Herpesvirus DNA in peripheral blood mononuclear cells of some patients with Meniere's disease

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.

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

Despite considerable research, it remains controversial as to whether viral-infections are associated with Meniere’s Disease (MD), a clinically heterogeneous set of chronic inner-ear disorders strongly associated with endolymphatic hydrops. Here, we investigated whether viral-infections are associated with MD through a systematic review and meta-analysis of observational clinical studies using molecular-diagnostics. Eligible for inclusion were case-controlled studies which ascertained molecular-determinants of past or present viral-infection through either viral nucleic acids or host serological marker in MD cases and non-MD controls. Across online databases and grey literature, we identified 210 potentially relevant articles in the English language, from which a total of 14 articles fully satisfied our eligibility criteria such that meta-groups of 611 MD-cases and 373 controls resulted. The aggregate quality of the modest-sized (14 studies) body of evidence was limited and varied considerably with regards to participant selection, matching, and ascertainment(s) and determinant(s) of viral-infection. Most data identified concerned the human cytomegalovirus (CMV), and meta-analysis of eligible studies revealed that evidence of CMV-infection was associated approximately three-fold with MD compared to controls, however the timing of the infections was indeterminate as the pooled analyses combined antiviral serological markers with viral nucleic acid markers. No association was found for any of HSV-1, -2, VZV, or EBV. Associative analyses of any viral species not aforementioned were precluded by limited data, and thus potential associations between other viral species and MD, especially other than Herpesviridae, are yet to be characterised. Overall, we have found a small association between CMV-infection and MD, however it is to be determined for what sub-groups of MD this finding may be relevant, and ideally the reported association remains would be reproduced by a greater volume of higher quality evidence.

Looking back to move forward: a twenty-year audit of herpes zoster in Asia-Pacific

Background

Herpes zoster (HZ) is a prevalent viral disease that inflicts substantial morbidity and associated healthcare and socioeconomic burdens. Current treatments are not fully effective, especially among the most vulnerable patients. Although widely recommended, vaccination against HZ is not routine; barriers in Asia-Pacific include long-standing neglect of adult immunisation and sparse local data. To address knowledge gaps, raise awareness, and disseminate best practice, we reviewed recent data and guidelines on HZ from the Asia-Pacific region.

Methods

We searched PubMed, Scopus, and World Health Organization databases for articles about HZ published from 1994 to 2014 by authors from Australia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, New Zealand, the Philippines, Singapore, Taiwan, Thailand, and Vietnam. We selected articles about epidemiology, burden, complications, comorbidities, management, prevention, and recommendations/guidelines. Internet searches retrieved additional HZ immunisation guidelines.

Results

From 4007 retrieved articles, we screened-out 1501 duplicates and excluded 1264 extraneous articles, leaving 1242 unique articles. We found guidelines on adult immunisation from Australia, India, Indonesia, Malaysia, New Zealand, the Philippines, South Korea, and Thailand.

HZ epidemiology in Asia-Pacific is similar to elsewhere; incidence rises with age and peaks at around 70 years – lifetime risk is approximately one-third. Average incidence of 3–10/1000 person-years is rising at around 5% per year. The principal risk factors are immunosenescence and immunosuppression. HZ almost always causes pain, and post-herpetic neuralgia is its most common complication. Half or more of hospitalised HZ patients have post-herpetic neuralgia, secondary infections, or inflammatory sequelae that are occasionally fatal. These disease burdens severely diminish patients’ quality of life and incur heavy healthcare utilisation.

Conclusions

Several countries have abundant data on HZ, but others, especially in South-East Asia, very few. However, Asia-Pacific countries generally lack data on HZ vaccine safety, efficacy and cost-effectiveness. Physicians treating HZ and its complications in Asia-Pacific face familiar challenges but, with a vast aged population, Asia bears a unique and growing burden of disease. Given the strong rationale for prevention, most adult immunisation guidelines include HZ vaccine, yet it remains underused. We urge all stakeholders to give higher priority to adult immunisation in general and HZ in particular.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2198-y) contains supplementary material, which is available to authorized users.

Viral causes of hearing loss: a review for hearing health professionals

A number of viral infections can cause hearing loss. Hearing loss induced by these viruses can be congenital or acquired, unilateral or bilateral. Certain viral infections can directly damage inner ear structures, others can induce inflammatory responses which then cause this damage, and still others can increase susceptibility or bacterial or fungal infection, leading to hearing loss. Typically, virus-induced hearing loss is sensorineural, although conductive and mixed hearing losses can be seen following infection with certain viruses. Occasionally, recovery of hearing after these infections can occur spontaneously. Most importantly, some of these viral infections can be prevented or treated. For many of these viruses, guidelines for their treatment or prevention have recently been revised. In this review, we outline many of the viruses that cause hearing loss, their epidemiology, course, prevention, and treatment.

Obstructing Lesions of the Endolymphatic Sac and Duct Mimicking Ménière's Disease

In this retrospective case series and literature review, we demonstrate that temporal bone lesions that obstruct the endolymphatic sac or duct can cause symptoms of Ménière's disease. This finding is likely attributable to endolymphatic hydrops; initially, such cases typically masquerade as Ménière's disease. Between July 1995 and April 2002, a total of 379 patients were treated for an initial diagnosis of Ménière's disease at our institution. Among this group, 3 patients were found to have an obstructing lesion of the endolymphatic sac or duct that we felt was causally related to their Ménière's-like symptomatology. We reviewed these cases and noted the similarities in each patient's presentation, including a common pathophysiology. On imaging studies, each patient had a different pathologic lesion that involved the endolymphatic sac or duct: patient 1 had a jugular megabulb, and she was ultimately treated with vestibular nerve section; patient 2 had a cholesterol granuloma, which was treated with surgical excision; patient 3 had an endolymphatic sac tumor that was treated with surgical excision. As has been suggested in previous reports, not all cases of Ménière's disease are idiopathic. We conclude that obstruction of the endolymphatic sac or vestibular aqueduct by a mass lesion or vascular anomaly can lead to vestibulocochlear pathology that mimics Ménière's disease.