You should most definitely have more than one consult with more than one neurosurgeon or otolaryngologist to find out what your options are. Dr. Chen is quite well known in Toronto for working with AN patients. Contact ANAC (Acoustic Neuroma Association of Canada) they will give you contact info for the Toronto group, and they will provide names of other well known AN specialists in the city.
I would then go back to your GP. Find out who the other Dr. is that they want to refer you to and find out if they have extensive experience with AN's. If they have extensive experience, I would take the recommended appointment. If they do not have extensive experience, I would decline the appointment. I would advise your Dr. that you have the right to see more than one specialist and that while you may agree to see whomever they are suggesting, I would firmly request a referral to see Dr. Chen. If your GP does not wish to provide you with that referral, I would find another GP!! He/she is not looking out for your best care in my opinion. OHIP does not restrict you to one consult only!
You could always try contacting Dr. Chen's office directly and explaining your situation, but given how our referral system works, you may not get far.
Cathie.