Your symptoms along with your dx of ON (optic neuritis)are just like mine were 11 yrs. ago. But it was actually a "pins and needles"
sensation I had when diagnosed 20yrs. ago. Was it your eye Dr. who ordered an MRI or a neuro.? There is so much new info. regarding MS now that I wish I never persued a dx till I did research. Here is a website that you might find interesting and helpful www.ccsvi.org
The symptoms I have now are alot like yours. It doesn't take a major (exacerbation) physical health issue for something to show on MRI. My "pins & needles" sensation was all it took for the MRI results to show "brain stem lesions". Was it the same Dr. a year ago who ordered this MRI? I wish you all the best and there is so much helpful info. on all the threads here. Ask many questions, we're here to help.