I've had ms over 17 years and many things may have changed in the medical profression since my diagnosis. I was 'lucky' enough to have textbook ms. 1st symptom was optic neuritis and was sent by md to opthomoligist who was very kind to inform me optic neuritis was usually the 1st symptom of ms so I must probably have it and sent me on to a neurologist.
Neurologist had quite a fit and said the eye doc had no business even suggesting ms to an unsuspecting person. I did have an mri then but the neuro said it would more than likely be negative which it was. I went home and freaked out about having ms anyway and didn't even know what it was! Just a couple months later I lost the use of a foot/leg, back to neuro-and by then very well book educated on ms-had the mri, positive.
My neuro then told me an mri won't catch ms immediatly because SCLEROSIS is either Greek or Latin for SCARRING. When you cut your hand you have a CUT. It takes a while to form a SCAR which is the same for ms. There's alot to read about but this is the bottom line.
Back then most neuros wouldn't bring up ms until you had 2 completly seperate attacks, ie:optic neritus at 1 time then before or after, say, numbness or any thing else.
Sure hope this can at least help 1 person as it is more hard to anticipate the unknown than suffer the real ms.