This short handbook has been produced in response to the questions raised by those involved in the care of patients suffering from Creutzfeldt-Jakob disease, and their friends and relatives. It is by no means an entirely comprehensive work, and further questions which may arise can be directed to the address shown at the end.
Creutzfeldt-Jakob disease was named after the two doctors from Austria who in 1920 separately described a total of six patients with peculiar neurological illnesses. Although the illnesses were not very similar, the appearances of the brain when viewed under the microscope were alike; many of the normal brain nerve cells had died, and the brain had developed numerous tiny holes, too small to be seen by the naked eye, and a meshwork of delicate fibres. The entire appearance resembled a microscopic "sponge", and thus was born the expression "spongiform encephalopathy".
After this first recognition, more cases throughout the world came to be described that had similar features. Eventually, in 1957, two English doctors, Nevin and McMenemey, were able to identify particular features of the illness that sufferers had in common.
Creutzfeldt-Jakob disease (CJD) occurs worldwide, from Chile to Japan, and from Australia to the United States. There is approximately one new case per two million people per year, and about 30 cases occur per year in the United Kingdom. The most common age of onset is over the age of 55, but it appears to be rare over the age of 80.
CJD can affect more than one member of a family but this is rare. In these instances, the family are usually already aware that the disease has occurred in a relative.
Other spongiform encephalopathies
This was first recognised in 1730 and is a disease of sheep, so named after the habit of affected animals to repeatedly scrape themselves against objects. Eventually, the animals become unsteady on their feet, uninterested in their surroundings, and stop feeding. Examination of the brains of affected sheep after death shows many of the same changes that are found in people with Creutzfeldt-Jakob disease.
This is a disease of the Fore people in the mountains of New Guinea, and results in an illness similar to Creutzfeldt-Jakob disease. The tribe practised cannibalism during funerals. It is believed that the disease was passed to other tribe members during this ritual. Now that cannablism has died out in this tribe, so has Kuru.
Bovine spongiform encephalopathy is a disease of cows which was first described in 1987. The animals affected become unsteady on their feet, lose weight and often assume a fearful disposition. The term "mad cow disease" is not always appropriate as many animals do not become overtly aggressive, and towards the end, may lose interest in their surroundings, and become too unsteady to even stand.
Spongiform encephalopathies have been now recognised in a number of other species; The disease has been transmitted to one pig which had an extract of BSE-affected cow brain injected into its abdomen, bloodstream, and brain, all at the same time, but there have been no natural cases in the pig.
DESCRIPTION OF CREUTZFELDT-JAKOB DISEASE
Features of the illness:
The exact time of onset of the illness can be very difficult to determine. Often at first there are subtle lapses of memory for day-to-day events, although sometimes mood changes, in particular, loss of interest and withdrawal from involvement in social activities are apparent. Decline in ability at work for tasks that were previously simple is often noted. At this point, the illness may be passed off by friends, relatives, and doctors as a mild depression. However, within a few weeks other features quickly appear: a vague unsteadiness and hesitancy in walking, deteriorating vision (often the patient may mistake everday objects for something else, or even experience hallucinations), slight slurring and slowing of speech, and a difficulty in finding the right word when trying to hold a conversation. There is usually a rapid downhill course, with the development of incontinence of urine, jerky movements, shakiness, stiffness of the limbs, and loss of the ability to move or speak.
Mercifully, only in the very early stages are the patients aware of anything amiss, and usually complain of clumsiness, feeling muddled, or blurring of eyesight. As the disease progresses they lose awareness of their surroundings and of their disabilities. Some of the agitation that may be seen is a reflex phenomenon rather than true distress, this is particularly the case as regards the shakiness.
Individuals affected by CJD usually succumb within 6 months of the onset of the disease, often through penumonia. In only 10% of cases does the disease run a more prolonged course of 2-5 years, and in these cases, the first years may only involve loss of memory and some difficulty with complex tasks.
As already mentioned, many of the initial symptoms can be confused with a depressive illness, but the telling feature is the rapidity with which other signs appear. It must be emphasised that only in very rare instances does the presence of mild forgetfulness and vague unsteadiness herald the development of Creutzfeldt-Jakob disease.
Sadly, there is no known cure or treatment that can halt the progress of the disease. However, there are many drugs which can be used to make the last weeks and months easier for the sufferer.
Tests performed and their meaning:
Also known as a "CAT" scan, which stands for computerized axial tomography. It is a form of specialised x-ray where it is possible to look at the brain, although it is not possible to see "spongy" change which is microscopic. The usual reason for obtaining a scan is to rule out any other cause of the illness.
MRI stands for magnetic resonance imaging and is a way of looking at the brain without x-rays. Again it is not possible to se the "spongy" change.
This is short for electroencephalogram. By putting a number of small electrodes on the scalp, it is possible to record the electrical activity of the brain itself.
Under local anaesthesia, a thin hollow needle is inserted in the patient's back and a small amount of fluid which surrounds the spinal cord is removed for examination. This test is often done to ensure there is no infection of the brain which could be treated.
The only way in which the diagnosis can be made with certainty is to examine the brain after death, and this can take 2-3 months before all the results of the microscope tests are available. During life, the priority is to ensure that the person does not have a condition which could be easily treated such as liver or kidney failure, vitamin deficiency, or brain tumour, and so most of the tests are planned with this in mind. It is particularly important to remember that there is no blood test or x-ray which can diagnose Creutzfeldt-Jakob disease with absolute certainty.
Research into spongiform encephalopathies
There are presently a large number of doctors and scientists carrying out various research projects on the spongiform encephalopathies, including diseases of both man and animals. The first major finding was in 1967, when brain extract from a person from the Fore tribe who had died of Kuru was injected into the brain of a monkey. Within a few years, the monkey developed a disease similar to Kuru, and when its brain was examined microscopically, it showed similar spongy changes. It was therefore shown that the disease could be transmitted from one species to another, at least artificially. It was already well known that sheep affected with scrapie could pass the condition to other members of the flock, and experimental transmission of scrapie had been documented many years previously. In 1968 Creutzfeldt-Jakob disease was transmitted to laboratory animals by inoculating extracts of brain from a person who had died of the condition.
This research led to the conclusion that all these diseases were related in that they caused the same type of illness, looked the same under the microscope, and were caused by agents which had infectious properties, but were different from normal bacteria and viruses.
The next step forward was the identification of a protein normally produced by the brain cells which had become altered. The function of this protein is not known, even in its normal form. When produced by the brain cells in cases of Creutzfeldt-Jakob disease, it was produced in larger than normal amounts. Under a very powerful microscope, the scientists were able to see the protein as it clumped together to form minature stick-like structures which were named "scrapie-associated-fibrils" or "prion rods". The exact significance of these fibrils is unknown, although when they are found in brain tissue specimens, they can help to diagnose the condition.
Some scientists believe that the protein forms part of the infectious agent that causes the condition, where its function is rather like a "coat" around the agent itself. Others believe that it is simply a by-product of the illness.
It is still not possible to see the actual particle which causes these diseases and we are only able to see the effects on the body.
Since the agent which causes Creutzfeldt-Jakob disease is obviously very small, some scientists believed that it could be a virus. However, if this was the case it should have been able to detect some reaction of the body to it, in the same way that the body forms antibodies. It should also have been possible to see the virus using powerful electron microscopes. Neither of these occurred. Therefore it was assumed that this was some very minute virus (a "virino"), or perhaps a virus that had become altered in some way. As yet, this theory remains unproven.
Common Questions About CJD
Can you catch it from somebody?
Creutzfeldt-Jakob disease does not spread from person to person. It is not a "catching" disease like measles or mumps. People who look after, handle, sleep with, or eat off the same plates as sufferers of the condition do not get Creutzfeldt-Jakob disease any more frequently than members of the general public. Indeed, doctors and nurses who would be expected to come into contact with people with the disease are not more likely to develop CJD.
Nevertheless, it is sensible to wear gloves when in danger of exposure to blood from people with Creutzfeldt-Jakob disease, as with any exposure to human blood. Bedding and clothing should be treated in the normal way, and there is no need for a separate set of cooking or eating utensils.
Why did my friend/relative get it?
The truth is, no one knows. Without yet knowing what causes the condition, we do not have an answer to this question. A number of cases have occurred in particular circumstances, all with a logical explanation:
(i) Some people who had received treatment with human growth hormone developed Creutzfeldt-Jakob disease. In the past, growth hormone was obtained from the pituitary glands (a small gland at the base of the brain) of people who had died. It is suspected that one or more of the people from whom the glands were obtained had died of CJD. At that time it was not known that CJD could be passed on from one person to another by this means. Since 1985 the hormone has been made artificially and there are now no risks of acquiring the disease this way.
(ii) A few cases were described in people who had contracted the disease after receiving corneal transplants (where the clear part at the front of the eye is taken after death and used to replace that of someone else's that has become damaged), or other human tissue. Again the explanation was that the tissue had come from someone with Creutzfeldt-Jakob disease. This occurred at a time when it was not known that Creutzfeldt-Jakob disease could be transmitted from one person to another in this way. Since then, no organs or tissues of any type are taken from victims of Creutzfeldt- Jakob disease for use in donation.
(iii) Three cases occurred in people who had undergone brain surgery. It was shown that someone with Creutzfeldt-Jakob disease had been operated on earlier in the same day and the same surgical instrument had been used, and presumably this was how the infection was transferred from one patient to another. It has been standard practice since then for all instruments used during an operation on a patient with Creutzfeldt-Jakob disease to either be destroyed, or to go through a more extensive sterilization process which is known to eradicate the agent completely.
Can you catch it from food or animals?
This is the point about which there has been much debate. If animals can suffer from diseases such as scrapie and BSE, is it possible that the disease could be transmitted to man when he eats meat and animal products? Already a number of studies have been carried out to look at this question, and the overall answer is almost certainly no. In particular, Creutzfeldt-Jakob disease has occurred in life-long vegetarians, and occurs in countries which do not have scrapie or similar diseases. Neither is Creutzfeldt-Jakob disease more common among farmers, vets, or people who handle or keep animals.
Is the sufferer in pain?
Individuals may feel some discomfort but there is no pain associated with CJD. However this can be a very distressing disease for the persons loved ones.
What can the doctors and nurses do?
There are many treatments which can be used to alleviate some of the features which can accompany the illness. Frequent changes of position of an immobile person are necessary to ensure comfort, and prevent the development of pressure sores. A catheter to drain urine is often necessary if incontinence of urine is a problem. A catheter is a narrow rubber tube which is painlessly inserted into the bladder. Sometimes the ability to swallow may be lost, and then the patient can be fed via a tube through the nose, or receive fluid by means of a plastic needle in their vein (a "drip").
The shakiness or jerks which some patients experience can be treated with sedative drugs or pain-killers. The object is to keep the patient as comfortable as possible up to the time of death.
What is being done to investigate the disease at present?
Throughout the world much research is being carried out to try to find the cause of Creutzfeldt-Jakob disease. The Department of Health in this country has set up a nationwide survey to identify all new cases of the condition. Information is then gathered from a close relative or friend regarding the patient's past medical history, work, places of residence, and dietary history so that any factors which might link sufferers of the disease can be identified. The numbers of cases occurring each year, and in what parts of the United Kingdom, can be ascertained to see if there is any change with time.
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