Screening & Detection Tests for Alzheimer's Disease: The Benefits & Costs

Opening Announcer:
You're listening to ReachMD. Uncover the truth about Alzheimer's in this special series, Alzheimer's Disease: Towards Earlier Detection.

Dr. Matt Birnholz:
Welcome to the ReachMD series Alzheimer’s Disease: Towards Earlier Detection. I’m Dr. Matt Birnholz. On this episode, we catch up with Dr. Douglas Scharre, Professor of Clinical Neurology and Psychiatry with the Center for Cognitive and Memory Disorder at The Ohio State University Wexner Medical Center. Dr. Scharre speaks to the methods used for early detection of Alzheimer’s Disease, and their respective advantages in practice.

Dr. Douglas Scharre:
Early detection for Alzheimer’s disease is going to be very important, particularly if we develop more disease-modifying agents, which work better the earlier you identify it.  So we have some very specific ways to identify Alzheimer’s disease based on amyloid and tau that build up in the brain of these patients.  So we have spinal fluid biomarkers, as you know, tau and amyloid that we can test that sometimes can be detected many years before you may forget your keys for the first time. Spinal fluid, however, is somewhat invasive, there is a significant expense to it, and so these are some of the barriers of using those tests early on. 

Neuroimaging, we have great amyloid imaging tests on PET.  We have fluorodeoxyglucose PET that can help differentiate Alzheimer’s, perhaps, from frontotemporal dementias.  If we see amyloid in the brain of PET scans, this is a fairly specific test that might suggest they have an amyloid condition and would suggest that Alzheimer’s is more likely than not.  Again, neuroimaging is very expensive and with PET images, of course, there is radiation exposure, so there is some safety concerns with that.

And so, I think, in the future we are going to have to have an individual that comes in with some cognitive complaint or a family member saying they have had some decline in cognitive abilities.  And we will start with the inexpensive tests first, I would imagine, and as this is what we do at our center.  So we do screening of cognitive complaints.  These are pen and paper tests, brief evaluations.  There are many that are out there and available that one can use to help decide, “no they are doing really well, let’s just recheck them in a year or two,” or “gosh, there seems to be some issues here with cognition.  Let’s ask the caregiver, they have been noticing some issues as well.”  So that would make us decide, let’s get some further evaluation. Let’s maybe exclude other conditions of cognitive impairment and, perhaps, even proceed with more expensive tests for the diagnosis of Alzheimer’s disease with the use of, perhaps, CSF biomarkers or neuroimaging.

Dr. Matt Birnholz:
That was Dr. Douglas Scharre from The Ohio State University Wexner Medical Center. For access to continuing episodes of Alzheimer’s Disease: Towards Earlier Detection, visit our series page at ReachMD.com. Thanks for joining us.

Closing Announcer:
You've listening to ReachMD. Uncover the truth about Alzheimer's in this special series, Alzheimer's Disease: Towards Earlier Detection. To revisit any part of this discussion and to access other episodes visit ReachMD.com/timehidesalzheimers. Thank you for listening.