I have had the same problem that you describe. I also had facial paralysis long before I was dx'd, which probably was the cause for me.
I saw my neuro last week and he said he was 99% sure it was MS related. I had some blood tests to double check it wasn't anything else and am still waiting for the results. If it is something else, he said it was curable!!
He said that with the facial paralysis the nerve root is affected, so that was that really! Likely culprit is MS I think....in my case anyway.
It is worth mentioning to your neuro though. Apparently certain drugs can help with this - gabapentine I think (sp?) so I am waiting for a prescription for this from my GP once the blood test results are ready.
Your neuro should do the tests (blood test) and offer you something if it is MS related.
Best of luck