Bilateral facial palsy.

Background and Objectives: Because the incidence of bilateral facial palsy is extremely low, clinical diagnosis and treatment may be delayed and the possibility of misdiagnosis is high. This systematic review, therefore, evaluated the clinical manifestations of bilateral facial palsy. Methods: The SCOPUS and PubMed databases were searched through 31 August 2018, using the search term 'bilateral facial palsy'. Reference lists of identified studies were also reviewed. Results: A search of titles and abstracts identified 390 studies; after eliminating duplicates and inappropriate studies, 10 studies, involving 75 patients from four countries, were analyzed. The percentage of patients with facial nerve palsy who experienced simultaneous bilateral facial palsy ranged from 0.3% to 2.0%. There were no differences between men and women in all age groups. The causes of bilateral facial palsy differed, and 51% were associated with other cranial nerves. Complete recovery was achieved in 80% of patients and incomplete recovery in 20%. Conclusions: Bilateral facial palsy has various causes. Prognosis for recovery is good.