Hi Xander & welcome to the site!
The best test for getting diagnosed with ES is a CT scan of the head & neck, down to the hyoid bone. It’s best to request that it’s evaluated for ES, & the the length, width & angle of the styloids are noted. As well as elongated styloid processes, the stylo-hyoid ligaments can get calcified & cause symptoms , so that needs checking.
If you suspect that you have IH, it can be caused by the styloid processes compressing the jugular veins, so a CT with contrast would be an idea, it might confirm it (although sometimes this only happens with your head in a certain position )
There are a few discussions at the moment by members with IH; if you search for jugular compression it’s probably come up with discussions you might find helpful.
Also there’s info in the Newbies Guide Section about Vascular ES; here’s a link:
So try to get a CT done, & then take it from there- if you can get copies of the images & the report, as it’ll be helpful to send to any doctors if you do get a diagnosis, plus if you want to you can always post them on here.
Hope that you get some answers soon…