I have been diagnosed with both. MS 15 years ago, Sjogren's about a year ago. These diseases mimic each other. From what I have been told, you can know for sure that you have Sjogren's, but not MS. The symptoms and test results are the same. You can have legions in your brain and spine, neuropathy, optic neuritis, etc. with both. I am told I might have Sjogren's with neurological involvement and not MS at all. Again, there is no way to know for sure. The reason it is important to know is that the treatments to slow down the progression of these diseases is different. Right now, I don't know what to do about that. I am taking a few meds for each ailment, but not the heavy hitting drugs like interferon injections for MS and immune modulators like Cellcept for Sjogren's. I see both a neurologist and a rheumatologist. We are all confused. It is doubtful that a person has both, but not impossible.
If anyone knows more about this, let us know! If the person who started this thread (sorry, I can't see your name now that I am writing a note) would like more information from me, just let me know!