Hi and welcome to the Chiari forum.
The term borderline is a term for drs to try to put something in a category...but r they looking at a MRI and putting what they see in a category or the whole picture?Symptoms are just as important as the chiari itself and if u have chiari u have chiari...how u feel and how it is affecting ur health will determine if it is borderline or not....
What u need to have done is more testing to see if u have a CSF blockage and a syrinx or ne related chiari conditions
From what u have mentioned so far, u may want to find a ML that is well informed on chiari to do some testing, in the meantime get all copies of ur MRI's and the reports so u can send off to a chiari specialist for review....many will give u an opinion for a nominal fee.
I went thru many of the issues u mentioned and it took until I was 48 to get my dx.....
My drs told me it was early onset menopause...36...none looked at the pituitary being a possibility for me....and I just think u should push for the answers u know ur body more than they do....if it does not seem right , get a diff dr.....but try until u get someone to listen.
Not knowing where u live I am not sure which list of drs is the one u will need , so I will include the one for the US and hope u can use that to research drs...the list is not a referral, just to help u get started on researching.
http://www.medhelp.org/posts/Chiari-Malformation/LIST-OF-CHIARI-SPECIALISTS/show/1293483
We r happy to have u join us, but not happy with the reasons that bring u.
"selma"