Deadly brain disorderAbraham Eisenstein, M.D. | Thursday 10 June 2010 00:01 CEST
Creutzfeldt-Jakob disease (CJD) is a rare but unfortunately deadly brain disorder which usually appears after 60 years of age and progresses rapidly.
CJD has very high mortality rate: 90 percent of patients will die in the first year after first symptoms. There are three major types of Creutzfeldt-Jakob disease. Sporadic CJD appears although the patient has no known risk factors for the disease, and this is the most common type which accounts for at least 85 percent of cases. Hereditary CJD means that the patient has a family history of the disease or that tests for a genetic mutation associated with CJD are positive. In the case of acquired CJD, the disease is transmitted by exposure to brain or nervous system tissue, usually through a medical procedure.
Spongiform is the name of the characteristic of infected brains: it becomes filled with holes until those holes resemble sponges under a microscope. CJD is a member of the group of diseases which includes bovine spongiform encephalopathy (BSE) which attack cows and it is called "mad cow" disease. However, although they are very similar, those are not the same diseases: humans don't have "mad cow" disease.
The main characteristic of Creutzfeldt-Jakob disease is very fast dementia. At first stage, the patient has problems with muscular coordination, personality changes, impaired memory and thinking, problems with vision, insomnia and depression. As the awful disease progress the patients' mental state becomes very severs, there are involuntary muscle jerks called myoclonus, and the patient may go blind. At the end, he loses the ability to move and speak and enters a coma. At that stage infections often occur and that can lead to death.
At this moment, there is currently no single test for CJD, so a series of tests must be performed. As the first move, the doctor must rule out other forms of dementia such as encephalitis or chronic meningitis. Then a neurological examination must be performed, and an electroencephalogram to record brain's activity.
Computerized tomography of the brain and magnetic resonance imaging brain scans also can reveal characteristic patterns of brain degeneration that can help diagnose CJD. However, the only way to confirm a diagnosis of CJD is by brain biopsy or autopsy. However, since a correct diagnosis of CJD can't help the patient, a brain biopsy is not performed unless it is needed to rule out a treatable disorder.
Unfortunately there is no treatment that can cure or control CJD. Scientists have tested many drugs, studies of a variety of other drugs are now in progress, an enormous amount of time and money is included, but no therapy has been found yet. The only thing we can do is to treat symptoms and make the patient as comfortable as possible.
What causes Creutzfeldt-Jakob disease? Unfortunately, we don't know the answer. The agent that causes it is not a virus not bacteria. For example, the incubation period may be 40 years and it seems that the agent has no genetic information in DNA or RNA. The leading scientific theory at this time is that CJD is caused by a type of protein called a prion.
This is the protein that can live harmlessly in body cell but normal prions can change into the infectious form and alter the prions in other cells which starts chain reaction. Those abnormal prion proteins aggregate and that may lead to the neuron loss and brain damage. However, we don't know how that damage exactly occurs.
Creutzfeldt-Jakob disease cannot be transmitted through the air, by touch or via other forms of casual person to person contact. However, exposure to brain tissue and spinal cord fluid from infected patients should be avoided to prevent transmission of the disease through these materials. That obviously means that surgeons and other medical stuff must be extremely careful and use all available protection while dealing with the patient that has CJD.