Long COVID, audiovestibular symptoms and persistent chemosensory dysfunction: a systematic review of the current evidence.

Objective: The persistence of auditory, vestibular, olfactory, and gustatory dysfunction for an extended time after COVID-19 has been documented, which represents an emerging challenge of which ENT specialists must be aware. This systematic review aims to evaluate the prevalence of persistent audiovestibolar and olfactory/gustatory symptoms in patients with "long-COVID". Methods: The literature was systematically reviewed according to PRISMA guidelines; PubMed, Scopus and Google Scholar were screened by searching articles on audiovestibular symptoms and olfactory/gustatory dysfunction after SARS-CoV-2 infection. The keywords used were hearing loss, tinnitus, vertigo, smell disorders, parosmia, anosmia, hyposmia, dysgeusia combined with COVID-19 or SARS-CoV-2. Results: 1100 articles were identified. After removal of duplicates (382), 702 articles were excluded, and 16 were included in the systematic review. All articles included identified an association between SARS-CoV-2 infection and persistent hearing or chemosensory impairment. The studies were published over a period of 2 years, between 2019 and 2021. Conclusions: The likelihood of patients with persistent audiovestibular symptoms related to COVID-19 was different among the articles; however, olfactory and gustatory disturbances were more consistently reported. Studies with longer follow-up are required to fully evaluate the long-term impact of these conditions.

The effect of coronavirus disease 2019 on the hearing system.

OBJECTIVE: This study aimed to evaluate different auditory regions with audiological tests, based on the presumption that there may be damage to the structures in the hearing system after coronavirus disease 2019. METHODS: Twenty individuals with no history of coronavirus disease 2019 and 27 individuals diagnosed with coronavirus disease 2019 were compared. Pure tone, speech and extended high-frequency audiometry, acoustic immitansmetry, transient evoked and distortion product otoacoustic emissions testing, and auditory brainstem response testing were conducted. RESULTS: The pure tone audiometry and extended high-frequency mean threshold values were higher in the coronavirus disease 2019 group. The transient evoked otoacoustic emissions signal-to-noise ratios were bilaterally lower at 4 kHz in individuals with a coronavirus disease 2019 history. In the auditory brainstem response test, only the interpeak latencies of waves III-V were significantly different between groups. CONCLUSION: Coronavirus disease 2019 may cause damage to the hearing system. Patients should be followed up in the long term with advanced audiological evaluation methods in order to determine the extent and level of damage.

Hearing screening outcomes in neonates of SARS-CoV-2 positive pregnant women.

OBJECTIVE: The current study aimed to investigate possible association of maternal SARS-CoV-2 with newborn hearing loss. We compared hearing screening outcomes in neonates born to women with positive SARS-CoV-2 PCR test results during pregnancy with healthy controls. METHODS: Neonates born between April and December 2020 in our hospital to mothers with positive SARS-CoV-2 PCR test results during pregnancy were included in this study. Neonates with risk factors for universal newborn hearing screening (NHS) were excluded. Neonates born to mothers with positive SARS-CoV-2 PCR test results during pregnancy were compared with healthy controls in terms of newborn hearing screening results and independent variables. RESULTS: Neonates in the COVID-19 group were more likely to have a "refer" result in auditory brainstem responses (ABR) compared with the control group (53/118 and 28/118, respectively; p = 0.001). The second ABR test results did not differ significantly between the groups (p = 0.618). Logistic regression revealed that birth week and type of birth were not associated with the "refer" result. PCR positivity in the second trimester was more likely to produce the "refer" result in the first ABR test (p = 0.014). CONCLUSION: SARS-CoV-2 PCR positivity in pregnancy is significantly associated with an increased risk of abnormal NHS results. Also, the timing of PCR positivity in pregnancy (trimester) may be related to abnormal NHS results.

Does coronavirus affect the audio-vestibular system? A rapid systematic review.

Objective: This rapid systematic review investigated audio-vestibular symptoms associated with coronavirus.Design: The protocol for the rapid review was registered in the International Prospective Register of Systematic Reviews and the review methods were developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Risk of bias was assessed using the National Institute of Heath quality assessment tools.Study sample: After rejecting more than 2300 records, there were five case reports and two cross-sectional studies that met the inclusion criteria.Results: No records of audio-vestibular symptoms were reported with the earlier types of coronavirus (i.e. severe acute respiratory syndrome [SARS] and Middle East respiratory syndrome [MERS]). Reports of hearing loss, tinnitus, and vertigo have rarely been reported in individuals who tested positive for the SARS-CoV-2.Conclusion: Reports of audio-vestibular symptoms in confirmed COVID-19 cases are few, with mostly minor symptoms, and the studies are of poor quality. Emphasis over time is likely to shift from life-threatening concerns to longer-term health-related consequences such as audio-vestibular dysfunction. High-quality studies are needed to investigate the acute effects of COVID-19, as well as for understanding long-term risks, on the audio-vestibular system. Review registration: Prospective Register of Systematic Reviews (PROSPERO; registration number CRD42020184932).