Delayed Facial Nerve Paralysis After Vestibular Schwannoma Resection

To report the long-term outcome of delayed facial nerve paralysis (DFNP) after surgical resection of vestibular schwannoma and evaluate the influence of various factors on the prognosis of facial nerve function.

Of 265 patients who underwent surgical excision of VS through a retrosigmoid approach between April 2019 and October 2021, 15 (5.7%) developed DFNP and were retrospectively studied. Preoperative and postoperative data were collected and analyzed.

The mean age of patients with DFNP was 42.6 years (range, 27-63 years), and 11 (73.3%) were male. Tumor size ranged from 12 to 37 mm (mean 24 mm) in largest dimension. All patients had normal (House-Brackmann [HB] I) facial nerve function preoperatively. Immediate postoperative facial nerve function was HB I in 12 patients (80%) and HB II in 3 patients (20%). The mean severity of DFNP onset was HB 4.7 (range, HB III-V). The average day of onset was postoperative day 12.6 (range, day 5-28). At 1-year follow-up, 12 patients (80%) were HB I, 1 patient (6.7%) was HB III, and 2 patients (13.3%) were HB IV. All patients who were HB III and IV at the last follow-up had immediate postoperative facial nerve function of HB II.

Most patients who develop DFNP have a favorable prognosis. However, a small proportion of patients with deteriorated facial nerve function immediately after surgery have poor long-term outcomes, despite confirmation of their facial nerve integrity anatomically and by electrical stimulation.