March 1, 2006 Using new computer software that analyzes EEG data, psychiatrists can now better distinguish early signs of Alzheimer's from normal aging, by spotting marked differences between the left and right sides of the brain. Diagnosing Alzheimer's early can be vital because new drugs can now slow the progression the disease. The new technique is cheaper and less invasive than using MRIs or PET scans for the same diagnosis.
NEW YORK CITY--Alzheimer's is a devastating illness affecting 4 million Americans and their families. Would you want to know if Alzheimer's is in your future? Now, a new twist to a common and inexpensive test may tell relatives if they, too, will suffer from the mind-altering disease.
Beth Cenicola's and her sister Dianne Burke's mother has Alzheimer's. They remember her as someone who loved to go places and do things. At 94, however, their mother has been battling Alzheimer's for eight years. "The hardest part is seeing your mother and knowing that she doesn't know who you are," Beth says.
Both sisters are getting a basic EEG scan as part of a new test that will predict if Alzheimer's is in their futures.
Leslie Prichep, an associate director of the Brain Research Laboratories of the Department of Psychiatry at New York University School of Medicine, says, "Going from the squiggly lines to a description of those events, we are then comparing those numbers to the expected numbers for the age of the individual."
Using new computer software that converts the EEG scan into numbers, psychiatrists can more easily determine normal aging vs. early signs of dementia. For instance, the left EEG shows the left and right sides of the brain are normal size, shape and similar between regions, suggesting no dementia. The right EEG, however, shows big differences between left and right sides -- indicating signs of future dementia. Prichep says this is significant, because there are now drugs that show to be very useful in stopping and slowing the progression of dementia.
Beth says she is getting the test done because she doesn't want her children to go through what they are going through. She wants a chance to change the future.
Currently, MRIs and PET scans can also detect future dementia, but they are much more invasive and expensive. The seven-year NYU study revealed the program is 95 percent accurate in predicting decline.
Researchers are expanding their study, running the new program through its database of thousands of elderly patients' records.
BACKGROUND: A new study demonstrates that the earliest hints of Alzheimer's disease, when the first signs of memory loss appear, can be screened with a less inexpensive, painless and easy-to-use tool called an EEG, combined with computer software. The ability to identify the disease at its earliest stages could enable treatment to delay or prevent its progress from memory loss into dementia.
HOW IT WORKS: An electroencephalogram (EEG) measures the brain's electrical activity. Electrodes are attached to the scalp and the electrical signals coming form the brain are recorded and analyzed by a computer. Brain cells make very weak electrical signals, so the equipment amplifies them more than ten thousand times in order to see the patterns of the brain's electrical rhythms. EEGs look like a mass of squiggly lines to the untrained eye, but those lines are actually mathematical descriptions of the electrical signals based on how their amplitude and frequency changes over time.
WHAT THEY FOUND: The NYU researchers were able to determine which EEG lines indicated normal aging and which ones indicated dementia or early Alzheimer's. Then they developed a computer program to help other doctors detect the same patterns. Their method proved almost 95 percent accurate in identifying those who would decline in terms of brain function, and those who would not. For instance, a brain wave called theta was much more prominent in people likely to decline, and was especially abnormal in the frontal regions of the brain. Theta brain waves originate in the hippocampus, a brain region that has been shown to be impaired in dementia.
WHAT'S NEXT: The new EEG method will likely become an important tool in evaluating someone's likelihood for developing Alzheimer's disease. But before that can happen, the NYU results must be replicated with similar results, repeatedly, in much larger studies in order to validate the method for widespread use. This requirement for reproducibility and constant retesting is a benchmark of the scientific method.
Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.