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I sent thisearlier but I don't think it went through... "Brain Mammogram" May Detect Parkinson's Before Symptoms Begin July 2, 1999 (Medical Tribune) - A widely available brain scan used in conjunction with an experimental drug may identify Parkinson's disease early, before there are any symptoms, a preliminary study suggests. Detecting the disease in its early stages with this ``brain mammogram'' may help stop the illness in its tracks, if drugs under development prove effective in preventing symptoms like tremors and rigid movement, the study's authors report. ``For every case of Parkinson's disease in the elderly, it's estimated that there are 10 presymptomatic cases walking around,'' according to the lead investigator, Dr. Demetrius M. Maraganore, an associate professor of neurology at the Mayo Clinic in Rochester, Minn. ``Our concern is that as the population continues to live longer, more and more of these cases will become symptomatic.'' ``We have a challenge before us'' to detect Parkinson's, which is a progressive and degenerative neurological disease, before it causes symptoms, he said. People with Parkinson's disease have a severe shortage of a brain chemical called dopamine. The chemical, which is a neurotransmitter, is essential for certain brain cells involved in controlling movement. A decline in dopamine levels causes these brain cells to degenerate. When a person takes a dose of beta CIT, the radioactive medication used in the study, it binds to these dopamine-dependent brain cells, according to Maraganore. Using a scan called single-photon emission computed tomography (SPECT), the researchers were able to detect beta CIT in the brain. Low levels of beta CIT signify deterioration in the section of the brain known as the striatum. Not surprisingly, levels of visible beta CIT were lower in 10 people with Parkinson's disease than in 10 people without the disease or in a control group of 10 people who had a family history of Parkinson's, the researchers reported in the July issue of Mayo Clinic Proceedings. But beta CIT levels i n the family history group were lower than in the control group, leading Maraganore and his colleagues to suspect early stages of Parkinson's. And levels were lower in family members who had the greatest risk of developing the disease, either because they had more than one relative with Parkinson's or because they had at least one symptom. In order for a person to be diagnosed with Parkinson's disease, at least two major symptoms must be present, according to Maraganore. The Minnesota neurologist estimated that about 3 percent of the population will develop Parkinson's disease. However, the risk triples when one close relative has the illness and jumps to 30 percent if two relatives are affected, he said. Maraganore called the detection procedure a ``kind of mammography of the brain.'' Just as early detection of breast cancers often results in more promising treatment, he said he hopes that the same may be true with Parkinson's one day soon. Although another test known as PET can detect early signs of Parkinson's disease, it is only available in a handful of research centers around the country, he noted. On the other hand, most large medical centers already have SPECT cameras, he said. Beta CIT has not been approved by the federal Food and Drug Administration. Its maker, Guilford Pharmaceuticals, provided funding for the current study, as did the Mayo Foundation and the National Institute of Neurological Disorders and Stroke. Using SPECT and beta CIT to detect Parkinson's ``might be very important'' in the future, commented Dr. William G. Ondo, an assistant professor of neurology at Baylor College of Medicine in Houston. But for the test to be useful, drugs under development that aim to prevent the damage caused by the disease will have to be proven effective, he cautioned. Assuming such treatments do work, then early detection will be essential for preventing symptoms, according to Maraganore. Unfortunately, most of such drugs are in ``the pipe-dream stage,'' said Dr. Caroline M. Tanner, the director of clinical research and patient services at the Parkinson's Institute in Sunnyvale, Calif. So far, no one has been able to stop or slow down Parkinson's disease, she noted. And while Tanner said the study is ``a step in the right direction,'' she cautioned against reading too much into the findings. ``We need to be really careful,'' she noted, since whether the high-risk people in the study definitely will develop Parkinson's disease remains to be seen. A brief summary of the research is available on the Web at http://www.mayo.edu/pub-rst/proceedings/jul1999.html. Mayo Clinic Proceedings (1999;74:) Copyright 1999 The Medical Tribune News Service. All rights reserved. ©1996-1999 Inteli-Health, Inc.