrogenic

Iatrogenic cases are caused by contact with prions in a health care setting or due to biological products. There have been six known CJD cases caused by surgical or medical equipment contaminated with prions is used on another patient.

People who received prion-contaminated human growth hormone prior to 1978 may also develop iatrogenic CJD. Even 50 years later, cases are still being identified.

Finally, cases can occur in people who receive a transplant of specific materials. These include corneal (eye) grafts or dura mater (a membrane in the brain and spinal cord) grafts. If the donor had CJD that was not discovered before the donation, recipients can contract CJD.

Symptoms

People with Creutzfeldt-Jakob disease suffer from dementia. Other symptoms may include trouble walking, sudden jerky movements, and visual disturbances.

Testing

Health care providers can diagnose an illness as a suspect case based on:

  • Symptoms and course of illness
  • Tests of a person’s spinal fluid
  • Magnetic resonance imaging (MRI), a brain scan
  • EEG, a test of electrical activity in the brain

The only way to confirm CJD is through testing brain tissue from a biopsy or an autopsy.