“ Alzheimer’s is a specific diagnosis that requires MRIs or other scans.”
Not true in practice. True in definitive diagnosis which can generally only happen after death
Alzheimer’s and most dementias are diagnosed behaviorally.
Specific types need post Mortem for definitive identification.
Neurofibrillary tangles, amyloid plaque, lewy bodies, etc cannot be imaged.
In highly progressed cases imaging can see enlarged ventricles associated with neurodegeneration, for example.
But dementia can be present with no obvious physical neuropathological observations being seen.
Things are happening at a cellular and molecular level (eg loss of myelin sheath)/ that can’t be imaged.
Over time gross anatomical effects can be seen.
I had heard that. But in the last couple of weeks I had read that the MRI process had progressed.
It’s been a few years since I was on “the front lines” of that. Most of the cases I dealt with were very early onset (55 yr old) or elderly vascular, run of the mill, dementia.
I happily stand corrected.