Alzheimer’s disease claims tens of thousands of American lives each year. A positive diagnosis, of the disease, is a process of eliminating all other possible causes with an incorrect diagnosis estimated to occur 10% of the time. It is only after someone dies can a pathologists examine slices of the brain under a microscope to positively identify the disease.

Eugene Hanlon, researcher, Bedford, Massachusetts, and collaborators at Harvard Medical School/Beth Israel Deaconess Medical Center and Boston University, have developed a way to examine living brain tissue with near-infrared light to detect signs of Alzheimer’s disease.

For several years the researchers looked at the possibility of analyzing the brain with near-infrared light. Near-infrared light safely passes through the skull, then scatters. It is how the near-infrared light scatters that indicates the presence of Amyloid plaques–a telltale sign of Alzheimer’s disease.

Near-infrared can detect alterations to the optical properties of the brain as the tissue undergoes microscopic changes due to Alzheimer’s–sometimes far in advance of clinical symptoms. This technique is now being tested for its effectiveness at diagnosing Alzheimer’s disease in living people.