For me it was a lumbar puncture. My MRI head been just ambiguous enough that my doctor did not feel comfortable putting me on long term meds. I also leaked spinal fluid, which was the worst.

I'd had MRIs as requested my by primary care physician. She recommended I then go a neurologist. He didn't bother looking at the MRIs. Said I MUST have a spinal tap to make a determination whether I had MS. He did the procedure in his office and sent me home in 15 minutes. OH my, that was AWFUL!!! Before he sent me home, he told me I had no markers and definitely didn't have MS. I chose the next neuro ... he looked at the MRIs and said "What's your question? I said, what's wrong with me. You've got MS." Wow!

I had a brain mri which showed spots so my primary care physician sent me to a neurologist who ordered c spine and t spine mris. One of those also showed spots so since I had spots in two places he was confidant it was MS. He was then going to do a lumbar puncture which I would have gone along with but I first asked him what the benefit would be. Would it change the diagnosis in any way? When he said no, I asked what was the point then so he dropped the issue

I've had MRIs so many times it's surprising my insurance didn't say something .. I always had them with and without contrast ... and nothing was noted .. THEN after 20+ years, I had a major attack of vertigo, which wasn't something new, just the onset was devastating ..falling, inability to move, etc ... went to the doctor, put in the hospital for 6 days, had every test known to mankind .. everything came back fairly normal until the dreaded spinal tap was suggested .. I freaked out ..but honestly, it was not such a big deal .. a little pain, and a huge headache (a can of Coke helped tons) but the spinal tap was the definitive test that showed I did have MS ... so after all the years of wondering, a name was finally put on my symptoms ...I experienced a grand sense of relief just knowing a name had been given to years of wonder ... treatment began .. steroids, then Rebif .. at least now I know .... things aren't perfect, but each day I wake up is a blessing ...

MRI and ruling out other possible diagnoses that cause similar lesions.