I wanted to update my posting because it may be useful to others. The cognitive issues I described are related to my balance issues, which are indirectly caused by my AN and now being diagnosed as Meniere's disease. So if anyone is having episodic vertigo (fullness, tinnitus, dizziness, temporary loss of hearing), you may want to talk to your doctor about Meniere's disease and how to manage it.
If you are suffering from the cognitive issues I described, do not let your doctors dismiss it. The vestibular system is an amazing system that incorporates your ears, eyes and brain. If you have one area damaged (like an AN on your balance nerve), you may suffer from some disorientation, bouncing letters, fatigue, etc.
I think the biggest challenge that I encountered was calling it "cognitive issues". Doctors quickly dismiss the idea, because an AN is not impacting the brain. Once I began talking more about my episodes of imbalance/vertigo, and explaining moments when I get disoriented, lose my way with direction, forget my pin number, and having more "senior moments" than normal, then the doctor was able to talk more about the way the vestibular system works and how these are side effects from damage to the balance nerve.
I hope this helps folks that are forced to stop working and that are so desperate for a solution that the risks of surgery seem minor compared to the debilitating condition caused by the episodic vertigo. Although surgery is likely in my future, my surgeon is not willing to perform the surgery if we can manage the dizziness.