Peripheral blood T and B lymphocyte subpopulations in Bell's palsy

Depressive disorder and elevated risk of bell's palsy: a nationwide propensity score-weighting study

BACKGROUND

Prior studies have reported a potential relationship between depressive disorder (DD), immune function, and inflammatory response. Some studies have also confirmed the correlation between immune and inflammatory responses and Bell's palsy. Considering that the pathophysiology of these two diseases has several similarities, this study investigates if DD raises the risk of developing Bell's palsy.

METHODS

This nationwide propensity score-weighting cohort study utilized Taiwan National Health Insurance data. 44,198 patients with DD were identified as the DD cohort and 1,433,650 adult subjects without DD were identified as the comparison cohort. The inverse probability of treatment weighting (IPTW) strategy was used to balance the differences of covariates between two groups. The 5-year incidence of Bell's palsy was evaluated using the Cox proportional-hazard model, presenting results in terms of hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

The average age of DD patients was 48.3 ± 17.3 years, and 61.86% were female. After propensity score-weighting strategy, no significant demographic differences emerged between the DD and comparison cohort. The Cox proportional hazards model revealed a statistically significant adjusted IPTW-HR of 1.315 (95% CI: 1.168-1.481) for Bell's palsy in DD patients compared to comparison subjects. Further independent factors for Bell's palsy in this model were age (IPTW-HR: 1.012, 95% CI: 1.010-1.013, p < 0.0001), sex (IPTW-HR: 0.909, 95% CI: 0.869-0.952, p < 0.0001), hypertension (IPTW-HR: 1.268, 95% CI: 1.186-1.355, p < 0.0001), hyperlipidemia (IPTW-HR: 1.084, 95% CI: 1.001-1.173, p = 0.047), and diabetes (IPTW-HR: 1.513, 95% CI: 1.398-1.637, p < 0.0001) CONCLUSION: This Study confirmed that individuals with DD face an elevated risk of developing Bell's palsy. These findings hold significant implications for both clinicians and researchers, shedding light on the potential interplay between mental health and the risk of certain physical health outcomes.

Progress in treatment of facial neuritis by acupuncture combined with medicine from the perspective of modern medicine: A review

Facial neuritis is a common clinical disease with high incidence, also known as Bell palsy or idiopathic facial nerve paralysis, which is an acute onset of peripheral facial neuropathy. In modern medicine, there have been obstacles to the effective treatment of facial neuritis. At present, the clinical use of Western medicine treatment is also a summary of clinical experience, the reason is that the cause of facial neuritis is unknown. Facial neuritis belongs to the category of "facial paralysis" in traditional Chinese medicine. For thousands of years, Chinese medicine has accumulated a lot of relevant treatment experience in the process of diagnosis and treatment. At the same time, traditional Chinese medicine, acupuncture and the combination of acupuncture and medicine play an important role in the treatment of facial neuritis. This article discusses the treatment of facial neuritis with acupuncture combined with Chinese medicine, based on the research progress of modern medicine. In this review, we provide an overview of the effectiveness of acupuncture and medication combinations and facial neuritis with current studies investigating acupuncture and medication combinations in the treatment of facial neuritis.

The Significance of Bell's Palsy That Presents as Monocranial Versus Polycranial Neuropathy: A Case Series and Systematic Literature Review

PURPOSE

To investigate the effect of Bell's palsy (BP) presenting as polycranial neuropathy (PCN) compared with BP caused by isolated facial nerve (CNVII).

METHODS

We carried out a retrospective cohort study of the medical records of all consecutive patients who were diagnosed with BP at a single tertiary referral center between 2010 and 2017. Included were patients 18 years or older who were clinically diagnosed with BP and completed 7 days of systemic steroidal treatment and at least 6 months of follow-up. The patients were divided into two groups according to whether the BP derived from a monocranial neuropathy or a PCN. Demographics and BP severity and outcome were compared between these groups. A systematic literature review using Medline via "PubMed," "Embase," and "Web of Science" was conducted.

RESULTS

In total, 321 patients with BP were enrolled. The median (interquartile range) age at presentation was 44 (33-60) years. Sex distribution showed male predominance of 57.6% (n = 185) versus 42.4% (n = 136), and 21.2% (n = 68) had PCN. The most concomitantly affected cranial nerve (CN) was the trigeminal (CNV; n = 32, 47%), followed by the glossopharyngeal nerve (CNIX; n = 14, 21%) and the audiovestibular nerve (CNVIII; n = 10, 15%). Age, House-Brackmann score on presentation, and diabetes mellitus (DM) were independent predictors for PCN etiology ( p = 0.001, p = 0.034, and p < 0.001, respectively). Each increase in 1 year of age was associated with additional odds ratio (95% confidence interval) of 0.97 (0.95-0.99) for PCN. The odds ratio (95% confidence interval) associated with DM was 8.19 (4.02-16.70). Our systematic literature review identified 1,440 patients with the PCN type of BP. The most commonly affected CN was the trigeminus (25-48%), followed by the glossopharyngeal and audiovestibular nerves (2-19% and 0-43%, respectively).

CONCLUSION

The severity of facial weakness on initial presentation among PCN patients was significantly higher compared with the monocranial neuropathy-type BP patients. The authors believe that the significant association and prevalence rate ratio between DM and PCN warrant that a patient presenting with PCN undergo screening for DM.

Association of Overweight and Obesity With Bell Palsy in Children

BACKGROUND

In the Division of Pediatric Neurology at the University Medical Center Göttingen we observed that many patients with Bell palsy are overweight or obese. To evaluate whether overweight and obesity are associated with increased risk of Bell palsy in children we conducted this single-centered retrospective study by performing a database search for International Classification of Diseases (ICD)-10 primary and secondary diagnosis of G51.0 (facial nerve palsy) between January 1, 2010, and December 31, 2020.

METHODS

For risk assessment, patients' body mass indices (BMIs) were compared with BMI data of controls from a nationwide child health survey.

RESULTS

In total, 202 patients with peripheral facial nerve palsies (pFPs) were included, of which nearly half were classified as Bell palsies; 38% and 24% of the patients with Bell palsy and pFP had a BMI above the 90th percentile, respectively. High BMI was associated with statistically increased odds of Bell palsy in the group of overweight and obese patients (BMI >90th percentile; odds ratio [OR], 2.42; 95% confidence interval [CI], 1.6 to 3.8; P < 0.001) and solely obese patients (BMI >97th percentile; OR, 2.43; 95% CI, 1.4 to 4.3; P = 0.003).

CONCLUSIONS

We could confirm our observation that overweight and obesity are associated with increased risk of Bell palsy in children.

Role of Biomarkers as Prognostic Factors in Acute Peripheral Facial Palsy

Acute peripheral facial palsy (APFP), including Bell's palsy and Ramsay Hunt syndrome, is a disease that affects daily life through facial motor dysfunction, causing psychological problems. Various tests to evaluate prognosis have been studied; however, there are no validated predictive biomarkers to guide clinical decision making. Therefore, specific biomarkers that respond to treatment are required to understand prognostic outcomes. In this review, we discuss existing literature regarding the role of APFP biomarkers in prognosis and recovery. We searched the PubMed, EMBASE, and Cochrane Library databases for relevant papers. Our screening identified relevant studies and biomarkers correlating with the identification of predictive biomarkers. Only studies published between January 2000 and October 2021 were included. Our search identified 5835 abstracts, of which 35 were selected. All biomarker samples were obtained from blood and were used in the evaluation of disease severity and prognosis associated with recovery. These biomarkers have been effective prognostic or predictive factors under various conditions. Finally, we classified them into five categories. There is no consensus in the literature on the correlation between outcomes and prognostic factors for APFP. Furthermore, the correlation between hematologic laboratory values and APFP prognosis remains unclear. However, it is important to identify new methods for improving the accuracy of facial paralysis prognosis prediction. Therefore, we systematically evaluated prognostic and potentially predictive APFP biomarkers. Unfortunately, a predictive biomarker validating APFP prognosis remains unknown. More prospective studies are required to reveal and identify promising biomarkers providing accurate prognosis.

Acute Lagophthalmos due to Bell's Palsy could be a Sign of COVID-19

We sought to investigate whether lagophthalmos was associated with coronavirus infection (COVID-19). Patients diagnosed with lagophthalmos in 2019 were included in group one (n = 9), while those diagnosed with lagophthalmos in 2020 were included in group two (n = 33). With the onset of COVID-19, we observed that the number of patients seen with lagophthalmia increased compared with the same period from the previous year. To confirm this, reverse transcriptase-polymerase chain reaction for severe acute respiratory syndrome coronavirus 2 test results were followed in patients with suspicious findings, after which blood test results were compared. The reported lagophthalmos cases increased by 367% in 2020 compared with 2019. Additionally, the mean white blood cell, lymphocyte and platelet counts of patients in group two were all significantly decreased compared with group one. Lagophthalmos due to Bell's palsy could be a sign of COVID-19.

The Potential Role of Human Papillomavirus Infection in Bell's Palsy: A Hypothesis-Generating Study Based on a Nationwide Cohort

Objective: Our purpose was to investigate whether people with a previous human papillomavirus (HPV) infection were associated with an increased risk of Bell's palsy (BP).

Methods: By using Taiwan population-based data, patients aged > 18 years with HPV infection (n = 22,260) from 2000 to 2012 were enrolled and compared with control subjects who had never been diagnosed with an HPV infection at a 1:4 ratio matched by sex, age, index date, and co-morbidities (n = 89,040). The index date was the first date of HPV diagnosis. All the patients were tracked until the occurrence of BP. Cox proportional hazards regression was applied to estimate the hazard ratios (HRs) for the development of BP in both groups.

Results: The HPV group had 1.25 [95% confidence interval (CI) = 1.03–1.51] times higher risk of BP compared with the non-HPV group after adjusting for sex, age, and co-morbidities. The association of HPV and BP was significant in the sensitivity analyses. In the subgroup analysis, the impact of HPV infection on the risk of BP was more pronounced in the elderly > 50 years [adjusted hazard ratio (aHR) =1.86; 95% CI = 1.37–2.52], hypertension (aHR = 1.65; 95% CI = 1.17–2.31), and chronic obstructive pulmonary disease (aHR = 2.14, 95% CI 1.333.43) subgroups.

Conclusions: Patients with HPV infection have a higher risk of subsequent BP compared with non-HPV patients. More rigorous studies are needed to confirm if and how specific HPV genotypes are associated with BP and the possible role of vaccines in disease prevention.

Is There Any Relation between Serum Levels of Interleukin-10 and Neurophysiological Abnormalities in Bell's Palsy?

Background

Bell's palsy is the most common cause of peripheral facial palsy. The etiology and treatment of Bell's palsy are still controversial. Previous studies emphasize the role of herpes simplex and herpes zoster viruses in this ailment. The role of Interleukin-10 (IL-10) in Bell's palsy is yet unknown, and few studies have shed light on the matter. This study intended to assess the prognostic value of IL-10 and its relation to the intensity of electrodiagnostic abnormalities and evaluate its potential use as a factor for judging the need for medical or surgical interventions.

Materials and Methods

30 patients in the acute phase of Bell's palsy participated in this study. Peripheral blood samples were obtained for IL-10 assessment within the first 72 hours (before commencing treatment), and a nerve conduction study (NCS) was performed six days after symptom onset.

Results

There was no significant correlation between IL-10 serum levels and the severity of nerve conduction pathology in Orbicularis oculi and Orbicularis oris muscles. Also, IL-10 serum levels did not show any meaningful relationships with participants' age, gender, or symptoms.

Conclusion

The IL-10 serum levels are not relevant to the pathology of Bell's palsy, and the assessment of IL-10 serum levels cannot be used as an alternative to NCS for evaluating the severity of acute Bell's palsy.

Autosomal recessive hyper-IgE syndrome caused by DOCK8 gene mutation with new clinical features: a case report

BACKGROUND

Autosomal recessive hyper-IgE syndrome (AR-HIES) caused by DOCK8 gene is a rare immunodeficiency disease, the main clinical manifestations include recurrent Eczema-like rash, skin and lung abscesses, accompanied with increased serum IgE level. Here, we report a 7-year-old Chinese girl with a new clinic features caused by DOCK8 gene mutations.

CASE PRESENTATION

A 7-year-old girl was admitted to our hospital because of abnormal walking posture. The clinical manifestations of the patient included abnormal gait, eczema-like rash, fingertip abscess, high muscle tone, and facial paralysis. Among them, high muscle tone and facial paralysis are new clinic features which have not been reported previously. The blood eosinophils and serum IgE levels were significantly increased, and the lymphocyte subsets indicated a decrease of T lymphocytes. The magnetic resonance imaging (MRI) of her brain suggested myelin dysplasia and brain atrophy. Two novel compound heterozygous mutations (c.1868 + 2 T > C and c.5962-2A > G) of DOCK8 gene were identified by whole exome sequencing. By literature review, there are 11 mutations of DOCK8 gene in Chinese AR-HIES patients.

CONCLUSIONS

Two novel splice-site mutations(c.1868 + 2 T > C and c.5962-2A > G) of DOCK8 gene and new clinic features were found in a Chinese girl with AR-HIES, which extends our understanding of DOCK8 gene mutation spectrum and phenotype of AR-HIES in children.

The etiology of Bell's palsy: a review

Bell’s palsy is the most common condition involving a rapid and unilateral onset of peripheral paresis/paralysis of the seventh cranial nerve. It affects 11.5–53.3 per 100,000 individuals a year across different populations. Bell’s palsy is a health issue causing concern and has an extremely negative effect on both patients and their families. Therefore, diagnosis and prompt cause determination are key for early treatment. However, the etiology of Bell’s palsy is unclear, and this affects its treatment. Thus, it is critical to determine the causes of Bell’s palsy so that targeted treatment approaches can be developed and employed. This article reviews the literature on the diagnosis of Bell’s palsy and examines possible etiologies of the disorder. It also suggests that the diagnosis of idiopathic facial palsy is based on exclusion and is most often made based on five factors including anatomical structure, viral infection, ischemia, inflammation, and cold stimulation responsivity.

Granulomatosis with polyangiitis and facial palsy: Literature review and insight in the autoimmune pathogenesis

Granulomatosis with polyangiitis (GPA) is an autoimmune systemic necrotizing small-vessel vasculitis associated with the presence of anti-neutrophil cytoplasmic antibodies (ANCA). Oto-neurological manifestations of ANCA-associated vasculitis according to PR3-ANCA positivity and MPO-ANCA positivity are usually reported. Facial nerve palsy is usually reported during the clinical course of the disease but it might appear as the presenting sign of GPA. Necrotizing vasculitis of the facial nerve 'vasa nervorum' is nowadays the most widely accepted etiopathogenetic theory to explain facial damage in GPA patients. A central role for PR3-ANCA in the pathophysiology of vasculitis in GPA patients with oto-neurological manifestation is reported. GPA requires prompt, effective management of the acute and chronic manifestations. Once the diagnosis of GPA has been established, clinicians should devise an appropriate treatment strategy for each individual patient, based on current clinical evidence, treatment guidelines and recommendations.

Varicella Zoster Aseptic Meningitis: Report of an Atypical Case and Literature Review

Patient: Female, 15

Final Diagnosis: Varicella Zoster aseptic meningitis

Symptoms: —

Medication: —

Clinical Procedure: Lumber punctur

Specialty: Infectious Diseases

Facial nerve palsy after reactivation of herpes simplex virus type 1 in diabetic mice

OBJECTIVES/HYPOTHESIS

Bell's palsy is highly associated with diabetes mellitus (DM). Either the reactivation of herpes simplex virus type 1 (HSV-1) or diabetic mononeuropathy has been proposed to cause the facial paralysis observed in DM patients. However, distinguishing whether the facial palsy is caused by herpetic neuritis or diabetic mononeuropathy is difficult. We previously reported that facial paralysis was aggravated in DM mice after HSV-1 inoculation of the murine auricle. In the current study, we induced HSV-1 reactivation by an auricular scratch following DM induction with streptozotocin (STZ).

STUDY DESIGN

Controlled animal study.

METHODS

Diabetes mellitus was induced with streptozotocin injection in only mice that developed transient facial nerve paralysis with HSV-1. Recurrent facial palsy was induced after HSV-1 reactivation by auricular scratch.

RESULTS

After DM induction, the number of cluster of differentiation 3 (CD3)(+) T cells decreased by 70% in the DM mice, and facial nerve palsy recurred in 13% of the DM mice. Herpes simplex virus type 1 deoxyribonucleic acid (DNA) was detected in the facial nerve of all of the DM mice with palsy, and HSV-1 capsids were found in the geniculate ganglion using electron microscopy. Herpes simplex virus type 1 DNA was also found in some of the DM mice without palsy, which suggested the subclinical reactivation of HSV-1.

CONCLUSIONS

These results suggested that HSV-1 reactivation in the geniculate ganglion may be the main causative factor of the increased incidence of facial paralysis in DM patients.

The neurologist's dilemma: a comprehensive clinical review of Bell's palsy, with emphasis on current management trends

Background

Recent advances in Bell’s palsy (BP) were reviewed to assess the current trends in its management and prognosis.

Material/Methods

We retrieved the literature on BP using the Cochrane Database of Systematic Reviews, PubMed, and Google Scholar. Key words and phrases used during the search included ‘Bell’s palsy’, ‘Bell’s phenomenon’, ‘facial palsy’, and ‘idiopathic facial paralysis’. Emphasis was placed on articles and randomized controlled trails (RCTs) published within the last 5 years.

Results

BP is currently considered the leading disorder affecting the facial nerve. The literature is replete with theories of its etiology, but the reactivation of herpes simplex virus isoform 1 (HSV-1) and/or herpes zoster virus (HZV) from the geniculate ganglia is now the most strongly suspected cause. Despite the advancements in neuroimaging techniques, the diagnosis of BP remains one of exclusion. In addition, most patients with BP recover spontaneously within 3 weeks.

Conclusions

Corticosteroids are currently the drug of choice when medical therapy is needed. Antivirals, in contrast, are not superior to placebo according to most reliable studies. At the time of publication, there is no consensus as to the benefit of acupuncture or surgical decompression of the facial nerve. Long-term therapeutic agents and adjuvant medications for BP are necessary due to recurrence and intractable cases. In the future, large RCTs will be required to determine whether BP is associated with an increased risk of stroke.

Ophthalmic Management of Facial Nerve Palsy: A Review

Facial nerve palsy affects individuals of all ages, races, and sexes. Psychological and functional implications of the paralysis present a devastating management problem to those afflicted, as well as the carriers. Since Sir Charles Bell's original description of facial palsy in 1821, our understanding and treatment options have expanded. It is essential that a multidisciplinary approach, encompassing ophthalmologists; Ear, Nose, and Throat surgeons; plastic surgeons; and psychologists work closely to optimize patient management in a staged approach. Although the etiology remains unknown, strong histological, cerebral spinal fluid, and radiological evidence suggests a possible association with herpes simplex virus in idiopathic facial nerve palsy (Bell's palsy). The use of steroids has been suggested as a means of limiting facial nerve damage in the acute phase. Unfortunately, no single randomized control trial has achieved an unquestionable benefit with the use of oral steroid therapy and thus remains controversial. In the acute phase, ophthalmologists play a pivotal role in preventing irreversible blindness from corneal exposure. This may be successfully achieved by using intensive lubrication, medical therapy (botulinum toxin), or surgery (upper lid weighting or tarsorraphy). Once the cornea is adequately protected and recovery deemed unlikely, longer term planning for eyelid and facial reanimation may take place in an individualized manner. Onset is sudden and management potentially lengthy. Physician empathy, knowledge, and experience are essential in averting long-term lifestyle and psychological discomfort for patients.

Comparisons of steroid, acyclovir, lipoprostoglandin E1 and steroid + acyclovir treatments in facial paralysis: a rat study

OBJECTIVE

To induce experimental peripheral facial paralysis by inoculation of HSV1 and to compare the effects of steroid, acyclovir, lipoprostoglandin E2 and steroid + acyclovir treatments in terms of clinical recovery, electrophysiologically and histopathologically.

MATERIALS AND METHODS

A total of 132 adult female rats were used in this study. HSV type 1 strain was inoculated at the back of the left ear by using 27 gauge needle. Of all animals, 70 (53%) rats which developed facial paralysis were divided into five groups (n = 14 for each group) as control, steroid + acyclovir, lipoprostaglandin E1, steroid only and acyclovir only. At the end of the 21 days period, the rats were clinically examined and electrophysiological tests were performed, then decapitated and the nerve specimens were obtained.

RESULTS

A modified electroneurography (ENoG) test was performed and the latencies and the amplitudes were compared. The findings of the intact side were better, but with no significant difference. Histopathologicaly edema was significantly smaller in all groups compared to the controls (p < 0.05). Similarly, no difference was seen in terms of vacuolar degeneration and Schwann cell hyperchromatisation among the groups and no significant difference in recovery period and rate of facial paralysis when all groups were compared.

CONCLUSION

Facial paralysis induced by HSV1 recovered spontaneously within a week. In the treatment of facial paralysis, steroid alone, acyclovir alone, steroid + acyclovir, or lipoprostaglandin E1 all reduced edema in the infected facial nerve but there was no statistical difference in of the rate or degree of recovery.

Lymphocyte subsets in Bell's palsy: immune pathogenesis and outcome prediction

The aim of this prospective study is to define the prognostic significance of lymphocyte subset analysis in children with Bell's palsy. Lymphocyte subgroup analysis in peripheral blood was performed in 17 children with Bell's palsy by using flow cytometry. Before a standard protocol of corticosteroid treatment, patients were categorized into two groups for facial nerve impairment on the basis of the clinical findings: Group 1 (mild to moderate impairment), 7 patients; and Group 2 (severe impairment), 10 patients. Outcome of the patients was evaluated at the end of 3 months follow-up and categorized as satisfactory recovery (n = 12) or unsatisfactory recovery (n = 5). Decreased percentages of B cells (CD19) and T helper/inducer (CD4) subsets were measured in patients with Bell's palsy compared with age-matched healthy control patients. Patients with severe impairment had significantly lower percentages of CD4 and CD19 subsets, whereas patients with mild to moderate impairment had only decreased percentage of CD19 subsets. There was no statistically significant difference in the percentage of lymphocyte subsets between the patients with satisfactory and unsatisfactory recovery. These results provide additional support for cell-mediated immunopathogenesis in patients with Bell's palsy, without any prognostic significance for the outcome.

Mouse model of Bell's palsy induced by reactivation of herpes simplex virus type 1

In order to investigate the mechanism of Bell's palsy, we developed an animal model of facial nerve paralysis induced by the reactivation of herpes simplex virus type 1 (HSV-1). Eight weeks after recovery from facial nerve paralysis caused by inoculation with HSV-1, the mice were treated with auricular skin scratch at the site of the previous inoculation, or with intraperitoneal injection of anti-CD3 monoclonal antibody (mAb), or combination of both procedures. No mice developed facial nerve paralysis when they were treated with either auricular scratch or mAb injection alone. In contrast, 20% of mice developed facial nerve paralysis with the combined treatment. With one exception, no mouse treated with either auricular scratch or mAb injection showed HSV-I DNA in their facial nerve tissue, whereas 4 out of 6 mice receiving both treatments showed HSV-1 DNA on day 10 after treatment. Histopathological findings showed neuronal degeneration in the geniculate ganglion and demyelination of the facial motor nerve in paralyzed mice. These findings suggest that a combination of stimuli, local skin irritation, and general immunosuppression is essential for successfully inducing facial nerve paralysis in mice with latent HSV-1 infection.

Bell's palsy associated with herpes simplex gingivostomatitis. A case report

Bell's palsy is a sudden, isolated, peripheral facial paralysis caused by various known and sometimes unknown factors. The case of an 18-year-old man who developed Bell's palsy after onset of primary herpetic gingivostomatitis is presented. Although Bell's palsy has already been associated with herpes simplex virus type 1, the described case is the first in the literature in which enzyme-linked immunosorbent assays for immunoglobulin G to herpes simplex virus type 1 and herpes simplex virus type 1 culture were both positive. The recent literature regarding the possible relationship between herpes simplex virus type 1 and Bell's palsy is reviewed and discussed.

Immunologic aspects of facial nerve paralysis induced by herpes simplex virus infection in mice

This immunologic aspects of facial nerve paralysis due to herpes simplex virus type 1 (HSV-1) infection were investigated in a mouse model system. Half of the 4- to 5-week-old mice developed facial nerve paralysis, whereas none of the 6-week-old mice died or developed facial nerve paralysis on inoculation with HSV-1. Six-week-old mice showed significantly higher titers of anti-HSV-1 neutralizing antibody than did 4-week-old animals. Passive transfer of either anti-HSV-1 antibody or HSV-1-immunized splenic T cells into 4-week-old mice 3 hours after HSV-1 inoculation prevented development of facial nerve paralysis and death, whereas such transfers 48 or 96 hours after HSV-1 inoculation did not prevent or exacerbate facial nerve paralysis. These results demonstrate that the age and the immunologic potency of mice are closely related to the pathogenesis of facial nerve paralysis. That facial nerve paralysis developed even in 6-week-old mice whose T-cell function was suppressed with anti-CD3 antibody suggests that virus-induced cellular demyelination is unlikely as a cause of facial nerve paralysis in this animal model.

Idiopathic facial paralysis: a randomized, prospective, and controlled study using single-dose prednisone versus acyclovir three times daily

In a prospective, controlled, and randomized study, we compared the outcome of 101 Bell's palsy patients treated with acyclovir (54 patients) or prednisone (47 patients). The acyclovir dosage was 2400 mg (800 mg three times a day) for 10 days, and prednisone was given as a single daily dose of 1 mg/kg of body weight for 10 days and tapered to 0 over the next 6 days. Minimum follow-up was 3 months in all patients. Patients in the prednisone group had better clinical recovery than those treated with acyclovir. Less degree of neural degeneration was observed in the prednisone group compared with acyclovir patients. The incidence of sequelae was the same in both groups. According to these results, in a 10-day treatment cycle acyclovir given 800 mg three times is not as useful as prednisone given 1 mg/kg of body weight once a day in patients with idiopathic facial nerve paralysis.

Bell's palsy treatment with acyclovir and prednisone compared with prednisone alone: a double-blind, randomized, controlled trial

In a double-blind study, we compared the final outcome of 99 Bell's palsy patients treated with either acyclovir-prednisone (53 patients) or placebo-prednisone (46 patients). For patients receiving acyclovir, the dosage was 2,000 mg (400 mg 5 times daily) for 10 days. Electrical tests included electroneurography and the maximal stimulation test. Univariate comparisons of outcome and electrical tests between the two groups were made with chi 2 analysis, Fisher's exact test, and t-tests. The outcome in acyclovir-prednisone-treated patients was superior to that in placebo-prednisone-treated patients. Treatment with acyclovir-prednisone was statistically more effective in returning volitional muscle motion (recovery profile of 10; p = .02) and in preventing partial nerve degeneration (p = .05) than placebo-prednisone treatment. The t-tests indicated that the recovery profile and index means were significantly better for the acyclovir-treated group (recovery profile t = 1.99, p = .051; recovery index t = 2.10, p = .040). We conclude that acyclovir-prednisone is superior to prednisone alone in treating Bell's palsy patients and suggest that herpes simplex is the probable cause of Bell's palsy.

Role of herpes simplex virus infection in the pathogenesis of facial paralysis in mice

To clarify the role and site of herpes simplex virus (HSV) infection in the pathogenesis of facial paralysis, we examined the viral genome by the polymerase chain reaction and the neutralization antibody titer using microplates in an animal model. Following inoculation with HSV type 1 of the KOS strain into mouse auricles, HSV DNA appeared in the ipsilateral facial nerve on the 3rd day, and in bilateral facial nerves and the brain stem on the 10th day only in animals with facial paralysis. In animals without facial paralysis, no HSV DNA was detected in these tissues. The neutralization antibody titer was elevated between 4 and 20 days in all animals, with or without facial paralysis. Facial paralysis developed only on the inoculated side, even though HSV DNA was also present in the contralateral facial nerve. We conclude that HSV infection in the facial nerve and brain stem is prerequisite for facial paralysis, and suggest that an immunologic reaction following viral infection plays a key role in the pathogenesis.

Facial nerve paralysis induced by herpes simplex virus in mice: an animal model of acute and transient facial paralysis

We have been the first to succeed in producing an acute and transient facial paralysis simulating Bell's palsy, by inoculating herpes simplex virus into the auricles or tongues of mice. The KOS strain of the virus was injected into the auricle of 104 mice and the anterior two thirds of the tongue in 30 mice. Facial paralysis developed between 6 and 9 days after virus inoculation, continued for 3 to 7 days, and then recovered spontaneously. The animals were painlessly sacrificed between 6 and 20 days after inoculation for histopathologic and immunocytochemical study. Histopathologically, severe nerve swelling, inflammatory cell infiltration, and vacuolar degeneration were manifested in the affected facial nerve and nuclei. Herpes simplex virus antigens were also detected in the facial nerve, geniculate ganglion, and facial nerve nucleus. The pathophysiologic mechanisms of the facial paralysis are discussed in light of the histopathologic findings, in association with the causation of Bell's palsy.

The HLA system and T-cell subsets in Bell's palsy

The etiology of Bell's palsy (BP) is still unknown, but infectious, immunological and genetic factors have been suggested to play a role in the pathogenesis of the disease. We analyzed blood samples of 92 Mexican Mestizo patients diagnosed as having BP according to established international criteria, and the results were compared to a group of apparently healthy controls of the same ethnic origin. HLA class I (A, B, C) and Class II (DR, DQ) products of the major histocompatibility complex (MHC), and the percentages of CD3, CD4 and CD8 T-cell subsets were investigated. The number of family antecedents was surprisingly high (46%), supporting a genetic basis. There was a slight increase of DRw13, suggesting a possible susceptibility class II-linked gene. A significant decrease of DR4 (pc = 0.001) was detected, which may indicate the existence of a resistance DR-linked gene. Thus, a non DR4 carrier may be in high risk of expressing BP. In the acute phase of the disease, the T-cell subsets showed a decrease in CD3 and CD4 cells when compared to controls. CD8 cells were increased in the same stage. A transient T-cell imbalance was thus observed which recovered in the convalescent phase. None of the patients with CD4 lower than 40% were DR4, suggesting that the DR-linked resistance gene may predispose to the T-cell defect.

Depression of T cells in Bell's palsy

We analyzed T-lymphocytes and their subsets in 20 patients with Bell's palsy. We used the monoclonal antibodies anti-Leu-1, anti-Leu-2a, and anti-Leu-3a directed against T-lymphocytes and T suppressor/cytotoxic (Ts) and T helper/inducer (Th) cell subsets. Blood samples taken in the acute and convalescent phases of the illness were compared. The percentage of T cells (Leu-1+ cells) was decreased during the acute stage, mainly because of a reduction of the Th cell subset (Leu-3+ cells). No significant alteration was found in the Ts cell subset (Leu-2+ cells). The T cell and Th cell subset depressions were restored to normal within 4 to 6 weeks of the onset of the palsy. The T cell changes in the peripheral blood in the acute stage of Bell's palsy indicate the involvement of cellular immune mechanisms.

Activated T cells and Leu-7+ cells in Bell's palsy

Patients with Bell's palsy were investigated with regard to the cellular immune response during the acute and convalescent stages with the purpose of acquiring information concerning the etiology of the condition. In order to ascertain whether there was activation of the immune system, the proportion of activated T cells in the peripheral blood of 14 patients with Bell's palsy was analysed using monoclonal antibodies. A transient increase of these cells occurred in the acute stage, with a return to normal in the convalescent stage. The Leu-7+ cells which play a role in the natural cellular defence against viral infections, were also studied by using monoclonal antibodies in 25 patients. A significant change in the percentage of Leu-7+ cells was not found when the samples from the entire group were analysed. However, 10 patients who were investigated between September and October 1984, when the incidence of Bell's palsy was comparatively high, showed significantly lower percentages of Leu-7+ cells in the acute stage compared with the convalescent stage. The increase in the activated T cells in the acute phase of the palsy suggests a cell-mediated, immuno-regulatory abnormality with primary or secondary immune activation. Similar cellular immune alterations are found also in multiple sclerosis. Further, the differences in the proportions of Leu-7+ cells which occurred in these 10 patients may denote a contribution of various etiological factors to the disease.

Cellular immunity abnormalities in patients with recurrent Bell's palsy

Recurrent Bell's palsy is a rare form of facial paralysis. To investigate the role which cellular immunity plays in the aetiology of recurrent Bell's palsy, we evaluated a series of such patients using a laboratory test specially formulated to test the cellular immune system. We measured T-lymphocyte and T-lymphocyte subsets in the peripheral blood of 10 recurrent Bell's palsy patients and in 30 healthy volunteers. T-lymphocytes and T-lymphocyte subsets were reduced significantly in the patients, but the T-helper: T-cytotoxic ratio was normal. Cellular immunity abnormalities were therefore found in the peripheral blood of patients with recurrent Bell's palsy, supporting the concept that this is an immunomediated demyelinating disease.

Immune reactivity in Bell's palsy

Although the pathogenesis of acute facial (Bell's) palsy is probably multifactorial, some investigators believe that the disorder results from autoimmune demyelination and is perhaps related to previous viral infection. The purpose of this study was to identify immune mechanisms which might contribute to Bell's palsy. The lymphocyte transformation test and immunofluorescence were evaluated with a soluble homogenate of unrefined peripheral nerve antigens. Three antigen-nonspecific tests were also studied. Results in 14 patients with Bell's palsy were compared with those in 21 controls. To be eligible for study, patients with Bell's palsy had to be seen within 10 days of onset of weakness. The control group included 5 patients with facial nerve dysfunction from other causes and 16 normal volunteers. No patient or control had previously received steroids. Five patients with Bell's palsy and one normal volunteer had abnormal lymphocyte transformation (p less than .05). Virtually all other tests were normal. These results. suggest that some instances of Bell's palsy result from cell-mediated immunity against peripheral nerve antigens. They also encourage further research in steroid and other immunotherapy.

Vestibular abnormalities in patients with Bell's palsy

In order to assess the extent of the underlying pathology in Bell's palsy, the vestibular function of 24 patients was evaluated within the first week from the onset of facial paralysis. Seven patients had pathological findings by ENG and an additional three had subjective vestibular signs; four of these ten patients also showed abnormal auditory brain stem evoked potentials. There was no correlation between the severity of the paralysis or the prognosis for recovery and the presence of vestibular abnormalities.