Magnetic Resonance Imaging May Predict Alzheimer's Disease
25 Apr, 2007 11:39 am
The "holy grail" of Alzheimer's disease research is prevention. For prevention of Alzheimer's disease we need two components: a way of detecting normal people at high risk of later having Alzheimer's disease symptoms, and treatments to prevent the symptoms from occurring at all.
By combining information from magnetic resonance images of the brain and results of memory testing, the investigators could predict that normal persons would later develop symptoms of Alzheimer's disease with 87% accuracy. If the prediction is proven valid with further studies, new treatments in development which may slow the disease could be given to high-risk persons to prevent symptoms.
One hundred thirty-six normal persons in the research study had magnetic resonance imaging of the brain and extensive memory testing in 1999. Every year for the next five years they underwent medical examinations and extensive memory testing. Twenty-three of the original group developed early symptoms of Alzheimer's disease during this time. The grey matter in the hippocampus, and other structures in the temporal lobe of the brain known to be involved in memory formation, was decreased in this group of 23 compared to grey matter in the same regions of the 113 who remained normal. Based on the magnetic resonance imaging measurement of grey matter alone, the researchers could predict memory loss with 76% accuracy. By combining imaging with results of Weschler memory scale testing scores, accuracy rose to 87%. The study was sponsored by the National Institute on Aging (http://www.nia.nih.gov/) Alzheimer's Disease Centers Program. The study principal investigator was Charles D. Smith, MD, director of the University of Kentucky Magnetic Resonance Imaging and Spectroscopy Center (http://www.mc.uky.edu/mrisc/).
To use these results for prevention research trials, the next step is to predict symptoms in a group of normal subjects based on their scans, and then show how well the prediction works in practice. Other potential markers of Alzheimer's risk, such as other types of scans, apolipoprotein-E gene status, spinal fluid analysis, beta-amyloid in blood, and memory testing could be combined in these follow-up studies to improve prediction.
The study provides hope that we will one day be able to predict, delay the onset and even prevent memory symptoms in Alzheimer's disease.
C. D. Smith et al., journal of the American Academy of Neurology, April 17, 2007