Creutzfeldt-Jakob disease, or CJD, is a one of a family of diseases known as Transmissible Spongiform Encephalopathies (TSE's). It was first identified and described by both Creutzfeldt and Jakob in the 1920's.

It is a fatal neurological disease for which there is no treatment and no cure.

There is no vaccine available.

Other TSE's include Kuru (a disease associated with cannibalism in New Guinea), and Gerstmann-Straussler-Scheinker syndrome.¹

There are also similar diseases among animals. In sheep and goats it is called scrapie. In cows it is called Bovine Spongiform Encephalopathy (BSE), or "Mad Cow Disease". An outbreak of this disease in Great Britain in 1995 caused worldwide concern over whether or not this disease could be transferred from animal to human through the eating of contaminated meat or other animal products.²

As a result, shipment of cattle or meat products into the United States was halted. No cases of BSE have been found in the United States.

A new variant of CJD called nvCJD has been identified in Britain and has been proven to be associated with BSE. The new variant kills younger people (average age 28) and unlike classic CJD, the incubation period appears to be months (7-24) rather than years in length. Again, none of these cases have occurred in the United States.^{3 4}

Creutzfeldt-Jakob disease affects both men and women worldwide usually between the ages of 50 and 75.

CJD results when abnormal protein accumulates in the brain cells. Scientists do not know what triggers the conversion of protein from the normal to the abnormal form, although a genetic defect has been identified that might provide a clue.^{5 6} Some believe the conversion is caused by a spontaneous mutation of the normal protein itself, while other scientists believe a virus or virus-like entity may be involved.⁷

This abnormal protein, believed to be the causative agent of CJD, is known as a prion (pronounced "pry-on"),⁸ a protein based molecule with no RNA or DNA that is smaller than a virus.⁹

Actually, because the prion disease we see today differs in many respects from the original description of CJD, some scientists question whether or not the disease we see today is indeed the same disease described by Creutzfeldt and Jakob some 70 years ago.¹⁰

The initial symptoms are subtle and can include insomnia, depression, confusion, personality/behavioral changes, strange physical sensations, balance and coordination disorders, loss of memory, and visual problems.

Rapidly the patient deteriorates with progressive dementia and usually myoclonus (involuntary irregular jerking motions) as the disease progresses. Language, sight, muscular weakness and coordination problems worsen.

The patient finally loses all mental and physical functions. Coma follows and death is usually due to pneumonia precipitated by the bedridden, unconscious state.

The duration of CJD from the onset of symptoms to death is usually one year or less, most commonly 2-6 months.¹¹

The official mortality rate is approximately 1 death per million population worldwide per year.¹² CJD is still classified as a rare disease (although the National Center for Infectious Diseases considers it an "emerging infectious disease").¹³ This figure appears to be understated because CJD is often misdiagnosed. Because of the dementia it causes, it is often confused with Alzheimer's.

One study done by Yale University showed that 13% of Alzheimer's patients were found upon autopsy to actually have CJD.¹⁴

Approximately 80% of deaths were among persons age 60 or older. Among this age group, the death rate from CJD is 4.5 per million persons.¹⁵

There is no definitive diagnostic test for CJD. The disease is suspected when a patient develops a rapid dementia and myoclonus. A 14-3-3 spinal test is 95% effective in supporting a clinical diagnosis of CJD. Unfortunately, the only 100% effective diagnostic tool available is an autopsy with appropriate tests.¹⁶

The post-mortem finding of a coarse spongy-like surface of the brain (and the underlying microscopic cellular changes) is characteristic of CJD, thus the term, spongiform.

Brain surface of CJD patient on autopsy showing sponge-like appearance

A person can become infected with CJD and have no symptoms for typically 12-25 years, although the disease can run its course and result in death in less than three years from the time of infection.

Three epidemiologic forms of CJD are well recognized. The familiar (genetic) form (5-10% of cases) results from a genetic mutation.

Approximately 1% of cases are iatrogenic (resulting from a medical procedure) including neurological procedures using contaminated instruments, corneal transplant, from electroencephalographic electrodes, cadaveric dura mater grafts, and pituitary hormone administration.¹⁷

Sporadic CJD accounts for 80-85% of all cases. These cases result from the mutation of the protein by some unknown cause.¹⁸

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