with big words, when they have NO CLUE. This tactic is very effective with just about EVERYBODY...

In the case of this "diagnosis" followed by total ignorance of B12 and how it works...I decided to search this.

http://www.neurology.org/cgi/content/abstract/56/1/82
How rare is it? Totally so rare that less than 10 people have been written up. And those only had one person with some sensory loss.
Another:
http://neurology.jwatch.org/cgi/content/full/2001/328/1

This diagnosis of course, has no PROOF. But the big words do work a placebo magic of sorts.

Do this: Ask your doctor if you should avoid flu vaccines in the future. I'd be very interested in this answer. (most neurologists blame vaccines for GBS).
We've had patients on this board (and its sister that preceded it) for over a decade who developed GBS after vaccines.

In general when there are no "footprints"...doctors blame viruses. But the proof is always lacking. "Post viral syndrome" is more accurate, than sensory GBS, IMO.

A neighbor of mine had GBS following chemo for breast cancer. I watched her decline within HOURS to a vegetative state. I called her husband from out of town to come home, EMERGENCY and she ended up in the hospital for WEEKS...and luckily recovered with plasmapharesis (which was rather new at the time). There were MANY on her floor with the same diagnosis who could NOT afford the treatment, and they remained permanently paralyzed.