Adding up the Statistics: 60% of All Dementia Patients Have Lewy Body Dementia!

We still hear Lewy body dementia refered to as a "rare dementia."  However, in his recent article, Confronting 100 Years of Confusion about Lewy Body Dementia, Dr. James Leverenz, University of Washington, Seattle, states, “… up to half of Alzheimer’s disease patients have the “Lewy body variant” [Lewy bodies in the brain upon autopsy] … and most Parkinson’s disease patients develop dementia….” Here are some statistics:

• 60-80% (let’s say 70%) of all dementia patients have Alzheimer’s. (Alz. Assn.)
• 20% of all dementia patients are diagnosed with a Lewy Body Dementia. (LBDA.org)
• Many  Parkinson’s patients develop dementia but never see a dementia specialist and are not included in the LBD statistics.

For the percentage of all dementia patients with LBD, we can add: 

• the approximately 35% of dementia patients with both AD and LBD, per Dr. Leverenz,
• the 20% of those diagnosed with LBD,
• and a very conservative 5% for the unidentified number of Parkinson’s patients with undiagnosed LBD.

That's a conservative 60%. We can safely say that LBD is no longer rare.

Thoughts about PiB, a PET scan compound

We attended the Arizona Alzheimer’s Consortium Scientific Conference today. Our keynote speaker was Dr. W. E. Klunk, the inventor of PiB, a compound used with PET scans to identify Alzheimer’s plaques. Most of the information was way over our heads but we did come away with some thoughts:

1. When Dr. Klunk talked about comparing the results of PiB scans with later autopsy results, we learned that if PiB finds plaques, there’s a 97% chance of AD* on autopsy. Since Lewy bodies do not show up on a PiB scan, one would hope that it could be used to differentiate AD and LBD. You know, if the scan shows plaques, the dementia is AD and if it doesn’t show plaques, the dementia is likely LBD. Not so, because 24% of the time, a PiB scan doesn’t find plaques that do show up later on autopsy.

2. And here are some more statistics. According to Dr. Klunk, autopsies show that 40% of AD patients also have Lewy bodies—and that 80% of DLB* patients will have AD. (We also learned that is unusual for a patient with PDD* to have AD pathology—but this is another, if equally interesting issue, to be discussed in a later entry.) Therefore, even if the PiB worked perfectly, i.e., identified all patients with AD, there would still be many patients with accompanying, but unidentified, LBD.

For LBDers, these figures are sad. It means that because AD is known so well, many physicians will stop at diagnosing the AD and the accompanying LBD may never be diagnosed. Or it is diagnosed only after a serious reaction to some medication that would never have been given to someone with known LBD.

* Acronyms:

AD: Alzheimer's disease

DLB: Dementia with Lewy bodies (the LBD where demenia appears first)

PDD: Parkinson's with dementia (where Parkinson's appears first)

Welcome to our blog. We're new at this but we hope to share some of the information we've learned in our journey with Lewy body dementia. Just a little history first:

Jim became aware of this disorder in 1999, when his first wife, Anique, was diagnosed with Alzheimer's. Jim researched it on the internet and found that her symptoms better fit something called "Lewy body disease." In 2003, he and some other LBD caregivers started the Lewy Body Dementia Association (lbda.org). I didn't join the bandwagon until 2005, when she married Jim. A retired nurse, educator, writer and artist hopeful, I added another dimension to Jim's mission and we started doing programs about LBD, and eventually wrote a book, Riding a Rollercoaser with Lewy Body Dementia. And in 2010, we wrote A Caregiver's Guide to Lewy Body Dementia, published by Demos Medical Publishing. Now we have perfected a system whereby care facilities can easily do the programs we have been doing for years. You can find out about our LBD Training Kit at lbdtools.com.