Sorry to hear the turbinate reduction didn't work for you, that was actually what I was considering next.

I seem to remember that the dementia thing was to do with long term use of first generation antihistamines (the drowsy kind). I can't quite remember if second generation antihistamines were a problem or not so might be worth check out with a doctor if you're worried.

https://www.health.harvard.edu/blog/common-anticholinergic-d...