The hidden impact of COVID-19 on balance: a VNG evaluation

Abstract Background The new coronavirus disease-2019 (COVID-19) mostly affects the respiratory system; other clinical observations and symptoms show that the digestive, hematological, cardiovascular, endocrine, and neurological systems are also affected. Neurological affection of COVID-19 involves both central and peripheral nervous systems, with symptoms such as dizziness, headaches, exhaustion, and loss of consciousness. Objectives To assess the long-term effects of COVID-19 on the vestibular system using videonystagmography (VNG). Methods The current study was a case–control study, which included 60 subjects; 30 subjects had a history of COVID-19 infection. They were examined at least 2 weeks and maximally 1 year following the onset of the infection. Thirty matched subjects with no history of COVID-19 infection for at least 1 year served as the control group. A full history, pure tone audiometry, and tympanometry were done for both groups. Both groups were tested using VNG, and the test battery included spontaneous nystagmus, gaze stabilization, static positional, Dix–Hallpike, oculomotor function (including saccade and smooth pursuit tests), and bithermal caloric tests. Results The VNG results revealed that the saccade velocity was significantly increased in the study group in comparison to the control group, while the saccade accuracy and latency showed no statistically significant difference. In the smooth pursuit test, the phase shift was significantly higher in the study group in the mid frequency region with no significant difference in both low and high frequencies. Findings from the Dix–Hallpike maneuver and positional test confirmed the diagnosis of benign paroxysmal positional vertigo (BPPV) in 6 out of the 30 cases (20%) included in the study. Conclusion The most prevalent vestibular symptom of COVID-19 in the current study was dizziness. BPPV was the most prevalent vestibular disorder in our cases, with the posterior semicircular canal being the most commonly affected. Our patients showed a significant increase in saccade velocity and smooth pursuit phase shift.