You have every reason to be out of your mind. Ms can affect the autonomic nervous system - digestion, breathing...But this one symptom is just not enough. People with ms often have mri's twice a year! I cannot imagine this being overlooked. A thorough neurological evaluation, including visual evoked potentials, lumbar puncture, etc. And the vital mri. You should investigate for the best neurological center and have her diagnosed and treated there. We have to grow and stand up effectively to doctors sometimes. No emotion. Calm resolution. Hospitals have special offices for patient's rights and info on what you can do as a parent. This is your baby!