New Technique to Discover Early Alzheimer

A new computerized analysis technique will identify early cellular damage in Alzheimer's disease (AD). "With increasing longevity among the population, the incidence of AD is expected to rise rapidly, creating a great burden not only for patients and their families, but also for society," said Min-Ying Su, Ph.D., author and associate professor in the Department of Radiological Sciences & the Tu and Yuen Center for Functional Onco-Imaging at the University of California. "Our methods may enable earlier diagnosis of AD, allowing earlier intervention to slow down disease progression," she added.

AD provoke damages in cell membranes of the brain neurons and water moves throughout the brain more freely. This stops neural functions and neurons die, but also increases the "apparent diffusion coefficient" (ADC) or water distribution in the brain.

Dr. Su compared elderly patients with mild cognitive impairment (MCI) with control subjects. Patients with MCI are at high risk for developing AD. All the patients underwent magnetic resonance imaging (MRI) of the brain and performed recall tasks.

In patients with MCI, researchers visualized regions of brain atrophy and increased water content. High ADC values were found in the hippocampus, temporal lobe gray matter and the corpus callosum, which connects the two cerebral hemispheres. ADC values in the hippocampus were correlated with worse memory performances."The results have supported our objective to develop a computer-based analysis technique that can analyze different regions in the entire brain, to provide a comprehensive evaluation of cellular changes," Dr. Su said.

ADC values of the different parts of the brain had not been reported till now due to the difficulty of the techniques.

The new technology may allow researchers to learn more about how AD develops in the brain and to propose better treatments based on individual cases of the patients. "Patients with MCI who are very likely to progress to AD may start early treatment interventions, while patients who may remain stable with MCI can be spared from treatment and the associated side effects," added Dr. Su. "The diagnostic accuracy in identifying AD needs to be greatly improved."

AD is the most common form of dementia, affecting more than 4.5 million Americans. Since the initial symptoms manifest, AD patients have an average life expectancy of eight years.

Image: Comparison between an Alzheimer brain (left) and a normal brain (right)