Effect of COVID-19 on hearing and balance
Reviewed by Victor Osei-Lah

Rhinological symptoms are cardinal features of COVID-19. However there have only been anecdotal reports on the involvement of the ear, the closest neighbour to the nose and throat. The aim of this study was ‘to assess the presence of persistent audiovestibular damage in the recovered COVID-19 patients, and the distribution and onset of other general and neurological symptoms’. The authors recruited 48 COVID-19-positive patients from their institution and compared their audiovestibular data with 28 age- and sex-matched healthy volunteers. None of the patients were hospitalised. Recovery was determined by two consecutive PCR negative results 48 hours apart. Symptoms present at diagnosis (early onset), and during and after recovery (late onset), as well as those that resolved, were recorded. The audiovestibular symptoms explored included tinnitus, hearing loss, dizziness, rotatory vertigo, static and dynamic imbalance/disequilibrium, head motion intolerance and visually-triggered dizziness. The objective tests undertaken after the second negative PCR test were 8-frequency PTA, stapedial reflexes, video head impulse (vHIT) and SHIPM. Seven patients were excluded due to pre-existing hearing loss, and three due to pre-existing vertigo and vestibular symptoms. Four (8.3%) and two (4.2%) patients reported subjective hearing loss tinnitus respectively, of which one reported persistent hearing loss. However, all these patients had normal PTA thresholds. Five patients (10.4%) reported one or more vestibular symptoms, namely dizziness in four cases (8.3%), rotatory vertigo in one case (2%), dynamic imbalance in one case (2%) and static imbalance in three cases (6.3%). With the exception of imbalance which occurred early, most of the vestibular symptoms occurred late, that is at least a week after diagnosis. Only one patient reported isolated imbalance at the time of testing. Vestibular symptoms had resolved in the rest. Video head impulse was essentially normal in all patients. There were no significant differences between patients and controls. The authors concluded that audiovestibular symptoms, when present, were temporary and resolved quickly. They addressed the limitations of the study, such as the limited repertoire of audiovestibular tests, lack of baseline tests, small sample size and lack of longitudinal data. They admitted that the mechanism of the vestibular symptoms was unknown and may well be part of the profound fatigue experienced by COVID-19 patients. The study adds to the growing literature on the effects of this global disease.

Audiovestibular symptoms and sequelae in COVID-19 patients.
Gallus R, Melis A, Rizzo D, et al.
J VESTIB RES
2021;31(5):381-7.