Hi Gary .....
In regards to balance post-op, much depends on how much compensating your brain has already done before surgery. It sounds like your tumor is already destroying your vestibular nerve (by the fact you are lightheaded/dizzy and have balance problems) and thus your brain has already begun compensating by the vestibular nerve on the other side taking over the job. Often, for people in a similar situation, balance recovery afterwards is rather quick. What happens before surgery is the brain does not know what to do with the erratic signals from the damaged vestibular nerve on your AN side. Once it is removed during surgery, the brain knows to use only the remaining good vestibular nerve.
In my case ...... unbeknownst to me or my surgeon, I had only one working vestibular nerve, which was on the AN side. Therefore, when I woke up post-up following my first surgery 3 1/2 yrs ago, I had no working vestibular system on either side (and now will remain that way forever). This is a very unusual situation so do not expect this to happen. I used a walker for about two weeks, graduated to a cane for several months, and with extensive vestibular rehab, now walk unassisted with little difficulty. I had to learn to strengthen my redundant balance systems (vision and sensorineuro), as well as strengthen my overall core muscles. Even the Ponto Pro bone-anchored hearing device I have is further assistance with my balance. Now the only time I even think about it is in the dark, in nearly all white situations (snow or white shower curtains in white tubs), or walking on very uneven surfaces. My case is really one of the "worst case scenarios," certainly not the norm.