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.