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. 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.

Individuals affected by CJD usually succumb within 6 months of the onset of the disease, often through pneumonia. 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.

The exact time of onset of the illness can be very difficult to determine. Often at first there are subtle lapses in 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 mild depression. However, within a few weeks other features can quickly appear: a vague unsteadiness and hesitancy in walking, deteriorating vision, slight slurring and slowing of speech, and difficulties in holding everyday conversation. There is usually a rapid downhill course, with the development of incontinence of urine, jerky movements, shakiness, stiffness of limbs, and the 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 in regards to the shakiness.

As already mentioned, many of the initial symptoms can be confused with a depressive illness, but the telling feature is usually 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 CJD.

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.