On 30 January 2020, the World Health Organization (WHO) officially declared an outbreak of the coronavirus disease 2019 (COVID-19) to be a global health emergency. Research has focused on the impact and response to life-threatening symptoms of COVID-19 across the lifespan; however, there is a need to investigate the effects of COVID-19 on the cochleovestibular system, as viral infections are known to impact this system. This is particularly important for contexts where resources are limited and prioritisation of resources requires strong risk versus benefit evaluations.
Therefore, the purpose of this scoping review was to investigate published evidence on the impact of COVID-19 on the cochleovestibular system across the lifespan in order to allow for strategic clinical care planning in South Africa, where capacity versus demand challenges exist.
Electronic bibliographic databases such as CINAHL, EBSCOHost, MEDLINE, ProQuest, PubMed, Scopus and ScienceDirect were searched for peer-reviewed publications between January 2020 and January 2022. These had to be published in English and related to the impact of COVID-19 on the cochleovestibular system, where the question was: ‘what evidence has been published on the impact of COVID-19 on the cochleovestibular system?’ Review selection and characterisation was performed by the researcher with an independent review by a colleague using pretested forms.
Of a total of 24 studies that met the inclusion criteria, the current scoping review revealed limited conclusive published evidence linking COVID-19 to permanent hearing function symptoms. Current evidence supports the possibility of COVID-19, similar to other viral infections in adults, impacting the cochleovestibular system and causing tinnitus, vertigo and sudden sensorineural hearing loss (SSNHL), with the symptoms being generally temporary and resolving either partially or completely following therapy with steroids, with very inconclusive findings in the paediatric population.
These findings raise global implications for properly designed studies, which include longitudinal follow-up of cases across the lifespan, examining this link with some focus on establishing the pathophysiologic mechanisms at play as well. In the meanwhile, current findings raise the value of polymerase chain reaction (PCR) testing for all patients presenting with unexplained cochleovestibular symptoms during the pandemic, as these may be the only presenting symptoms indicating COVID-19, thus requiring careful treatment and management.
Since the advent of coronavirus disease 2019 (COVID-19), which was first reported in Wuhan, China, the World Health Organization (WHO) officially declared this novel coronavirus outbreak an international global public health emergency on 30 January 2020 and finally a pandemic on 11 March 2020 (WHO,
During the current COVID-19 pandemic, the wearing of face coverings globally is one of the key prevention strategies recommended and in some countries mandated. Community-wide face covering wearing, particularly in public areas, as is the requirement in South Africa (Balkaran & Lukman,
Evidence suggests that universal wearing of face coverings and adherence to physical distancing during COVID-19 has a serious negative impact on communication for the hearing impaired (Naylor, Burke, & Holman,
In a recent online survey within the United Kingdom, where the goal was to explore experiences of interactions where face masks were worn and how these masks affected communication, Saunders et al. (
Viral infections such as cytomegalovirus, measles, herpes simplex virus, HIV, rubella and others have been associated with hearing loss (Assuiti et al.,
The commonly documented clinical features of COVID-19 include dry cough, sore throat, headache, fever, fatigue, loss of taste, loss of sense of smell and shortness of breath (Alimohamadi, Sepandi, Taghdir, & Hosamirudsari,
If COVID-19 impacts cochleovestibular function in a similar manner to other viruses such as HIV, that is, either directly (virus itself) or indirectly (iatrogenic causes because of the medications prescribed to treat it) (Khoza-Shangase,
This clear categorisation of symptomatology is important because of numerous reasons that are risk factors for cochleovestibular pathology and would impact ear and hearing care in the South African context, including (1) the unique circumstances presenting in South Africa when compared with China or various other regions such as North America and Europe in terms of quadruple burden of disease (Khoza-Shangase,
At the initial stages of the COVID-19 pandemic, understandably, significant focus was placed on life-threatening symptoms of the disease; however, with increasing numbers of infections and more evidence becoming available, new symptoms are being reported and scrutinised as the virus presents deleterious effects on particular organs and structures of the body. These innumerable other symptoms that are constantly documented indicate involvement of multiple systems by COVID-19 (Eravci et al., 2020; Savtale, Hippargekar, Bhise, & Kothule,
While other rapid and systematic reviews have been conducted on this topic (Almufarrij & Munro,
This scoping review aimed to analyse published evidence on the impact of COVID-19 on the cochleovestibular system in line with the pandemic changes.
The Arksey and O’Malley’s (
The population (COVID-19 infected and/or exposed), concept (cochleovestibular symptoms or effects) and context (globally) (PCC) framework by the Joanna Briggs Institute was used to formulate the research question. For this review, the following question was formulated, ‘What evidence has been published on the impact of COVID-19 on the cochleovestibular system?’
Levac, Colquhoun and O’Brien (
To yield contemporary evidence, the search was restricted to peer-reviewed studies published in English during the COVID-19 era (between January 2020 and January 2022). To be part of the scoping review, the studies had to report on cochleovestibular symptoms or effects of COVID-19.
Review studies and studies not published in English were not eligible for inclusion. Studies were excluded if they did not address the research question, and if they did not include the combination of the search keywords. Studies that spoke about tinnitus on its own were excluded because of the limited objective evaluation of tinnitus in such studies and the multiple possible causal factors in the absence of hearing loss. Studies across the lifespan were included to ensure that findings assist with clinical planning across the lifespan, although it was obvious that identification of vestibular symptoms in the paediatric population would be challenging; however, hearing function findings would be valuable.
All in all, the database search from all databases identified 114 articles. All identified database citations were exported to a web-based bibliography manager, Endnote. Through this bibliography manager, duplicate studies were identified and removed. Following removal of duplicate studies, 79 studies remained, and these were brought down to 45 after title screening, where 34 articles were eliminated. The 45 abstracts were consequently screened, guided by the search question, and 5 studies were excluded because they did not report on cochleovestibular effects of COVID-19. A total of 40 studies were then assessed for eligibility, and of these, 15 were excluded because they did not meet the inclusion criteria. Ultimately, a full-text screening resulted in 24 studies meeting the inclusion criteria and being included in this scoping review.
Preferred Reporting Items for Systematic Reviews and Meta-Analysis flow diagram for the current scoping review.
Following Peters et al.’s (
researcher(s) and the year of publication
title of the study
country of publication
aim of the article
signs and symptoms reported
conclusions
recommendations.
Summary of studies included in the scoping review documenting cochleovestibular impact of coronavirus disease 2019.
Manuscript number | Authors and date | Publication title | Context or country | Aim | Signs and symptoms | Conclusions | Recommendations |
---|---|---|---|---|---|---|---|
1 | Karimi-Galougahi et al. ( |
Vertigo and hearing loss during the COVID-19 pandemic: Is there an association? | Iran | Determining if there is an association between COVID-19 and vertigo and hearing loss | Acute-onset hearing loss and vertigo in six patients, with three presenting with positive polymerase chain reaction (PCR) findings. | Remains unknown if COVID-19 can invade the auditory and vestibular neural pathways, but it is possible. |
Prioritise performing screening PCR tests to determine a link, particularly in patients presenting with isolated balance disorder or hearing loss. |
2 | Koparal and Yılmazer ( |
Evaluation of post-infection hearing with audiological tests in patients with COVID-19: A case-control study | Turkey | Evaluating the effects of COVID-19 infection on pure-tone average | Statistically significant differences at 4000 Hz, 6000 Hz and 8000 Hz between the two groups. |
Significantly worse pure-tone average scores in the COVID-19 positive patients than in the healthy control group. | In cases presenting with unexplained hearing loss, COVID-19 should also be considered as a possible cause. Future studies should investigate the effects of COVID-19 on hearing and the pathophysiology underlying hearing loss in this population. |
3 | Jin et al. ( |
Analysis of the characteristics of outpatient and emergency diseases in the department of otolaryngology during the ‘COVID-19’ pandemic | Shanghai, China | To evaluate changes in ordinary outpatient and emergency cases in otolaryngology during the COVID-19 pandemic | Different ranking of cases by diseases to previous ranking was found. |
Highlights the value of mental health observing, monitoring and maintaining. | Mental health should also be considered during this time. |
4 | Gallus et al. ( |
Audiovestibular symptoms and sequelae in COVID-19 patients | Italy | Investigating general and audiovestibular features and sequelae in recovered patients and exploring for signs of residual or permanent hearing or vestibular loss | Hearing loss reported in 4 (8.3%) patients, tinnitus in 2 (4.2%), dizziness in 4 (8.3%), spinning in 1, vertigo (2%), dynamic imbalance 1 (2%) and static imbalance in 3 (6.3%). |
Audiovestibular symptoms mainly temporary in nature, when they do occur. |
Further investigations are required. |
5 | Korkmaz, Eğilmez, Özçelik and Güven ( |
Otolaryngological manifestations of hospitalised patients with confirmed COVID-19 infection | Turkey | Evaluating the incidence and characteristics of otolaryngology symptoms in COVID-19 patients | Hyposmia or anosmia (37.9%) and hypogeusia or ageusia (41.37%) were the most common otolaryngological conditions found. In descending order, the rate of otological or vestibular symptoms was dizziness (31.8%), tinnitus (11%), true vertigo (6%) and hearing loss (5.1%). | Otolaryngological manifestations occur in COVID-19 positive patients. | The COVID-19 should be considered in such cases, and proper investigations carried out. |
6 | Ricciardiello et al. ( |
Sudden sensorineural hearing loss in mild COVID-19: Case series and analysis of the literature | Italy | Investigating the role of COVID-19 as a cause of sudden sensorineural hearing loss (SSNHL) |
The SSNHL did not present as a first symptom of COVID-19. |
The SSNHL could be an infrequent feature of COVID-19, even in cases where COVID-19 disease manifestation is mild. | Highlight the significance of early detection and management of SSNHL and other occasional symptoms, facilitating early treatment. |
7 | Beckers, Chouvel, Cassetto and Mustin ( |
Sudden sensorineural hearing loss in COVID-19: A case report and literature review | Belgium | Presenting the 9th case of SSNHL in a SARS-CoV-2- positive patient | Clinical and technical assessment indicated cophosis on the right side with normal tympanometry and otomicroscopy. A deficit of the right anterior semi-circular canal was found on Video Head Impulse Testing. |
Case report contributes towards documented evidence on links between hearing loss and COVID-19. | Inclusion of PCR testing in the diagnostic workup of patients with SSNHL during COVID-19. |
8 | Pokharel, Tamang, Pokharel and Mahaseth ( |
Sudden sensorineural hearing loss in a post-COVID-19 patient | Nepal | Presenting a case of an apparently healthy 27-year-old male with SSNHL without any known ear pathology or comorbidities | Normal outer and middle ear. |
Direct links to COVID-19 as cause of hearing loss speculated. |
Comprehensive case history and diagnostic assessment be conducted in SSNHL cases with recent or past COVID-19 infection because SSNHL could be a consequence of COVID-19. |
9 | Kilic et al. ( |
Could sudden sensorineural hearing loss be the sole manifestation of COVID-19? An investigation into SARS-COV-2 in the aetiology of sudden sensorineural hearing loss | Turkey | Investigating the presence of COVID-19 in patients with only SSNHL during COVID-19 | Five male patients unilateral SSNHL as a sole complaint. |
The SSNHL could be the only sign of COVID-19 infection. | Raised awareness of this phenomenon is important during the COVID-19 pandemic so as to prevent the infectious spread through adhering to regulations such as isolation and institution of early COVID-19 targeted treatment. |
10 | Chern, Famuyide, Moonis and Lalwani ( |
Bilateral sudden sensorineural hearing loss and intralabyrinthine haemorrhage in a patient with COVID-19 | United States of America | Describing a case of bilateral SSNHL and intralabyrinthine haemorrhage in a patient with COVID-19 | Bilateral moderate-severe SSNHL, vertigo and bilateral aural fullness in an adult woman with COVID-19. |
Otologic symptoms possibly because of intralabyrinthine haemorrhage caused by direct viral invasion of the labyrinth or cochlear nerve and COVID-19-associated coagulopathy. | Consider COVID-19 as a possible cause. |
11 | Kimura et al. ( |
The COVID-19 findings revealed via otolaryngological examination: Findings of a Japan Otorhinolaryngologist Association questionnaire | Japan | Analysing the characteristics of otorhinolaryngological findings to improve COVID-19 diagnostic systems in a primary care setting | Of the 350 cases considered in this study, hearing impairment was found in 2 (1%) and otalgia in 2 (1%). | Challenging to differentiate presenting symptoms from those of bacterial infections. | No conclusive published links to COVID-19 established. |
12 | Alan and Alan ( |
Hearing screening outcomes in neonates of SARS-CoV-2 positive pregnant women | Turkey | Investigating potential links between maternal COVID-19 and newborn hearing loss | Neonates in the COVID-19 group more likely to present with a ‘refer’ finding in ABR when compared with the control group. |
Positive COVID-19 PCR results during pregnancy are significantly linked with a higher risk of abnormal newborn hearing screening (NHS) outcomes. |
Maternal COVID-19 infection is a possible risk factor for hearing loss in infants in this population, even if the hearing loss in temporary. |
13 | Munro et al. ( |
Persistent self-reported changes in hearing and tinnitus in post-hospitalisation COVID-19 cases | UK | Reporting on hearing changes in 138 adults following hospitalisation for COVID-19 | Hearing changes and tinnitus was reported by 16 (13.2%) patients since COVID-19 diagnosis. |
Because audiological testing was not conducted, results were not conclusive as various confounding factors such as surrounding environmental changes because of hospitalisation, use of face masks and ototoxic medications as part of critical care, etc., are potential explanations for changes in subjective hearing and sudden awareness of pre-existing hearing loss and tinnitus. |
High-quality studies to examine the acute and temporary effects, as well as the longstanding risks of COVID-19 on the audiovestibular system are required. |
14 | Parrino et al. ( |
Sudden hearing loss and vestibular disorders during and before COVID-19 pandemic: An audiology tertiary referral centre experience | Italy | Evaluating the impact of the COVID-19 pandemic on the incidence of acute hearing and vestibular disorders | Increased annual incidence of total acute audiovestibular disorders during COVID-19, but no statistically significant differences when compared with pre-non-COVID-19 years. |
The SSNHL during COVID-19 seemed worse using pure-tone average, with an increased incidence of associated vestibular involvement. | Further studies are required to clearly establish the relationship between COVID-19 and audiovestibular disorders incidence and pathophysiology. |
15 | Degen, Lenarz and Willenborg ( |
Acute profound sensorineural hearing loss after COVID-19 pneumonia | Germany | Presenting a 60-year-old man with COVID-19 and reported deafness with a loud tinnitus (white noise) bilaterally after recovery | Complete right deafness and profound left SNHL from audiologic testing. |
An immune-mediated inflammation could be triggered by COVID-19 because the virus, in severe cases, has been linked to a dysregulation of the immune system. | The value of prompt radiologic and audiologic assessments in COVID-19 patients with sudden hearing loss highlighted, particularly if the patient also presents with neurologic symptoms. |
16 | Mustafa ( |
Audiological profile of asymptomatic COVID-19 PCR-positive cases | Egypt | Comparing the amplitude of transient evoked otoacoustic emissions (TEOAEs) and pure tone audiometry thresholds between asymptomatic COVID-19 positive cases and normal noninfected individuals | Significantly worse high-frequency pure-tone thresholds and TEOAE amplitudes in the COVID-19 positive group. | Possibility of COVID-19 infection having adverse effects on cochlear hair cell function even where patients are asymptomatic established. |
Further research is required to establish the mechanism of the COVID-19 cochlear effects. |
17 | Yıldız et al. ( |
Hearing test results of newborns born from the coronavirus disease 2019 (COVID-19) infected mothers: A tertiary centre experience in Turkey | Turkey | Establishing whether COVID-19 infection during pregnancy can cause congenital hearing loss | Of the newborns sample, 10.5% presented with unilateral hearing loss on initial testing. |
The lack of hearing loss in the current sample does not preclude COVID-19 as a possible cause of congenital hearing loss. | Larger patient series should be investigated for more conclusive findings. |
18 | Koumpa et al. ( |
Sudden irreversible hearing loss post- COVID-19 | UK | Presenting the first case of SSNHL following COVID-19 | Unilateral left severe-profound high frequency SNHL with tinnitus post 1 week hospitalisation and treatment for COVID-19. |
Consider COVID-19 in sudden SNHL cases during the pandemic. | Raised awareness and standard screening for SSNHL following COVID-19 infection facilitates prompt prescription of steroids, which enables better outcomes in terms of recovering hearing. |
19 | Oskovi-Kaplan et al. ( |
Newborn hearing screening results of infants born to mothers who had COVID-19 disease during pregnancy: A retrospective cohort study | Turkey | Investigating the incidence of hearing loss in infants born to mothers who had COVID-19 infection during pregnancy, through neonatal hearing screening | No significant difference in hearing screening results between the two groups at final screening. | No evidence of COVID-19 infection during pregnancy being a risk factor for neonatal hearing loss. | Large-scale, multicentre studies are required to confirm or dispute current findings regarding neonatal outcomes. |
20 | Bhatta et al. ( |
Study of hearing status in COVID-19 patients: A multicentred review | Nepal and India | Evaluating the hearing status of COVID-19 patients and comparing that with a control group, using pure tone and impedance audiometry | All aural symptoms present at initial assessment resolved at 3 month follow-up. |
No significant difference in the hearing status of the COVID-19 positive patients when compared with the control group. | Future studies required. |
21 | Dharmarajan et al. ( |
Hearing loss: A camouflaged manifestation of COVID-19 infection. | India | Assessing the audiological profile of 100 mild to moderately affected COVID-19 individuals to establish otologic manifestations of COVID-19 | High frequency hearing loss and referred OAE findings, with SNHL being the most prevalent type of hearing loss. |
To maintain and improve quality of life of affected individuals, early identification and intervention is important. | - |
22 | Savtale et al. ( |
Prevalence of otorhinolaryngological symptoms in COVID-19 patients | India | Determining the prevalence of ENT symptoms in COVID-19 positive patients | In a sample of 180 patients, 112 presented with one or more ENT symptoms that included throat pain (47.2%), loss of smell (55.5%), loss of taste (58.8%) and hearing loss and tinnitus (54.44%) – with generalised COVID-19 symptoms. |
The ENT symptoms can be regarded as cardinal features for early diagnosis of COVID-19, thus facilitating prompt intervention and isolation for infection spread control. | Coronavirus disease 2019 should be considered a possible cause and thus proper investigations should be performed so that appropriate management can be instituted. |
23 | Sriwijitalai and Wiwanitkit ( |
Hearing loss and COVID-19: A note | Thailand | A case note | One (first reported case) of an elderly female COVID-19 patient with unilateral SNHL. | Possibility of COVID-19 causing hearing loss raised. | - |
24 | Rhman and Wahid ( |
The COVID-19 and sudden sensorineural hearing loss: A case report | Egypt | Case report of a 52-year-old man with sudden onset left hearing loss, following progressive tinnitus. No otalgia, otorrhea, dizziness or vertigo | Unilateral hearing loss – left severe SNHL. |
The SSNHL can be the sole presenting symptom during COVID-19 infection. | Considerations around intra-tympanic corticosteroid injection versus use of systemic steroids in the treatment of COVID-19 patients. |
Data analysis was carried out through descriptive analysis, as the last step set out by Arksey and O’Malley (
This scoping review followed all ethical standards for a study that does not involve direct contact with human or animal participants, including reflexivity and informed subjectivity, audience-appropriate transparency and purposefully informed selective inclusivity (Suri, 2020).
The characteristics and main cochleovestibular findings documented in the 24 studies that met the eligibility criteria are depicted in
As far as the cochleovestibular symptoms are concerned, there is no conclusive published evidence of cochlear or vestibular damage that is persistent and clinically relevant following COVID-19 recovery (Gallus et al.,
Nonetheless, notwithstanding this research quality challenge, the limited evidence that exists seems to warrant the need for careful audiological assessment and monitoring and polymerase chain reaction (PCR) testing for COVID-19 diagnosis in patients with sudden unexplained cochleovestibular features during COVID-19 (Beckers et al.,
Analysis in this review leads the current author to conclude that generally, cochleovestibular symptoms that have been reported in adults include sudden onset sensorineural hearing loss with varying severity levels, which can be unilateral or bilateral, mostly high-frequency configuration, with or without tinnitus and vertigo, with the presentation in the paediatric population remaining relatively obscure. The occurrence of cochleovestibular symptoms is reported to vary, with some patients presenting with SSNHL as a leading symptom of COVID-19, while in others the symptoms occur greater than 6 days after the COVID-19 diagnosis or long after recovery from the infection (Kilic et al.,
The type of onset of the cochleovestibular symptoms is reported to be acute (Gallus et al.,
From their review, Almufarrij et al. (
Ricciardiello et al. (
Among the paediatric population, COVID-19 positivity in pregnancy has been associated with an increased risk of
Findings from the review reveal uncertainty and inconsistency regarding the underlying pathophysiology of the cochleovestibular symptoms in COVID-19 positive patients, with Pokharel et al. (
Numerous recommendations were found in the studies reviewed regarding establishment and assessment and management of cochleovestibular symptoms in patients with COVID-19. Key to the recommendations is one by Karimi-Galougahi et al. (
Fancello et al. (
The current scoping review aimed at answering the question ‘what evidence has been published on the impact of COVID-19 on the cochleovestibular system?’ revealed findings that highlight a need for high-quality research in the area so that definitive answers can be provided. Current evidence suggesting the possibility of cochleovestibular impact of COVID-19 across the lifespan is not strong enough; however, it does show that tinnitus, vertigo and SSNHL of mostly high frequencies occur either singly or in combination in adults and
The author declares that she has no financial or personal relationships that may have inappropriately influenced her in writing this article.
K.K.-S. declares that she is the sole author of this research article.
The author thanks the National Institute for the Humanities and Social Sciences (NIHSS) for providing financial assistance for the publication of this manuscript.
Data sharing is not applicable to this article as no new data were created or analysed in this study.
The views and opinions expressed in this article are those of the author and do not necessarily reflect the official policy or position of any affiliated agency of the author.