Under the new McDonald Criteria, you would need to have at least 1 lesion to be dx with MS. (http://www.mult-sclerosis.org/DiagnosticCriteria.html) I was diagnosed under the 1st criteria. I have both brain and spinal lesions. I never had an LP so I don't know what my o bands are. However, o bands can occur in other conditions as well. It's the pattern of o bands that can assist in a dx of MS or other conditions.

But, MRI's are not 100% dependable. MRI's are done in 1/4" slices. Within that 1/4" a lesion may have been missed. I know that may sound scary to you but it does happen. I think many of us have experienced going for an MRI and getting the results and finding out that a few lesions are "gone" and on the next MRI they are back again. It's that 1/4" slice issue. Additionally, spinal lesions are very difficult to find not only due to the 1/4" slice but also due to all the things that are compacted in the spinal cord. They are easy to miss. Mine are in my thoracic spine. They show up best when I am in a flare and gadolinium is used.

Since your neuro took back his dx, he may have decided to be a little more conservative since at this point you don't fit the McDonald Criteria and there may be something else going.

I do hope you start feeling better soon and can find out what is going on.