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 More Alzheimer-type pathology in DLB than PDD 
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Joined: Fri Aug 11, 2006 1:46 pm
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Post More Alzheimer-type pathology in DLB than PDD
"Lewy body dementia" is an umbrella term that includes Parkinson's Disease Dementia (PDD) and Dementia with Lewy Bodies (DLB). If someone has had parkinsonism symptoms for a year or more, then the diagnosis is PDD. Otherwise, it's DLB. The diagnostic accuracy of DLB is quite low but the diagnostic accuracy of PDD is quite high.

This Japanese research is an attempt to explore what pathological differences there may be in DLB and PDD. They found differences in the distribution of amyloid-beta (one aspect of "Alzheimer-type pathology") in the brain. Not surprisingly, DLB brains had amyloid-beta in more places.

"[There] was no difference in neurofibrillary tangle (NFT) Braak stages or in Lewy body scores." (NFT Braak stages is another aspect of "Alzheimer-type pathology".)

After dividing the cases into whether dementia or parkinsonism occurred first, researchers found that in those cases where dementia occurred first there was a greater distribution of amyloid-beta.

"These results suggest that amyloid deposition may contribute to the timing of the onset of dementia relative to that of parkinsonism in Lewy body dementia."

Robin



Neuroscience Letters. 2010 Dec 3;486(1):19-23. Epub 2010 Sep 17.

Distribution of cerebral amyloid deposition and its relevance to clinical phenotype in Lewy body dementia.

Fujishiro H, Iseki E, Higashi S, Kasanuki K, Murayama N, Togo T, Katsuse O, Uchikado H, Aoki N, Kosaka K, Arai H, Sato K.
PET/CT Dementia Research Center, Juntendo Tokyo Koto Geriatric Medical Center, Juntendo University School of Medicine, Tokyo. Japan.

Abstract
Parkinson's disease dementia (PDD) and dementia with Lewy bodies (DLB) are clinically distinguished based only on the duration of parkinsonism prior to dementia. It is known that there is considerable pathological overlap between these two conditions, but the pathological difference between them remains unknown.

We evaluated Alzheimer-type pathology in 30 brains of patients with Lewy body dementia using standardized methods based on those of the Brain-Net Europe (BNE) Consortium.

Only 2 of 13 PDD cases (15%) showed Aß-immunoreactive pathology in the midbrain (amyloid phase IV). In contrast, 12 of 17 DLB cases (71%) exhibited midbrain involvement.

Four of the DLB cases (24%) but none of the PDD cases exhibited Aß-immunoreactive pathology in the cerebellum (amyloid phase V).

The ratio of cases with subtentorial involvement of amyloid deposition was significantly higher in DLB than in PDD.

The median of amyloid phases was significantly greater in DLB than in PDD, but there was no difference in neurofibrillary tangle (NFT) Braak stages or in Lewy body scores.

When patients were classified according to whether dementia or parkinsonism had occurred first, the rate of dementia having occurred first was significantly greater in amyloid phase IV and V than in phase 0-I, with phase III in the middle, though there was no significant difference in median NFT Braak stage or mean Lewy body score associated with amyloid phase.

These results suggest that amyloid deposition may contribute to the timing of the onset of dementia relative to that of parkinsonism in Lewy body dementia.

Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

PubMed ID#: 20851165 (see pubmed.gov for this abstract only)


Thu Oct 28, 2010 8:44 pm
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Joined: Wed Oct 28, 2009 11:53 am
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Location: Ocala, FL
Post Re: More Alzheimer-type pathology in DLB than PDD
Robin - please explain 'Alzheimer-type pathology.'

Dale has never had typical Parkinson's movement problems. His sleep walking came first long ago and then dizziness followed by hallucinations. He has confusion occasionally but I would not characterize that as a problem with memory. He proof reads my writing for spelling errors. His memory is often better than mine.

All of this doesn't add up to Parkinson's or Alzheimer's. Is there another category of dementia?

In the end, perhaps there will be many more sub-categories of this disease... right?

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Leone Carroll (75); wife of Dale (75) who passed away March 23, 2011


Fri Oct 29, 2010 8:21 am
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Post Re: More Alzheimer-type pathology in DLB than PDD
There are two Alzheimer's type pathologies -- amyloid plaques and neurofibrillary tau tangles.

There are many, many types of dementia. The Alzheimer's Association website (alz.org) or the Family Caregiver Alliance website (caregiver.org) probably has a good description of the top 10 dementias.

Have you looked at the diagnostic criteria for DLB? It's listed on lbda.org. Hallucinations are a supportive feature but not a core feature. Parkinsonism is not required.

Memory problems don't occur in "pure DLB." Pure DLB is DLB without Alzheimer's.

Does your husband have RBD (REM sleep behavior disorder)?

I don't think there are sub-categories of LBD. There are 3 different presentations possible, and your husband seems to have the neuropsychiatric one.


Fri Oct 29, 2010 11:30 am
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Post Re: More Alzheimer-type pathology in DLB than PDD
Yes, Robin.... Dale has been a sleep walker since his 20s. He acts out his dreams regularly. Isn't that REM sleep behavior disorder? Is there a connection between that and dementia?

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Leone Carroll (75); wife of Dale (75) who passed away March 23, 2011


Fri Oct 29, 2010 12:13 pm
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Post Re: More Alzheimer-type pathology in DLB than PDD
Quote:
Memory problems don't occur in "pure DLB." Pure DLB is DLB without Alzheimer's.
Since these Lewy bodies occur anywhere in the brain, why should this be so?

And, the LBDA has this on the symptoms page:
Quote:
Core features:

* Fluctuating cognition with pronounced variations in attention and alertness.
* Recurrent complex visual hallucinations, typically well formed and detailed.
* Spontaneous features of parkinsonism.
It would appear that parkinsonian symptoms are a core feature.

_________________
Pat [68] married to Derek [84] for 38 years; husband dx PDD/LBD 2005, probably began 2002 or earlier; late stage and in a SNF as of January 2011. Hospitalized 11/2/2013 and discharged to home Hospice. Passed away at home on 11/9/2013.


Fri Oct 29, 2010 12:23 pm
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Post Re: More Alzheimer-type pathology in DLB than PDD
mockturtle -

Re: memory problems
You seem to be equating memory problems with Lewy bodies. Those with AD, where memory problems are severe, have amyloid plaques and NFTs. This pathology is in the hippocampus, the memory center of the problem.

Re: core features
Right, parkinsonism is a core feature but it is NOT required. You need the central feature plus two core features to have a diagnosis of probable DLB or probable PDD.

Robin


Fri Oct 29, 2010 1:47 pm
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Post Re: More Alzheimer-type pathology in DLB than PDD
Leone,

RBD can only be diagnosed via a sleep study.

RBD is highly associated with alpha-synuclein disorders, which include PD (no dementia), MSA (no dementia), PDD (dementia), and DLB (dementia). There is a lot posted here on the Forum on this topic.

Robin


Fri Oct 29, 2010 1:50 pm
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Post Re: More Alzheimer-type pathology in DLB than PDD
This article certainly implies that Lewy Bodies can form in the hippocampus: http://www.pnas.org/content/96/23/13450.full

And this more recent article: http://www.ncbi.nlm.nih.gov/pubmed/18467130

_________________
Pat [68] married to Derek [84] for 38 years; husband dx PDD/LBD 2005, probably began 2002 or earlier; late stage and in a SNF as of January 2011. Hospitalized 11/2/2013 and discharged to home Hospice. Passed away at home on 11/9/2013.


Fri Oct 29, 2010 2:09 pm
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Post Re: More Alzheimer-type pathology in DLB than PDD
Severe memory impairment is NOT associated with Lewy Body Dementia. (Those with LBD often do very well on the MMSE, which is largely a test of memory.) Severe memory impairment is associated with Alzheimer's Disease.


Fri Oct 29, 2010 2:20 pm
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Post Re: More Alzheimer-type pathology in DLB than PDD
But you did say that:
Quote:
Memory problems don't occur in "pure DLB." Pure DLB is DLB without Alzheimer's.

Most of the research articles I have read would disagree. I do agree that 'severe' memory problems, or memory deficit as an early or primary symptom is associated more with AD. And another difference that I have personally observed is that, with AD, the memory seems to be irretrievable, once lost, whereas with Lewy it can be gone one day and back the next.

_________________
Pat [68] married to Derek [84] for 38 years; husband dx PDD/LBD 2005, probably began 2002 or earlier; late stage and in a SNF as of January 2011. Hospitalized 11/2/2013 and discharged to home Hospice. Passed away at home on 11/9/2013.


Fri Oct 29, 2010 2:54 pm
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Post Re: More Alzheimer-type pathology in DLB than PDD
Sorry, I'm not getting your point. I'm ready to let this to-and-fro end on the topic of Alzheimer-type pathology in DLB and PDD.


Fri Oct 29, 2010 4:12 pm
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Post Re: More Alzheimer-type pathology in DLB than PDD
Thanks, Robin, for setting me on the track of trying to understand why Dale seems different from the others suffering this disease in so many ways. He is a retired attorney and that may explain his curiosity. He once had a very sharp mind. In fact, it was a very creative mind.

Even at this point, he has delusions and hallucinations but later, he remembers what he thought was true and is puzzled by his own strange thinking. He is a remarkable man.

He still reads a great deal and I've printed out some of the material you've recommended.
So thank you very much.

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Leone Carroll (75); wife of Dale (75) who passed away March 23, 2011


Fri Oct 29, 2010 7:00 pm
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