Ask the Doctors: Creutzfeldt-Jakob disease unknown to many

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Q: Could you please explain Creutzfeldt-Jakob disease? Some people call it "mad cow disease," which gives it a stigma. I lost my twin brother to this disease, and it's left our family shattered.

A: I am truly sorry for your loss. My family also lost a loved one to this devastating disease. We could only watch helplessly as it quickly took away all vestiges of the person we once knew.

For those unfamiliar with it, I'll explain: Creutzfeldt-Jakob disease (CJD) is the most common prion disease in humans. (The others are predominantly found outside the United States.) Prions are infectious, but they're not viruses or bacteria; they're proteins. They appear to be created from normal proteins found on cell membranes. The normal proteins may help inhibit cell death, but in prion diseases, they reconfigure. This initial change is believed to be related to an external agent, possibly a virus, chemical or drug, in 85 to 95 percent of patients and to a genetic cause in 5 to 15 percent of patients.

The term "mad cow disease" is actually a misnomer, because the majority of cases are not related to prion transmission between cows and humans. It can happen, of course, such as the 1990s outbreaks in the United Kingdom that led to the term. But these animal-to-human transmissions of prions, termed Variant Creutzfeldt-Jakob disease, are very rare. Even more rare is human-to-human transmission via transplanted livers, cornea and brain tissue.

Regardless of the cause, exposure to abnormal prions leads to a cascading effect -- the creation of more abnormal prions that disrupt nerve cells' function and lead to their death. This destruction causes holes within the brain tissue, leaving it with a spongelike appearance.

The disease initially interferes with concentration, memory and judgment and leads to episodes of sleep throughout the day. In terms of mood, a person may at first seem neglectful, apathetic and depressed, quickly giving way to unrelenting mental deterioration. Patients eventually develop dementia and can lose the ability to control muscle movements, resulting in twitching or jerking contractions of the muscles. Progression is slower for people younger than 50, but regardless, death usually occurs within one year of symptom onset, with an average time to death of six months.

The only positive in this scenario is that CJD is rare, affecting one in a million people per year.

Many other diseases can initially appear similar to CJD, which is diagnosed with an assessment of symptoms, aided by electroencephalograms (EEGs) and MRIs of the brain. Protein markers in spinal fluid can also help. But the best way to definitively diagnose CJD is to look at brain tissue, most often done at autopsy.

As you already know, there is no good treatment for CJD. Flupirtine, a drug available in Europe, can protect cognitive function to some degree, but does not alter survival. Quinacrine and chlorpromazine can inhibit the formation of abnormal prions but have not shown an ability to stop the disease.

That isn't to say research has stopped, only that it hasn't made huge strides. Everyone who has watched anyone suffer with CJD is hoping science can ultimately find a way to treat this terrible disease. In the meantime, we can all help educate others as to the real nature, and name, of Creutzfeldt-Jakob disease.

Robert Ashley, M.D., is an internist and assistant professor of medicine at the University of California, Los Angeles. Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.

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