Alzheimer’s disease is the sixth leading cause of death in the US, affecting more than 5 million Americans. But researchers from the Mayo Clinic in Florida say they have identified a subtype of the disease that is often misdiagnosed.
The research team, led by Dr. Melissa Murray, an assistant professor of neuroscience at the Mayo Clinic, says their study suggests that around 600,000 Americans may have this variant, which they call “hippocampal sparing” Alzheimer’s disease.
To reach their findings, recently presented at the American Academy of Neurology’s Annual Meeting in Philadelphia, PA, they analyzed 1,821 brains with confirmed Alzheimer’s disease.
All subtypes of Alzheimer’s have two specific hallmarks in the brain. Amyloid beta is responsible for the formation of brain plaques, while tau produces tangles in the brain.
In order to classify each subtype, the team used tangle counts to create a mathematical algorithm. They found that while all Alzheimer’s subtypes had the same amount of amyloid beta, the hippocampal sparing variant showed tau tangles in unequal areas of the hippocampus.
Dr. Murray further explains the findings in the video below: