A group of rare, terminal (end-stage) neurodegenerative diseases that occur when specific proteins in the brain turn into abnormal proteins known as prions is called prion disease. This condition causes significant damage to the brain that may lead to dementia. The treatment goal is to reduce the symptoms and improve your quality of life. They often recommend medications to relieve the symptoms.
In some cases, this condition is called transmissible spongiform encephalopathy. Usually, the symptoms of this disorder appear and worsen quickly. In general, this condition occurs quite rarely and affects about 1 in 1 million people in the entire world.
These neurodegenerative diseases are terminal conditions. It is important to understand that all types of prion disease are deadly. Usually, people with this disorder live for several months to 2-3 years before the symptoms appear.
Symptoms
The symptoms of people with prion disease can be different because they depend on how the condition affects the brain. Usually, people experience progressive neurologic problems. Check below some symptoms of this disorder:
- Problems with memory, thinking, and judgment
- Sleep disturbances (insomnia)
- Confusion
- Aphasia
- Ataxia
- Hypokinetic movement disorders (these disorders cause muscle stiffness and mobility problems)
- Mental disorders (such as anxiety, depression, or hallucinations)
- Personality changes
- Myoclonus (jerking movements or involuntary twitching)
Immediately contact your healthcare professional if any of the previous symptoms occur. Early diagnosis can delay serious complications (such as death).
Causes
This condition occurs when the normal prion protein (PrPc) turns into a misfolded form (PrPSc). These abnormal prions usually clump together or bind with normal prions to produce more prions. Over time, they cause damage to the nerve cells in the brain, which leads to loss of brain function (including the ability to talk, think, and others).
How Do People Get Prion Disease?
While prion disease can occur due to an inherited genetic mutation (familial prion disease), it can also occur due to certain infections (acquired prion disease). In most cases, this disorder occurs without genetic mutations or exposure to prion infection. In this case, the condition is called sporadic prion disease.
Sporadic Prion Diseases
In such cases, healthy prions turn into abnormal ones for an unknown reason. These include:
- Creutzfeldt-Jakob disease (CJD) – This is one of the most common types of sporadic prion diseases, and it affects about 85% of all diagnosed cases.
- Sporadic fatal insomnia – It is a very rare type of sporadic prion disease, even less common than fatal familial insomnia.
- Variably protease-sensitive prionopathy – This is another type of sporadic prion disease that occurs very rarely.
Familial Prion Diseases
This form of prion disease occurs due to PRNP gene mutations, which cause the abnormal proteins. Those who develop familial prion diseases often inherit the abnormal gene from one of their biological parents during pregnancy (autosomal dominant inheritance). However, there are more than 50 PRNP mutations that may cause inherited prion diseases. Familial prion diseases include two subtypes of CJD. For example:
- Gerstmann-Straussler-Scheinker (GSS) syndrome – This disorder occurs very rarely, and it affects between 1 and 10 out of every 100 million people worldwide.
- Fatal familial insomnia – This subtype occurs more rarely than GSS syndrome. In general, there are about 50 to 70 families that carry the abnormal genes that cause the disease. However, there are other prion conditions with PNRP gene mutations, including diarrhea, sensory autonomic neuropathy, seizures, and dementia. Furthermore, autonomic neuropathy may also affect blood pressure and heart rate, and may also cause bowel or urinary incontinence.
Acquired Prion Disease
In such cases, the conditions occur due to contaminated food or medical equipment. However, this is the less common way that people develop prion diseases. One of the first transmissible neurodegenerative disorders studied is Kuru. According to some research, it is transmitted among people of Papua New Guinea by ritual cannibalism.
What Happens if Prion Disease is Left Untreated?
People with prion diseases can also experience some complications (especially if the disease is found in advanced stages). The following long-term effects of prion diseases often occur within several months to one year from the first symptoms. Check below some examples:
- Dementia
- Coma (end-stage)
- Mutism
- Losing the ability to take care of yourself
- Mobility problems
- Memory loss
- Personality and mood disorders (including behavioral changes, depression, anxiety, and others)
- Confusion
- Vision disorders (such as blindness or hallucinations)
- Seizures
Commonly, people with prion diseases become dependent on their family and other people who take care of them.
Diagnosis
Usually, healthcare professionals perform the following tests to diagnose prion diseases. Examples include:
- Blood tests and lumbar puncture (also known as a spinal tap) – These tests are done to find biomarkers that indicate genetic mutations. These are specific substances in the blood or cerebrospinal fluid that indicate damage or disease.
- Brain MRI (magnetic resonance imaging) scan – This is an imaging test used to get detailed images of the brain. It often shows signs of prion diseases.
- Electroencephalogram (EEG) – This test is used to measure the electrical activity of the brain.
- RT-QuIC (real-time quaking-induced conversion assay) – During this test, doctors will check for prions in the cerebrospinal fluid.
Treatment
Unfortunately, there is no way to slow down or cure this condition. All types of prion disease are life-threatening. Mostly, those who suffer from these disorders die within a few months to years after diagnosis. However, there are some medicines that help ease the symptoms. For example:
- Antiseizure drugs
- Muscle relaxants used for myoclonus (muscle twitch)
- Opioid medicines to relieve pain
Frequently Asked Questions
When should I see my healthcare provider?
The symptoms of this condition often worsen quickly. If you or a loved one experiences any of the prion disease symptoms, immediately contact your healthcare professional.
What are examples of prion disease?
These include Creutzfeldt-Jakob disease (CJD), variant CJD (vCJD), fatal familial insomnia, Kuru in humans, chronic wasting disease (CWD), and others. For more details, discuss it with your physician.
Is it possible to cure prion disease?
There is no way to cure these neurodegenerative disorders. That’s why the treatment goal is to relieve the symptoms and delay the progression of the disease as long as possible. If you have additional questions, ask your healthcare provider.
