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PET scans show many Alzheimer’s patients may not actually have the disease

washingtonpost.com

21–30 of 68 posts

Re: PET scans show many Alzheimer’s patients may not actually have the disease

#21
post #18

Earlier quoted context omitted.

why does an IV bag cost $500? I want professional operators and physicians to look at my details. What I don't want is dozens of layers of middlemen or ticket clippers (or healthcare driven by profit).

> why does an IV bag cost $500? It doesn't outside of the US.

Indeed. In the US, it does because manufacturers have gamed the system. Through bundled contracting with hospitals etc, for example.

Re: PET scans show many Alzheimer’s patients may not actually have the disease

#22
I suspect that AD diagnoses are driven largely by caregiver frustration with unhappy old people. Just as ADHD etc diagnoses are arguably driven by caregiver frustration with unhappy young people. The simplest solution is drugging unhappy people to keep them manageable.

Re: PET scans show many Alzheimer’s patients may not actually have the disease

#25
post #18

Earlier quoted context omitted.

why does an IV bag cost $500? I want professional operators and physicians to look at my details. What I don't want is dozens of layers of middlemen or ticket clippers (or healthcare driven by profit).

> why does an IV bag cost $500? It doesn't outside of the US.

Doesn't at Kaiser either. You just get all that stuff under a single line item "Emergency Room visit Level 2: $650". Funny how that happens when the hospital and the insurance are the same company.

Re: PET scans show many Alzheimer’s patients may not actually have the disease

#26

Does that invalidate any studies on treatments for Alzheimer? If it turns out many people who show symptoms don't actually have it, it's no wonder that a treatment is so hard to find.

There seem to be a lot of loose ends in this article: how many of these patients will go on to develop Alzheimer's? On what basis are the current treatments for Alzheimer's considered to be effective, if we did not previously have a test to determine who has developed it? On what basis would the physicians whose patients were enrolled in this study change their care plans, and in what way? At one point, the article s…

Not an expert, but I read Derek Lowe's blog[1] and he tends to report on pretty much all the drug trials in the Alzheimer's space.

The amyloid hypothesis (that the cause of Alzheimers is the buildup of beta amyloid plaques) seems pretty weak at this point. The drugs that remove or reduce amyloid buildup don't seem to stop the progression of the disease. The current best guess seems to be that the amyloid plaques are a symptom of whatever the underlying cause is. And the key takeaway is that we have NO IDEA what the actual cause is. We've got a bunch of guesses. One of them might even be right. Or possibly multiple, there are probably several diseases that cause the same symptoms.

So if we can detect the non-presence of amyloid plaques but detect symptoms that would be good as a way to distinguish between the different diseases. Of course there might be more than two variants...

[1] http://blogs.sciencemag.org/pipeline/archives/category/alzhe...

Re: PET scans show many Alzheimer’s patients may not actually have the disease

#27
post #7

Not surprising to me. A family member just had a stroke... the entire system is designed around maximizing billing. If someone is in a longer term situation and a Alzheimer's diagnosis makes a buck, you'll get that diagnosis. Never mind the mental condition is probably a result of the institutional environment and drugs.

> the entire system is designed around maximizing billing

Our entire world is built that way, it isn't unique to medicine.

Re: PET scans show many Alzheimer’s patients may not actually have the disease

#28

Earlier quoted context omitted.

There seem to be a lot of loose ends in this article: how many of these patients will go on to develop Alzheimer's? On what basis are the current treatments for Alzheimer's considered to be effective, if we did not previously have a test to determine who has developed it? On what basis would the physicians whose patients were enrolled in this study change their care plans, and in what way? At one point, the article s…

Not an expert, but I read Derek Lowe's blog[1] and he tends to report on pretty much all the drug trials in the Alzheimer's space. The amyloid hypothesis (that the cause of Alzheimers is the buildup of beta amyloid plaques) seems pretty weak at this point. The drugs that remove or reduce amyloid buildup don't seem to stop the progression of the disease. The current best guess seems to be that the amyloid plaques are…

I'll admit I wasn't aware in the 1980s when the hypothesis took hold, but it never seemed like a good one to me just because amyloids are so thermodynamically favored. There must be constant and diverse measures functioning correctly to avoid their formation.

Re: PET scans show many Alzheimer’s patients may not actually have the disease

#29
post #28

Earlier quoted context omitted.

Not an expert, but I read Derek Lowe's blog[1] and he tends to report on pretty much all the drug trials in the Alzheimer's space. The amyloid hypothesis (that the cause of Alzheimers is the buildup of beta amyloid plaques) seems pretty weak at this point. The drugs that remove or reduce amyloid buildup don't seem to stop the progression of the disease. The current best guess seems to be that the amyloid plaques are…

I'll admit I wasn't aware in the 1980s when the hypothesis took hold, but it never seemed like a good one to me just because amyloids are so thermodynamically favored. There must be constant and diverse measures functioning correctly to avoid their formation.

Huh?

Re: PET scans show many Alzheimer’s patients may not actually have the disease

#30
post #28

Earlier quoted context omitted.

I'll admit I wasn't aware in the 1980s when the hypothesis took hold, but it never seemed like a good one to me just because amyloids are so thermodynamically favored. There must be constant and diverse measures functioning correctly to avoid their formation.

Huh?

nonbel 469 days ago [-]

>"Of all the myriad way a protien can fold, it happens to find one that induces the same malformation when it interacts with another protein."

It doesn't really "just happen", amyloids consist of peptides folded into beta-sheets and aggregates of these seem to be the most thermodynamically stable structures it is possible for polypeptide chains (regardless of sequence) to form:

"From a wide range of in vitro experiments on peptides and proteins we now know that the formation of amyloid structures is not a rare phenomenon associated with a small number of diseases but rather that it reflects a well-defined structural form of the protein that is an alternative to the native state — a form that may in principle be adopted by many, if not all, polypeptide sequences

[...]

These observations, therefore, have led to the remarkable conclusion that, at the concentrations present in living systems, the native states may not always represent the absolute free energy minima of the corresponding polypeptide chains — the native form of a protein could in some cases simply be a metastable monomeric (or functionally oligomeric) state that is separated from its polymeric amyloid form by high kinetic barriers" http://www.ncbi.nlm.nih.gov/pubmed/24854788

https://news.ycombinator.com/item?id=11535494

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