FAQ’s

CJD and prion diseases happen when there is an abnormality in the prion protein. The prion protein is one of many normal proteins found in humans, and is found most abundantly in the brain. Proteins are chains of amino acids which fold into important molecules that have structural and functional roles in the body. Proteins, including the prion protein, are constantly being made, used, destroyed, and replaced, in our cells.

Prion disease happens when there is an abnormality in the folding of the prion protein, resulting in misfolding. The misfolded prion protein is more resistant to being broken down and is able to convert other normally folded prion protein into misfolded protein; there is, therefore, a progressive increase in the amount of this protein in the brain, once it is present.

Human prion diseases have been divided into three main types, relating to how the disease occurs: Sporadic, Genetic (inherited), and Acquired.

In genetic (inherited) prion disease – An abnormality in the gene code causes a different amino acid chain to be formed that is then more likely to fold incorrectly. This is the general explanation of genetic prion disease; it is the result of an abnormal gene. For more information on genetic prion disease, see our factsheet here.

In acquired prion disease – Abnormally folded prion protein is introduced into the body in the diet or by medical procedures. This causes the individual’s prion protein to misfold. For more information on acquired prion disease, see our factsheets on variant and iatrogenic CJD.

In sporadic prion disease – Misfolding might occur as a simple accident. Protein molecules are being made all the time, then processed and folded. If a random error occurs and abnormally folded prion protein is produced, it might then go on to convert other normal prion protein. Currently, this is held to be the most likely explanation for sporadic prion disease. For more information on sporadic prion disease, see our factsheet here.

CJD and prion diseases are not infectious in the usual way. For example, they are not spread by airborne droplets like colds and flu, or by sexual contact like HIV.

The evidence suggests there is no risk of developing CJD from ordinary (even intimate) contact with someone with the condition. No special precautions are required. However, it is sensible for anyone who might be exposed to the blood of a CJD patient (usually medical staff) to wear gloves, as is routine in the management of any illness.

CJD and prion diseases mainly affect the brain. The symptoms are, therefore, essentially ones of brain dysfunction. Inside the brain, prion disease involves loss of neurons and build-up of the abnormally folded prion protein in the brain tissue. Neurons are one of the main cell types found in the brain. They are electrically active, connected to each other and form circuits. The activity in these circuits is responsible for all of our brain functions (sensation, movement, thinking, talking etc).

The course of symptoms will vary depending on the form of the disease, and also from individual to individual. However, particularly common features include:

Impairment of memory, thinking, language and behaviour, resulting in dementia

Impairment of co-ordination and balance

Involuntary movements, in particular jerking movements called ‘myoclonus’

The illness eventually causes major neurological impairments leading to severe mental impairment, loss of mobility, loss of speech, impaired swallowing, incontinence and immobility. Loss of vision or even blindness may occur. The disease process is always progressive often rapidly so, and these illnesses are, currently, inevitably fatal and without cure. Most individuals lose awareness or insight in the later stages and therefore their condition may be more upsetting to others than themselves.

The accuracy of a clinical diagnosis varies depending on the form of the disease. However, in most cases, a very reliable clinical diagnosis is possible.

A clinical diagnosis rests on the presence of typical symptoms and signs, the exclusion (by tests) of other possible illnesses and may be supported by certain specific test results.

In genetic (inherited) CJD, testing for the genetic mutation can be undertaken (usually on a blood sample).

In acquired CJD, Iatrogenic CJD is diagnosed on the basis of symptoms developing in someone with a relevant past exposure, for example, in those given human growth hormone. The diagnosis of variant CJD may be very difficult, but MR brain scanning, a prion protein blood test and a tonsil biopsy may be helpful.

In sporadic CJD, the EEG (electroencephalogram), CSF (cerebrospinal fluid) tests and MR (Magnetic Resonance) brain imaging are often very helpful.

An absolutely definite diagnosis is generally only possible after death when a post mortem has been performed. Post-mortem examination is not compulsory when CJD is suspected – the doctor will need the permission of the next of kin. In some specific instances, the matter may be referred to the coroner (in England & Wales) or the Procurator Fiscal (in Scotland).

The Chief Medical Officer has requested that individuals suspected of having CJD or prion disease should be referred to the National CJD Research & Surveillance Unit and the National Prion Clinic. These units will try, when possible, to visit all referred patients and their families but involvement with these organisations is entirely voluntary for the patients and their families. Aside from their research functions, these organisations are able to provide additional information, help, advice and support with care coordination.

Please keep an eye on our factsheets as we hope to add more information on care processes following diagnosis, soon.

CJD affects 1 – 2 people per million of the population per year. The lifetime risk of CJD is around 1 in 5,000.

In the UK, all cases of suspected CJD are reported to the National CJD Surveillance Unit in Edinburgh and to the National Prion Clinic in London. The number of cases of sporadic CJD in the UK has increased since 1970, when organised records were begun.

There has been a similar increase in numbers in other countries where CJD surveillance is undertaken; it is not specific to the UK.

At least some of this increase is due to greater awareness of CJD among the medical profession and the availability of better diagnostic tests but some might represent a genuine increase in the incidence of the disease.

The latest available surveillance data can be found here.

The time course of the disease depends on a number of factors, including the type of CJD. The commonest form, sporadic CJD, is typically very rapidly progressive with an average duration of only around 4 months from first symptom. Duration from diagnosis is, of course, generally less, because diagnosis takes some time. However, a few people with sporadic CJD can live 1-2 years or more. To some degree, how long people live depends on factors other than simply the disease process, such as whether complications such as chest infections occur, and what sort of medical care they receive.

Variant CJD (vCJD) first arose due to human dietary exposure to Bovine Spongiform Encephalopathy (BSE), a prion disease found in cattle. Some media outlets have used the term ‘Mad Cow Disease’ to refer to the bovine form of the disease. This is a term which can be, understandably, distressing for those connected to any form of CJD, and should therefore be avoided.

In the UK, specific measures were put into action in 1989 to protect human diet, and no one born after 1989 has so far been diagnosed with vCJD. There are no known living vCJD patients in the world. There have been a total of 178 reported UK cases, with no reports of definite or probable cases in the UK since 2016.

There are good reasons for believing that the incubation period for dietary-related vCJD could be very long and certain genetic factors can influence this. Therefore, the possibility of further cases cannot be excluded, although analysis suggests that, if there are further cases, the number will be relatively small.

There is no cure, at present, for CJD, although scientists are researching into the causes of and potential treatments for the disease. There has been significant funding of research in many countries, including European countries, the USA, Canada, Japan and Australia. This research is often collaborative and there have been several international collaborative research groups. Research in all countries has made contributions to our knowledge and understanding of CJD.

Information on treatment matters can be obtained from the National Prion Clinic. The National CJD Research & Surveillance Unit website also contains some information about treatment matters.

Whilst no cure or treatment for the disease itself currently exists, there are a number of drugs already available which can relieve symptoms and make the patient more comfortable. Relevant consulting clinicians should support with symptom management.  Equally important are general support and care for both the person and their family. Services should be involved as early as possible to advise on benefits, day centres, respite and long-term care. Speech and occupational therapists can help with specific problems, while the district nurse may provide more general nursing care and advice. Referral to palliative care should also be offered. 

A series of videos are available via our YouTube channel to support carers with managing different symptoms. There are also specialist nurses who are employed by both the National Prion Clinic and the National CJD Research & Surveillance Unit; they can give advice and support to families and other health professionals.

The CJD Support Network is here to support anyone who has a connection with any form of CJD, and can also signpost and link you in with other forms of support depending on your individual circumstances. Our helpline is open on a Tuesday and a Friday from 8am-6pm (0800 774 7317) and we can also be contacted via email at [email protected]. We have an active and supportive Facebook community for those based in the UK, and hold regular support meetings online as well as an annual in person meeting. Details of meetings can be found on our events page here.

If you are based outside of the UK, please visit the International CJD Support Alliance here.

The CJD Support Network is here not only to provide emotional support but also information, as far as this is available. Contact us via our helpline on 0800 774 7317 (open on Tuesdays and Fridays from 8am-6pm) or via email at [email protected] and we will be happy to discuss any questions and either answer them as best we can ourselves, or seek out information via the relevant channels, including our connections with national experts in the disease.

Q: Our family is struggling with the decision of whether to proceed with genetic testing. How can we navigate this and decide what to do? It affects so many of us and our children.

It is a very difficult decision, not least because – as you say it may affect many others, not just the person tested. The most important thing is to have all the necessary factual information, to think carefully about how you would react to any test result and to discuss it with all who may be affected. It is also necessary to be referred to a genetic counsellor who is experienced in discussing the relevant issues. If you are considering having children, it is worth discussing this with a suitable medical practitioner as there are techniques which may allow you to have children without the disease mutation.

Q: After the first signs/symptoms, what is the longest anyone has lived with CJD? Also, from diagnosis, how long has anyone lived?

Firstly, it depends on the type of CJD. The commonest form, sporadic CJD, is typically very rapidly progressive with an average duration of only around 4 months from first symptom. Duration from diagnosis is, of course, generally less, because diagnosis takes some time. However, a few people with sporadic CJD can live 1-2 years or more. To some degree, how long people live depends on factors other than simply the disease process, such as whether complications such as chest infections occur, and what sort of medical care they receive.

Q: Are there significant grant contributions for research into CJD in other countries and have any breakthroughs been made?

There has been significant funding of research in many countries, including European countries, the USA, Canada, Japan and Australia. This research is often collaborative and there have been several international collaborative research groups. Research in all countries has made contributions to our knowledge and understanding of CJD.

Q: Is it too early to tell whether there is a link between Covid 19 and neurological diseases? If it doesn’t directly cause the disease initially, could it perhaps cause symptoms to increase faster than they usually would? And, if not Covid 19, then Covid vaccine?

It can be difficult to confirm or exclude a possible causative or exacerbating factor. The general approach researchers take is to (1) consider if there is a reasonable possible mechanism whereby a proposed factor might cause or worsen a disease and (2) to study diseases in a population to see if there is any evidence. In relation to cause and Covid 19, the answer to both these is negative. There is no obvious theoretical reason why Covid 19 or Covid vaccines would cause CJD and there is no evidence that CJD has become commoner since Covid. Covid 19 is one of many viruses and there are many vaccines in use. Past study has looked for possible links to virus infections and vaccines and has found none. Of course, it is possible that another illness like Covid might cause an existing CJD illness to progress faster or shorten survival because of complications (such as pneumonia) but there are no hard observations to support this, and, if it were true, it would very probably be a non-specific effect, i.e. true for other viral infections.

[Updated 2024] There has not been any evidence to link Covid or Covid vaccination with CJD. So many people have had Covid and been vaccinated that it is unsurprising that some had either in the time before developing CJD coincidentally. Surveillance researchers haven’t seen any increase in CJD related to Covid. It is possible that a bad infection of any sort might accelerate the CJD disease process but only in someone who is developing it anyway, and researchers haven’t seen any conclusive evidence to suggest this.

Q: Can traumatised grief bring on/accelerate diseases such as sCJD?

It is very natural, and understandable, that people take preceding events such as bereavement, stress, loss of job and so on, to be a possible cause of sCJD. It reflects their need to find some reason for the illness, although, in truth, sCJD appears to be a random illness. In any individual case, it is impossible to know whether some preceding event has contributed to the onset of CJD. Traumatic events are, sadly, not uncommon in ordinary life and one needs to recognise that they affect many people in the general population without leading to CJD. Studies of large numbers of cases have not suggested that traumatic experiences are relevant.

Q: Can anti-oxidants play a role in emboldening the brain top prevent the build up of proteins? Israeli scientists have reported delaying the onset of genetic disease in 500 families taking nano-pomegranate seed oil capsules, which cross the blood-brain barrier.

Anti-oxidants have been proposed as possible treatments in a number of brain diseases, not only CJD. There is no present evidence to suggest they benefit CJD. Of course, whether proposed treatments , whatever their theoretical basis, have benefit or not has to assessed in proper clinical studies. There is, currently, no proven significant treatments for CJD. Treating genetic family members to delay or prevent disease is a theoretically attractive proposition and one that may well be more likely to succeed than treating established symptomatic disease. There is a current trial of doxycycline in families in Italy and there have been reports of a study of families in Israel using a pomegranate extract. Such trials would have to run a long time before definite results could be declared. There is no published report of a definite positive result in such studies at this time.

Q: Really concerned about the decline of post-mortems…Why is this happening?…If reversing this trend is desirable, how? Is premortem typing (sCJD, iCJD, gCJD, vCJD) giving families the answers they need?

The decline in autopsies in the UK is a general phenomenon and not just relating to CJD. Autopsy facilities suitable for CJD are not available in every locality and UK Neuropathology is a small medical speciality. In arranging autopsies, there are a number of factors to consider including: availability of resources, costs, disruption to funeral arrangements and consent from the family. The only exception to family consent is where a Coroner (In England & Wales), or a Procurator Fiscal (in Scotland), has a reason for mandating an autopsy. If families wish for an autopsy, both the NCJDRSU and the NPC will try to help to arrange one, though this is not always possible. In general, both Units agree that autopsy is important, especially in cases where there are unusual clinical features and negative or atypical investigation results. In addition, autopsy definitive diagnosis is important for assessing the accuracy of clinical tests (such as the CSF Rt-QuIC test). Finally, autopsies aid research into these diseases. However, a highly probable diagnosis, without significant doubt, of CJD, and its type, is possible in many cases, because of improved diagnostic testing in recent years. Given this, and the limitation on resources, the Units tend to concentrate their efforts to obtain autopsy on those cases where there is uncertainty, a specific opportunity for research, or where the families particularly wish for it.

Q: Do relatives of sCJD sufferers have an increased likeliness of acquiring sCJD themselves?

There is no evidence that relatives of sporadic CJD have an increased likelihood of acquiring sCJD themselves.

Q: Has there been an increase in numbers of sCJD…is the rate constant at 1-2/million?

Are there more cases in particular areas?

Q: Are the numbers in the UK and worldwide the same?

There has been an increase in the numbers of sCJD cases over the years, both in the UK and in other countries. In the UK, and indeed, in all countries where it has been studied, the annual mortality rate is around 1-2/million/year. The increase in numbers has tended to take the figure nearer to 2. The increase in numbers is explained by increased awareness of the condition and, particularly, by better diagnostic tests.

There is no good evidence that sCJD is intrinsically commoner in one part of the UK, or, indeed, one part of the world, if adjusted for population size and age structure. sCJD is commoner in older populations and the actual number of cases will get higher in bigger, older, populations. It is noteworthy that the number of sCJD cases is broadly the same in all countries with good surveillance systems, regardless of whether those countries have scrapie in the sheep, or BSE in their cattle.

Q: What opportunities are there in the UK for research studies/testing for familial cases?

Families may contact the National Prion Clinic (NPC) and the National CJD Research and Surveillance Unit (NCJDRSU) about possible involvement in research. The NPC is interested is currently interested in trying to find markers of early disease in genetic CJD.

Testing for genetic mutations is readily available. Such testing in individuals who are clinically ill is a matter for the relevant clinicians. If currently well individuals from families wish to be tested, it needs to through a referral to a genetic counselling service.

Q: Has there been research on the prevalence of brain stem dysfunction in CJD patients? Would this be a consideration for either of the prion centres?

The illness tends to involve most, or all, parts of the brain, and, in most cases, rapidly so. There are individuals where symptoms arise relating to one part of the brain (for example, visual or coordination/balance areas) before more global brain symptoms appear. However, brain stem symptoms are not particularly prominent in this way. In diseases like CJD, where the brain is generally involved in the disease process, it may be difficult to determine where certain symptoms arise from. Symptoms that characteristically arise from the brain stem are: double vision, slurred speech, swallowing difficulties, and a certain kind of facial weakness or numbness. However, things like slurred speech and swallowing difficulties can arise for other reasons. Incoordination, poor balance, limb weakness and limb numbness, could reflect brain stem problems, but could arise from disease affecting the brain itself. The study of CJD has included a careful analysis of symptoms and signs in CJD. There is no research particularly into brain stem symptoms, and there is no indication that this would be useful.

Q: If tissues are donated post-mortem for research, what happens to them? Do such tissues stay at one site or could they be shared with other research centres?

When tissues are obtained for research (as opposed to diagnosis), what happens to them depends entirely on the particular consent obtained from the family. Consent may vary from a limited to an indefinite period of holding; from being used for restricted, to any, research purposes; from being shared to not being shared with other research groups. If any family has uncertainty, they could contact the group that obtained the consent. Some consents may include an option for the family to be notified of any outcomes of research.

Q: To what extent has the form of contact with patients/families by the Edinburgh & London teams, adjusted back to pre-Covid times? Are patients/families always given the option of face-to-face contact?

The aim has been to return to face-to-face contact, as far as possible. Sometimes, because of pressure of work, distance, transport, or family preferences, contact may be digital. If families particularly wish for face-to-face contact, they can discuss this with the teams. The Covid restrictions did increase awareness and understanding that digital or phone contact can have a useful place in clinical or research practice. However, both teams agree that face-to-face contact is very important in many situations.