INFORMATION ON CREUTZFELDT-JAKOB DISEASE

Creutzfeldt-Jakob disease (CJD) is a rapidly progressive disease causing harm to the brain. It is one of a group of rare diseases that affects humans and animals, known as transmissible spongiform encephalopathies (TSE) and is believed to be caused by a prion, a newly known type of disease-causing agent. Creutzfeldt-Jakob disease is characterized by dementia and walking trouble. Death can occur up to two years after the first symptoms; however, most people die within seven months. There is no treatment or cure.

CAUSES OF CREUTZFELDT-JAKOB DISEASE

All forms of Creutzfeldt-Jakob disease are caused by the presence of a faulty protein in the brain, called prion. Prions occur in both a normal form, which is a harmless protein found in the body's cells, and in an infectious form, which causes disease. The harmless and infectious forms of the prion protein are nearly identical, but the infectious form takes a different folded shape. Sporadic Creutzfeldt-Jakob disease may show growth because some of a person's normal prions spontaneously change into the infectious form of the protein and then alter the prions in other cells in a chain reaction by a mechanism that is not yet understood. Misfolded protein molecules then increase through the brain and stick together to form fibers and/or clumps called plaques that can be visible with powerful microscopes. These bundles of twisted protein disrupt brain cells and ultimately leave large holes in the brain tissue, giving the brain a spongy appearance. Fibers and plaques may start to collect years before symptoms of Creutzfeldt-Jakob disease begin become visible. It is still unclear what role these abnormalities play in the disease or how they might influence symptoms.

About 5–10% of all Creutzfeldt-Jakob disease cases are present at birth. These cases arise from a mutation, or change, in the gene PRPN that controls formation of the normal prion protein. While prions themselves do not hold genetic information and do not require genes to reproduce themselves, infectious prions can take place if a mutation occurs in the gene for the body's normal prions. If the prion gene is altered in a person's sperm or egg cells, the mutation can be transmitted to the person's progeny. A number of different mutations in the prion gene have been identified. The particular mutation create in each family affects how commonly the disease appears and what symptoms are most obvious. However, not all people with mutations in the prion gene develop Creutzfeldt-Jakob disease. This suggests that the mutations merely increase susceptibility to Creutzfeldt-Jakob disease and that other, still-unknown factors also play a role in the disease.  

SYMPTOMS OF CREUTZFELDT-JAKOB DISEASE

Creutzfeldt-Jakob disease does not cause any symptoms at first. The first symptoms to appear include slow thinking, difficulty in concentrating, impaired judgment, memory loss, personality and behavioral changes, and difficulties with coordination and vision. These signs rapidly give way to increasing mental deficits leading to severe, progressive dementia (mental decline) associated with self-neglect, apathy or irritability, and prominent muscle spasms (myoclonus). Fits commonly occur as the disease develops. Symptoms continue to worsen until both mental and physical functions are lost; patients are fully bedridden, and ultimately lapse into coma. Comatose patients may die as a result of infection connected with being immobile, such as pneumonia.

TREATMENT OF CREUTZFELDT-JAKOB DISEASE

As of 2004, no treatment has been shown to be effective against Creutzfeldt-Jakob disease. Treatments are obtainable to ease some symptoms, such as morphine for muscle pain, and clonazepam (Rivotril) or sodium valproate (Epilim) for rough movements. A wide range of drugs has been tested for their ability to slow the development of the disease, but none has been shown to be helpful.

At present, care consists of managing the specific problems faced by patients with Creutzfeldt-Jakob disease. Speech therapy and occupational therapy may help.