Has Coranavirus Disease 2019 Changed the Incidence and Outcome of Bell's Palsy?

BACKGROUND

Objectives

(1) To determine whether the incidence of Bell's Palsy (BP) increased during the pandemic. (2) To investigate whether the outcomes of patients with BP and COVID-19 infection or vaccination differ from those in the pre-pandemic era.

METHODS

Patients with BP were studied in 2 periods retrospectively (March 2021-March 2022 and August 2018-August 2019). A prospective study from March 2021 to March 2022 was also performed. Primary outcome was grade ≤Ⅱ in the House-Brackmann (HB) and/or >70 in the Sunnybrook facial grading system (SFGS) scales at the 12-week visit. Reverse transcriptase polymerase chain reaction (PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and enzyme-linked immunosorbent assay-based SARS-CoV-2 immuonoglobulin G (IgG) test (blood) were measured.

RESULTS

About 162 and 196 patients with BP were identified between March 2021 and March 2022 and August 2018 and August 2019, respectively. Forty-seven patients (29%) entered the prospective study; 85% had HB grades I or II, while 92% had an SFGS score of 71-100 at the last visit. Only 3 patients (6.5%) had a positive PCR during the initial episode, whereas 35 patients (77%) had positive IgG SARS-CoV-2. There was no association between positive PCR and facial function outcomes. Of the 162 patients, 105 (67%) had received COVID-19 vaccine. In 23 of them (22%), the paralysis appeared within the first 30 days after a vaccine dose.

CONCLUSION

Coronavirus disease 2019 did not increase the incidence of BP. A direct association between the coronavirus and BP outcome cannot be established. The considerable number of patients developing BP within the first month suggests a possible association between COVID-19 vaccines and BP.