One thing I can recommend to anyone who thinks they may have dementia (or who has a loved one showing symptoms) is to write a detailed diary ASAP.
Mum wrote a diary for Dad from the first few months he displayed memory loss. We have gone back to the notes in that diary hundreds of times. Every time you see a doctor, deal with nurses ambos, physicians, pharmacists or nursing home staff there are always questions about medical history.
To have the entire story on hand can be extremely beneficial and save a lot of time and memory power. Write down all the medications, the doses and the reasons why they are diagnosed. Document behaviours and anything unusual.
With dementia you end up having to almost take control of the medications as much of what is prescribed is based on information provided by family members.