Delayed Facial Nerve Palsy after tympano-mastoid Surgery

Abstract

Aim: Data on delayed facial nerve palsy (DFNP) following tymanomastoid surgery are limited. We conducted a retrospective chart review to determine the incidence, possible predisposing factors, treatment, and prognosis of DFNP in such cases. Materials and Method: We reviewed 430 cases of tympano mastoid surgeries performed in rural tertiary centre over a period of 5 years from Jan 2012 to Dec 2016. In all patients who developed delayed facial palsy, the dates of onset and subside of facial palsy, the duration, severity and prognosis of the DFNP were recorded. The House – Brackmann grading system was used to evaluate the facial function. Results: Delayed onset facial palsy occurred in 5 out of 430 tympanomastoid surgeries. The onset of DFNP occurred between 7 and 18 days postoperatively (mean: 9). The palsy was incomplete in all 5 cases. One patient showed a facial palsy H-B grade II, 2 a grade III, and 2 a grade IV. The all 5 patients had been treated with a steroid with an antiviral, and all 5 experienced a complete recovery of facial nerve function within 8 weeks of the onset of their paralysis. It is difficult to delineate the exact aetiology of DFNP following tympanomastoid surgery, but we speculate that factors such as physical injury to the nerve and/or a viral reactivation might have played a role. Conclusion: The incidence of delayed facial nerve palsy following tympano-mastoid surgery is low. Thus delayed facial nerve palsy remains an under reported and consequently not very known phenomenon in the otological practice and literature. Because of the favourable rate of recovery, patients should be reassured in the interim and should not undergo any corrective surgical procedures to improve facial nerve function. Keywords: Tympanomastoid, delayed onset, Facial nerve palsy