Late Facial Nerve Paralysis Following Tympanomastoid Surgery

Abstract

Background: Although uncommon, late or delayed facial nerve paralysis has been reported after tympanomastoid surgeries. The exact etiopathogenesis for late-onset facial nerve paralysis after tympanomastoid surgery is still debatable. Objective: The objective of the study was to assess the potential etiology and outcomes of the late facial nerve paralysis after the tympanomastoid surgery. Materials and Methods: Eighteen patients of the late facial nerve paralysis out of the 1434 cases after tympanomastoid surgery were analyzed. The potential etiologies of the late facial nerve paralysis and its outcome were evaluated. Results: There was fallopian canal dehiscence in 10 patients (55.55%) out of the 18 patients with late-onset facial nerve paralysis in contrast to 262 of 1434 patients (18.27%) without late facial nerve paralysis (P < 0.01). Chorda tympani nerve was injured in three cases (16.66%) and overstretched in three cases (16.66%) whereas 2 (11.11%) had herpes labialis out of the 18 patients with late-onset facial nerve paralysis after tympanomastoid surgery. Conclusion: The risk for late/delayed facial nerve paralysis after tympanomastoid surgery is very rare. Exposure of the facial nerve and fallopian canal dehiscence is important risk factors for late facial nerve paralysis after tympanomastoid surgery. The viral reactivation and injury of the chorda tympani nerve may be triggered factor for the late facial nerve paralysis. The outcome of the posttympanomastoid surgery late facial nerve paralysis is excellent.