Acquired bilateral facial palsy: a systematic review on aetiologies and management

Objective: To systematically review the published cases of bilateral facial palsy (BFP) to gather evidence on the clinical assessment and management of this pathology. Methods: Following PRISMA statement recommendations, 338 abstracts were screened independently by two authors. Inclusion criteria were research articles of human patients affected by BFP, either central or peripheral; English, Italian, French or Spanish language; availability of the abstract, while exclusion criteria were topics unrelated to FP, and mention of unilateral or congenital FP. Only full-text articles reporting the diagnostic work-up, the management, and the prognosis of the BFP considered for further specific data analysis. Results: A total of 143 articles were included, resulting a total of 326 patients with a mean age of 36 years. The most common type of the paralysis was peripheral (91.7%), and the autoimmune disease was the most frequent aetiology (31.3%). The mean time of onset after first symptoms was 12 days and most patients presented with a grade higher than III. Associated symptoms in idiopathic BFP were mostly non-specific. The most frequently positive laboratory exams were cerebrospinal fluid analysis, autoimmune screening and peripheral blood smear, and the most performed imaging was MRI. Most patients (74%) underwent exclusive medical treatment, while a minority were selected for a surgical or combined approach. Finally, in more than half of cases a complete bilateral recovery (60.3%) was achieved. Conclusions: BFP is a disabling condition. If a correct diagnosis is formulated, possibilities to recover are elevated and directly correlated to the administration of an adequate treatment.