Antiviral treatment of Bell's palsy based on baseline severity: a systematic review and meta-analysis

Association between cytomegalovirus infection and neurological disorders: A systematic review

Cytomegalovirus (CMV) belongs to the Herpesviridae family and is also known as human herpesvirus type 5. It is a common virus that usually doesn't cause any symptoms in healthy individuals. However, once infected, the virus remains in the host's body for life and can reactivate when the host's immune system weakens. This virus has been linked to several neurological disorders, including Alzheimer's disease, Parkinson's disease, Autism spectrum disorder, Huntington's disease (HD), ataxia, Bell's palsy (BP), and brain tumours, which can cause a wide range of symptoms and challenges for those affected. CMV may influence inflammation, contribute to brain tissue damage, and elevate the risk of moderate-to-severe dementia. Multiple studies suggest a potential association between CMV and ataxia in various conditions, including Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, acute cerebellitis, etc. On the other hand, the evidence regarding CMV involvement in BP is conflicting, and also early indications of a link between CMV and HD were challenged by subsequent research disproving CMV's presence. This systematic review aims to comprehensively investigate any link between the pathogenesis of CMV and its potential role in neurological disorders and follows the preferred reporting items for systematic review and meta-analysis checklist. Despite significant research into the potential links between CMV infection and various neurological disorders, the direct cause-effect relationship is not fully understood and several gaps in knowledge persist. Therefore, continued research is necessary to gain a better understanding of the role of CMV in neurological disorders and potential treatment avenues.

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.

Computed tomographic features of the proximal petrous facial nerve canal in recurrent Bell's palsy

OBJECTIVES

The primary objective was to determine whether the narrowest dimensions of the labyrinthine facial nerve (LFN) canal on the symptomatic side in patients with unilateral recurrent Bell's palsy (BP) differ from those on the contralateral side or in asymptomatic, age- and gender-matched controls on computed tomography (CT). The secondary objectives were to assess the extent of bony covering at the geniculate ganglion and to record inter-observer reliability of the CT measurements.

METHODS

The dimensions of the LFN canal at its narrowest point perpendicular to the long axis and the extent of bony covering at the geniculate ganglion were assessed by two radiologists. Statistical analysis was performed using the Wilcoxon signed-rank and Mann-Whitney U tests (LFN canal dimensions) and the Chi-squared test (bony covering at the geniculate ganglion). Inter-observer reliability was evaluated using Intra-Class Correlation (ICC) and Cohen's kappa.

RESULTS

The study included 21 patients with unilateral recurrent BP and 21 asymptomatic controls. There was no significant difference in the narrowest dimensions of the ipsilateral LFN canal when compared to the contralateral side or controls (P = .43-.94). Similarly, there was no significant difference in the extent of bony covering at the geniculate ganglion when compared to either group (P = .19-.8). Good inter-observer reliability was observed for LFN measurements (ICC = 0.75-0.88) but not for the bony covering at the geniculate ganglion (Cohen's kappa = 0.53).

CONCLUSION

The narrowest dimensions of the LFN canal and the extent of bony covering at the geniculate ganglion do not differ in unilateral recurrent BP, casting doubt over their etiological significance.

LEVEL OF EVIDENCE

Level IV.

Efficacy of low-level laser therapy on management of Bell's palsy: a systematic review

The aim of this study is to evaluate the efficacy of low-level laser therapy (LLLT) in patients with Bell's palsy (BP) through a systematic review method. We systematically searched international databases including PubMed, Scopus, and Web of Science to find eligible articles without language limitation. All relevant randomized controlled trials (RCTs) that compared the efficacy of the LLLT with placebo laser, exercise, massage, or no intervention on BP patients were included. Four studies (out of 259) had met our inclusion criteria involving 171 patients and were entered to the systematic review. Full texts of the selected studies were retrieved and critically appraised using Physiotherapy Evidence Database (PEDro) scale. The patients of all trials were in sub-acute (less than 1 week) stage. Both of LLLT and control groups showed significant improvement after trials. Two authors reported significant differences between the groups after 6 weeks of laser application (830 nm, 100 mW). In converse, two other authors did not identify any effectiveness following 4 weeks and 15 days of LLLT application with 670 and 830 nm wavelength, sequentially. There is clear lack of information lead to get and evidence-based suggestion for the LLLT application on Bells' palsy; however, the LLLT irradiation with 830 nm and 100 mW power for a period of 6 weeks might be beneficial on recovery for the patients with sub-acute Bell's palsy. There were no reported adverse effects during treatment and/or follow-up sessions.

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.