Bell Palsy: Facts and Current Research Perspectives

Bell palsy is a non-progressive neurological condition characterized by the acute onset of ipsilateral seventh cranial nerve paralysis. People who suffer from this type of facial paralysis develop a droop on one side of their face, or sometimes both. This condition is distinguished by a sudden onset of facial paralysis accompanied by clinical features such as mild fever, postauricular pain, dysgeusia, hyperacusis, facial changes, and drooling or dry eyes. Epidemiological evidence suggests that 15 to 23 people per 100,000 are affected each year, with a recurrence rate of 12%. It could be caused by ischaemic compression of the seventh cranial nerve, which could be caused by viral inflammation. Pregnant women, people with diabetes, and people with respiratory infections are more likely to have facial paralysis than the general population. Immune, viral, and ischemic pathways are all thought to play a role in the development of Bell paralysis, but the exact cause is unknown. However, there is evidence that Bell's hereditary proclivity to cause paralysis is a public health issue that has a greater impact on patients and their families. Delay or untreated Bell paralysis may contribute to an increased risk of facial impairment, as well as a negative impact on the patient's quality of life. For management, antiviral agents such as acyclovir and valacyclovir, and steroid treatment are recommended. Thus, early diagnosis accompanied by treatment of the uncertain etiology of the disorder is crucial. This paper reviews mechanistic approaches, and emerging medical perspectives on recent developments that encounter Bell palsy disorder.

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.

Bell Palsy and the Risk of Cardio-Cerebrovascular Disease: A Population-Based Follow-Up Study

OBJECTIVE

To evaluate the risk of cardio-cerebrovascular disease (CCVD), such as ischemic stroke and acute myocardial infarction (AMI), in patients diagnosed with Bell palsy STUDY DESIGN: Population-based follow-up study.

METHODS

We used the National Sample Cohort 2002 to 2013 data from the Korea National Health Insurance Service. The Bell palsy group comprised all patients diagnosed with Bell palsy (n = 730). The comparison group comprised patients selected randomly using propensity score matching (n = 1,460). The Kaplan-Meier survival analysis, log-rank test, and Cox proportional-hazards regression models were used to calculate the disease-free survival rate and hazard ratio (HR) of CCVD for each group.

RESULTS

Of the total study population, ischemic stroke developed in 15.7% of patients with Bell palsy and 9% of patients in the comparison group during the 12-year follow-up period. After adjusting for other factors, the HR of ischemic stroke during the 12-year follow-up period was 1.84 times greater in the Bell palsy group than in the comparison group (95% confidence interval [CI], 1.43-2.36). However, the adjusted HR of developing ischemic stroke for patients with Bell palsy treated concurrently with antiviral agents and steroids was 1.12 (95% CI, 0.62.-2.04). There was no significant relationship between Bell palsy and risk of AMI development (HR, 1.13; 95% CI, 0.71-1.82).

CONCLUSION

Bell palsy is linked with an increased incidence of ischemic stroke. Our data suggest that Bell palsy may be used as an indicator of increased stroke risk, and concurrent treatment with antiviral agents and steroids may be effective in preventing ischemic stroke.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:2371-2377, 2019.

Antiviral agents convey added benefit over steroids alone in Bell's palsy; decompression should be considered in patients who are not recovering

BACKGROUND

The management of Bell's palsy has been the subject of much debate, with corticosteroids being the preferred medication. However, evidence also supports the use of antiviral drugs for severe cases and even decompression surgery in patients who, despite medical treatment, are not recovering.

METHOD

A literature review was conducted on the management of Bell's palsy.

RESULTS

This paper describes the background, statistical evidence, study results and pathophysiological theories that support more aggressive treatment for patients with severe palsy and those who have inadequate recovery.

CONCLUSION

Combination therapy including antiviral medication significantly improves outcomes in patients with severe Bell's palsy. Decompression should be considered in patients who have not recovered with drug treatment.

Management of Bell's palsy in children: an audit of current practice, review of the literature and a proposed management algorithm

OBJECTIVE

We carried out a complete audit cycle, reviewing our management of paediatric patients with Bell's palsy within 72 h of symptom onset. Our protocol was published after the initial audit in 2009, and a re-audit was carried out in 2011. We aimed to improve our current practice in accordance with up-to-date evidence-based research on the use of steroids and antivirals.

PATIENTS AND METHODS

A total of 17 patients were included in the first cycle, but only eight patients met our inclusion and exclusion criteria for the re-audit. We assessed documentation of House-Brackmann (HB) grade on presentation, initial treatment, follow-up and recovery.

RESULTS

The first cycle revealed inconsistent management with steroids (41%), antivirals (6%), steroids and antivirals (6%) or nothing at all (47%). In addition, only 65% of patients were followed-up in the ear, nose and throat (ENT) clinic. Our management protocol was published in 2010, and a re-audit was completed. Our results showed 100% compliance with steroid treatment and 100% follow-up with the ENT team. A thorough literature review revealed some additional benefit from the use of antivirals.

CONCLUSIONS

At present there is insufficient evidence to discount the use of steroids and antivirals. Therefore, with our new management protocol, we recommend the use of steroids in patients presenting within 72 h of symptom onset, and antivirals for patients with a HB grade of IV or higher.

Prognostic factors of Bell's palsy: prospective patient collected observational study

The purpose of this study was to evaluate various parameters potentially influencing poor prognosis in Bell's palsy and to assess the predictive value for Bell's palsy. A single-center prospective patient collected observation and validation study was conducted. To evaluate the correlation between patient characteristics and poor prognosis, we performed univariate and multivariate analyzes of age, gender, side of palsy, diabetes mellitus, hypertension, and facial grading score 1 week after onset. To evaluate the accuracy of the facial grading score, we prepared a receiver operating characteristic (ROC) curve and calculated the area under the ROC curve (AUROC). We also calculated sensitivity, specificity, positive/negative likelihood ratio, and positive/negative predictive value. We included Bell's palsy patients who attended Ehime University Hospital within 1 week after onset between 1977 and 2011. We excluded patients who were less than 15 years old and lost-to-follow-up within 6 months. The main outcome was defined as non-recovery at 6 months after onset. In total, 679 adults with Bell's palsy were included. The facial grading score at 1 week showed a correlation with non-recovery in the multivariate analysis, although age, gender, side of palsy, diabetes mellitus, and hypertension did not. The AUROC of the facial grading score was 0.793. The Y-system score at 1 week moderate accurately predicted non-recovery at 6 months in Bell's palsy.

Steroid-antiviral treatment improves the recovery rate in patients with severe Bell's palsy

BACKGROUND

The extent of facial nerve damage is expected to be more severe in higher grades of facial palsy, and the outcome after applying different treatment methods may reveal obvious differences between severe Bell's palsy and mild to moderate palsy. This study aimed to systematically evaluate the effects of different treatment methods and related prognostic factors in severe to complete Bell's palsy.

METHODS

This randomized, prospective study was performed in patients with severe to complete Bell's palsy. Patients were assigned randomly to treatment with a steroid or a combination of a steroid and an antiviral agent. We collected data about recovery and other prognostic factors.

RESULTS

The steroid treatment group (S group) comprised 107 patients, and the combination treatment group (S+A group) comprised 99 patients. There were no significant intergroup differences in age, sex, accompanying disease, period from onset to treatment, or results of an electrophysiology test (P >.05). There was a significant difference in complete recovery between the 2 groups. The recovery (grades I and II) of the S group was 66.4% and that of the S+A group was 82.8% (P=.010). The S+A group showed a 2.6-times higher possibility of complete recovery than the S group, and patients with favorable electromyography showed a 2.2-times higher possibility of complete recovery.

CONCLUSIONS

Combined treatment with a steroid and an antiviral agent is more effective in treating severe to complete Bell's palsy than steroid treatment alone.

Correlation between the incidence and severity of Bell's palsy and seasonal variations in Taiwan

OBJECTIVE

To investigate possible correlations between the incidence and severity of Bell's palsy and seasonal variations in Taiwan.

METHODS

We studied data on the incidence of Bell's palsy over a 3-year period in Taiwan. The electroneurographic quotient was used as an index for the severity of nerve involvement. A higher electroneurographic quotient indicates less severe disease.

RESULTS

Data were collected from 775 patients. We analyzed the data using the chi-square goodness-of-fit test, and the results showed that seasonality was significantly associated with the incidence of Bell's palsy among men, with the incidence increasing during the cold months (p = 0.012). A significant association was evident between age and incidence, with a higher incidence among patients aged 50 years or younger (p = 0.027). By contrast, no significant relationship was found between seasonality and either female sex or older age. No statistical association was found between the degree of nerve involvement and season of onset in patients with Bell's palsy.

CONCLUSION

Bell's palsy increased among men and among younger patients during the cold seasons in Taiwan. No association emerged between the severity of Bell's palsy and the season of onset.