Husband seems to have FTD. How do I get him to get more testing?

The head of the local dementia dept said he had it & then changed his mind. Now husband doesn't want more testing. We have taken off from testing from February till now (October 2018). He has an annual physical with a relatively new PCP. I was wondering about writing the dr. and hoping that he will do some testing and refer him to a neurologist (which he has already done 2 yrs ago). He is getting worse and also built a house (after no houses to build for 4 yrs) and he put it on the one acre lot sideways?!

He has learned to lie to cover his tracks when he realizes that he has screwed up. This could potentially cost us a lot of money. I hope the guy lets him go so we can move on with the testing. We need to know for lots of reasons.

Any thoughts about this?