AdditionalRabbit4516 t1_j268mbx wrote on December 29, 2022 at 11:21 PM

Alzheimer’s is known to be related to a specific protein in the brain that affects a very certain area first, and has classic symptoms, like memory loss.

Another kind of dementia is caused by chronic high blood pressure and mini brain strokes, causing lots of little spots where the tissue has died. This could range from mild to severe and look different for everyone, but it’s called “multi-infarct” because the cause is known to be infarcts.

Other dementias could be from injury, or viral infections, or autoimmunity, such as MS. Other people have mild or slower advancing dementia, where the cause is not known. Imaging and blood tests could come back normal but we call it dementia because of cognitive or mood changes reported by family and seen on neuro cognitive testing.

Side note: neuro cognitive testing can tell us if a person’s deficits are in executive function, memory, multitasking, language, etc.

tacogamer20 t1_j27o7fu wrote on December 30, 2022 at 5:58 AM

The link between Alzheimer's and amyloid plaques has fallen out of favor the last decade or so. Tau tangles, for example, have been linked to Alzheimer's like symptoms. There have also been many cases where plaques are present without symptoms, and symptoms present without plaques as seen after autopsy.

AdditionalRabbit4516 t1_j28jhq8 wrote on December 30, 2022 at 12:31 PM

That’s why I said “related” and not “caused by,” since we don’t know the exact causal mechanism. But beta amyloid PET imaging is used to make Alzheimer’s diagnoses because levels do correspond to severity, for the most part. I work in neurology research.

Edit: also the article you’re referencing really only proved one lab was completely corrupt and shady. There are DOZENS of other b amyloid labs (and subtypes) and quite literally HUNDREDS of preclinical studies whose b amyloid work is supported, which is why clinical trials keep going that direction. Unfortunately they fail. There isn’t some big conspiracy to NOT cure AD. The Science article claiming otherwise was really really sensationalist. But I agree we don’t have a handle on it right now, and other therapeutics are needed.