PET scans show many Alzheimer’s patients may not actually have the disease
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Re: PET scans show many Alzheimer’s patients may not actually have the disease
#2Does 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.
Re: PET scans show many Alzheimer’s patients may not actually have the disease
#3Does 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.
It reduces these studies' power to detect results. If you thought you had 100 cases and 100 controls, it turns out perhaps you really had 30 cases and 100 controls, and 70 controls misclassified as cases. Power is going to be substantially hurt.
Re: PET scans show many Alzheimer’s patients may not actually have the disease
#4Does 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 says "A positive test for amyloid does not mean someone has Alzheimer’s... But a negative test definitively means a person does not have it". To me, there seems to be a hint of "these patients' condition does not fit the dictionary definition of Alzheimer's, so clearly it would be wrong to treat them as if they had it", yet the article seems to leave open the door to the possibility that it is the progression of Alzheimer's that is not fully understood. I hope an expert can chime in and set me straight.
Re: PET scans show many Alzheimer’s patients may not actually have the disease
#5Does 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.
It reduces these studies' power to detect results. If you thought you had 100 cases and 100 controls, it turns out perhaps you really had 30 cases and 100 controls, and 70 controls misclassified as cases. Power is going to be substantially hurt.
I could see it having more implications than just measurement error reducing power. It's entirely plausible that a drug which has an effect on Alzheimers would come with side-effects that would damage those who just have senile dementia; imagine a drug which dissolves amyloid plaques while doing some moderate damage, in a trial with a mix of dementia and Alzheimers, the Alzheimers getting better is masked by the dementia ones getting worse, for a net average zero compared to the placebo group.
Re: PET scans show many Alzheimer’s patients may not actually have the disease
#6This is amazing news. I love the advances we're making as a society.
In that $3-5k cost of running a PET scan, I wonder how much of that is paying professional operators and physicians to interpret the results?
Could ML be applied to this problem to reduce the cost of a PET scan?
Re: PET scans show many Alzheimer’s patients may not actually have the disease
#7Not 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.
Re: PET scans show many Alzheimer’s patients may not actually have the disease
#8This is amazing news. I love the advances we're making as a society. In that $3-5k cost of running a PET scan, I wonder how much of that is paying professional operators and physicians to interpret the results? Could ML be applied to this problem to reduce the cost of a PET scan?
Yes eventually
Re: PET scans show many Alzheimer’s patients may not actually have the disease
#9Fungus amungus
Re: PET scans show many Alzheimer’s patients may not actually have the disease
#10Historically, a bunch of symptom-defined diseases (e.g. hepatitis, diabetes, etc) have turned out to actually be a set of different diseases with different causes, different treatments but similar symptoms - and understanding that split has been a big milestone in treating them. This now might be the case for Alzheimer's as well.