Classic CJD is a human prion disease. It is a neurodegenerative disorder with characteristic clinical and diagnostic features. This disease is rapidly progressive and always fatal. Infection with this disease leads to death usually within 1 year of onset of illness.
There are four types of CJD:
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Sporadic (classical) CJD – most common type; usually affects people age 50 and older.
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Familial CJD – an inherited form of the disease.
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Iatrogenic CJD – contracted through medical procedures, such as injections of growth hormone.
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New Variant CJD (nvCJD) – a relatively new form of CJD. It is caused by eating contaminated beef products, which may cause bovine spongiform encephalopathy (BSE). (BSE is commonly known as mad cow disease.) nvCJD differs from other forms of CJD because it affects younger people and has a longer average time course.
Causes
There has been a great deal of scientific research and debate about the cause of CJD. Today, it is generally believed that CJD is caused by infectious proteins called prions. Prions can transform normal protein molecules into abnormal, disease-causing molecules.
Classic CJD has been recognized since the early 1920s. The most common form of classic CJD is believed to occur sporadically, caused by the spontaneous transformation of normal prion proteins into abnormal prions. This sporadic disease occurs worldwide, including the United States, at a rate of approximately one case per 1 million population per year, although rates of up to two cases per million are not unusual. The risk of CJD increases with age, and in persons aged over 50 years of age, the annual rate is approximately 3.4 cases per million. In recent years, the United States has reported fewer than 300 cases of CJD a year.
Whereas the majority of cases of CJD (about 85%) occur as sporadic disease, a smaller proportion of patients (5-15%) develop CJD because of inherited mutations of the prion protein gene. These inherited forms include Gerstmann-Straussler-Scheinker syndrome and fatal familial insomnia.
Risk Factors
A risk factor is something that increases your chances of getting a disease or condition.
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Age: CJD most commonly occurs in people ages 50-75
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Use of cadaveric growth hormone
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Cornea transplants
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Dura mater grafts
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Family members with CJD
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Eating beef products produced by countries with an epidemic of BSE (mad cow disease)
Symptoms
Initially, there are no symptoms. As CJD progresses, symptoms that may occur include:
Depending on the type of CJD, the disease may last from 3-12 months, or occasionally longer, and is almost always fatal.
Diagnosis
Your doctor will ask about your symptoms and medical history, and perform a physical exam.
CJD is a difficult disease to diagnose, as there is no single test for detection. The following tests may be used to help make a diagnosis:
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Electroencephelogram (EEG) – a test that records the brain's activity by measuring electrical currents through the brain.
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CT Scan – a type of x-ray that uses a computer to make pictures of the inside of the body, in this case the brain
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MRI Scan – a test that uses magnetic waves to make pictures of the inside of the body, in this case the brain
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Brain Biopsy – removal of a sample of brain tissue for testing
Treatment
There is no cure for CJD. The aim of treatment is to relieve pain and alleviate symptoms.
Drug therapy may include:
Prevention
To avoid nvCJD, it is recommended that you avoid eating beef produced in areas that may have BSE (mad cow disease). There are no known ways to prevent other forms of CJD.
RESOURCES:
Creutzfeldt-Jakob Disease Foundation, Inc.
http://www.cjdfoundation.org
National Institute of Neurological Disorders and Stroke
http://www.ninds.nih.gov
World Health Organization
http://www.who.org
References:
Creutzfeldt-Jakob Disease Foundation, Inc. website. Available at: http://www.cjdfoundation.org.
Kasper DL, Braunwald E, Fauci AS, et al. Harrison's Principles of Internal Medicine. 16th ed. New York, NY: The McGraw-Hill Companies; 2005.
