But preserving good hearing in the affected ear remained an elusive goal. Even during observation, although tumors showed no significant growth, hearing deterioration occurred. Stangerup et al. reported (2010) that most patients with 100% speech discrimination at diagnosis had the best chance of maintaining good hearing after ten years of observation. Structured surgical training of neurosurgeons and official accreditation replaced the ages-old informal apprenticeship model. Advances in microsurgical instrumentation, the refinement of operative techniques including the introduction of intraoperative facial and cochlear nerve monitoring, and the development of multidisciplinary team-based patient care reduced the incidence of complications related to treatment. There was a trend toward the emergence of high-patient-volume centers for VS surgery where good outcomes and routine patient discharges could become commonplace. The mortality rate for VS surgery fell to less than 1%. In 1991 the NIH Consensus Statement for Acoustic Neuroma observed: "The best published surgical outcomes in the treatment of vestibular schwannoma are from medical centers that have highly organized and dedicated teams with a specific interest in these tumors and sufficient continuing experience to develop, refine and maintain proficiency. "ref>Sweeney A, Breen JT, Vrabec JT (2019). "Chapter 29: Training in Vestibular Schwannoma Surgery". In Carlson ML, Link MJ, Driscoll CL,  et al. (eds.). Comprehensive Management of Vestibular Schwannoma. New York. ISBN 978-1-62623-332-4.</ref>

Radiosurgery and radiotherapy
The 1991 NIH Consensus Statement recognized radiation therapy as "a treatment option limited in current practice primarily to patients unable or unwilling to undergo otherwise indicated surgery." The beneficiaries of radiation therapy soon greatly exceeded this limited clientele.
The elemental diet demonstrates a high rate of response (almost 90% in children, 70% in adults), with a rapid relief of symptoms associated with histological remission. This diet involves using amino-acid based liquid formulas for 4-6 wk, followed by the histological evaluation of response. If remission is achieved, foods are slowly reintroduced. Pharmacologic treatment
In patients diagnosed with EoE, a trial of proton-pump inhibitors (PPI), such as esomeprazole 20 mg to 40 mg oral daily or twice daily as a first line therapy is a reasonable option. Nexium®, brand name esomeprazole, may be preferred as these tablets can be dispersed in half a glass of water and drank for those with difficulty swallowing pills. Those who respond to PPI therapy with symptomatic improvement, should have endoscopy with esophageal biopsy should be repeated. If no eosinophils are present in the repeat biopsy, the diagnosis is either acid mediated GERD with eosinophilia or non GERD PPI responsive EoE with unknown mechanism. If both symptoms and eosinophils persists after treatment with PPI, the diagnosis is immune mediated EoE.Medical therapy for immune mediated EoE primarily involves using corticosteroids. Systemic (oral) corticosteroids were one of the first treatment options shown to be effective in patients with EoE. Both clinical and histologic improvement have been noted in approximately 95% of EoE patients using systemic corticosteroids. However, upon discontinuation of therapy, 90% of patients using corticosteroids experience a recurrence in symptoms.