BRAIN BIOPSY?

Hello, my wife has been suffering from headaches for approx 2.5 years. She has had multiple tests ran from blood work, an angiogram, 3 spinal taps and 6 MRIs. All of her tests come back negative for anything with the exception of the MRIs which show "mini-strokes" "lesions". She has seen a hemotologist(she has had TTP 14 years ago that went into remission after plamapherisis and blood transfusions she has had low platelet counts since then around 100000,) a rheumetologist, and a dermatologist(because she has blotchy patches on her legs that the dermatologist says is lavido reticulas) After all of these tests our nuerologist has no idea what can be causing these ministrokes due to her test results and now wants to perform a brain biopsy. It has been very difficult to reach out to our nuerologist because it seems that there arent too many in this area and we cant get an appt with him but every 1 to 3 mos. It seems like and he has eluded to the fact he is looking for MS or Vasculitis. I have been doing research on the internet and I feel she may have Sneddons Syndrome, but cant get i nto see the nueologist soon enough to speak with him about it. (they called to schedule the brain biopsy by phone but I have sooo many questions before this is done. We are terrified because so far every procedure/medication we have tried she has suffered the side effect of so a brain biopsy is terrifying. Can anyone tell me if a brain biopsy can diagnose Sneddons or what can we find out from a brain biopsy other than testing for MS or Vasculitis. Also, reading the signs/symptoms of Sneddons I really feel that this could be what she is experiencing. Does anyone know of a nuerologist that is familiar with Sneddons anywhere in the Pacific NW? Also, we could possibly be in a period of transition where we could move to Phoenix Az. Its taken 2 years to get the dr to think of anything aside from migraines and the prospect of starting over with a new Dr is concerning, but the idea of being near the Mayo Clinic with an army of nuerokogists other than the one we are seeing and his partner seems like we should wait. But it is so hard to consider waiting as she suffers daily and Im powerless to help her. Plus the idea of going on this long with no answers has been difficult. Does anyone have any suggestions thoughts on Sneddons or ecperience with Brain Biopsies? Thanks