August 22, 2017 – PET Questions


Anchor lead: Many people with a diagnosis of Alzheimer’s disease may not actually have it, Elizabeth Tracey reports

If you’ve been told you have Alzheimer’s disease and are taking medications that may help, it’s possible you really don’t have Alzheimer’s at all. That’s the rather startling conclusion of a study presented recently at the international Alzheimer’s meeting, where PET scanning failed to confirm the diagnosis in a large number of people.  Constantine Lyketsos, an Alzheimer’s expert at Johns Hopkins, agrees that there’s a lot of controversy between the clinical picture and what’s going on in the brain.

Lyketsos: The brain state is where words like Alzheimer’s come into play, characterized by amyloid plaques and tau tangles and so forth. So what we’re struggling with to understand is how the two relate. We know that if you have dementia that’s bad, whether or not you have plaques and tangles. If you have dementia and you don’t have plaques and tangles yes, you do have something else bad we just don’t have the right PET scan to know what it is, or the right stain under the microscope to know what it is.   :26

At Johns Hopkins, I’m Elizabeth Tracey.