What is Creutzfeldt-Jakob Disease?
Creutzfeldt Jakob disease is a lethal brain disorder which displays a variety of symptoms. Creutzfeldt-Jakob disease (CJD) is a disorder where the brain is damaged, and this damage to the brain will eventually lead to a marked and rapid decrease of motor skills and mental functioning. It is a rare disease which is progressively degenerative. It has been invariably lethal to those who suffer from it. There are only about two hundred cases of CJD in the US per year, and it typically affects the elderly. Most people die are highly likely to die within one year of getting CJD. Symptoms of CJD include visual disturbances, behavioral changes, failing memory, and lack of coordination. Towards the end of this rapidly progressive and degenerative disease, patients may experience blindness, mental deterioration, weakness of extremities and involuntary movements, as well as coma.1
Types of CJD
There are three types of CJD. Acquired CJD, the least common form, is when the patient contracts the disease during certain medical procedures (where the brain or nervous system tissues are somehow able to come into contact with CJD). Hereditary CJD accounts for some of the cases, where there is a family history or genetic mutation present in the patient. Most of the known cases are sporadic CJD, where the disease is able to develop even though the patient has not been exposed to or had a history of known risk factors otherwise.
Creutzfeldt-Jakob disease is part of both the animal and human disease category of “transmissible spongiform encephalopathies (TSEs)”. The term spongiform originates from the appearance of the brains of those who have been afflicted with the disease. The brains become “filled with holes” and start to look like sponges, due to the onset and progressively degenerative nature of the infection. There are a few other human TSEs. One more commonly known animal infection which is known as “bovine spongiform encephalopathy (BSE)” or “mad cow disease”. Similar degenerative diseases can affect other members of the animal kingdom as well.2
Patients who have contracted CJD first show signs of the disease through symptoms like dementia, memory loss, and personality changes. They can have mood disorders, the manifestation of random hallucinations, and psychosis. Physical problems could include difficulty with speech, jerky movements, and seizures. Patients can die within weeks or months after the first signs of the disease appear. Although some patients may have symptoms which persist as they survive for years. Pneumonia is often a cause of death in patients who have developed CJD, due to problems with the coughing reflex.3
Causes of CJD
Creutzfeldt-Jakob disease became famous in the 1990s when some people acquired and developed a form of it (variant CJD or vCJD), in the United Kingdom, from eating beef which was contaminated with the disease. “Classic” CJD has not been linked to cattle; it is the variant form of the disease which caused the infection. vCJD can affect younger people, but this particular variation of the disease is more rare.4 CJD is caused by an infection. The infection comes from “misfolded proteins”, called prions, which reproduce by changing the normally folded proteins. The prions act as part of the catalyst for neurodegeneration, through the development of holes in the brain.
While most cases are sporadic, and some are familial, the form of CJD that comes from medical procedures, sometimes called iatrogenic, can be spread by meningeal transplants, corneal transplants, or using “human-derived pituitary growth hormones”. Acquired CJD is still the least common cause when compared to the other two. A similar disorder, kuru, was thought to have been transmitted via cannibalism in Papua New Guinea. The prions form amyloids (protein aggregates), and where the nerve cells are dead, holes can be seen under the microscope. Prions increase exponentially, rapidly creating more holes in the brain and speeding up the rate of mental degeneration.
Because of the fear of risking transmission, blood donations have come under restrictions in cases where donors have traveled to certain parts of the world, or if donors have a biological relative with CJD. The risk is potentially too great to allow the blood of those patients who fall under these categories to be spread around.
There is no known treatment or cure for CJD, but research is still ongoing.5 Iatrogenic CJD can be prevented if hospitals follow strict safety measures such as using only synthetic human growth hormone, destroying infected instruments, and utilizing only single-use spinal tap (lumbar puncture) kits. Strict blood donation restrictions should also be employed and adhered to. As for vCJD, it is important that BSE does not enter the food supply; therefore, animals which are going to enter the food supply should be tested regularly, and other safety measures should be followed, to prevent infected tissue from spreading.6
1, 2 www.ninds.nih.gov
3, 5 en.wikipedia.org
4, 6 mayoclinic.com