What about Lupus - was that investigated?
It sounds like the doctors in NY did all that major tests to help evalaute for stroke, MS, clotting didorders, and inflammatory conditions. Are you a migraine sufferer? If you are these could represent a form of complicated migraine. The alternating examination in the hospital is difficult to explain. If it was not done by the same physician, it may just be technique. If you are still in doubt perhaps a second opinion as an out-patient would be reasonable. Good luck.