Hi Jan, It's really a difficult place to be---in limbo land. I am in the same situation and have test results that are attributed to odd things.
Alex is right about the need to be completely sure. Neurologists live in a world all their own I think. They are dismissive and withholding at times. My areas of hyperintensity they say are 'ischemic in nature'.
I wish I knew a better answer. Quixote has a really good thread called about stupid things neurologists say. I would read that if for no other reason than to know you are not alone.
Hang in there, lois
It just takes time in many cases to be sure it is MS. There are over 800 Neurological disorders and over 30 mimics.
The medications are expensive and have not so fun side effects.
Then there is the fact once you are diagnosed it is hard to get medical, long term, or life insurance again.
Lastly they have to be sure so the insurance companies will pay for your treatment.
It is basically a diagnosis of excluding everything else.
Alex