I have been using a service dog for the past 2 years. A Standard Poodle that was originally trained to help a veteran with Post Traumatic Stress Disorder (PTSD). Acoustic neuroma is like Traumatic Brain Injury (TBI) and many training organizations that train dogs for veterans with PTSD also will help train the dog for TBI with the veteran. Canine Companions for Independence and Bergen University in Santa Rosa CA come to mind. Some offer the dog and training at no cost. Some charge for both. Some restrict for state, or county, or city clients. Some come with a 3 year waiting list. It will take some research, a doctor that thinks such will benefit you, and a commitment to take care of the service dog and train with it. It will take personal training, as no two ANA patients are identical.
If you came up with anything in the past 9 months, please post an update.