Your doc is right and wrong.

You may very well have a B12 deficiency, and this could be causing your symptoms. If a B12 deficiency goes on for too long, your nervous system can be affected, and you may end up with peripheral nerve damage (and Paresthesia). In fact, that is one of the first things they should rule in/out when we present with MS-type symptoms.

http://www.b12patch.com/about-b12deficiency.html

The part that he/she is wrong on, is that we won't get symptoms bilaterally . . . that is not true. Numbness is one of my most prevalent symptoms with my attacks, due to spinal lesions. I will get it on one side OR both sides (either at the same time, or progressively affecting both sides over time).

Cherie