If they are in the same practice and that is how you came to get the appointment with the second neuro they should be consulting each other already.

If you went to another practice before your appointment I would let your original neuro know that you felt you needed to be seen sooner than she could accommodate so you scheduled with the new guy. Your insurance might not even pay for another office visit since you just had one. You will probably need to pick one doctor to work with because although they will pass along information to each other it is unlikely for two doctors of the same specialty to work as a team on a patient who isn't in the same practice.

The only other thing I'd say since you are posting on a MS board is that hopefully at least one of them is a MS specialist. To me that is the most valuable second opinion for all of us here. Good luck.