Risk Factors for the Development of Bilateral Ménière's Disease and the Establishment of a National Ménière's Disease Registry.

Ménière's disease is an inner ear disorder characterised by recurrent episodes of spontaneous vertigo, fluctuating hearing loss and tinnitus, often with a feeling of fullness in the ear. The exact aetiology remains unknown. Ménière's disease is estimated to have a prevalence of 0.25% in the UK (around 162,000 individuals) (Tyrrell 2016) and is associated with significant physical, psychological and socioeconomic morbidity (Anderson 2001, Tyrrell 2014).

There is a substantial lack of knowledge regarding many aspects of Ménière's disease, including a fuller understanding of epidemiological aspects of the disease, aetiological factors, pathogenesis, clinical course and treatment outcomes. The James Lind Alliance cites Ménière's disease as the theme for four of their top ten priorities for addressing uncertainties in the field of balance disorders (JLA 2018).

There is mounting unease regarding the definition of Ménière's disease as a single clinical entity. Many consider it to represent the final pathway of a number of individual disease processes. This is reflected by the progressive and varied development of diagnostic criteria over the last few decades (Gurkov 2016). It is in the context of these observations that Ménière's disease is likely to represent a heterogeneous clinical condition defined only by small groups of common, but not always mandatory, symptoms. Understanding how Ménière's disease may exist as a cluster of clinical sub-types is key to allowing further research into its underlying pathophysiological mechanisms, and the targeting of specific treatment strategies; as well as allowing a better understanding of the physiology of the inner ear micro-environment (Phillips 2018).

This project will provide the initial steps necessary to set-up a UK Ménière's disease registry by primarily investigating a single clinical subtype of Ménière's disease: bilateral disease. The development of bilateral Ménière's disease has significant implications for short and long-term opportunities for treatment and rehabilitation; this in turn has significant implications for communication and employment. Previous literature on bilateral disease has offered widely ranging estimates of the likelihood that it will occur in cases where unilateral disease is confirmed, and no clear predictors have been identified (Huppert 2010). However, it is a sub-type which is relatively well-defined with standard internationally agreed criteria for diagnosis.

In areas of research such as this, the implementation of bespoke data collection platforms and national registries have been demonstrated to be both effective and efficient (Mandavia 2017). The use of national registries has many advantages over conventional data collection methods. When implemented correctly, national registries can allow the appraisal of a more representative sample of the target population. Furthermore, a national approach broadens the opportunities both for participation among the patient population to be served by such a venture, and for public engagement and dissemination activities.