There is no single test for MS. Remember, there are over 400 disease possibilities. It is like a giant buffet. Everything must be tried and the end result will be MS if nothing on the buffet fits! Though it may be difficult, you are, with each test, stepping closer to a diagnosis. According to the National Institute of Health (NIH) here in the states, studies showing that the presence or absence of ANAs in patients with MS is not really very significant. If your doctor is counting on one test alone to diagnose you, RUN! The best MS doctors will run the revised McDonald Criteria.