On Namenda for 12-15 years by psychiatrist. 3+ years ago first neurologist diagnosed Parkinson's. Then second severe brain atrophy. Then atrophy with a compressed spine and Alzheimer's. Now Parkinson's with a duel diagnosis of Alzheimer's. The doc is beyond reputable. The brain must really be an elusive organ to master. I find it so confusing as a caregiver to know what to look for, how to proceed. I like to be prepared (yes probably control issues). I guess it is a lesson in living in this 24 hours and look for tomorrow's needs tomorrow.
Despite what some of them might think, doctors are not omniscient, and they don't have crystal balls. (no pun intended) This is especially true when it comes to disorders of the human brain. IMO, the best way you can help your LO (AND his/her doctors) is keep a daily log or journal, write down your observations - even things that might not seem all that important - and before each appointment make a list that you can give the doctor, a "consolidation" so to speak of your observations since the last visit. As the caregiver YOU are the one that knows your LO best, and any doctor worth his/her salt will be grateful for your input.
And, improving the dementia seems to out of the question. Switching to a geriatric specialty physician is a consideration.
You ever hear of Occam's Razor? Wellll, it doesn't work all the time.