in my journey with acqueduct stenosis and enlarged ventricles written on my charts... I came across the Hydrocephalus Association. There really aren't too many doctors that do that condition actually. I looked on the Hydrocephalus Association website and realized I had spoken to a few doctors not on this list. Just a friendly suggestion is to check with the association and see if you are seeing somebody registered with them. There are few places that treat adults is what I found, doctors listed only treat children born with hydro. This was a few years ago. I'd suggest initiating the request for the Mayo appointment, it may take 4-6 weeks to get in.
https://www.hydroassoc.org/