Acute Unilateral Peripheral Vestibulopathy After COVID-19 Vaccination: Initial Experience in a Tertiary Neurotology Center

Abstract

Objective: The aim of the present study was to identify patients who developed acute unilateral peripheral vestibulopathy (AUPVP) after COVID-19 vaccination.

Methods: For this single-center, retrospective study, we screened the medical records of our tertiary interdisciplinary neurotology center for patients who had presented with AUPVP within 30 days after COVID-19 vaccination (study period: 1 June-31 December 2021). The initial diagnosis of AUPVP was based on a comprehensive bedside neurotological examination. Laboratory vestibular testing (video head impulse test, cervical and ocular vestibular evoked myogenic potentials, dynamic visual acuity, subjective visual vertical, video-oculography, caloric testing) was performed 1-5 months later.

Results: Twenty-six patients were diagnosed with AUPVP within the study period. Of those, n = 8 (31%) had developed acute vestibular symptoms within 30 days after COVID-19 vaccination (mean interval: 11.9 days, SD: 4.8, range: 6-20) and were thus included in the study. The mean age of the patients (two females, six males) was 46 years (SD: 11.7). Seven patients had received the Moderna mRNA vaccine and one the Pfizer/BioNTech mRNA vaccine. All patients displayed a horizontal(-torsional) spontaneous nystagmus toward the unaffected ear and a pathological clinical head impulse test toward the affected ear on initial clinical examination. Receptor-specific laboratory vestibular testing performed 1-5 months later revealed recovery of vestibular function in two patients, and heterogeneous lesion patterns of vestibular endorgans in the remaining six patients.

Discussion and conclusions: The present study should raise clinicians' awareness for AUPVP after COVID-19 vaccination. The relatively high fraction of such cases among our AUPVP patients may be due to a certain selection bias at a tertiary neurotology center. Patients presenting with acute vestibular symptoms should be questioned about their vaccination status and the date of the last vaccination dose. Furthermore, cases of AUPVP occurring shortly after a COVID-19 vaccination should be reported to the health authorities to help determining a possible causal relationship.

Keywords: COVID-19; SARS-CoV-2; acute unilateral peripheral vestibulopathy; autoimmune cross-reactivity; herpes simplex virus; vaccination; vestibular neuritis.

Figure 1

Vestibular function tests in patient #2 (right superior vestibular nerve or its endorgans affected). (A–F) Video head impulse test (vHIT) results of all six semicircular canals. Eye velocity is right-left mirrored for better comparison with head velocity. (A,C,E) Head impulses stimulating left-sided semicircular canals. Blue traces: head velocity. Green traces: eye velocity of the vestibulo-ocular reflex. (B,D,F) Head impulses stimulating right-sided semicircular canals. Red traces: head velocity. Green traces: eye velocity of the vestibulo-ocular reflex. Red traces superimposed on green traces: catch-up saccades. The eye velocity traces indicate hypofunction of the right lateral semicircular canal (gain = 0.7). (G,H) Cervical vestibular-evoked myogenic potentials (cVEMPs) in response to air-conducted sound. Y-axis indicates the normalized p13n23 amplitude (unitless). The traces show slightly reduced cVEMP responses for the right (red traces) as compared to the left saccule (blue traces), which are still within normal range (asymmetry ratio, AR = 0.26). (I,J) Ocular vestibular evoked myogenic potentials (oVEMPs). Y-axis indicates absolute amplitude (μV). The response of the right utricle (blue traces – crossed reflex pathway) is smaller compared to the left side (red traces), AR = 0.42. X-axis represents time in all graphs.

Figure 2

Vestibular function tests in patient #6 (left superior and inferior vestibular nerves or their endorgans affected). See legend of Figure 1 for general features of (A–J). The vHIT traces indicate hypofunction of the left lateral and posterior semicircular canals (gain = 0.6 each), loss of the cVEMP response of the left saccule (AR = −1) and symmetrical oVEMP responses (AR = −0.14). (K) Video-oculography recordings during a 100 Hz vibration stimulus applied to the left mastoid. The magenta trace shows horizontal eye position (°) and the green trace shows vertical shows eye position (°) as indicated on the y-axis. Nystagmus quick phases are labeled with arrow heads. The right-beating vibration-induced nystagmus is consistent with hypofunction of the left lateral semicircular canal. X-axis represents time in all graphs.