Predictors of postoperative gustatory disturbance and gustatory recovery following microsurgical resection of vestibular schwannoma

Background: Gustatory dysfunction is a complication of vestibular schwannoma (VS) resection and a frequent patient concern, but there is comparatively little in the literature on this topic to guide surgeons in counseling. In this study, we aimed to identify factors contributing to postoperative gustatory dysfunction and subsequent recovery. Methods: We included consecutive VS patients who underwent microsurgical resection between July 2016 and April 2024 at our institution. Preoperative data included patient demographic information, tumor characteristics, facial nerve function (classified by House-Brackmann (HB) grade), and the presence of gustatory disturbance. Univariable analysis and multivariable logistic regression were used to determine independent predictors of postoperative gustatory disturbance. Cox regression analysis was used to determine predictors of taste recovery. Results: The study sample included 433 VS patients who underwent microsurgical resection, of whom 89 (20.6%) reported gustatory disturbance at a median of 32 days postoperatively. Older age, preoperative gustatory disturbance, and mild-to-moderate facial nerve injury (HB grade II or III) at discharge were significantly associated with postoperative gustatory disturbance. By the end of the follow-up period, 71.9% of affected patients had recovered gustatory function at a median time of six months since symptom onset. Older age, particularly > 57 years, was significantly associated with a higher risk of prolonged gustatory disturbance. Conclusion: Partial as opposed to complete facial nerve injury may be a stronger predictor of postoperative gustatory disturbance. Patients should be counseled that this complication is typically self-resolving; however, older patients may be at increased risk for prolonged gustatory dysfunction.