Nancy, my first symptom was vertigo, although I don't think mine was as bad as what you're describing. The spinning/dizziness/lack of balance was what made me go to the doctor in the first place. When the typical inner-ear treatments didn't work, he sent me for an MRI and (happy day!) they found the AN.
If your experience is anything like mine, you'll have a hard time finding a doctor that will tell you that your AN and your vertigo are related. I saw five doctors (primary, balance disorders doctor, local neurosurgeon, and two radiation oncologists) before the neurosurgeon at the hospital where I had my radiosurgery told me that the AN was probably the cause of my vertigo. Prior to that, the doctors would say "what do you mean you're not deaf? We're sending you for a hearing test" or "there's no way the vertigo is caused by the tumor, come back in a week and let us blow some air and water into your ears."
Finally, the day before my radiosurgery, I asked the neurosurgeon about the vertigo and he said that, while it could be caused by something else, he'd be willing to blame the vertigo on the AN. He said that since we know there's a tumor sitting on the nerve in charge of balance, it's often best to assume that is the most likely cause.