Creutzfeldt-Jakob Disease

What is Creutzfeldt-Jakob disease?

Creutzfeldt-Jakob disease (CJD) is a rare, rapidly progressing brain disorder. It belongs to a family of diseases known as prion diseases, also known as transmissible spongiform encephalopathies (TSEs). 

Spongiform refers to the way affected brains look. With prion diseases, the brain is filled with holes and looks like a sponge when the tissue is examined under a microscope. 

Like other prion diseases, CJD causes problems with muscle coordination, thinking, and memory. There are about 350 cases per year in the United States. This disease tends to progress rapidly. About 70% of people with CJD die within one year of getting the disease. 

CJD and other prion diseases are caused by abnormal forms of proteins called prions. Healthy and harmless prion proteins are found throughout the body but mostly in the nervous system. Their overall role isn’t fully understood. 

When abnormal prions form, they can transmit their incorrect and damaging form to nearby healthy prion proteins and cause the healthy prions to change into abnormal prions. Once they’re formed, prions can clump together and build up in brain tissue, which may lead to the nerve cell loss and other brain damage seen in CJD and other prion diseases.

Symptoms of CJD 

The main symptoms of CJD are cognitive decline leading to dementia, involuntary muscle jerks (myoclonus), and lack of coordination of movements.

Early symptoms of the disease may include:

As CJD progresses, other symptoms can appear, including:

• Weakness of the arms and legs
• Blindness
• Inability to move or speak
• Problems swallowing
• Coma

Some people with CJD have an increased risk of pneumonia and other infections. Also, some symptoms of CJD can look like symptoms of other progressive neurological disorders, such as Alzheimer's disease and Huntington's disease. But these symptoms tend to worsen faster in CJD than in Alzheimer's disease and most other types of dementia.

Who is more likely to get Creutzfeldt-Jakob disease?

There are three different ways a person might develop CJD:

• Sporadic: In these cases, the disease develops in a person with no known cause. The majority of cases of CJD are sporadic. Sporadic CJD and other prion diseases may develop because some of a person's normal prion proteins suddenly change into abnormal prions. Harmful prions are believed to be made from an error in the “quality control” part of the cell that makes sure proteins are made properly. These errors are more likely to happen with aging. Symptoms usually first appear in people between ages 60 and 70, and quickly get worse. 
• Hereditary: Gene mutations that affect normal prion protein production can run in families. If the prion protein gene is changed in a parent’s cells, the changed gene can be passed on to their children. But not all people with mutations in the prion protein gene develop CJD. About 10% to 15% of CJD cases in the U.S. are hereditary. Hereditary CJD typically affects people at a younger age than sporadic CJD, generally under age 55. In rare cases, this can happen in a person’s 20s. 
• Acquired: CJD and other TSEs can’t transmit through the air or through touching or most other forms of casual contact. But they may transmit by exposure to infected brain or nervous system tissue. This can happen through certain medical procedures such as surgical grafts of dura mater (a tissue that covers the brain), cornea transplantation, and electrodes implanted in the brain that have not been thoroughly sterilized. Fewer than 1% of documented CJD cases are acquired.
  • A type of CJD called variant CJD (or vCJD) comes from eating meat from cattle affected by a prion disease called bovine spongiform encephalopathy (BSE, or “mad cow” disease). Variant CJD begins at first with psychiatric symptoms and affects younger people (sometimes in their teens) more than other types of CJD. It has a longer than usual duration from onset of symptoms to death. Fortunately, U.S. government regulations have basically eliminated this chance of transmission. 

There’s a very small risk that a surgeon or others who handle brain tissue following a brain biopsy or autopsy may become accidentally infected. Special surgical and disinfection procedures can greatly reduce this risk. 

There’s no evidence that caregivers, healthcare workers, and those who prepare bodies for funerals and cremation have an increased risk of prion diseases, like CJD, compared to the general population.

How is Creutzfeldt-Jakob disease diagnosed and treated?

Diagnosing CJD

To diagnose CJD, a healthcare provider, typically a neurologist, will do a physical exam and ask about the person’s medical history. Depending on the findings, a doctor can use a few other tests to help diagnose CJD:

• A neurological exam can identify changes in reflexes, muscle twitching and spasms, poor coordination, and vision problems or blindness that may be signs of CJD.
• Electroencephalography (EEG) is a test that records the brain's electrical patterns and can detect a specific type of abnormality in some types of CJD. 
• MRI (magnetic resonance imaging) creates detailed images of the brain using radio waves and a magnetic field and can detect changes in the brain that are common in about 90% of CJD cases.
• Cerebrospinal fluid (CSF) tests of the fluid that surrounds the brain and spinal cord looks for elevations in 14-3-3 and tau proteins (non-specific markers of rapid brain cell death, which is seen in CJD). A newer test called Real-time quaking-induced conversion assay (RT-QulC), which is a much more specific test for prion disease, can detect the prions that cause CJD. A lumbar puncture (also called a spinal tap) can collect CSF.

Learn more about neurological diagnostic tests and procedures. 

The only way to confirm a diagnosis of CJD is by brain biopsy or an autopsy. In a brain biopsy, which is now rarely done, a neurosurgeon removes a small piece of tissue from the living person's brain so it can be examined by a neuropathologist. This procedure may be dangerous for the person and is generally discouraged unless it is needed to rule out a treatable disorder. In an autopsy, the whole brain is examined after death. 

Treating CJD

Currently there’s no cure for CJD or any other prion disease, although researchers are testing some drugs to control CJD. Today's treatments focus on making the person comfortable and easing symptoms. Medications may help relieve behavioral changes, seizures that may develop, and muscle jerks. 

During later stages of the disease, people may need IV (intravenous) fluids and machine feeding. But because CJD and other prion diseases are incurable, these approaches can have limited use. Toward the end of life, people with CJD may receive hospice services. 

What are the latest updates on Creutzfeldt-Jakob disease?

NINDS, part of the National Institutes of Health (NIH), is the nation’s leading federal funder of research on neurological disorders. NINDS supports new and innovative research to better understand, diagnose, and treat CJD. Other NIH institutes, including the National Institute of Allergy and Infectious Diseases, also conduct research on CJD.   

Researchers are examining and characterizing the prions associated with CJD and other human and animal prion diseases. A better understanding of these diseases may help scientists discover factors that influence how prion changes infect nearby cells, how they are transmitted, and how the disorder damages the brain.

Researchers are also investigating the cellular mechanisms involved in abnormal prion formation and buildup, as well as their replication by subsets of specific types of cells in the brain. 

Other projects are examining how abnormal prions cross the protective blood-brain barrier and spread throughout the central nervous system. These projects are also working to improve tests that measure the biological activity of prions. Findings may identify new therapeutic targets to treat prion diseases. 

Scientists have developed a 3D brain tissue model of CJD to evaluate potential treatments and to study specific human prion diseases. The lack of a completely human CJD model has been a considerable barrier to the discovery of potential therapies. But the 3D brain tissue CJD model holds promise to remove this barrier.

Cerebral organoids have organization, structure, and electrical signaling systems similar to human brain tissue. Because they can survive in a controlled environment for months to years, cerebral organoids also are ideal for studying nervous system diseases over lengthy periods of time. Cerebral organoids have been used as models to study Zika virus infection, Alzheimer’s disease, and Down syndrome and may help improve understanding of prion diseases.

Researchers are exploring genetic regulation of the prion protein gene to change the course of prion disease and hopefully significantly slow it or stop it altogether. Researchers are testing this in an early-stage clinical trial, to learn more about the safety and potential benefit of the treatment.

For more information on research about CJD, check NIH RePORTER, a searchable database of current and past research projects supported by NIH and other federal agencies. RePORTER also includes links to publications and resources from these projects.

For research articles and summaries on CJD, search PubMed, which contains citations from medical journals and other sites.

How can I or my loved one help improve care for people with Creutzfeldt-Jakob disease?

Consider participating in a clinical trial so clinicians and scientists can learn more about CJD. Clinical research with human study participants helps researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.

All types of participants are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

For information about participating in clinical research, visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with CJD at ClinicalTrials.gov, a searchable database of current and past clinical studies and research results.

Scientists are conducting biochemical analyses of brain tissue, blood, spinal fluid, urine, and serum to help determine the nature of the transmissible agent or agents causing CJD. To help with this research, they’re seeking biopsy and autopsy tissue, blood, and cerebrospinal fluid from individuals with CJD and related diseases. The following facility collects this type of material:

National Prion Disease Pathology Surveillance Center
Case Western Reserve University
216-368-0587

Learn about related topics

• Transmissible Spongiform Encephalopathies