Introduction
Hearing loss, tinnitus and vertigo are often hidden but devastating symptoms, that have a significant effect on an individual’s ability to contribute to, and function within, society. In 2019, the UK Ménière’s Society funded the development of a disease registry for individuals with Ménière’s disease. In 2020, the world was subjected to nationally enforced lockdowns. The subsequent effects of isolation, changes to normal routines and an increase in reported mental health conditions, had the potential to adversely affect the symptoms of hearing loss, tinnitus, and vertigo in individuals with Ménière’s disease. In view of this, the lead investigator for the Ménière’s Disease Registry project identified a unique opportunity to supplement the main project questionnaires with further questions to prospectively investigate the effect of a positive coronavirus disease 2019 (Covid-19) diagnosis and national lockdown on the progression of audio-vestibular symptoms.
Methods
In 2020, ethics approval was granted to invite patients diagnosed with Ménière’s disease to have their clinical data entered into a bespoke study data-collection platform (North West – Liverpool Central Research Ethics Committee, United Kingdom – IRAS ID:275749). Further details regarding the development of the Ménière’s Disease Registry are available elsewhere.Reference Phillips, Murdin, Rea, Harcourt, Shepstone and Sims1
Patients with Ménière’s disease were identified from eight hospital sites; four were National Health Service (NHS) sites and four were independent sites. Table 1 lists the hospital sites from which patients were identified. Potential participants with a diagnosis of probable or definite unilateral or bilateral Ménière’s disease, as defined by the 2015 edition of the American Academy of Otolaryngology–Head and Neck Surgery (AAO–HNS) criteria,Reference Goebel2 in their hospital records were identified at ENT secondary care and private clinics (including services provided by audio-vestibular medicine). All potential participants had received a diagnosis of Ménière’sdisease within the previous 10 years by a consultant ENT surgeon or audio-vestibular physician specialising in balance disorders or had received a new diagnosis during the recruitment window of the study. A full list of inclusion and exclusion criteria for participant recruitment is provided in Table 2.
Table 1. Hospital recruitment sites
Table 2. Eligibility criteria
For this study, recruited individuals were asked whether they had contracted Covid-19. All participants were asked to report whether their symptoms of hearing loss, tinnitus, vertigo and migraine improved, remained stable or worsened. The format of these questions in displayed in Table 3.
Table 3. Questions posed to trial participants regarding changes to a. hearing, b. tinnitus, c. vertigo and d. migraine symptoms.
Data were securely collected and managed using REDCap electronic data-capture tools hosted at the University of East Anglia. Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines were followed where relevant.
Statistical methods
The sign test was used to test for a change in symptoms of hearing loss, tinnitus, vertigo and migraine in individuals overall during the pandemic, regardless of their Covid-19 diagnosis. The Mann–Whitney U test was used to test for a difference between Covid-19-positive and Covid-19-negative individuals with respect to the change in symptoms of hearing loss, tinnitus, vertigo and migraine. Statistical significance was set at the (two-sided) 5 per cent level.
Results
Recruitment to this study began in November 2020 and ended in September 2021. Over this 10-month period, 411 participants were recruited into this study. Of these, Covid test information was self-reported by 382 participants. A positive test for Covid-19 was reported in 43 (11.3 per cent) and 339 (88.7 per cent) participants reported not testing positive for Covid-19, at the time of recruitment. This study was completed before the widespread introduction of vaccinations throughout the United Kingdom.
Table 4 displays self-reported change in hearing loss, tinnitus, vertigo and migraine in all 411 participants during the pandemic. These results indicate strong evidence that symptoms of tinnitus (frequency, duration, loudness, intrusiveness) and hearing loss were more likely to worsen than improve during the pandemic. To a lesser degree, there was evidence of an improvement in symptoms of vertigo (duration and severity) during the pandemic.
Table 4. Change in audio-vestibular symptoms since the beginning of the pandemic for all consented participants
Table 5 displays how the symptoms of hearing loss, tinnitus, vertigo and migraine in Covid-positive individuals compared with Covid-negative individuals. For the following symptoms: vertigo (frequency, duration, severity), tinnitus (frequency, duration) and migraine (frequency, duration, severity), there was no evidence of a difference between Covid groups in the symptom levels. However, for symptoms of tinnitus loudness and tinnitus intrusiveness, there is evidence of a difference between Covid groups in the symptom levels: a greater percentage of those in the Covid-positive group, compared to the Covid-negative group, reported an increase in tinnitus loudness (35.0 per cent vs 20.5 per cent) and an increase in tinnitus intrusiveness (32.5 per cent vs 16.2 per cent). There was strong evidence of a difference between Covid groups in hearing levels. The Covid-positive group were more likely to report a worsening of hearing than the Covid-negative group (52.4 per cent vs 27.4 per cent).
Table 5. Change in audio-vestibular symptoms since the beginning of the pandemic, for those that are, versus those that are not, suspected/diagnosed with Covid
Discussion
Covid-19 infection (SARS-CoV-2) is primarily a pulmonary condition but can lead to a wide range of non-pulmonary, sensory, and neural complications. In addition to this, the psychological and societal effects of Covid have been broad, severe and are continuing to have long-lasting and profound effects on the quality of life of most individuals around the globe. Many retrospective studies have been published regarding the progression of audio-vestibular symptoms during the pandemic; mostly individual cases or case series. The outcomes of narrative and systematic reviews have largely been inconclusive.Reference Jafari, Kolb and Mohajerani3–Reference Almufarrij and Munro5 This is the only study known to us to have captured data from a defined clinical population to determine how Covid-19 diagnosis and national lockdown affected symptoms of hearing loss, tinnitus, vertigo and migraine.
• Numerous reports have been produced since the beginning of the coronavirus disease 2019 pandemic regarding the effects of diagnosis and national lockdown on a broad range of audio-vestibular symptoms
• We set up a data-collection platform to acquire a large and diverse range of clinical patient data for individuals diagnosed with Ménière’s disease
• Data collection for this project was initiated at beginning of the coronavirus disease 2019 pandemic, providing a unique opportunity to consider the effects of coronavirus disease 2019 diagnosis on the symptoms of hearing loss, tinnitus, vertigo and migraine in individuals diagnosed with Ménière’s disease
• A diagnosis of coronavirus disease 2019 and/or experiencing the consequences of a national lockdown potentially resulted in a worsening of hearing loss and tinnitus symptoms
• A diagnosis of coronavirus disease 2019 and/or experiencing the consequences of a national lockdown potentially resulted in an improvement of vertigo symptoms during the same period
Covid-19 diagnosis
Our study found that Covid-19 diagnosis has been associated with a statistically significant tendency for a worsening of tinnitus loudness and tinnitus intrusiveness. A Covid-19 diagnosis was also associated with a statistically significant tendency for a worsening of hearing ability. Some of these findings are in keeping with other studies.Reference Beukes, Baguley, Jacquemin, Lourenco, Allen and Onozuka6 The effects of contracting Covid-19 on individuals with pre-existing tinnitus has been investigated by BeukesReference Beukes, Baguley, Jacquemin, Lourenco, Allen and Onozuka6 where it was found that the majority of individuals reported no change in their symptoms but that 40 per cent of individuals reported a worsening of their tinnitus experience.Reference Beukes, Baguley, Jacquemin, Lourenco, Allen and Onozuka6 A number of potential mechanisms have been proposed to explain how Covid-19 might cause a range of audio-vestibular symptoms, including cochleitis or neuronitis,Reference Lang, Hintze and Conlon7 autoimmune mediated damage to the inner ear,Reference Lang, Hintze and Conlon7 microvascular compromiseReference Chandrasekhar, Tsai, Schwartz, Bontempo, Faucett and Finestone8 and the sequelae of immune-mediated disorders (such as the overzealous production of proinflammatory cytokines).Reference Degen, Lenarz and Willenborg9
National lockdown
National lockdown had a wide-ranging effect on public health. Onyeaka et al. explored crucial aspects of daily life that were affected by global lockdown, including food security, global economics, education, tourism, hospitality, sports and leisure, gender relationships, domestic violence/abuse, mental health and environmental air pollution.Reference Onyeaka, Anumudu, Al-Sharify, Egele-Godswill and Mbaegbu10 Our study in individuals with Ménière’s disease found that regardless of Covid-19 diagnosis during UK lockdown, self-reported symptoms of tinnitus and hearing difficulty had a tendency towards becoming worse, whereas symptoms of vertigo had a tendency towards improvement.
The worsening of tinnitus symptoms is perhaps not unexpected. The Covid-19 pandemic resulted in demonstrable increases in rates of stress, anxiety and depression.Reference Salari, Hosseinian-Far, Jalali, Vaisi-Raygani, Rasoulpoor and Mohammadi11 In the United Kingdom, a large population-based cohort study using primary care records identified a greater severity of mental illness and increasing incidence of non-fatal self-harm and suicide during 2020.Reference Steeg, John, Gunnell, Kapur, Dekel and Schmidt12 Anxiety during the pandemic has been identified as a risk factor for the deterioration of symptoms for other chronic conditions, for example in patients with severe asthma.Reference Lacwik, Szydłowska, Kupczyk, Pałczyński and Kuna13 The link between adverse mental health and tinnitus severity has been long established.Reference McFerran and Phillips14 Other studies have suggested that factors that were found to exacerbate an individual’s tinnitus experience included self-isolation, loneliness, poor sleep and reduced levels of exercise.Reference Beukes, Ulep, Eubank and Manchaiah15 This work also highlighted how increased depression, anxiety, irritability and financial worries further significantly contributed to tinnitus being more bothersome during the pandemic period.Reference Beukes, Ulep, Eubank and Manchaiah15
Whilst a range of explanations could be proposed for the perceived deterioration in hearing ability for individuals during lockdown, a worsening of hearing ability overall is possibly due to an unfavourable hearing environment instigated by the use of facemasks. Poor or no access to hearing aid services likely would have exacerbated hearing difficulties for those members of society who rely on hearing aids for communication. This is particularly relevant as we observed a 30 per cent deterioration overall, regardless of Covid-19 diagnosis.
The tendency towards an improvement of vertigo symptoms is a little more difficult to explain than the observations for tinnitus and hearing loss, particularly as our findings are in contrast with other studies.Reference Lovato, Frosolini, Marioni and de Filippis16, Reference Yeo, White, Ronan, Whinney, Curnow and Tyrrell17 In a study by Lovato et al.Reference Lovato, Frosolini, Marioni and de Filippis16 during the Covid-19 pandemic, their patients reported a significantly higher number of vertigo attacks as compared with pre-Covid numbers. Yeo et al.Reference Yeo, White, Ronan, Whinney, Curnow and Tyrrell17 reported higher odds of vertigo in individuals with Ménière’s disease and more severe symptoms during periods of greater stress. The effects of national lockdown in the UK have been notably different for individuals suffering from vertigo. Depending on an individual’s pre-Covid activity levels, enforced ‘limits’ on exercise might have reduced activity for some, whilst encouraging activity for others. Similarly, an opportunity for fresh air for some individuals might have been considered to be a reward, whilst the idea of isolation for the majority of patients might have had the opposite effect. The enforced break from demanding work duties, and the benefits from less exposure to dizziness-triggering activities for those with associated persistent posturo-perceptual dizziness, are other factors worthy of consideration.
This study has benefitted from seeking data directly from patients. A unique opportunity was identified at the beginning of the pandemic which has allowed new insights into the symptoms of a ‘primed’ population who are particularly susceptible to the distress associated with hearing loss, tinnitus, vertigo and migraine. Whilst changes have been reported for hearing loss, tinnitus and vertigo, no statistically significant changes in the severity of migraine overall were identified, which mirrors the literature studying chronic migraine during lockdown using comparable methodology.Reference Currò, Ciacciarelli, Vitale, Vinci, Toscano and Vita18
There are areas where this study has weaknesses. Firstly, the population studied might not represent individuals with hearing loss, tinnitus, vertigo and/or migraine who do not have Ménière’s disease, and therefore their experiences with Covid-19 and national lockdown might be different. Secondly, the relative proportion of individuals with a positive test for Covid-19 was relatively small. This might be, in part, due to lower numbers of individuals with Covid-19 in the UK at the time that the study ran, alternatively this might have been due to a group of individuals with Covid-19 who never went ahead to have their Covid-19 status tested. Thirdly, we have relied on patient-reported diagnosis of Covid-19, so an accurate confirmation of how a Covid-19 diagnosis was made or how many times a diagnosis was made was not possible. Fourthly, we have no data to consider how the reported changes in hearing loss, tinnitus, vertigo and/or migraine symptoms might have been observed in the absence of a national lockdown. Finally, whilst we broadly requested participants to report a change in their symptoms retrospectively, the data would be stronger had they been acquired pre-Covid and post-Covid, using a validated questionnaire and audiometric data. Again, this was not possible due to the unexpected manner by which Covid-19 spread across the globe. Ménière’s disease is a condition whereby symptoms fluctuate over time. In an ideal scenario, a comparison between our cohort of participants and a similarly selected historical cohort of participants could be compared. However, due to the nature of this current study, this comparison has not been possible.
Conclusion
This study of individuals with Ménière’s disease has provided new insights into the audio-vestibular effects of Covid-19 diagnosis and national lockdown. A diagnosis of Covid-19 and/or experiencing the consequences of a national lockdown was associated with a worsening of hearing loss and tinnitus symptoms in the population we studied. Symptoms of vertigo were observed to improve during the national lockdown.
