Creutzfeldt-Jakob disease (CJD)

 

 

Contents

 

 

 

 

 

 

 

 


CJD, also known as the human form of Mad Cow Disease, is the most common known human TSEs. It is a rare, degenerative, invariably fatal brain disorder. It affects about one in a million per year, with the onset of symptoms appearing at an average age of 50. CJD can be developed in three different ways. Majority of them occur sporadically, and very rarely they are inherited or acquired.      

CJD is caused by a type of protein know as Prions. In sporadic cases, the normal form of Prions found in the body undergoes spontaneous changes, in terms if their shape, and become infectious form. These altered Prions in turn, convert other Prions into infectious forms. These abnormal Prions will then start to aggregate, clumping together. The aggregation of these proteins results in loss of neuron and other brain damages.

 

Fig 1. Picture showing two different types of Prions. The on one left shows the normal Prion and the one on the right shows the abnormal Prion

As for those inherited cases, they result from the mutation in the gene that controls the formation of the normal form of Prions. If these mutated genes are found in the person’s sperm or egg cells, these mutations can then be passed down to the person’s offspring. As for those acquired cases, CJD can be transmitted through a number of ways. These include, through tansplanted corneas, implantation of inadequately sterilized electrodes in the brain and injections of contaminated pituitary growth hormone derived from human pituitary glands taken from cadavers, exposure to brain tissue and spinal cord fluid from infected patients.

During the initial stages of the disease, several symptoms may be observed. This includes, failing memory, personality changes, muscle twitching and stiffness, lack of coordination, sleepiness poor enunciation, anxiety, stress and visual disturbances. When the condition deteriorates, the mental deterioration becomes pronounced. Also, there maybe blindness, weakness of extremities and coma can occur. The duration of this illness from evidence of first symptoms to death is roughly about one year.

Recently, this disease has become widely known because a variant form of CJD, called the new variant Creutzfeldt-Jakob Disease (vCJD). It is known to develop in people who may have consumed meat that is contaminated with "Mad Cow Disease." This vCJD was first reported in the UK amongst people who had eaten meat from cows who were fed infected bone meal. The difference between CJD and vCJD is that the latter tend to affect younger people and has a shorter incubation period.

 

Like CJD, there is no available treatment and cure. There is also no available test for CJD and the only way to confirm the diagnosis of CJD is to obtain brain tissues through brain biopsy or autopsy. Microscopic examination for the abnormal form of Prion protein in the brain tissues will then be carried out.

 

 

Fig 2. Picture showing the microscopic view of brain tissue that had been infected with CJD