Technically no, because MS is still suppose to be based on a patients clinical signs because MS doesn't as yet have 'one' definitive diagnostic test.
Diagnostic test results, such as blood work, MRI's etc etc all aid in creating a list of the 'more likely' conditions, negative results minimise the likelyhood of a condition but a clear MRI can't really rule out MS definitively because MS develops over time. [see health page to the right of your screen "How Can a Person with MS Have a Negative MRI?"]
MS does have many mimics, other conditions that produce some similar sx's and in your situation, your positive ANA and normal MRI's place conditions that produce positive ANA, at the top of your list of possible's, and places MS lower on your list of possible's.
I think you may find that your neurologist could be basing his opinion on more than just the clear MRI's. Additionally to having clear MRI's, the neuro testing may not of yielded any positive "clinical signs" of lesions either. So if there isn't any evidence or suspicion that the cause of your sx's are from a neurological issue and with you actually having blood work that additionally points away from a neurological cause, then from that perspective it does make sense that MS would be a least likely cause.
Cheers......JJ
PS I hope that made sense :o)
There is no testing that absolutely confirms or rules out MS - or SLE (lupus) for that matter. Evidence for a specific diagnosis comes together quickly in some cases but very often it takes years of observation, testing and treatment before a doctor feels confident enough to pronounce a diagnosis.
I'm sorry to hear you're in this difficult period when you know nothing other than this is NOT the normal You. Try not to stress too much. Both these diseases have extremely variable courses. There is no telling what your future would be like with either one.
I do hope your doc is working on getting you feeling as good as possible while he works on getting to the root of the problem. Thanks for coming by to ask your question. We're always glad to welcome new faces.