The focus of vestibular schwannoma surgery has shifted from low mortality and tumor resection to retention of neurological function. Hearing preservation is another point in addition to facial nerve function preservation. Hearing preservation rates overall ranged from 2% to 93% in recent studies. Characteristics such as approach, pre-operative neurological function, tumor size, nerve of origin and fundal fluid of the internal auditory canal have been reported as possible influencing factors ¹⁾.

The presence of fluid in the fundus on preoperative MRI is predictive of hearing outcomes and should be used in counseling patients who are considering hearing preservation surgery via a middle cranial fossa approach for the treatment of isolated vestibular schwannoma ²⁾.