The classic form of Creutzfeldt-Jakob disease, or CJD, is disease that causes a rapid progressive dementia resulting in death in a matter of weeks to months.
Both classic and new variant CJD are two examples of several known prion diseases. These types of diseases can be inherited, occur sporadically, or secondary to infection after exposure to prions.
In general, prion diseases are disorders of protein folding. In other words, a prion is an abnormally folded protein. This abnormally folded protein can propagate or multiply a process that is not yet fully understood.
A build up of prions results in damage and ultimately death of brain cells resulting in progressive and relentless dementia and death.
The classic form of CJD causes a rapid, progressive dementia usually associated with abnormal movements called myoclonus ( brief small fleeting jerks ) that persist even in sleep.
Importantly, myoclonus is seen in many diseases other than CJD. The person with CJD may complain of blurry vision prior to the onset of dementia. The individual becomes increasingly more confused and disoriented and behavioral or psychiatric issues may be prominent. Ultimately, all intellectual functioning will be affected.
CJD is invariably fatal.
New variant CJD has different symptoms from the classic form. The individuals with nvCJD are usually younger. The disease progresses slower than in the classic form, and death occurs early in the course of the disease. The person may have psychiatric disorders such as anxiety or psychosis and sensory complaints like tingling or numbness
Later, the person can develop ataxia, or difficulty walking. Myoclonus and dementia show can appear later in the illness. There may be visual impairments, paralysis, and sleep disorders.
There are three main causes for classic CJD.
Inherited CJD runs in families and is caused by a mutation in the gene coding for the normal prion protein.
Sporadic CJD has no known genetic or infectious cause.
Creutzfeldt-Jakob disease can be transmitted to others. An individual may be infected through direct or indirect contact with body tissues of an infected person.
Following are examples of how this transmission has occurred: after surgery where contaminated surgical instruments were usedafter corneal transplantation, where eye tissue was taken from an infected personfollowing surgery, where grafts of brain membranes were derived from an infected individual after injection of human growth hormone from the pituitary of an infected cadaverfollowing the ingestion of beef from a cow with a prion disease commonly known as mad cow disease
At the present time, infected cattle are found mostly in Europe, particularly the United Kingdom although a few infected animals have been discovered in the United States and Canada.
Travelers to the UK, an area with a relatively high risk for mad cow disease, can limit their risk for new variant CJD by avoiding beef and beef products. If the person chooses to eat meat, he or she should select solid pieces of muscle meat, such as a steak or roast. Sausage and hamburger should be avoided.
Public health measures are important such as educating beef farmers about the disease, screening cattle herds by testing for prion disease in "downers" (cattle that are too sick to stand), and then eliminating infected cattle thereby preventing them from getting into the food supply.
Diagnosis of CJD begins with a medical history and physical exam. A spinal tap can be performed to look for abnormalities consistent with CJD.
In addition an EEG, or recording of the brain waves, may show abnormalities. A brain scan such as magnetic resonance imaging (MRI) of the brain may help in diagnosis.
A definitive diagnosis can only be made with a biopsy of the brain. This involves taking a small piece of brain tissue with a special needle. The piece of tissue can then be examined with a microscope.
CJD causes progressive brain deterioration and death.
CJD does not seem to spread from person to person. However, it may be spread through direct or indirect contact with infected body tissue, particularly any tissue relating to the spinal cord or brain.
There is no treatment for CJD. Medications may used to treat psychiatric problems or relieve the symptoms resulting from CJD.
Medications may cause allergic reactions and stomach upset.
CJD causes progressive brain damage and death. The classic form usually causes death within 6 to 12 months of the initial symptoms. Someone who has new variant CJD usually dies within 1 to 2 years of the initial symptoms.
The individual may have periodic visits with the healthcare provider to monitor the disease. Any new or worsening symptoms should be reported to the provider.