Creutzfeldt-Jakob Disease

Creutzfeldt-Jakob disease (CJD) is a rare and fatal brain disorder that belongs to a group of diseases called prion diseases. Here is important information about CJD:

About

Prion diseases, including CJD, occur when normal prion proteins in the body undergo an abnormal shape change and begin to fold into an abnormal three-dimensional structure. This abnormal shape triggers a similar folding of prion proteins in the brain, causing the destruction of brain cells. CJD causes a rapidly progressing type of dementia, which is different from other more common types of dementia that progress more slowly, such as Alzheimer’s disease, dementia with Lewy bodies, and frontotemporal dementia.

Creutzfeldt-Jakob Disease Types

There are three main types of CJD:
1. Sporadic CJD: This type develops spontaneously for unknown reasons and accounts for about 85% of cases. It usually occurs in people aged 60 to 65.
2. Familial CJD: This type is caused by specific genetic changes in the prion protein gene on chromosome 20. People with familial CJD inherit these genetic changes from a parent and account for about 10 to 15% of cases. Familial CJD tends to develop at a younger age, with some cases appearing as early as ages 20 to 40.
3. Acquired CJD: This type results from exposure to external sources of abnormal prion protein. It accounts for about 1% of CJD cases. The two common sources are certain medical procedures involving instruments, growth hormone, or transplanted tissues, as well as consumption of beef from cattle infected with bovine spongiform encephalopathy (BSE), also known as “mad cow disease.”

Causes and Risk Factors

The exact cause of sporadic CJD is unknown, but it is believed to occur spontaneously due to misfolding of prion proteins in the brain. Familial CJD is caused by specific genetic changes in the prion protein gene. Acquired CJD can result from exposure to contaminated medical instruments or consumption of infected meat.

Symptoms

The symptoms of CJD can vary among individuals, but common signs include depression, agitation, rapid worsening of confusion, memory problems, difficulties with movement and walking, muscle stiffness and twitching, vision problems, and hallucinations.

Diagnosis

There is no single test that can definitively diagnose sporadic CJD in a living person, but certain tests can help determine the likelihood of CJD. These tests include electroencephalogram (EEG), brain magnetic resonance imaging (MRI), lumbar puncture (spinal tap), and protein misfolding cyclic amplification (PMCA) to detect misfolded proteins.

Outcomes and Treatment

Currently, there is no treatment available to stop or slow down the brain cell destruction caused by CJD. Treatment focuses on managing symptoms and providing support to patients and their families. Painkillers, muscle relaxants, and antiseizure drugs may be prescribed to alleviate symptoms. CJD progresses rapidly, and individuals with the disease lose their ability to move or speak, eventually requiring full-time care. The prognosis for CJD is poor, with most individuals dying within one year of diagnosis.

It’s important to note that chronic wasting disease, a prion disease found in certain animals, has not been shown to transmit to humans, including hunters who consume affected animals. Studies are ongoing to understand the potential risk of chronic wasting disease to humans.