Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio as Prognostic Hematologic Markers of Bellʼs Palsy: A Meta-analysis

OBJECTIVE: Bell's palsy (BP) is the most common cause of unilateral peripheral facial paralysis, and inflammation has been proposed as the main pathological cause. The study aim was to investigate the relationship between hematologic inflammatory markers, including the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR), and BP. DATA SOURCES: The following key words were used to search PubMed and Scopus for English language articles: Bell's palsy, facial palsy, facial paresis or facial paralysis, neutrophil, lymphocyte, and platelet. STUDY SELECTION: Articles related to BP with NLR or PLR data. DATA EXTRACTION: The data included patient profiles, House-Brackmann score, treatment modality, NLR, and PLR. DATA SYNTHESIS: Seven articles were selected. A random effect model was used to analyze the aggregated data. Six of these articles that included the NLR and two that included the PLR of BP and control patients were analyzed for the difference between BP and control patients. Three articles that included the NLR of the recovery and nonrecovery groups were analyzed for the relationship between NLR and recovery. CONCLUSIONS: The NLR was significantly higher for the BP patients than for the controls. Furthermore, the NLR was significantly lower for the recovery group than for the nonrecovery group. A high NLR was associated with poor prognosis and related to the severity of facial nerve inflammation. There was no significant difference between the PLRs of the BP patients and controls. The NLR, but not the PLR, was found to be a useful prognostic indicator of BP.