You have not mentioned any information about an angiogram. If this has not been completed, it may be reasonable. Your disease course and history could be consistent with a vasculitis or small vessel arterial disease. You should discuss this with your physicians. Otherwise, I would recommend a second opinion at a large academic center. Good luck.
Could use please tell us what your neurologist's diagnosis was? I am having some trouble understanding all the jargon, so if you can explain what your neurologist told you, first-hand, with regard to what's happening, I would appreciate it.....