Are viral-infections associated with Ménière's Disease? A systematic review and meta-analysis of molecular-markers of viral-infection in case-controlled observational studies of MD

Infectious causes and mimickers of meniere's disease

PURPOSE OF REVIEW

To review the evidence of a possible viral etiology of Meniere's disease, the role of antiviral therapy, as well as other infectious disease processes that may mimic Meniere's disease. Better understanding of the etiology of Meniere's disease and the role of various infectious disease processes may allow for more effective diagnosis and management.

RECENT FINDINGS

There is evidence that viral infections - to Herpes simplex virus, cytomegalovirus, Epstein Barr virus, influenza, adenovirus, Coxsackie virus B, and Varicella Zoster Virus - may be involved in the development of Meniere's disease, however the evidence is inconsistent and the underlying mechanism remains theoretical. Nevertheless, antiviral therapy may be effective for a subset of patients with Meniere's disease. Lastly, other infectious diseases including Lyme disease and syphilis can present with symptoms similar to Meniere's disease. It is important to discern these from Meniere's disease to determine the appropriate treatment.

SUMMARY

There is a paucity of high-quality evidence to support a viral etiology of Meniere's disease, and the current evidence appears circumstantial and inconsistent. Additional research is necessary to establish the mechanism and causative pathogens. Antiviral therapy may provide therapeutic benefit for a subset of patients with Meniere's disease. Furthermore, clinicians should be aware of other infectious mimics of Meniere's disease and include them in the differential diagnosis of patients presenting with Meniere's-like symptoms. Research on this subject continues to evolve, and data from these studies represent a growing repository of evidence that can be used to guide clinical decision-making.

A Review of Sensorineural Hearing Loss in Congenital Cytomegalovirus Infection

The intrauterine transmission of the TORCH group (toxoplasmosis, rubella cytomegalovirus (CMV), herpes simplex, and HIV) produces severe complications in the fetus, leading to major life challenges for the newborns. CMV is considered one of the leading causes of congenital hearing loss in babies born to infected mothers. The majority of the cases are asymptomatic but a certain proportion show symptoms, which may not be present until later. The human cytomegalovirus (HCMV) infection can also be transferred to the baby postnatally through breastfeeding. Mothers facing primary infection from the CMV have a greater tendency to transmit the infection to the fetus, whereas secondary infection due to reactivation of the virus in females who were affected before pregnancy, delivers asymptomatic babies in most cases. Vertical transmission of HCMV, that is via the placenta from infected mother to fetus, is one of the leading causes of congenital sensorineural hearing loss (SNHL) and neurodevelopmental complications in newborns. It accounts for up to 10% of SNHL cases in newborns, of both unilateral and bilateral types. Antiviral therapy is helpful in such cases if administered within the first month of life, and for hearing impairment, cochlear implants have been used to treat children who develop profound hearing loss. The child can present with hearing loss at birth or it may be late in onset and of progressive type. Suspected children should be evaluated regularly for the early detection of hearing loss and to provide the appropriate treatment.

Prevalence of symptoms in 1512 COVID-19 patients: have dizziness and vertigo been underestimated thus far?

The relationship between SARS-CoV-2 infection and dizziness is still unclear. The aim of this study is to assess the prevalence and characteristics of dizziness and vertigo among patients with mild-to-moderate COVID-19. Patients discharged from the emergency rooms with a confirmed SARS-CoV-2 diagnosis were assisted by daily telephone calls until nasopharyngeal swab negativization, and specific symptoms concerning balance disorders were investigated through targeted questions posed by experienced physicians. The study included 1512 subjects (765 females, 747 males), with a median age of 51 ± 18.4 years. New-onset dizziness was reported by 251 (16.6%) patients, among whom 110 (43.8%) complained of lightheadedness, 70 (27.9%) of disequilibrium, 41 (16.3%) of presyncope, and 30 (12%) of vertigo. This study analyzed in detail the prevalence and pathophysiological mechanisms of the different types of balance disorders in a large sample, and the results suggest that dizziness should be included among the main symptoms of COVID-19 because one-sixth of patients reported this symptom, with females being significantly more affected than males (20.3 vs 12.9%, P < 0.001). Most cases of dizziness were attributable to lightheadedness, which was probably exacerbated by psychophysical stress following acute infection and mandatory quarantine. Vertigo should not be underestimated because it might underlie serious vestibular disorders, and disequilibrium in elderly individuals should be monitored due to the possible risk of falls.

Audiovestibular Consequences of Congenital Cytomegalovirus Infection: Greater Vulnerability of the Vestibular Part of the Inner Ear

OBJECTIVES

To investigate the impact of congenital cytomegalovirus infection on cochlear and vestibular function.

DESIGN

This retrospective study conducted between March 2014 and March 2020 included children with confirmed congenital cytomegalovirus infection who underwent a complete audio-vestibular evaluation. It included a bithermal caloric test, a video head impulse test and a cervical vestibular evoked myogenic potential associated with a complete hearing assessment.

RESULTS

The cohort of 130 children included in the study had a median age of 21 months (interquartile range: 12 to 37 months). Eighty-three children (64%) showed an inner ear impairment (both cochlear and vestibular). The vestibular part of the inner ear was significantly more frequently impaired than the cochlear part (ρ = 0.003). Sixty-two children (48%) showed confirmed hearing impairment. The severity of hearing loss was variable, with a high proportion of profound hearing loss (30/62, 48%), which was often bilateral (47/62, 76%). The vestibular assessment showed a canal function disorder in 67 children (88%) and an otolith function disorder in 63 children (83%; ρ = 0.36). The video head impulse test was significantly less altered (64%) compared with the bithermal caloric test (80%; ρ = 0.02) and the cervical vestibular evoked myogenic potential (83%; ρ = 0.009). Only seven out of 83 children (8%) showed hearing loss without vestibular dysfunction, of which only one had a normal hearing screening test at birth. For the children who passed the hearing screening test at birth and presented an inner ear impairment [n = 36, median age: 16 (11 to 34) months], vestibular disorders were later found in 35 children (97%) and 17 of them (47%) developed hearing loss secondarily. This underlines the importance of assessing both vestibular and auditory parts of the inner ear. When comparing the agreement of cochlear and vestibular impairment, the severity and the laterality of the impairment were low [Cohen's kappa 0.31 (0.22 to 0.40) and 0.43 (0.32 to 0.55), respectively].

CONCLUSION

In our study, we demonstrated that although both cochlear and vestibular parts of the inner ear can be impaired by congenital cytomegalovirus infection, the vestibular part seems more often impaired compared with the cochlear part. This underlines the importance of vestibular evaluation in the follow-up of cytomegalovirus-infected children associated with hearing assessment.

Pathogenesis and Etiology of Ménière Disease: A Scoping Review of a Century of Evidence

Importance

Ménière disease is a rare chronic benign disorder of the inner ear with a natural history of multiple clinical phenotypes of variable severity and a tendency to burnout with time. Although multiple treatment modalities have been shown to improve the disease process-some adversely affecting cochleovestibular function-it remains uncertain whether one, several separate, or a combination of pathophysiologic mechanisms affect the disease process. A scoping review of the evidence underlying proposed pathophysiologic mechanisms of Ménière disease is needed to determine which processes are most likely to be etiopathogenic factors.

Observations

Of the 4602 relevant articles found through Embase, Ovid, and PubMed, 444 met inclusion criteria. The most common reported causes of Ménière disease were autoimmune or immune-mediated, genetic, or structural dysfunction of the inner ear. During the study period from inception to March 2021, etiologic theories shifted from structural dysfunction to autoimmune and genetic causes of Ménière disease.

Conclusions and Relevance

This scoping review found that Ménière disease is a multifactorial disease with lifelong comorbidities and loss of quality-associated life-years whose most commonly reported causes were structural dysfunction, immunologic damage, and genetic susceptibility. Recent studies have examined how autoinflammatory processes and vestibular migraine may be associated with Ménière disease. Large heterogeneity among studies may be explained by historical differences in the clinical understanding of the disease, as well as evolving intervention methodologies and practitioner expertise. Ménière disease is a multifactorial disease with lifelong comorbidities and loss of quality-associated life-years; therefore, future studies of reliable biomarkers of endolymphatic hydrops and real-time imaging are warranted to improve understanding and treatment.

Association Between Serum Vitamin D Level and Ménière's Disease

OBJECTIVES

Ménière's disease (MD) is a well-known inner ear disease; however, the etiopathogenesis is unknown. Several factors may be involved. Meanwhile, vitamin D is reported to have an important role in inner ear physiology. The aim of this study is to evaluate the relation between vitamin D deficiency and MD.

STUDY DESIGN

This matched case-control study compared serum vitamin D levels between patients with definite MD and those without it.

SETTING

The study was done between August 2018 and December 2019 at Ghaem University Hospital in Mashhad, Iran.

METHODS

Twenty-eight patients with definite MD were matched with a group of 84 healthy individuals, regarding age, sex, body mass index, and occupation (indoor vs outdoor). The serum level of vitamin D (25-hydroxyvitamin D3) was measured in both groups.

RESULTS

The mean ± SD vitamin D level was 18.9 ± 9.7 ng/mL in the case group and 25.2 ± 13.7 ng/mL in the control group (P = .027). There was a significant difference between the case and control groups according to the results of the conditional logistic regression model (P = .03; adjusted odds ratio, 0.96). In the MD group, 17 (60.7%) patients were vitamin D deficient, 6 (21.4%) insufficient, and only 5 (17.9%) sufficient.

CONCLUSIONS

The results of this study show that serum vitamin D level in MD is significantly lower than that of the control group. However, the role of vitamin D supplementation in the management of MD needs further study.

LEVEL OF EVIDENCE

4.

A Systematic Review on the Association of Acquired Human Cytomegalovirus Infection with Hearing Loss

Congenital cytomegalovirus (CMV) infection induces a clinical syndrome usually associated with hearing loss. However, the effect of acquired CVM infection in adults and children has not been clearly defined. The objective of this review is to critically appraise scientific evidence regarding the association of acquired CMV infection with postnatal hearing loss or tinnitus. A systematic review of records reporting sensorineural hearing loss (SNHL) or tinnitus and acquired CMV infection including articles published in English was performed. Search strategy was limited to human studies with acquired CMV infection. After screening and quality assessment, nine studies involving 1528 individuals fulfilled the inclusion criteria. A total of 14% of patients with SNHL showed evidence of previous exposure to CMV, while in individuals without SNHL (controls) the percentage rose up to 19.3%. SNHL was reported as unilateral or bilateral in 15.3%, and not specified in 84.7% of cases. The degree of SNHL ranged from mild to profound for both children and adults. None of the records reported tinnitus. The prevalence of children or adults with acquired SNHL with a confirmed acquired CMV infection by Polymerase Chain Reaction (PCR) or IgM anti-CMV antibodies is low. Phenotyping of patients with acquired CMV infection was limited to hearing loss by pure tone audiometry and no additional audiological testing was performed in most of the studies. Additional symptoms deserve more attention, including episodic vertigo or tinnitus, since some patients with the clinical spectrum of Meniere Disease could result from a CMV latent infection.

Menière's disease caused by CGRP - A new hypothesis explaining etiology and pathophysiology. Redirecting Menière's syndrome to Menière's disease

This paper provides a new hypothetical explanation for the etiopathology and pathophysiology of Menière's Disease (MD), which to date remain unexplained, or incompletely understood. The suggested hypothesis will explain the close connection of MD and Migraine, the coexistence of endolymphatic hydrops (ELH) and Menière attacks and the signs of inflammation detected in the inner ears of MD patients. Although as yet unproven, the explanations provided appear highly plausible and could pave the way for the generation of the first animal model of MD - an invaluable asset for developing new treatment strategies. Furthermore, if proven correct, this hypothesis could redefine and also reset the actual name of Menière's Syndrome to Menière's Disease.