So sorry to hear you're still searching for a diagnosis! I was on Topamax for a couple of years. It was a miracle drug for my migraines! I had to be on a high dose to get the benefit though, and eventually I realized that I couldn't add simple numbers (my kids' reading minutes!). I'm sure I was slowly getting "dopey", but I was coping until I had that scary realization! At that point my doc said it was time to get off it. It's very important to titrate as prescribed by your doc and be patient- you really want that lowest dose that gives you relief! I begged my doc to let me increase quickly on Topamax and it was a mistake... very disoriented, horrible feeling until it leveled out! I also experienced other side effects (including weight loss), but I decided to accept them so I could be out of bed. It's a balancing act...symptoms/meds/job/life. I hope Topamax helps you!
Yes, I can relate to the difficulty in what info to give your doc! I went to my kids' specialist (both have POTS) after I got headache relief, b/c I still felt so sick (dizzy, nausea, increased HR , fatigue all worse when sitting and worse standing...) I told him I've had migraines forever, but I feel like this is different- and maybe I've been attributing it all to migraine, but I don't think it is. I told him I wanted him to evaluate for POTS or similar. The doc knows I'm educated about POTS and HE'S THE ONE WHO REFERRED ME TO THIS SITE seven yrs ago when my daughter was diagnosed. I think it's good to be up front with your doc about your suspicions. As long as you don't throw out a bunch of random illnesses and bad sources, I'd hope your doc would appreciate your knowledge. Still I it's always a balance with what info to give, how hard to push, how long to wait for a new med to work, etc.
*Just personal experience, but if the Topamax is really for migraine (*not addressing other issues), I'd ask your doc/neurologist about Botox for Migraine. Once you get over the thought of "Botox", it can be amazing. None of the usual side effects possible with the other preventative meds (positive side effect of smooth forehead! ). You have to fit the migraine profile, etc. to be eligible for Botox.
Good luck, and keep us updated... your info may help us, too!!