Causes and Risks:

Creutzfeldt-Jakob disease is an organic brain syndrome caused by a viral-type organism. The disorder is rare, occurring in about 1 out of 1,000,000 people. It usually first appears in midlife, beginning between ages 20 and 68, with the average age at onset of symptoms being between 57 and 62.

Cases have occurred in adolescents who have received growth hormone derived from cadavers, despite the production process, which is intended to kill all bacterial and viral material in the product. The causative agent, or prion, is thought to have been transmitted in the growth hormone (extracted from the pituitary of cadavers), which explains the abnormally early appearance of the disease. Cadaver-derived growth hormone has been replaced by synthetically manufactured growth hormone and contagion is no longer a problem.

Once symptoms appear there is rapid progression of the disorder with progressive loss of brain function. The lesion and deterioration of function is similar to that of senile dementia/Alzheimer’s type, but is distinguished by its very rapid course. There may be a familial tendency to acquire the disorder.

Early symptoms include personality changes and changes in coordination. Extreme dementia is accompanied by muscle tremors and rigid posture.

The virus associated with Creutzfeldt-Jakob disease is rarely ever contagious to humans and primates. Risks include exposure to the virus, directly or indirectly through contact with contaminated equipment or tissues (especially corneal transplant). Other risks include a family history of dementia.

Creutzfeldt-Jacob disease may be related to several other diseases also thought to be caused by prions, including kuru (seen in New Guinea headhunters), scrapie (seen in sheep) and bovine spongiform encephalitis (seen in cows).

Prevention:

Risk of transfer of the organism on equipment or tissue is minimized by the health care provider. Neurological examination and treatment equipment is sterilized to kill organisms that may cause the disease. Medical histories of potential cornea donors that indicate a history of diagnosed or possible Creutzfeldt-Jacob disease rule out the use of those corneas for transplantation.

In many cases, the disorder may not be preventable.

Symptoms:

• personality changes
• hallucinations
• muscle twitching
• muscle stiffness
• nervous, jumpy feelings
• changes in gait (walking, locomotion)
• lack of coordination--stumbling, falls
• speech impairment
• poor enunciation (hard-to-understand speech or mumbling)
• sleepiness
• delirium or dementia develops rapidly
• deterioration in all aspects of brain function
• profound confusion, disorientation

Additional symptoms that may be associated with this disease:

• memory loss
• anxiety, stress, and tension

Signs and Tests:

The history may be significant by the rapid onset and progression of symptoms. Characteristics of the disorder include rapidly progressive dementia, myoclonus (rapid and brief muscle contraction or "jerk"), and rigidity of the body.

A neurological and motor system examination shows muscle twitching and spasm (myoclonus). There is a strong startle response. Muscle tone may be increased, or there may be weakness and muscle wasting (loss of muscle tissue). There may be abnormal reflexes or an increase in response of normal reflexes. Examination of visual fields shows areas of blindness that the person may not realize are present. There is loss of coordination related to visual-spatial perception changes and changes in the cerebellum, the area of the brain that controls coordination (cerebellar ataxia).

An EEG (electroencephalograph, a reading of electrical activity of the brain) shows characteristic changes indicating Creutzfeldt-Jacob disease.

Treatment:

There is no known cure for Creutzfeldt-Jacob disease. Custodial care may be required early in the course of the disease. Medications may be needed to control aggressive behaviors. These include sedatives, antipsychotics, and others.

The need to provide a safe environment, control aggressive or agitated behavior, and meet physiologic needs may require monitoring and assistance in the home or in an institutionalized setting. This may include in-home care or institutionalization. Family counseling may help in coping with the changes required for home care.

Visiting nurses or aides, volunteer services, homemakers, adult protective services, and other community resources may be helpful in caring for the person with Creutzfeldt-Jacob disease.

Behavior modification may be helpful in some cases for controlling unacceptable or dangerous behaviors. This consists of rewarding appropriate or positive behaviors and ignoring inappropriate behaviors (within the bounds of safety). Reality orientation, with repeated reinforcement of environmental and other cues, may help reduce disorientation.

Legal advice may be appropriate early in the course of the disorder, to form advance directives, power of attorney, and other legal actions that may make it easier to make ethical decisions regarding the care of an individual with Creutzfeldt-Jacob disease.

Prognosis:

The outcome is usually very poor. Complete dementia commonly occurs within 6 months or less, with the person becoming totally incapable of self-care. The disorder is fatal in a short time, usually within 7 months, but a few people survive as long as 1 or 2 years after diagnosis of the disorder. The cause of death is usually infection, heart failure, or respiratory failure.

Complications:

• infection
• heart failure
• respiratory failure
• loss of ability to function or care for oneself
• loss of ability to interact with others
• side effects of medications used to treat the disorder (see the specific medication)

Creutzfeldt-Jacob disease is not an emergency disorder, but early diagnosis and treatment may make the symptoms easier to control.