As you've no doubt surmised from these posts, MS can be difficult to dx and not all neurologists are created equal! Your sx DO sound suspicious for MS -- it doesn't mean they ARE MS but I find it unsettling that your doctor is so dismissive. And sometimes when MS is suspected, there is not enough medical "evidence" for a dx. Sometimes it takes a long time for lesions to show up.
Did they tell you what those "white spots" were? MS lesions have certain characteristics like shape and location but it is still possible for lesions to present atypically. If you don't have a copy of the radiologist's report I'd recommend you getting a copy and any copies of any future reports as well.
It might be helpful to go to the links provided in the post toward the top of the page (The Differential Dx of MS). It's a good overview of many MSmimics and what it takes to get an MS dx.