Creutzfeldt-Jakob Disease: What it is and how it Differs from Alzheimer's
Creutzfeldt-Jakob disease (CJD) is a rare, very rapid progressive form of dementia. Unlike Alzheimer's where causes have been identified as neurofibrillary tangles and a sticky protein called beta amyloid, in CJD proteinaceous infectious particles, better known as prions, are the culprit. Compared with Alzheimer's, which is mainly associated with the older age group, CJD usually affects people between the ages of 50 and 70 years.
How the Causes of Creutzfeldt-Jakob Disease Differs from Alzheimer's
CJD affects animals as well as humans. CJD is known as scrapie in sheep, chronic wasting disease in deer and bovine spongiform encephalopathy (BSE), also known as mad cow disease, in cattle. It is believed that CJD can be transmitted through ingesting infected brain tissue. BSE is found in those who have been treated with growth hormone, by people who are exposed to poorly sterilized instruments. A tribe in New Guinea that used to practice cannibalism by eating the brains of dead relatives, also suffered a prion dementing disease called Kuru.
In previous years, regional populations of deer in the United States and some herds of cattle in the United Kingdom (in the 1980s and early 1990s) were eliminated to prevent any spread BSE. The BSE found in 40,000 cattle in the UK was believed to have come from herds being given feed containing infected neural tissue from other animals, a practice that was stopped.
Like Alzheimer's, there is a genetic component to Creutzfeldt-Jakob disease but with a lower incidence, between 5 and 15 per cent of all cases being familiar. This does suggest that there is a genetic susceptibility to prion infections.
How the Symptoms of Creutzfeldt-Jakob Disease Differ from Alzheimer's
The rapid progression of CJD and the development of uncontrollable muscle jerks, called myoclonus, distinguishes this disease from Alzheimer's. Other symptoms include fatigue, insomnia, anorexia, progressive deterioration of memory and behavior disturbances. In the final stages people with this disease become mute and rigid. Depression and psychosis is seen in 10 per cent of cases, along with delusions and hallucinations.
An EEG will show characteristic highly abnormal brainwave patterns and a test on cerebrospinal fluid will show the 14-3-3 protein, considered a key diagnostic factor for CJD.
New variant Creutzfeldt-Jakob disease (vCJD)
Since the outbreak of BSE in the UK, over a 100 cases of the dementia have been seen in humans. Research suggests that this new variant form of Creutzfeldt-Jakob (vCJD) is the direct result of exposure to the agent that causes Bovine Spongiform Encephalopathy (BSE) in cattle and followed an incubation period of six years after eating the infected meat. Unlike CJD the new variant form affects much younger people.
Treatment for Creutzfeldt-Jakob Disease
Like Alzheimer's disease there is no cure. Unlike Alzheimer's, where medication can be effective to slow its progression, there are no comparable treatments for CJD. Symptoms are treated to help alleviate distress, pain, and to make people with CJD as comfortable as possible.
Prognosis for Creutzfeldt-Jakob disease (CJD)
The big difference between these two types of dementia is life span following diagnosis. Death, following the first appearance of symptoms of CJD, is between three months and one year. In contrast people with Alzheimer's can live up to 20 years with the disease.
Other human prion diseases in humans include;
Kuru, CJD, Variant Creutzfeldt-Jakob disease (vCJD), Gerstmann-Straussler-Scheinker syndrome and fatal familiar insomnia.
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