Transient Ischemic Attack
The keep word here is "Transient" when it comes to being all but imposable to detect on a C scan or a MRI
The attacks "hit and run" making it Very hard to find with a imaging test. What you discribe sounds so close to what I went trew its all most scary. Please email me to the tempory Email box I set up. I can get you in conntact with a MD that is my brother in law who can explain this far better then I can and can answer any questions you will have.