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 Half of Alzheimer's cases misdiagnosed 
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Joined: Fri Aug 11, 2006 1:46 pm
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Post Half of Alzheimer's cases misdiagnosed
This blog post by Dr. Sanjay Gupta (of CNN) is about the low diagnostic accuracy rate of Alzheimer's Disease. Over 400 brain autopsies were done on Japanese-American men. "Only about half of those who had a diagnosis of Alzheimer's before death had the brain plaques that signal the disease. The dementia in the other half appeared to have been caused by abnormal protein deposits (known as Lewy bodies), stroke-related tissue death (microinfarcts), cell damage, or some combination thereof."

Why is an accurate diagnosis important? "Ruling out other forms of dementia may help relatives plan for future care and determine their own risk for Alzheimer's, for instance. Accurately diagnosing Alzheimer's is even more critical for research on potential treatments."

As many of you know, I'm a proponent of brain donation. If anyone wants help making these arrangements, I'm happy to volunteer my time to do this. It can never be too early to make these arrangements. A gentleman with a clinical diagnosis of Dementia with Lewy Bodies died this week. His wife and I made the brain donation arrangements nearly two years ago! She was very thankful that she didn't have to stress over these arrangements when her husband's death became imminent or after he died. All went according to plan.

I've copied the short blog post below and a link to it. This news article was posted today to one of the LBD-related Yahoo!Groups.



http://pagingdrgupta.blogs.cnn.com/2011 ... diagnosed/

Paging Dr. Gupta: Blog by Dr. Sanjay Gupta
CNN Health
February 23rd, 2011

Half of Alzheimer's cases misdiagnosed

Roughly half of the people who are told they have Alzheimer's disease may in fact have other forms of dementia that produce similar symptoms, according to a new study.

Doctors have known for some time that the confusion and memory loss caused by the brain lesions associated with Alzheimer's can also be caused by other types of brain changes, such as tissue damage stemming from strokes. The study suggests that it may be even harder than previously thought to identify the source of dementia while a patient is still alive, says lead researcher Lon White, M.D.

"There are at least five different kinds of important lesions which can produce a picture that looks like Alzheimer's," says White, a professor of geriatric medicine at the University of Hawaii in Honolulu. "Each of those five kinds of lesions is apparently driven by its own pathologic process, and having one doesn't protect you from having others. All are independent and all are increasing with age."

White and his colleagues performed brain autopsies—the only surefire way of diagnosing Alzheimer's—on more than 400 elderly Japanese-American men. Only about half of those who had a diagnosis of Alzheimer's before death had the brain plaques that signal the disease. The dementia in the other half appeared to have been caused by abnormal protein deposits (known as Lewy bodies), stroke-related tissue death (microinfarcts), cell damage, or some combination thereof.

The researchers have since completed another 400 or so autopsies with similar results, and will present their findings in April at the annual meeting of the American Academy of Neurology. Unlike studies published in medical journals, these findings are still preliminary and have yet to be thoroughly vetted by other experts in the field.

An Alzheimer's misdiagnosis doesn't have immediate consequences for the patient because no treatments exist that can stop the steady progression of the disease. And the drugs that, in some people, help slow Alzheimer's or make it more tolerable appear to work for other types of dementia, White says.

Patients and their families can nevertheless benefit from an early and accurate diagnosis. Ruling out other forms of dementia may help relatives plan for future care and determine their own risk for Alzheimer's, for instance.

Accurately diagnosing Alzheimer's is even more critical for research on potential treatments. Without knowing precisely who has Alzheimer's, pharmaceutical companies that have been developing new drugs "are not going to be able to see a true assessment of how effective their drug is," White says.

Some promising advances in diagnosis have been made recently. A study published last year found that spinal fluid tests can predict Alzheimer's with a high degree of accuracy, and the Food and Drug Administration is currently weighing the approval of a brain scan that uses dye to highlight the plaques characteristic of Alzheimer's. The reliability of these methods needs to be confirmed, however.

"Everybody knows we need to do a better job of diagnosing," says Maria Carrillo, Ph.D., the senior director of medical and scientific relations at the Alzheimer's Association, a research and advocacy organization based in Chicago. "We are all trying to make that diagnosis better, earlier, faster. All of those things are currently under way in terms of research study."


Fri Feb 25, 2011 1:48 am
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Post Re: Half of Alzheimer's cases misdiagnosed
Well, that is interesting, Robin, since, as you have reported, fewer than half of the brain autopsies of those diagnosed with LBD turn out to have it, instead having AD, etc. And so now we find that half of those diagnosed with AD actually have Lewy?

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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 Feb 25, 2011 11:19 am
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Post Re: Half of Alzheimer's cases misdiagnosed
I wouldn't say half of those diagnosed with AD actually had Lewy Body Disease. Certainly some percentage of the misdiagnosed had Lewy Body Disease but they also had Vascular Dementia, etc.


Fri Feb 25, 2011 12:29 pm
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Post Re: Half of Alzheimer's cases misdiagnosed
The bottom line is certainly TOTAL confusion. If I were a neurologist, I would be extremely reluctant to 'name' the condition regardless of the signs and symptoms. Since the meds given are so varied for the many different forms of this disease, it's no wonder we're all experimenting!

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


Fri Feb 25, 2011 5:23 pm
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Post Re: Half of Alzheimer's cases misdiagnosed
This is quite true. We have many neurologists locally who will say only things like "you are dealing with dementia" or "you are dealing with parkinsonism." They are reluctant to specify the disorder until quite late in the disease course when more distinguishing symptoms pop up. But confusion can also increase later on because the symptoms that can appear late in the disease course occur in multiple diseases. (Example: late-stage AD patients can get hallucinations.)


Fri Feb 25, 2011 5:35 pm
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Post Re: Half of Alzheimer's cases misdiagnosed
Do AD and PD patients react to meds the way LBD patients do? If not, I guess if I were a neurologist, I would err on the side of diagnosing LBD just so that patients didn't get the meds that are so harmful to LBD patients.

Julianne


Fri Feb 25, 2011 5:52 pm
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Post Re: Half of Alzheimer's cases misdiagnosed
The approximate 'stages' list that has circulated gives the impression that hallucinations are less at the late stage. Even though he can't sit, stand, or walk unaided and cannot feed himself, Dale's delusions and hallucinations are constant. I rarely pay much attention to what he says these days because his world is far from reality.

Is this common to all the 'dementia' conditions?

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


Fri Feb 25, 2011 5:53 pm
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Post Re: Half of Alzheimer's cases misdiagnosed
"Do AD patients react to meds the way LBD patients do?"

This is my layperson opinion... I wouldn't even say that there's a standard way that LBD patients react to meds. Generally speaking, LBD patients *do better* with AChEIs than AD patients do. Probably as many AD patients as LBD patients react negatively to anticholinergics. Half of LBD patients have a bad reaction to neuroleptics; half do not. Presumably some number -- less than half -- of AD patients have a bad reaction to neuroleptics.


Fri Feb 25, 2011 8:46 pm
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Post Re: Half of Alzheimer's cases misdiagnosed
Thanks, Robin, for the clarification.

Julianne


Fri Feb 25, 2011 8:51 pm
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Post Re: Half of Alzheimer's cases misdiagnosed
"Do PD patients react to meds the way LBD patients do?"

This is my layperson opinion... This is a somewhat challenging question to answer because an argument can be made that (much of) LBD *is* PD. Ignoring that linkage, my answer would be as follows. Generally speaking, PD patients and LBD patients both react negatively to typical neuroleptics. Half of LBD patients react negatively to any type of neuroleptic. Presumably fewer -- less than half -- of PD patients react negatively to any type of neuroleptic. Those with LBD should have a worse reaction to anticholinergics than those with PD but lots of elderly without dementia don't tolerate anticholinergics. Certainly those with PD tolerate dopaminergic meds, as a general rule. Those with PDD probably tolerate these meds not quite as well in the sense that these meds cause psychosis. And those with DLB have no sustained response to dopaminergic meds or don't tolerate them (due to the psychosis problem).


Fri Feb 25, 2011 8:53 pm
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