When I was diagnosed I had lesions on my brain MRI (with a couple of them enhanced by contrast) and the report stated I had demyelinating disease. I had slight blurry vision in my left eye (still 20/20) and dizziness.

My spinal tap showed no O-bands. I had every blood test imaginable. A few random tests were slightly elevated. I went to the Mayo Clinic for a second opinion. They said yes it was MS, no question. So theoretically you can have MS without the bands. It's not common but it is definitely possible.

I remember reading medical journal articles about people with MS and no
O-bands. Early on they thought it was indicative of a more mild/benign course but I don't think they believe that anymore. For what it's worth, it's been 5 years and I've had no relapses (knock on wood!).

Good luck with your doctor visit!