CT/MRI scan diagnosis

[PuddinAforeDinner]

I wonder if someone can help me with a question. This may sound silly but can you still have dementia, or some form of it, but have a normal brain scan? Thanks.

I am not sure that this is relevant but my mother had a hospital admission following a cat scan, the consultant told me that there was nothing noticeable about it (I had not been given any feed back), six months later we are looking at a Parkinson plus diagnosis with, now, very noticeable diminished cognitive ability.

Yes. Or rather there will likely be some changes but they come under ' normal changes' if that makes sense. Basically some people can go around almost normal but have significant brain matter loss and other ppl have symptoms that affect them quiet a bit but brain scan doesn't look that bad.
It depends on the area of the brain affected and also the persons cognitive level and ability before hand e.g someone who does cryptic cross words , or maths puzzles or has a more cognitive demanding job will notice symptoms ealier ( even if brain damage is more subtle). Some one else can have the same brain damage but they are able to mask the difficulties more so it doesnt their day to day life as much.

I've posted elsewhere for advice about my DM, who has cognitive symptoms which (in my view) are significantly worse than the MCI she's been diagnosed with. She had an MRI recently for a different reason, though the consultant was also aware of her memory issues. The scan apparently showed 'nothing of concern'. I'm convinced (based on my own reading and also the views of wise and experienced Mnetters) that she has dementia, regardless of the scan result, but I don't have any 'proof' of that.

Thank you very much for all your replies, this is very interesting. DM had a fall a couple of weeks ago and now can't walk unaided. She had memory issues before but since the fall she is declining. An occupational health nurse did the basic memory check, which she failed completely, and also couldn't remember the layout of her own home. I guess we wait for further tests.

Just to add @PuddinAforeDinner that if the scan was done for a fall, then typically the report is focussed on any acute issues, and won’t necessarily even comment on chronic changes seen in dementia.

But yes as PP implied, scans are a much less useful test than you might imagine with both false negatives and false positives!

The history of change and presentation of symptoms are key. If people are ‘passing’ cognitive tests, then maybe the wrong tests are being done. The better Memory Services would have access to detailed psychometric testing which could take a few hours!