Association between Initial Severity of Facial Weakness and Outcomes of Bell's Palsy

To establish whether clinical prognostic factor outcomes differed based on the initial severity of facial weakness and to determine the association between the initial severity of facial weakness and favorable outcomes. This retrospective cohort study analyzed all patients with Bell's palsy who visited the outpatient clinic of our university hospital from 1 January 2005 through 31 January 2021. The primary outcome was the rate of recovery at 6 months, evaluated separately in patients with initial House-Brackmann (H-B) grades 3-4 and 5-6. Secondary outcomes included clinical factors associated with favorable outcomes stratified by the initial H-B grade. The rate of favorable recovery was higher in patients with initial H-B grades 3-4 than initial H-B grades 5-6 (82.9% vs. 68.2%, p < 0.001). Multivariable logistic regression analysis showed that age 19-65 years and good electromyography (EMG) results were prognostic of good outcomes in patients with initial H-B grades 3-4. In addition, good EMG results, controlled hypertension, and combination antiviral therapy were significantly prognostic of favorable outcomes in patients with initial H-B grades 5-6. Subgroup analysis interactions showed that combination antiviral therapy (OR: 3.06, 95% CI 1.62-5.78, p < 0.001) in initial H-B grades 5-6 were associated with more favorable outcomes at 6 months than with initial H-B grades 3-4. Our results showed that the proportion of patients who achieved favorable outcomes at 6 months and multiple clinical factors affecting favorable outcomes differed significantly among patients differing in initial severity of Bell's palsy.