COVID-19

By Marcello Cherchi, MD PhD

The following text has been adapted from Cherchi (Cherchi 2022)

For patients

The COVID‑19 pandemic demanded the world’s attention, and although an extraordinary effort has been directed at understanding this disease and its management, an immense amount of research remains.

In 2020 the most common question that we faced was, “I’ve been diagnosed with COVID‑19, and now I have dizzy/hearing symptoms.  Are they related?”

In 2021 the most common question that we faced was, “I received a vaccination for COVID‑19, and now I have dizzy/hearing symptoms.  Are they related?”

These are excellent questions, and the answers are not straightforward.  Briefly, it appears that COVID‑19 may be the cause of symptoms of disequilibrium and hearing abnormalities.  It is less clear whether such symptoms can be confidently classified as true adverse effects of COVID‑19 vaccines and treatments.

 

For clinicians

0. Overview

The accumulating literature suggests that audiologic and vestibular systems can occur in association with COVID‑19 infection; such symptoms are not among the most common, nor are they rare. Whether the relationship is causal is difficult to establish, even though some data (such as evidence of viral infection of inner ear hair cells) are quite suggestive of causality. The mechanism through which auditory and vestibular symptoms could be provoked by COVID‑19 remains unclear; proposed mechanisms include vestibular (or vestibulocochlear) neuritis; direct infection of cochlear and/or vestibular hair cells; labyrinthine ischemia; intralabyrinthine hemorrhage; and autonomic dysfunction. The pandemic has lasted long enough for investigators to begin to recognize “long-haul” COVID‑19 symptoms, often defined as symptoms persisting >6 months beyond initial infection; a recent study of such patients reported that symptoms such as dizziness and tinnitus, if present at the initial evaluation, were either still present or had actually increased by the time of the followup evaluation at 6–9 months (Ali et al. 2022).

While it is sensible to include COVID‑19 on a differential diagnosis during a pandemic, it behooves the clinician to bear in mind that other diseases still merit consideration, and reasonable alternative explanations for a given symptom should be entertained.

As an example, there are emerging reports of patients with diagnosed COVID‑19 infection who also appear to have vestibular neuritis. While it may be impossible at this time to ascertain whether the vestibular neuritis is due to COVID‑19 itself or has occurred independently, it is still important to identify vestibular hypofunction in this circumstance, because such a deficit is potentially treatable with appropriately targeted vestibular rehabilitation therapy. Thus, in our patients diagnosed with COVID‑19 who appear to have an acute vestibular syndrome, we recommend undertaking at least a screening otovestibular workup for vestibular weakness, including video head impulse testing, videonystagmography, and ocular and cervical vestibular evoked myogenic potentials; if these results are compatible with vestibular weakness (whether unilateral or bilateral), then referral for vestibular rehabilitation therapy is logical.

Auditory and vestibular symptoms are also being reported in association with the vaccines and treatments for COVID‑19. While causality has not yet been proven, this relationship warrants further scrutiny. However, in view of the evidence of “long-haul” COVID‑19 symptoms (mentioned earlier), and the absence (so far) of evidence for similarly lasting symptoms from vaccines and treatments for COVID‑19, our current impression is that the overall the risk of harm from the vaccines and treatments seems significantly lower than the risks of SARS‑CoV‑2 infection itself.

1. Introduction

The coronavirus disease pandemic that began in 2019 (COVID‑19) poses a range of challenges for patients, physicians, and health care delivery systems. The pandemic’s rapidly changing consequences have necessitated commensurately rapid evolution in our understanding of this disease; thus, it is no exaggeration to say that manuscripts on this topic are already out of date even before going to press. The most common presentations (fever, respiratory symptoms, and fatigue) have understandably commanded the most attention, but experience has shown that most organ systems can suffer involvement. Auditory abnormalities and disorders of balance are not among the most common, but accumulating evidence suggests that they are not rare either. In this entry, the author reviews what is known and acknowledge what is not known about the audiologic and vestibular symptoms that have been associated with the disease itself. The author then closes with some comments regarding audiologic and vestibular symptoms reported in association with the vaccines and some of the antiviral treatments for the disease.

2. Pathobiology of COVID‑19

Transmission of SARS‑CoV‑2 and entry through the respiratory tract is fairly well understood. Our understanding of how SARS‑CoV‑2 enters the nervous system is evolving.

2.1. How SARS‑CoV‑2 Infects the Body

The severe acute respiratory syndrome coronavirus type 2 (“SARS‑CoV‑2”) is a member of a family of coronaviruses. This family comprises single-stranded RNA viruses. From their lipid bilayer envelope protrude spike glycoproteins that function as “hooks” that facilitate entry into host cells, where they replicate, and from where they propagate. The spoke glycoproteins bind to angiotensin-converting enzyme receptors (Ceccarelli et al. 2020; Yan et al. 2020) that are densely expressed in cells in the pulmonary system, which is believed to be the mechanism by which the most common initial symptoms of this infection involve the respiratory tract. However, the infection does not remain confined to the respiratory tract. A more detailed discussion of the molecular aspects underlying this mechanism can be found elsewhere in this Encyclopedia (De Masi et al. 2022).

2.2. How SARS‑CoV‑2 Infects the Nervous System

Investigators have a limited understanding of the factors that make an individual vulnerable to the coronavirus and the mechanisms by which these viruses invade the central nervous system (CNS) (Dales 1995; Dube et al. 2018), though there is evidence (Baig et al. 2020) of cells within the CNS that express angiotensin converting enzyme receptors—even if at a lower density than found in the lower respiratory tract. It appears that after these viruses have invaded the CNS, they are capable of advancing via axonal transport (Dube et al. 2018).

It has long been known that other coronaviruses can invade the central nervous system, as they have been isolated in the brain and spinal cord tissue or the cerebrospinal fluid of patients suffering from a variety of neurological diseases such as encephalitis (Arabi et al. 2015; Li et al. 2016; Morfopoulou et al. 2016; Nilsson et al. 2020; Shnayder et al. 2022), acute disseminated encephalomyelitis (Yeh et al. 2004), optic neuritis (Dessau, Lisby, Frederiksen 1999), Parkinson’s disease (Fazzini, Fleming, Fahn 1992), and multiple sclerosis (Burks et al. 1980; Hovanec and Flanagan 1983; Salmi et al. 1982). For some of these diseases (e.g., multiple sclerosis, Parkinson’s disease) it seems somewhat unlikely that coronaviruses play a causative role, whereas in others (e.g., optic neuritis, encephalitis, and encephalomyelitis), it is reasonable to entertain the possibility that the viruses themselves are the etiopathogenetic factor.

Early in the pandemic, clinicians began reporting neurologic symptoms in individuals infected with SARS‑CoV‑2 (Koralnik and Tyler 2020; Pinzon et al. 2020) who had been hospitalized (Liotta et al. 2020), especially among those in intensive care units (Pinna et al. 2020). Data regarding SARS‑CoV‑2 (Filatov et al. 2020; Nath 2020; Poyiadji et al. 2020) suggest that its capacity to invade the central nervous system is similar to that of other members of the coronavirus family (Zubair et al. 2020), though there also appear to be clear differences (Ceccarelli et al. 2020), such as the predilection of SARS‑CoV‑2 to cause anosmia and ageusia (Gautier and Ravussin 2020; Giacomelli et al. 2020; Mao et al. 2020; Mermelstein 2020; Vavougios 2020), which in turn suggests involvement of cranial nerves. Therefore it is logical to consider whether cranial nerve involvement by SARS‑CoV‑2 is the mechanism underlying other focal neurological manifestations, such as the vestibular and auditory symptoms observed in patients presenting to primary care offices, emergency rooms, and otoneurology/neuro‑otology clinics.

Early in the pandemic, the author began evaluating patients with laboratory confirmation of SARS‑CoV‑2 infection who complained of auditory symptoms (such as hearing loss or tinnitus) and/or dizziness. This matches the evolving clinical literature, which reports dizziness (Saniasiaya and Kulasegarah 2021), auditory symptoms (such as hearing loss or tinnitus), or both (Kaliyappan, Chen, Krishnan Muthaiah 2022).

3. Auditory and Vestibular Symptoms Associated with COVID‑19

The author will briefly review the representative literature regarding COVID‑19 and auditory and vestibular symptoms; the author discusses that it is difficult to prove a causal relationship between the infection and these symptoms; and we outline several pathogenetic hypotheses regarding the mechanisms that have been proposed in support of the idea that the relationship might be causal.

3.1. COVID‑19 Associated with Auditory Disorders

The literature is accumulating regarding an association between COVID‑19 infection and hearing loss. While a few papers failed to find any relationship between COVID‑19 and hearing loss (Bhatta et al. 2021; Chari et al. 2021), a growing number of case reports (Chern et al. 2021; Chirakkal et al. 2021; Degen, Lenarz, Willenborg 2020; Edwards et al. 2021; Gerstacker et al. 2021; Koumpa, Forde, Manjaly 2020; Lamounier et al. 2020) and case series (Dusan, Milan, Nikola 2021; Fidan, Akin, Koyuncu 2021; Gosavi et al. 2021; Munro et al. 2020; Ricciardiello et al. 2021)have documented clear instances of hearing loss in the context of SARS‑CoV‑2 infection. The summary article by De Luca et al. (De Luca et al. 2021) reviewed numerous case reports and a case series of COVID‑19 patients, including both sexes, with a broad range of ages (18–84 years), with unilateral or bilateral typically sudden onset sensorineural hearing loss. The summary article by Fancello et al. (Fancello et al. 2021) reviewed numerous case reports and two case series of COVID‑19 patients, including both sexes, with a similarly broad range of ages, with unilateral (more common) or bilateral (less common) sudden sensorineural hearing loss. The prospective single-institution study by Dusan et al. (Dusan, Milan, Nikola 2021) reported a similar variety.

A smaller but growing literature is also beginning to document an association between COVID‑19 and tinnitus (Ali et al. 2022; Beukes et al. 2021; Beukes et al. 2020; Chirakkal et al. 2021; Degen, Lenarz, Willenborg 2020; Elibol 2021; Fancello et al. 2021; Gerstacker et al. 2021; Gosavi et al. 2021; Liang et al. 2020; Munro et al. 2020). In many cases, the tinnitus accompanies hearing loss (Chirakkal et al. 2021; Degen, Lenarz, Willenborg 2020; Gerstacker et al. 2021). Some of the literature describes tinnitus occurring with or without concomitant hearing loss (Elibol 2021)or without any reported hearing loss (Liang et al. 2020).

3.2. COVID‑19 Associated with Disequilibrium

A case series from Wuhan of 799 patients described dizziness as a symptom in 8% of confirmed COVID‑19 patients (Chen et al. 2020). Another study, also from Wuhan, of 214 confirmed cases of COVID‑19 that specifically asked patients about neurological symptoms reported dizziness in 16.8% of patients (Mao et al. 2020). A study of 509 patients from several hospitals in Chicago reported dizziness in 29.7% of cases (Liotta et al. 2020). The variability reflected in this broad range (8–29.7%) among individual studies has been noted in reviews (Saniasiaya and Kulasegarah 2021), though it is clear that there is increasing recognition of an association between COVID‑19 and vestibular disorders (Fancello et al. 2021). The ability of COVID‑19 to cause auditory and vestibular symptoms appears to be distinct from the other SARS coronaviruses (Almufarrij, Uus, Munro 2020).

3.3. Potential Mechanisms for Auditory and Vestibular Symptoms from SARS‑CoV‑2

In view of the emerging evidence of cochlear symptoms (hearing loss, tinnitus) and vestibular symptoms (dizziness) occurring in the context of COVID‑19 infection, most reviews of this subject are concluding that the relationship between COVID‑19 and audiovestibular dysfunction may be causal rather than simply associative (AlJasser et al. 2021; Almufarrij and Munro 2021; Almufarrij, Uus, Munro 2020; Chao and Young 2021; Fancello et al. 2021; Gallus et al. 2021; Jafari, Kolb, Mohajerani 2021; Karimi-Galougahi et al. 2020; Maharaj et al. 2020; Tan et al. 2021; Viola et al. 2021; Wichova, Miller, Derebery 2021).

In COVID‑19 patients with auditory and vestibular symptoms, otovestibular testing is sometimes abnormal (Tan et al. 2021), though the mechanism by which SARS‑CoV‑2 causes such dysfunction is unclear. The author discusses several candidate mechanisms here.

First, as mentioned earlier, SARS‑CoV‑2 seems capable of affecting individual cranial nerves, manifesting with ophthalmoparesis (Dinkin et al. 2020), optic neuritis (Dessau, Lisby, Frederiksen 1999), and anosmia (Gautier and Ravussin 2020; Giacomelli et al. 2020; Mao et al. 2020; Mermelstein 2020; Vavougios 2020). It is therefore logical to consider the possibility of SARS‑CoV‑2 involving the vestibulocochlear nerve, manifesting as vestibular neuritis (Jeong 2021; Malayala and Raza 2020; Mat et al. 2021; Vanaparthy, Malayala, Balla 2020) and/or cochlear neuritis or labyrinthitis. It should be noted, however, that some publications (Malayala et al. 2021) describing “COVID‑19 vestibular neuritis” appear to base the diagnosis on clinical criteria rather than on objective otovestibular testing; so, this remains a conjecture requiring further study.

Second, there is emerging evidence that the SARS‑CoV‑2 virus can directly infect inner ear hair cells (Jeong et al. 2021), which may underlie reported cases of labyrinthitis (Perret et al. 2021). Whether such involvement by SARS‑CoV‑2 in turn increases the risk for other specific otologic diseases, such as Ménière’s disease (Lovato et al. 2021) and benign paroxysmal positional vertigo (Maslovara and Kosec 2021; Picciotti et al. 2021), remains unclear.

A third potential mechanism for inner ear dysfunction due to COVID‑19 infection is labyrinthine ischemia secondary to hypoxia (Kaliyappan, Chen, Krishnan Muthaiah 2022). COVID‑19 infection increases the risk of thrombosis and can deoxygenate erythrocytes; since the inner ear’s circulation is entirely dependent on the small and tenuous labyrinthine artery, this mechanism is plausible.

A fourth potential mechanism is hematologic, via intralabyrinthine hemorrhage, though so far this appears rare (Chern et al. 2021; Narozny, Tretiakow, Skorek 2021).

A fifth potential mechanism, at least for vestibular (not auditory) symptoms, is that SARS‑CoV‑2 appears to induce autonomic dysfunction in some patients (Dani et al. 2021; Eshak et al. 2020; Goodman et al. 2021; Lo 2021; Shouman et al. 2021); so, orthostatic intolerance (generally postural orthostatic tachycardia) may be another mechanism by which SARS‑CoV‑2 provokes dizziness (Blitshteyn and Whitelaw 2021; Goldstein 2021; Johansson et al. 2021; Kanjwal et al. 2020; Miglis et al. 2020; Novak 2020; Schofield 2021).

4. Auditory and Vestibular Symptoms Associated with Vaccination for SARS‑CoV‑2 and Treatment for COVID‑19

Concerted research and pharmaceutical efforts have been directed at developing vaccines for SARS‑CoV‑2 and treatments for COVID‑19. As these interventions have come to market, new questions have been raised regarding potential adverse effects, including auditory and vestibular symptoms. Here, the author briefly reviews several studies and reports regarding the vaccines and antiviral agents. Other interventions, such as interleukin modulators (anakinra, tocilizumab, and sarilumab) and other immunomodulators being used on an experimental basis in patients who are in (or who are at risk of entering) intensive care units, are covered elsewhere (Skarzynska, Matusiak, Skarzynski 2022).

4.1. Vaccines for COVID‑19

As of this writing, several vaccines have received FDA approval for use (Baden et al. 2021; Polack et al. 2020; Sadoff et al. 2021). A broader review of possible adverse effects associated with the vaccines can be found elsewhere in this volume (Ajmera 2022). We have received questions from patients regarding whether the vaccines themselves can cause otovestibular symptoms or exacerbate pre‑existing otovestibular diseases. There are still insufficient data to answer these questions confidently. Our general experience so far has been that (1) apparent adverse effects from the vaccines have been transient, lasting days to weeks; (2) although symptoms from COVID‑19 infection itself can be very mild, they can also be devastating (if a patient survives) or lethal. On the whole, the potential protection conferred by receiving the vaccines appears greatly to outweigh the risk of the vaccines.

4.1.1. Vaccines for COVID‑19 and Dizziness

The literature regarding potential adverse effects from the Pfizer vaccine (BNT162b2 mRNA) is somewhat difficult to interpret as it pertains to vestibular symptoms. The original trial (Polack et al. 2020) included 43,548 participants (of whom 21,720 received the intervention and 21,828 received a placebo). The report, and its supplementary material, do not list dizziness/vertigo as an adverse event. However, a much smaller study (Kadali, Janagama et al. 2021) of 1245 recipients of the vaccine (no placebo arm), documented that out of 803 patients with “generalized” or “neurological” symptoms, 67 (8.34%) reported “dizziness,” and 20 (2.49%) reported “vertigo.” There has additionally been a case report of postural orthostatic tachycardia occurring following receipt of this vaccine (Reddy, Reddy, Arora 2021). There is a case report (Jeong 2021) of a patient who received the Pfizer vaccine and subsequently developed vestibular neuritis (supposedly corroborated on video head impulse testing), but whether this relationship was causal or associative is not known.

It is also difficult to interpret the literature about the Moderna vaccine’s (mRNA-1273) association with vestibular symptoms. The original trial (Baden et al. 2021) studied 30,420 participants (of whom 15,210 received the vaccine and 15,210 received a placebo). Symptoms of “dizziness and “vertigo” were reported as adverse effects of zero patients in the trial’s supplementary material. In contrast, a much smaller study of 432 vaccine recipients (Kadali et al. 2021) reported “vertigo like symptoms” in 15 (3.47%) patients and “dizziness” in 63 (14.58%) patients.

It is similarly difficult to interpret the literature about the Johnson & Johnson’s Janssen vaccine (Ad26.COV2.S). The original trial (Sadoff et al. 2021) included 39,260 participants (of whom 19,630 received the vaccine and 19,630 received placebo). The supplementary material from the trial reported that no vaccine recipients endorsed symptoms of “dizziness” or “vertigo.” Yet, the product monograph (https://covid-vaccine.canada.ca/info/pdf/janssen-covid-19-vaccine-pm-en.pdf, accessed June 26, 2022) that reviewed data from 43,783 participants (of whom 21,895 received the vaccine and 21,888 received placebo) stated 13 patients in the treatment group and 7 patients in the placebo group endorsed the symptom of “vertigo.”

4.1.2. Vaccines for COVID‑19 and Hearing Loss

The Centers for Disease Control’s Vaccine Adverse Effects Reporting System (CDC VAERS) provides publicly available data regarding the two mRNA vaccines (Pfizer and Moderna). Analysis of these data revealed 40 cases of unilateral sensorineural hearing loss (confirmed on audiometric testing) thought “most likely” to be attributable to the vaccines themselves (Formeister et al. 2021). The report indicated that the unilateral hearing loss occurred within 3 weeks (mean 4 days) of having received the vaccines. The calculated incidence was 0.3 cases per 100,000 individuals (i.e., 3 per million).

4.1.3. Vaccines for COVID‑19 and Tinnitus

Tinnitus has been less studied as a potential adverse effect of COVID‑19 vaccines, but emerging literature is beginning to discuss this (Ahmed et al. 2022; Parrino et al. 2021).

4.2. Anti-Viral Therapies for COVID‑19

For an individual already infected with COVID‑19 the vaccines play no role in acute management, but treatments aiming at the virus itself are being investigated. These have recently been reviewed elsewhere (Coffin et al. 2021). Some of these agents are already known to be ototoxic, such as chloroquine, hydroxychloroquine, and ivermectin.

As of this writing there was considerable interest in the combination antiviral agent Paxlovid, which contains ritonavir (an agent already used in the treatment of HIV) and nirmatrelvir (an investigational agent); unfortunately, there is almost no literature about the potential ototoxicity of these agents; ritonavir is also one component of the combination antiviral drug, Kaletra (which also contains lopinavir), which has been reported to cause reversible bilateral hearing loss (Williams 2001), but whether that property is due to ritonavir or lopinavir remains unclear.

Bamlanivimab (LY‑CoV555 by Lilly) is a neutralizing IgG1 antibody for SARS‑CoV‑2 ([No authors] 2021). In a randomized phase 3 trial of 1035 patients (Dougan et al. 2021), of whom 518 individuals received bamlanivimab in combination with another antiviral agent (etesevimab), and 517 individuals received a placebo, the symptom of “dizziness” was reported in four patients (0.8%) from the treatment group and three patients (0.6%) from the control group. The comparable rate of this symptom in both groups and the fact that the intervention group received a combination agent (bamlanivimab + etesevimab) makes it unclear what risk of vestibular symptoms bamlanivimab actually incurs.

Molnupiravir (MK‑4882/EIDD‑2801 by Merck) is a nucleotide analogue that inhibits SARS‑CoV‑2 replication. In a randomized phase 3 trial completed by 1411 patients (Jayk Bernal et al. 2022), of whom 710 individuals received molnupiravir and 701 individuals received placebo, the symptom of “dizziness” was reported in 1% of the treatment group and 0.7% of the placebo group. The comparable rate of this symptom in both groups makes it unclear what risk of vestibular symptoms molnupiravir actually incurs.

5. Conclusions

• The acute, potentially life-threatening manifestations of COVID‑19 certainly merit the greatest scrutiny of public health officials, researchers and clinicians. However, once such threats are treated or excluded, the longer-term consequences of COVID‑19 are becoming more apparent.
• Among those consequences are auditory and vestibular symptoms associated with COVID‑19 itself and with its vaccines and treatments. While these consequences may not be lethal, they still impose significant morbidity which, in turn, can incur non-trivial economic consequences at the individual level and at the broader population-based level.
• Greater understanding of these auditory and vestibular symptoms associated with COVID‑19, its vaccines, and its treatments will be achieved partly through continued epidemiologic monitoring.
• Greater understanding of the pathobiological mechanisms underlying these symptoms will require more systematic evaluation of these patients, beginning with more regularly applied audiologic and vestibular testing. Facilitating such evaluations may require changes at the health-care-systems level, perhaps through promulgating practice guidelines.

Accumulating and analyzing such data will improve the likelihood of correctly diagnosing, and perhaps eventually treating, these aspects of the disease.

References

[No authors] (2021) An EUA for Bamlanivimab-A Monoclonal Antibody for COVID-19. JAMA 325: 880-881. doi: 10.1001/jama.2020.24415

Ahmed SH, Waseem S, Shaikh TG, Qadir NA, Siddiqui SA, Ullah I, Waris A, Yousaf Z (2022) SARS-CoV-2 vaccine-associated-tinnitus: A review. Ann Med Surg (Lond) 75: 103293. doi: 10.1016/j.amsu.2022.103293

Ajmera KM (2022) Adverse Events Profile of COVID-19 Preventative Strategies. Encyclopedia 2: 457–465. doi: 10.3390/encyclopedia2010028

Ali ST, Kang AK, Patel TR, Clark JR, Perez-Giraldo GS, Orban ZS, Lim PH, Jimenez M, Graham EL, Batra A, Liotta EM, Koralnik IJ (2022) Evolution of neurologic symptoms in non-hospitalized COVID-19 “long haulers”. Ann Clin Transl Neurol. doi: 10.1002/acn3.51570

AlJasser A, Alkeridy W, Munro KJ, Plack CJ (2021) Is COVID-19 associated with self-reported audio-vestibular symptoms? Int J Audiol: 1-9. doi: 10.1080/14992027.2021.1957161

Almufarrij I, Munro KJ (2021) One year on: an updated systematic review of SARS-CoV-2, COVID-19 and audio-vestibular symptoms. Int J Audiol 60: 935-945. doi: 10.1080/14992027.2021.1896793

Almufarrij I, Uus K, Munro KJ (2020) Does coronavirus affect the audio-vestibular system? A rapid systematic review. Int J Audiol 59: 487-491. doi: 10.1080/14992027.2020.1776406

Arabi YM, Harthi A, Hussein J, Bouchama A, Johani S, Hajeer AH, Saeed BT, Wahbi A, Saedy A, AlDabbagh T, Okaili R, Sadat M, Balkhy H (2015) Severe neurologic syndrome associated with Middle East respiratory syndrome corona virus (MERS-CoV). Infection 43: 495-501. doi: 10.1007/s15010-015-0720-y

Baden LR, El Sahly HM, Essink B, Kotloff K, Frey S, Novak R, Diemert D, Spector SA, Rouphael N, Creech CB, McGettigan J, Khetan S, Segall N, Solis J, Brosz A, Fierro C, Schwartz H, Neuzil K, Corey L, Gilbert P, Janes H, Follmann D, Marovich M, Mascola J, Polakowski L, Ledgerwood J, Graham BS, Bennett H, Pajon R, Knightly C, Leav B, Deng W, Zhou H, Han S, Ivarsson M, Miller J, Zaks T, Group CS (2021) Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine. N Engl J Med 384: 403-416. doi: 10.1056/NEJMoa2035389

Baig AM, Khaleeq A, Ali U, Syeda H (2020) Evidence of the COVID-19 Virus Targeting the CNS: Tissue Distribution, Host-Virus Interaction, and Proposed Neurotropic Mechanisms. ACS Chem Neurosci 11: 995-998. doi: 10.1021/acschemneuro.0c00122

Beukes E, Ulep AJ, Eubank T, Manchaiah V (2021) The Impact of COVID-19 and the Pandemic on Tinnitus: A Systematic Review. J Clin Med 10. doi: 10.3390/jcm10132763

Beukes EW, Baguley DM, Jacquemin L, Lourenco M, Allen PM, Onozuka J, Stockdale D, Kaldo V, Andersson G, Manchaiah V (2020) Changes in Tinnitus Experiences During the COVID-19 Pandemic. Front Public Health 8: 592878. doi: 10.3389/fpubh.2020.592878

Bhatta S, Sharma S, Sharma D, Maharjan L, Bhattachan S, Sah MK, Singhal A, Ghanpur AD, Ganesuni D (2021) Study of Hearing Status in COVID-19 Patients: A Multicentered Review. Indian J Otolaryngol Head Neck Surg: 1-7. doi: 10.1007/s12070-021-02710-w

Blitshteyn S, Whitelaw S (2021) Postural orthostatic tachycardia syndrome (POTS) and other autonomic disorders after COVID-19 infection: a case series of 20 patients. Immunologic Research 69: 205-211. doi: 10.1007/s12026-021-09185-5

Burks JS, DeVald BL, Jankovsky LD, Gerdes JC (1980) Two coronaviruses isolated from central nervous system tissue of two multiple sclerosis patients. Science 209: 933-4. doi: 10.1126/science.7403860

Ceccarelli M, Berretta M Fau – Venanzi Rullo E, Venanzi Rullo E Fau – Nunnari G, Nunnari G Fau – Cacopardo B, Cacopardo B (2020) Differences and similarities between Severe Acute Respiratory Syndrome (SARS)-CoronaVirus (CoV) and SARS-CoV-2. Would a rose by another name smell as sweet? European Review for Medical and Pharmacological Sciences 24.

Chao CH, Young YH (2021) Evolution of incidence of audiovestibular disorders during the pandemic COVID-19 period. Eur Arch Otorhinolaryngol 279: 3341-3345. doi: 10.1007/s00405-021-07037-4

Chari DA, Parikh A, Kozin ED, Reed M, Jung DH (2021) Impact of COVID-19 on Presentation of Sudden Sensorineural Hearing Loss at a Single Institution. Otolaryngol Head Neck Surg 165: 163-165. doi: 10.1177/0194599820974685

Chen T, Wu D, Chen H, Yan W, Yang D, Chen G, Ma K, Xu D, Yu H, Wang H, Wang T, Guo W, Chen J, Ding C, Zhang X, Huang J, Han M, Li S, Luo X, Zhao J, Ning Q (2020) Clinical characteristics of 113 deceased patients with coronavirus disease 2019: retrospective study. BMJ 368: m1091. doi: 10.1136/bmj.m1091

Cherchi M (2022) Otovestibular Symptoms of COVID-19 and Its Vaccines/Treatments. Encyclopedia 2: 1200-1209. doi: 10.3390/encyclopedia2030080

Chern A, Famuyide AO, Moonis G, Lalwani AK (2021) Bilateral Sudden Sensorineural Hearing Loss and Intralabyrinthine Hemorrhage in a Patient With COVID-19. Otol Neurotol 42: e10-e14. doi: 10.1097/MAO.0000000000002860

Chirakkal P, Al Hail AN, Zada N, Vijayakumar DS (2021) COVID-19 and Tinnitus. Ear Nose Throat J 100: 160S-162S. doi: 10.1177/0145561320974849

Coffin AB, Boney R, Hill J, Tian C, Steyger PS (2021) Detecting Novel Ototoxins and Potentiation of Ototoxicity by Disease Settings. Front Neurol 12: 725566. doi: 10.3389/fneur.2021.725566

Dales S (1995) Factors controlling coronavirus infections and disease of the central nervous system. A review. Adv Exp Med Biol 380: 13-22. doi: 10.1007/978-1-4615-1899-0_2

Dani M, Dirksen A, Taraborrelli P, Torocastro M, Panagopoulos D, Sutton R, Lim PB (2021) Autonomic dysfunction in ‘long COVID’: rationale, physiology and management strategies. Clin Med (Lond) 21: e63-e67. doi: 10.7861/clinmed.2020-0896

De Luca P, Scarpa A, Ralli M, Tassone D, Simone M, De Campora L, Cassandro C, Di Stadio A (2021) Auditory Disturbances and SARS-CoV-2 Infection: Brain Inflammation or Cochlear Affection? Systematic Review and Discussion of Potential Pathogenesis. Front Neurol 12: 707207. doi: 10.3389/fneur.2021.707207

De Masi L, Argenio MA, Giordano D, Facchiano A (2022) Molecular Aspects of Spike—ACE2 Interaction. Encyclopedia of COVID-19 2: 96-108. doi: 10.3390/encyclopedia2010007

Degen C, Lenarz T, Willenborg K (2020) Acute Profound Sensorineural Hearing Loss After COVID-19 Pneumonia. Mayo Clin Proc 95: 1801-1803. doi: 10.1016/j.mayocp.2020.05.034

Dessau RB, Lisby G, Frederiksen JL (1999) Coronaviruses in spinal fluid of patients with acute monosymptomatic optic neuritis. Acta Neurol Scand 100: 88-91. doi: 10.1111/j.1600-0404.1999.tb01043.x

Dinkin M, Gao V, Kahan J, Bobker S, Simonetto M, Wechsler P, Harpe J, Greer C, Mints G, Salama G, Tsiouris AJ, Leifer D (2020) COVID-19 presenting with ophthalmoparesis from cranial nerve palsy. Neurology 95: 221-223. doi: 10.1212/WNL.0000000000009700

Dougan M, Nirula A, Azizad M, Mocherla B, Gottlieb RL, Chen P, Hebert C, Perry R, Boscia J, Heller B, Morris J, Crystal C, Igbinadolor A, Huhn G, Cardona J, Shawa I, Kumar P, Adams AC, Van Naarden J, Custer KL, Durante M, Oakley G, Schade AE, Holzer TR, Ebert PJ, Higgs RE, Kallewaard NL, Sabo J, Patel DR, Dabora MC, Klekotka P, Shen L, Skovronsky DM, Investigators B- (2021) Bamlanivimab plus Etesevimab in Mild or Moderate Covid-19. N Engl J Med 385: 1382-1392. doi: 10.1056/NEJMoa2102685

Dube M, Le Coupanec A, Wong AHM, Rini JM, Desforges M, Talbot PJ (2018) Axonal Transport Enables Neuron-to-Neuron Propagation of Human Coronavirus OC43. J Virol 92. doi: 10.1128/JVI.00404-18

Dusan M, Milan S, Nikola D (2021) COVID-19 caused hearing loss. Eur Arch Otorhinolaryngol 279: 2363-2372. doi: 10.1007/s00405-021-06951-x

Edwards M, Muzaffar J, Naik P, Coulson C (2021) Catastrophic bilateral sudden sensorineural hearing loss following COVID-19. BMJ Case Rep 14: e243157. doi: 10.1136/bcr-2021-243157

Elibol E (2021) Otolaryngological symptoms in COVID-19. Eur Arch Otorhinolaryngol 278: 1233-1236. doi: 10.1007/s00405-020-06319-7

Eshak N, Abdelnabi M, Ball S, Elgwairi E, Creed K, Test V, Nugent K (2020) Dysautonomia: An Overlooked Neurological Manifestation in a Critically ill COVID-19 Patient. Am J Med Sci 360: 427-429. doi: 10.1016/j.amjms.2020.07.022

Fancello V, Hatzopoulos S, Corazzi V, Bianchini C, Skarzynska MB, Pelucchi S, Skarzynski PH, Ciorba A (2021) SARS-CoV-2 (COVID-19) and audio-vestibular disorders. Int J Immunopathol Pharmacol 35: 20587384211027373. doi: 10.1177/20587384211027373

Fazzini E, Fleming J, Fahn S (1992) Cerebrospinal fluid antibodies to coronavirus in patients with Parkinson’s disease. Mov Disord 7: 153-8. doi: 10.1002/mds.870070210

Fidan V, Akin O, Koyuncu H (2021) Rised sudden sensorineural hearing loss during COVID-19 widespread. Am J Otolaryngol 42: 102996. doi: 10.1016/j.amjoto.2021.102996

Filatov A, Sharma P, Hindi F, Espinosa PS (2020) Neurological complications of coronavirus disease (COVID-19): Encephalopathy. Cureus 12: e7352. doi: 10.7759/cureus.7352

Formeister EJ, Chien W, Agrawal Y, Carey JP, Stewart CM, Sun DQ (2021) Preliminary Analysis of Association Between COVID-19 Vaccination and Sudden Hearing Loss Using US Centers for Disease Control and Prevention Vaccine Adverse Events Reporting System Data. JAMA Otolaryngology–Head & Neck Surgery 147: 674-676. doi: 10.1001/jamaoto.2021.0869

Gallus R, Melis A, Rizzo D, Piras A, De Luca LM, Tramaloni P, Serra A, Longoni E, Soro GM, Bussu F (2021) Audiovestibular symptoms and sequelae in COVID-19 patients. J Vestib Res 31: 381-387. doi: 10.3233/VES-201505

Gautier JF, Ravussin Y (2020) A New Symptom of COVID-19: Loss of Taste and Smell. Obesity (Silver Spring). doi: 10.1002/oby.22809

Gerstacker K, Speck I, Riemann S, Aschendorff A, Knopf A, Arndt S (2021) Deafness after COVID-19? HNO 69: 92-95. doi: 10.1007/s00106-021-01041-0

Giacomelli A, Pezzati L, Conti F, Bernacchia D, Siano M, Oreni L, Rusconi S, Gervasoni C, Ridolfo AL, Rizzardini G, Antinori S, Galli M (2020) Self-reported olfactory and taste disorders in SARS-CoV-2 patients: a cross-sectional study. Clin Infect Dis. doi: 10.1093/cid/ciaa330

Goldstein DS (2021) The possible association between COVID-19 and postural tachycardia syndrome. Heart Rhythm 18: 508-509. doi: https://doi.org/10.1016/j.hrthm.2020.12.007

Goodman BP, Khoury JA, Blair JE, Grill MF (2021) COVID-19 Dysautonomia. Front Neurol 12: 624968. doi: 10.3389/fneur.2021.624968

Gosavi S, Nagarajan S, Shah NJ, Thomas NAT, Kumar KR, Sangole V (2021) ENT Symptomology in Active COVID-19 Patients in our Tertiary Care Centre. Indian J Otolaryngol Head Neck Surg: 1-6. doi: 10.1007/s12070-021-02815-2

Hovanec DL, Flanagan TD (1983) Detection of antibodies to human coronaviruses 229E and OC43 in the sera of multiple sclerosis patients and normal subjects. Infect Immun 41: 426-9.

Jafari Z, Kolb BE, Mohajerani MH (2021) Hearing Loss, Tinnitus, and Dizziness in COVID-19: A Systematic Review and Meta-Analysis. Can J Neurol Sci: 1-12. doi: 10.1017/cjn.2021.63

Jayk Bernal A, Gomes da Silva MM, Musungaie DB, Kovalchuk E, Gonzalez A, Delos Reyes V, Martin-Quiros A, Caraco Y, Williams-Diaz A, Brown ML, Du J, Pedley A, Assaid C, Strizki J, Grobler JA, Shamsuddin HH, Tipping R, Wan H, Paschke A, Butterton JR, Johnson MG, De Anda C, Group MO-OS (2022) Molnupiravir for Oral Treatment of Covid-19 in Nonhospitalized Patients. N Engl J Med 386: 509-520. doi: 10.1056/NEJMoa2116044

Jeong J (2021) Vestibular neuritis after COVID-19 vaccination. Hum Vaccin Immunother 17: 5126-5128. doi: 10.1080/21645515.2021.2013085

Jeong M, Ocwieja KE, Han D, Wackym PA, Zhang Y, Brown A, Moncada C, Vambutas A, Kanne T, Crain R, Siegel N, Leger V, Santos F, Welling DB, Gehrke L, Stankovic KM (2021) Direct SARS-CoV-2 infection of the human inner ear may underlie COVID-19-associated audiovestibular dysfunction. Communications Medicine 1: 44. doi: 10.1038/s43856-021-00044-w

Johansson M, Ståhlberg M, Runold M, Nygren-Bonnier M, Nilsson J, Olshansky B, Bruchfeld J, Fedorowski A (2021) Long-Haul Post-COVID-19 Symptoms Presenting as a Variant of Postural Orthostatic Tachycardia Syndrome: The Swedish Experience. JACC Case Reports 3: 573-580.

Kadali RAK, Janagama R, Peruru S, Gajula V, Madathala RR, Chennaiahgari N, Malayala SV (2021) Non-life-threatening adverse effects with COVID-19 mRNA-1273 vaccine: A randomized, cross-sectional study on healthcare workers with detailed self-reported symptoms. J Med Virol 93: 4420-4429. doi: 10.1002/jmv.26996

Kaliyappan K, Chen YC, Krishnan Muthaiah VP (2022) Vestibular Cochlear Manifestations in COVID-19 Cases. Front Neurol 13: 850337. doi: 10.3389/fneur.2022.850337

Kanjwal K, Jamal S, Kichloo A, Grubb BP (2020) New-onset Postural Orthostatic Tachycardia Syndrome Following Coronavirus Disease 2019 Infection. J Innov Card Rhythm Manag 11: 4302-4304. doi: 10.19102/icrm.2020.111102

Karimi-Galougahi M, Naeini AS, Raad N, Mikaniki N, Ghorbani J (2020) Vertigo and hearing loss during the COVID-19 pandemic – is there an association? Acta Otorhinolaryngol Ital 40: 463-465. doi: 10.14639/0392-100X-N0820

Koralnik IJ, Tyler KL (2020) COVID-19: A Global Threat to the Nervous System. Ann Neurol 88: 1-11. doi: 10.1002/ana.25807

Koumpa FS, Forde CT, Manjaly JG (2020) Sudden irreversible hearing loss post COVID-19. BMJ Case Rep 13: e238419. doi: 10.1136/bcr-2020-238419

Lamounier P, Franco Goncalves V, Ramos HVL, Gobbo DA, Teixeira RP, Dos Reis PC, Bahmad F, Jr., Candido Costa C (2020) A 67-Year-Old Woman with Sudden Hearing Loss Associated with SARS-CoV-2 Infection. Am J Case Rep 21: e927519. doi: 10.12659/AJCR.927519

Li Y, Li H, Fan R, Wen B, Zhang J, Cao X, Wang C, Song Z, Li S, Li X, Lv X, Qu X, Huang R, Liu W (2016) Coronavirus Infections in the Central Nervous System and Respiratory Tract Show Distinct Features in Hospitalized Children. Intervirology 59: 163-169. doi: 10.1159/000453066

Liang Y, Xu J, Chu M, Mai J, Lai N, Tang W, Yang T, Zhang S, Guan C, Zhong F, Yang L, Liao G (2020) Neurosensory dysfunction: A diagnostic marker of early COVID-19. Int J Infect Dis 98: 347-352. doi: 10.1016/j.ijid.2020.06.086

Liotta EM, Batra A, Clark JR, Shlobin NA, Hoffman SC, Orban ZS, Koralnik IJ (2020) Frequent neurologic manifestations and encephalopathy-associated morbidity in Covid-19 patients. Ann Clin Transl Neurol. doi: 10.1002/acn3.51210

Lo YL (2021) COVID-19, fatigue, and dysautonomia. Journal of Medical Virology 93: 1213-1213. doi: https://doi.org/10.1002/jmv.26552

Lovato A, Frosolini A, Marioni G, de Filippis C (2021) Higher incidence of Meniere’s disease during COVID-19 pandemic: a preliminary report. Acta Otolaryngol 141: 921-924. doi: 10.1080/00016489.2021.1913288

Maharaj S, Bello Alvarez M, Mungul S, Hari K (2020) Otologic dysfunction in patients with COVID-19: A systematic review. Laryngoscope Investig Otolaryngol 5: 1192-1196. doi: 10.1002/lio2.498

Malayala SV, Mohan G, Vasireddy D, Atluri P (2021) A case series of vestibular symptoms in positive or suspected COVID-19 patients. Infez Med 29: 117-122.

Malayala SV, Raza A (2020) A Case of COVID-19-Induced Vestibular Neuritis. Cureus 12: e8918. doi: 10.7759/cureus.8918

Mao L, Jin H, Wang M, Hu Y, Chen S, He Q, Chang J, Hong C, Zhou Y, Wang D, Miao X, Li Y, Hu B (2020) Neurologic Manifestations of Hospitalized Patients With Coronavirus Disease 2019 in Wuhan, China. JAMA Neurol. doi: 10.1001/jamaneurol.2020.1127

Maslovara S, Kosec A (2021) Post-COVID-19 Benign Paroxysmal Positional Vertigo. Case Rep Med 2021: 9967555. doi: 10.1155/2021/9967555

Mat Q, Noel A, Loiselet L, Tainmont S, Chiesa-Estomba CM, Lechien JR, Duterme JP (2021) Vestibular Neuritis as Clinical Presentation of COVID-19. Ear Nose Throat J: 145561321995021. doi: 10.1177/0145561321995021

Mermelstein S (2020) Acute anosmia from COVID-19 infection. Pract Neurol 20: 343-344. doi: 10.1136/practneurol-2020-002583

Miglis MG, Prieto T, Shaik R, Muppidi S, Sinn D-I, Jaradeh S (2020) A case report of postural tachycardia syndrome after COVID-19. Clinical Autonomic Research 30: 449-451. doi: 10.1007/s10286-020-00727-9

Morfopoulou S, Brown JR, Davies EG, Anderson G, Virasami A, Qasim W, Chong WK, Hubank M, Plagnol V, Desforges M, Jacques TS, Talbot PJ, Breuer J (2016) Human Coronavirus OC43 Associated with Fatal Encephalitis. N Engl J Med 375: 497-8. doi: 10.1056/NEJMc1509458

Munro KJ, Uus K, Almufarrij I, Chaudhuri N, Yioe V (2020) Persistent self-reported changes in hearing and tinnitus in post-hospitalisation COVID-19 cases. Int J Audiol 59: 889-890. doi: 10.1080/14992027.2020.1798519

Narozny W, Tretiakow D, Skorek A (2021) Intralabyrinthine Hemorrhage in a Patient with Covid-19 – a Challenge for an Otologist. Otol Neurotol 42: e967. doi: 10.1097/MAO.0000000000003232

Nath A (2020) Neurologic complications of coronavirus infections. Neurology. doi: 10.1212/WNL.0000000000009455

Nilsson A, Edner N, Albert J, Ternhag A (2020) Fatal encephalitis associated with coronavirus OC43 in an immunocompromised child. Infect Dis (Lond) 52: 1-4. doi: 10.1080/23744235.2020.1729403

Novak P (2020) Post COVID-19 syndrome associated with orthostatic cerebral hypoperfusion syndrome, small fiber neuropathy and benefit of immunotherapy: a case report. eNeurologicalSci 21: 100276. doi: 10.1016/j.ensci.2020.100276

Parrino D, Frosolini A, Gallo C, De Siati RD, Spinato G, de Filippis C (2021) Tinnitus following COVID-19 vaccination: report of three cases. Int J Audiol 61: 526-529. doi: 10.1080/14992027.2021.1931969

Perret M, Bernard A, Rahmani A, Manckoundia P, Putot A (2021) Acute Labyrinthitis Revealing COVID-19. Diagnostics (Basel) 11: 482. doi: 10.3390/diagnostics11030482

Picciotti PM, Passali GC, Sergi B, De Corso E (2021) Benign Paroxysmal Positional Vertigo (BPPV) in COVID-19. Audiol Res 11: 418-422. doi: 10.3390/audiolres11030039

Pinna P, Grewal P, Hall JP, Tavarez T, Dafer RM, Garg R, Osteraas ND, Pellack DR, Asthana A, Fegan K, Patel V, Conners JJ, John S, Silva ID (2020) Neurological manifestations and COVID-19: Experiences from a tertiary care center at the Frontline. J Neurol Sci 415: 116969. doi: 10.1016/j.jns.2020.116969

Pinzon RT, Wijaya VO, Buana RB, Al Jody A, Nunsio PN (2020) Neurologic Characteristics in Coronavirus Disease 2019 (COVID-19): A Systematic Review and Meta-Analysis. Front Neurol 11: 565. doi: 10.3389/fneur.2020.00565

Polack FP, Thomas SJ, Kitchin N, Absalon J, Gurtman A, Lockhart S, Perez JL, Perez Marc G, Moreira ED, Zerbini C, Bailey R, Swanson KA, Roychoudhury S, Koury K, Li P, Kalina WV, Cooper D, Frenck RW, Jr., Hammitt LL, Tureci O, Nell H, Schaefer A, Unal S, Tresnan DB, Mather S, Dormitzer PR, Sahin U, Jansen KU, Gruber WC, Group CCT (2020) Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. N Engl J Med 383: 2603-2615. doi: 10.1056/NEJMoa2034577

Poyiadji N, Shahin G, Noujaim D, Stone M, Patel S, Griffith B (2020) COVID-19-associated Acute Hemorrhagic Necrotizing Encephalopathy: CT and MRI Features. Radiology 296: E119-E120. doi: 10.1148/radiol.2020201187

Reddy S, Reddy S, Arora M (2021) A Case of Postural Orthostatic Tachycardia Syndrome Secondary to the Messenger RNA COVID-19 Vaccine. Cureus 13: e14837. doi: 10.7759/cureus.14837

Ricciardiello F, Pisani D, Viola P, Cristiano E, Scarpa A, Giannone A, Longo G, Russo G, Bocchetti M, Coppola C, Perrella M, Oliva F, Chiarella G (2021) Sudden Sensorineural Hearing Loss in Mild COVID-19: Case Series and Analysis of the Literature. Audiol Res 11: 313-326. doi: 10.3390/audiolres11030029

Sadoff J, Gray G, Vandebosch A, Cardenas V, Shukarev G, Grinsztejn B, Goepfert PA, Truyers C, Fennema H, Spiessens B, Offergeld K, Scheper G, Taylor KL, Robb ML, Treanor J, Barouch DH, Stoddard J, Ryser MF, Marovich MA, Neuzil KM, Corey L, Cauwenberghs N, Tanner T, Hardt K, Ruiz-Guinazu J, Le Gars M, Schuitemaker H, Van Hoof J, Struyf F, Douoguih M, Group ES (2021) Safety and Efficacy of Single-Dose Ad26.COV2.S Vaccine against Covid-19. N Engl J Med 384: 2187-2201. doi: 10.1056/NEJMoa2101544

Salmi A, Ziola B, Hovi T, Reunanen M (1982) Antibodies to coronaviruses OC43 and 229E in multiple sclerosis patients. Neurology 32: 292-5. doi: 10.1212/wnl.32.3.292

Saniasiaya J, Kulasegarah J (2021) Dizziness and COVID-19. Ear Nose Throat J 100: 29-30. doi: 10.1177/0145561320959573

Schofield JR (2021) Persistent Antiphospholipid Antibodies, Mast Cell Activation Syndrome, Postural Orthostatic Tachycardia Syndrome and Post-COVID Syndrome: 1 Year On. Eur J Case Rep Intern Med 8: 002378. doi: 10.12890/2021_002378

Shnayder NA, Sirbiladze TK, Demko IV, Petrova MM, Nasyrova RF (2022) Limbic Encephalitis Associated with COVID-19. Encyclopedia 2. doi: 10.3390/encyclopedia2010003

Shouman K, Vanichkachorn G, Cheshire WP, Suarez MD, Shelly S, Lamotte GJ, Sandroni P, Benarroch EE, Berini SE, Cutsforth-Gregory JK, Coon EA, Mauermann ML, Low PA, Singer W (2021) Autonomic dysfunction following COVID-19 infection: an early experience. Clinical Autonomic Research 31: 385-394. doi: 10.1007/s10286-021-00803-8

Skarzynska MB, Matusiak M, Skarzynski PH (2022) Adverse Audio-Vestibular Effects of Drugs and Vaccines Used in the Treatment and Prevention of COVID-19: A Review. Audiol Res 12: 224-248. doi: 10.3390/audiolres12030025

Tan M, Cengiz DU, Demir I, Demirel S, Colak SC, Karakas O, Bayindir T (2021) Effects of Covid-19 on the audio-vestibular system. Am J Otolaryngol 43: 103173. doi: 10.1016/j.amjoto.2021.103173

Vanaparthy R, Malayala SV, Balla M (2020) COVID-19-Induced Vestibular Neuritis, Hemi-Facial Spasms and Raynaud’s Phenomenon: A Case Report. Cureus 12: e11752. doi: 10.7759/cureus.11752

Vavougios GD (2020) Potentially irreversible olfactory and gustatory impairments in COVID-19: Indolent vs. fulminant SARS-CoV-2 neuroinfection. Brain Behav Immun 87: 107-108. doi: 10.1016/j.bbi.2020.04.071

Viola P, Ralli M, Pisani D, Malanga D, Sculco D, Messina L, Laria C, Aragona T, Leopardi G, Ursini F, Scarpa A, Topazio D, Cama A, Vespertini V, Quintieri F, Cosco L, Cunsolo EM, Chiarella G (2021) Tinnitus and equilibrium disorders in COVID-19 patients: preliminary results. Eur Arch Otorhinolaryngol 278: 3725-3730. doi: 10.1007/s00405-020-06440-7

Wichova H, Miller ME, Derebery MJ (2021) Otologic Manifestations After COVID-19 Vaccination: The House Ear Clinic Experience. Otol Neurotol 42: e1213-e1218. doi: 10.1097/MAO.0000000000003275

Williams B (2001) Ototoxicity may be associated with protease inhibitor therapy. Clin Infect Dis 33: 2100-2. doi: 10.1086/324361

Yan R, Zhang Y, Li Y, Xia L, Guo Y, Zhou Q (2020) Structural basis for the recognition of SARS-CoV-2 by full-length human ACE2. Science 367: 1444-1448. doi: 10.1126/science.abb2762

Yeh EA, Collins A, Cohen ME, Duffner PK, Faden H (2004) Detection of coronavirus in the central nervous system of a child with acute disseminated encephalomyelitis. Pediatrics 113: e73-6. doi: 10.1542/peds.113.1.e73

Zubair AS, McAlpine LS, Gardin T, Farhadian S, Kuruvilla DE, Spudich S (2020) Neuropathogenesis and Neurologic Manifestations of the Coronaviruses in the Age of Coronavirus Disease 2019: A Review. JAMA Neurol 77: 1018-1027. doi: 10.1001/jamaneurol.2020.2065