heya, i think optic neuritis and brain lesions are pretty common. optic neuritis is a common presenting issue. i did not have it though. for some unfathomable reason my optic nerves were the healthiest ones my neuro had ever seen (that's a quote lol). but i had brain lesions, spine lesions, and a bunch of disability.
the mri is creepy and noisy but fine, the vep is just a thing where you stare at a flashing screen with electrodes on your head, BAER i don't know that one, spinal tap just make sure you LIE DOWN for a while after the procedure. as in a few hours. you DO NOT want the post LP postural headache. particularly if you're in for migraine. my docs said lie down for half an hour, but it wasn't enough. i had the headache and it lasted so many days that they wanted me to come back in for a 'blood patch' procedure. riiiggghht another needle will fix things right up! anyway it was going to be decided on a monday. i spent the weekend flat on my back on the couch hoping that minimizing pressure changes would let it heal. on monday i was better, no blood patch, whew. the only other test i can think of was some sort of nerve conductivity test on my arms and legs. can't recall the name but it's more electrodes, those ones hurt a bit but not too bad, and nothing lasting.
no doc can tell you 100% if you have MS. they can only tell you statistically how likely you are to have it based on how many different tests point to it. if they are ordering those tests and they don't confirm the guess, you'll end up in limboland but the good news is, there's a lot you can do for your own health from there
if you want to start reading, my signature links might be of interest, plus you can have a browse of all the forums and recent topics of discussion, see if anything grabs your attention.
welcome to TiMS! regardless of your test results, there will be info here for you. try using the site search for migraine, ON, etc. also see the list of related topics below. ttfn!