Overview

Creutzfeldt-Jakob Disease (CJD) is a rare neurodegenerative condition wherein the afflicted rapidly suffers damage to the brain; this is caused by specific proteins called prions, and it is always fatal. Those with CJD may suffer a range of neurological symptoms; depending on the areas of the brain that the prions have damaged, they are faulty proteins that build up in the brain causing damage and large areas of open space within the brain. 

Incubation of CJD; the time needed for symptoms to appear after infection, can be between months and years but once symptoms begin to show the symptoms worsen rapidly. Symptoms may start mild with a change in behaviour or trouble with memory, quickly progressing to more severe symptoms such as the inability to control muscle movements.

CJD has no cure or treatment, there is no way to slow progression, and treating symptoms is often pointless due to the quick progression of the disease.

Cause of Creutzfeldt-Jakob disease

CJD is caused by misshapen, faulty proteins called prions, these prions occur in many cells around the body and are harmless; currently, their exact role is unknown, it is thought normal prions may have a role in several processes in the brain that keep everything working well.¹

The misshapen prions can cause other normal proteins to misfold, causing a build-up of them. This build-up causes brain cells to die, allowing the prions to spread to other cells and cause a cluster of cell death in the brain. This damage to large parts of the brain causes the symptoms suffered and creates holes within the brain giving it a ‘sponge-like’ appearance, the areas that are damaged correspond with the symptoms that would be sustained throughout the course of the disease.² 

Types of Creutzfeldt-Jakob disease

There are several types of Creutzfeldt-Jakob disease, the main difference between them being the reason faulty proteins (prions) occur in the brain.

Sporadic CJD- This occurs randomly and there is no known cause for why the disease develops; this is the most common form of CJD, accounting for roughly 85% of all CJD cases.

Inherited CJD- This occurs in those with a genetic mutation; passed down to them from their parents, giving them a greater chance of developing CJD. The gene causing this is dominant so only one parent needs to have the gene to pass it on, the symptoms of this usually begin to show around the age of 50.

Acquired CJD- This is rare and occurs during surgical procedures, where either surgical tools have not been properly cleaned after being used on someone with CJD, or some transplanted tissues from those with CJD can cause the person receiving to develop CJD. This is very rare due to increased awareness and knowledge.

Variant CJD- Variant CJD occurs when a person eats beef from cattle infected with bovine spongiform encephalopathy (mad cow disease), thanks to greater control on the production of beef the likelihood of this is low.³ 

Symptoms of Creutzfeldt-Jakob disease

Early symptoms of CJD begin, and within a few months decline rapidly, the early symptoms may be; but are not limited to–

• Personality changes
• Impaired memory
• Coordination issues
• Sudden, jerky movements - trouble controlling these
• Blurry/impaired vision

These symptoms indicate that the decline has begun and more severe symptoms may begin within a few weeks.

These symptoms may include–

• Further issues with coordination; walking and balance (ataxia)
• Loss of muscle control in bowels and bladder (incontinence)
• Unable to speak
• Loss of voluntary movement
• Severe loss of memory (dementia)

These severe symptoms continue to progress, with greater loss of muscle control and mental faculties, with those suffering from late-stage CJD requiring constant care, and an inability to move or communicate. Death is certain with Creutzfeld-Jakob disease, the death can result from another infection; affecting the ability to breathe, such as pneumonia and so the person completely loses the ability to breathe, resulting in death.

Diagnosing Creutzfeldt-Jakob disease

To diagnose CJD a doctor would use certain tests to inform their decision of a diagnosis; as early CJD presents with symptoms similar to other neurological conditions (Alzheimers), these tests would be:

• Magnetic Resonance Imaging (MRI) - This would show abnormalities (damage) in the brain and suggest to a doctor that CJD may be the cause
• Electroencephalography (EEG) - This test measures electrical activity in the brain, abnormalities would suggest CJD
• Lumbar Puncture - This test removes some cerebrospinal fluid, which can then be tested for marker proteins that suggest the presence of prions in the brain and maybe CJD
• The ultimate test to confirm a Creutzfeldt - Jakob disease diagnosis would be a brain biopsy, which is when a surgeon removes some brain tissue from a living patient for it to be analysed and confirm CJD. This is a risky procedure and may not be used unless needed to rule out potentially treatable conditions, usually, CJD will be confirmed post-death in an autopsy, as prions can remain in brain tissue for a while after death

Treatment and prognosis

There is no treatment for CJD as it is incurable, the majority of treatment is focused on making the remaining life of the person with CJD as comfortable as possible, treating symptoms as best as possible when they arise. Difficulties with this arise due to the rapid progression of the disease, from initial symptoms to death, which usually takes no longer than a year and can occur within months.² 

Research is advancing in the prediction and diagnosis of sporadic Creutzfeldt-Jakob disease. However, it is difficult due to no single underlying measure that can be used to predict CJD.⁵ This would help people in planning and preparing for the inevitable latter stages of the disease, but due to the nature of the disease treatment is unlikely.

Some studies in rodents showed the potential for increasing the time it takes to survive with the onset of symptoms, though this may not apply to humans and is not a definite cure.²

Summary

Creutzfeldt-Jakob Disease (CJD) is a rare neurodegenerative condition; that is fast progressing after the onset of symptoms, it is incurable and always fatal. It is caused by faulty proteins (Prions) that build up in the brain, they damage other proteins, eventually leading to the death of brain cells. This continuous damage leaves the brain damaged with a sponge-like appearance due to large gaps where the prions have caused damage to areas of the brain.

The symptoms are dependent on the area of the brain that CJD has caused damage in, though common initial symptoms are–

• Change in Behaviour
• Trouble with coordination
• Memory issues
• Sudden, jerky movements

As more of the brain is afflicted, these symptoms worsen, leaving people requiring more care, the symptoms are:

• Severe loss of memory (dementia)
• Severe lack of coordination (trouble walking and balancing)
• Loss of muscle control in the bowel and bladder
• Loss of speech

Those with CJD end up unable to control any muscles, bedridden, and requiring constant care, death is certain and can be made as comfortable as possible thanks to modern medicine.

Faulty protein causes Creutzfeldt-Jakob Disease, these can occur due to many reasons, giving rise to different forms of CJD, these are–

• Sporadic CJD- unknown cause, ~80-85% of cases occurring around the age of 50-60
• Inherited CJD- Some can be genetically predisposed to the formation of prions in the brain, occurring around the age of 50, about 15% of cases
• Acquired CJD- Rarely caused due to tainted surgical equipment or transfused blood/hormones or brain tissue from those that have CJD. It is very rare due to the current understanding of CJD and its transmission
• Variant CJD- caused by eating beef from cattle with Bovine Spongiform Encephalopathy (mad cow disease; the most well-known form, rare in more developed countries due to regulations on beef farming and production. It is still possible in less developed countries

Once CJD occurs there is no treatment, a prion cannot be destroyed with any medical intervention and once symptoms start, death usually occurs within a year, the main aim of any treatment is to make the remaining time of some that have CJD as comfortable as possible.