Predictors of Delayed Facial Nerve Palsy Following Acoustic Neuroma Surgery

OBJECTIVE: Delayed facial nerve palsy (DFP) may occur after acoustic neuroma surgery despite normal immediate postoperative facial nerve function. The mechanisms and predictors of this phenomenon remain poorly defined. This study aimed to identify factors associated with the development of delayed facial nerve palsy and characterize recovery at 1 year. METHODS: A retrospective cohort study with prospective follow-up was conducted including patients who underwent acoustic neuroma resection and demonstrated normal immediate postoperative facial nerve function (House-Brackmann [HB] grade I). Seven hundred ninety patients met the eligibility criteria. Delayed facial nerve palsy was defined as deterioration in HB grade occurring at least ≥3 days postoperatively. Candidate predictors included age, maximum tumor diameter, surgical approach, extent of resection, and side of intervention. Univariable and multivariable logistic regression analyses were performed to assess associations with delayed facial nerve palsy. RESULTS: Among the included cohort, delayed facial nerve palsy occurred in 93 patients. On univariable analysis, several perioperative factors demonstrated trends toward association with delayed facial nerve palsy. On multivariable analysis, subtotal resection remained independently associated with an increased risk of delayed facial nerve palsy. Seventy-five percent of patients with delayed facial nerve palsy made a complete recovery within 1 year. CONCLUSIONS: Subtotal resection is independently associated with delayed-onset facial nerve palsy after acoustic neuroma surgery in patients with initially normal postoperative facial nerve function. Most patients with delayed-onset facial nerve palsy recover to normal symmetry of the face at 1 year after surgery.