What Is Creutzfeldt-Jakob Disease?
Also called "classic" CJD, it worsens quickly. Most people die within a year of getting it.
Classic Creutzfeldt-Jakob disease is not the same as “mad cow disease," which only happens in cattle. It's also not linked to "variant" CJD, which comes from products made from cattle that had mad cow disease.
There are three types of classic CJD. Each has a different cause:
Sporadic: This is the most common type. It's caused by harmful proteins in the body called prions. Prion proteins are a normal part of your body. But sometimes they can fold the wrong way as they form. This “misfolded” prion infects the brain and destroys brain cells. Scientists don’t know why this happens.
Familial: This happens in people who inherit a bad gene from a parent. Only 10% to 15% of CJD cases each year are familial.
Acquired: The rarest form, It happens when someone comes into contact with a medical instrument (like a scalpel), organ (by transplantation), or growth hormone that’s infected with CJD. It makes up less than 1% of classic CJD cases.
The symptoms start and worsen very quickly. People with CJD often have signs of dementia, including:
- Trouble walking
- Jerky muscle movements or twitching
- Personality changes
- Trouble with memory and judgment
- Vision problems
Sometimes people with it have trouble sleeping or become depressed. In later stages of the disease, they often lose the ability to speak or move. They may also get pneumonia or other infections, or slip into a coma.
There is no single test for CJD. Doctors diagnose it from your symptoms. One sign of the disease is how fast it gets worse.
A few tests doctors can use include:
Magnetic resonance imaging (MRI). This brain scan puts together detailed images. Doctors use these images to see changes in the brain over time.
Electroencephalogram (EEG). This is another type of test using surface electrodes that measures the electrical activity in the brain.
Lumbar puncture (spinal tap). Doctors use a long, very thin needle to draw some of the fluid out of the spinal column to test for certain proteins.
The only way to know for sure someone has CJD is by taking a sample (called a biopsy) of their brain tissue, or by autopsy. Doctors don’t usually biopsy brain tissue, because it’s risky, both for the patient and the doctor. It’s hard to target which tissue in the brain is infected, so doing a biopsy may not give helpful information. And it puts the doctor at risk of getting the disease.
Since a positive diagnosis doesn't help someone with CJD, doctors often confirm cases only after someone dies of it.
There are no treatments for CJD. Researchers have tested several drugs, but none have been able to slow or stop the disease.
Doctors can prescribe pain medicine for the symptoms. Muscle relaxers or anti-seizure drugs can help with stiffness. People with CJD need full-time care once the disease is in its late stage.