Evaluation of the effects of Covid-19 on cochleovestibular system with audiovestibular tests

Purpose The purpose of the present study was to investigate the effects of COVID-19 on audiovestibular system with Transiently Evoked Distortion Otoacoustic Emissions (TOAE), Distortion Product Otoacoustic Emissions (DPOAE), video head impulse test (vHIT) and caloric test. Methods Audiovestibular findings of 24 patients with moderate/severe COVID-19 and 24 healthy controls were compared using pure tone audiometry, tympanometry, TOAE, DPOAE, caloric test, and vHIT. Results On audiometry, the pure tone averages of the COVID-19 patients were higher than the controls ( P = .038). The TEOAE amplitudes at 4000 and 5000 Hz ( P = .006 and P < .01), and DPOAE amplitudes at 3000, 6000, and 8000 Hz ( P < .001, P = .003 and P < .001) were significantly lower in COVID-19 patients compared to the controls. On vestibular tests, there was no significant difference between the caloric test results of the patients and the controls ( P > .05). On vHIT testing, amplitudes of right semicircular canal was found to be significantly lower in COVID-19 group compared to the control group ( P = .008). Conclusion COVID-19 may affect inner ear functions causing a subtle damage in the outer hair cells and lateral semicircular canals. It must be kept in mind that COVID-19 may cause cochleovestibular problems.

Temporal Relationship between Nystagmus and Perception during Bithermal Alternate Caloric Test

Objectives: During caloric irritation, the spinning/rotating sensation is predominant. However, there is no report on the temporal relationship between caloric nystagmus and perception.Methods: Consecutive 57 participants underwent bithermal caloric test in the dizziness clinic of Chungnam National University Hospital from February 2018 to September 2018. For vestibular perception, we asked the subject to report feelings of rotation and/or linear sensation during each warm and cold water irrigation period. Besides routine caloric parameters, the duration of nystagmus and vestibular sensation were analyzed.Results: In most participants, the caloric nystagmus preceded the vestibular sensation (79.6% in right warm, 83.3% in left warm, 88.5% in right cool, and 84.6% in left cool stimuli). The precedence of perception was observed in 5 normal persons and 15 patients with vestibular migraine (n=4), unilateral vestibulopathy (n=3), and Menière’s disease (n=2), multiple systemic atrophy (n=2), cerebellar ataxia (n=2), vertebrobasilar insufficiency (n=1), and post-earthquake dizziness (n=1). The mean latency between nystagmus and perception was 11.7 seconds. And the duration of nystagmus was longer than that of perception in all conditions. Non-spinning sensations during the caloric test were also observed in some participants (26.8% in right warm, 30.3% in left warm, 29.1% in right cool, and 24.1% in left cool stimuli).Conclusions: During the bithemal alternate caloric test, various vestibular perception and temporal relationship between perception and nystagmus suggest the bithermal caloric stimulation does not reflect only the signal originating from the horizontal canal pathway. A further validation study is needed.

Altered brain network functional connectivity patterns in patients with vestibular migraine diagnosed according to the diagnostic criteria of the Bárány Society and the International Headache Society

Background Vestibular migraine (VM) is considered one of the most common causes of episodic central vestibular disorders, the mechanism of VM is currently still unclear. The development of functional nuclear magnetic resonance (fMRI) in recent years offers the possibility to explore the altered functional connectivity patterns in patients with VM in depth. The study aimed to investigate altered patterns of brain network functional connectivity in patients with VM diagnosed based on the diagnostic criteria of the Bárány Society and the International Headache Society, and hope to provide a scientific theoretical basis for understanding whether VM is a no-structural central vestibular disease, i.e., functional central vestibular disease with altered brain function. Methods Seventeen patients with VM who received treatment in our hospital from December 2018 to December 2020 were enrolled. Eight patients with migraine and 17 health controls (HCs) were also included. Clinical data of all patients were collected. Blood pressure, blood routine tests and electrocardiography were conducted to exclude other diseases associated with chronic dizziness. Videonystagmography, the vestibular caloric test, the video head impulse test and vestibular-evoked myogenic potentials were measured to exclude peripheral vestibular lesions. MRI was utilized to exclude focal lesions and other neurological diseases. All subjects underwent fMRI. The independent component analysis was performed to explore changes in intra- and inter-network functional connectivity in patients with VM. Results Among 17 patients with VM, there were 7 males and 10 females with an average age of 39.47 ± 9.78 years old. All patients had a history of migraine. Twelve (70.6%) patients had recurrent spontaneous vertigo, 2 (11.7%) patients had visually induced vertigo, and 3 (17.6%) patients had head motion-induced vertigo. All 17 patients with VM reported worsening of dizziness vertigo during visual stimulation. The migraine-like symptoms were photophobia or phonophobia (n = 15, 88.2%), migraine-like headache (n = 8, 47.1%), visual aura during VM onset (n = 7, 41.2%). 5 (29.4%) patients with VM had hyperactive response during the caloric test, and 12 (70.6%) patients had caloric test intolerance. Eleven (64.7%) patients had a history of motion sickness. Totally 13 independent components were identified. Patients with VM showed decreased functional connectivity in the bilateral medial cingulate gyrus and paracingulate gyrus within sensorimotor network (SMN) compared with HCs. They also showed weakened functional connectivity between auditory network (AN) and anterior default mode network (aDMN) compared with HCs, and enhanced functional connectivity between AN and the salience network (SN) compared with patients with migraine. Conclusion Patients with vestibular migraine showed obvious altered functional connectivity in the bilateral medial cingulate gyrus and paracingulate gyrus within the SMN. The median cingulate and paracingulate gyri may be impaired, the disinhibition of sensorimotor network and vestibular cortical network may result in a hypersensitivity state (photophobia/phonophobia). Altered functional connectivity between AN and DMN, SN may lead to increased sensitivity to vestibular sensory processing.

Test Batteries and the Diagnostic Algorithm for Chronic Vestibular Syndromes

Objective: To develop a diagnostic algorithm for chronic vestibular syndromes by determining significant items that differ among diagnoses.Methods: Two hundred thirty-one patients with chronic vestibular syndromes lasting for &gt;3 months were included. Full vestibular tests and questionnaire surveys were performed: bithermal caloric test, cervical and ocular vestibular-evoked myogenic potential assessment, video head impulse test (vHIT), posturography, rotatory chair test, dizziness handicap inventory, hospital anxiety and depression scale (HADS), and Niigata persistent postural-perceptual dizziness (PPPD) questionnaire (NPQ). Differences in each item of the vestibular tests/questionnaires/demographic data were tested among the diagnoses. A receiver operating characteristic (ROC) curve was created for the significant items. The value that provided the best combination of sensitivity/specificity on the ROC curve was adopted as a threshold for diagnosing the targeted disease. Multiple diagnostic algorithms were proposed, and their diagnostic accuracy was calculated.Results: There were 92 patients with PPPD, 44 with chronic dizziness due to anxiety (CDA), 31 with unilateral vestibular hypofunction (UVH), 37 with undifferentiated dizziness (UD), and 27 with other conditions. The top four diagnoses accounted for 88% of all chronic vestibular syndromes. Five significant items that differed among the four diseases were identified. The visual stimulation and total NPQ scores were significantly higher in the patients with PPPD than in those with UVH and UD. The percentage of canal paresis (CP %) was significantly higher in the patients with UVH than in those with PPPD, CDA, and UD. The patients with CDA were significantly younger and had higher anxiety scores on the HADS (HADS-A) than those with UVH and UD. Moreover, catch-up saccades (CUSs) in the vHIT were more frequently seen in the patients with UVH than in those with PPPD. The most useful algorithm that tested the total and visual stimulation NPQ scores for PPPD followed by the CP%/CUSs for UVH and HADS-A score/age for CDA showed an overall diagnostic accuracy of 72.8%.Conclusions: Among the full vestibular tests and questionnaires, the items useful for differentiating chronic vestibular syndromes were identified. We proposed a diagnostic algorithm for chronic vestibular syndromes composed of these items, which could be useful in clinical settings.

Skull Vibration Induced Nystagmus Test: Correlations with Semicircular Canal and Otolith Asymmetries

Background: To establish in patients with peripheral vestibular disorders relations between skull vibration-induced nystagmus (SVIN) different components (horizontal, vertical, torsional) and the results of different structurally related vestibular tests. Methods: SVIN test, canal vestibular test (CVT: caloric test + video head impulse test: VHIT), otolithic vestibular test (OVT: ocular vestibular evoked myogenic potential oVEMP + cervical vestibular evoked myogenic potential cVEMP) performed on the same day in 52 patients with peripheral vestibular diseases (age < 65 years), and 11 control patients were analyzed. Mixed effects logistic regression analysis was performed to assert whether the presence of nystagmus in SVIN (3D analysis) have an association with the presence of peripheral vestibular dysfunction measured by vestibular explorations (CVT or OVT). Results: We obtained different groups: Group-Co (control group), Group-VNT (dizzy patients with no vestibular tests alterations), Group-O (OVT alterations only), Group-C (CVT alterations only), Group-M (mixed alterations). SVIN-SPV horizontal component was significantly higher in Group-M than in the other groups (p = 0.005) and correlated with alterations of lateral-VHIT (p < 0.001), caloric test (p = 0.002) and oVEMP (p = 0.006). SVIN-SPV vertical component was correlated with the anterior-VHIT and oVEMP alterations (p = 0.007; p = 0.017, respectively). SVIN-SPV torsional component was correlated with the anterior-VHIT positivity (p = 0.017). SVIN was the only positive test for 10% of patients (83% of Group-VNT). Conclusion: SVIN-SPV analysis in dizzy patients shows significant correlation to both CVT and OVT. SVIN horizontal component is mainly relevant to both vestibular tests exploring lateral canal and utricle responses. SVIN-SPV is significantly higher in patients with combined canal and otolith lesions. In some patients with dizziness, SVIN may be the only positive test.

Clinical Implication of Caloric and Video Head Impulse Tests for Patients With Enlarged Vestibular Aqueduct Presenting With Vertigo

Background: By examining the clinical features and results of video head impulse test (vHIT) and caloric tests in patients with enlarged vestibular aqueduct (EVA) presenting with vertigo, we aimed to investigate the function of angular vestibulo-ocular reflex (VOR) and its clinical implications.Methods: Nine patients with EVA manifesting with vertigo were enrolled. The medical history, audiological examination, imaging, and the results of the caloric test and the vHIT were analyzed.Results: Of the nine patients with EVA (eight bilateral and one unilateral case), five were pediatric cases. All 17 ears exhibited sensorineural hearing loss (SNHL). Enlarged vestibular aqueduct patients can present with recurrent (seven cases) or single (two cases) vertigo attack, trauma-induced (two cases), or spontaneous (seven cases) vertigo. Diminished caloric responses were observed in 77.8% (7/9) of the patients (four cases unilaterally and three bilaterally), while unilateral abnormal vHIT results in 11.1% (1/9) patients. Abnormal caloric and normal horizontal vHIT responses were found in 66.7% (6/9) of EVA patients.Conclusions: Vestibular manifestations in EVA are diverse. Enlarged vestibular aqueduct patients with vertigo can present with a reduced caloric response and normal horizontal vHIT, and this pattern of angular VOR impairment was also found in other hydropic ear diseases.

Objective vestibular function changes in children following cochlear implantation

BACKGROUND: To date, systematically objective evaluations of vestibular function in children with cochlear implantation (CI) have been conducted sparsely, especiallyin children with large vestibular aqueduct syndrome (LVAS). OBJECTIVE: Our goal was to investigate the function of all five vestibular end-organs pre- and post-cochlear implantation in children with LVAS and normal CT. METHODS: In this retrospective cohort study, 34 children (age 4–17 years) with bilateral profound sensorineural hearing loss (SNHL) undergoing unilateral CI were included. Participants included 18 (52.9%) children with LVAS. Objective modalities to evaluate vestibular function included the caloric test, cervical vestibular-evoked myogenic potentials (cVEMP), ocular vestibular-evoked myogenic potentials (oVEMP), and video head impulse test (vHIT). All measurements were performed before surgery and 9 months after surgery. RESULTS: Mean age at CI was 8.1±3.7 years. Caloric testing showed hypofunction in 38.2%of cases before implantation and in 50%after (p > 0.05). We found a significant increase of overall abnormality rate in cVEMP and oVEMP from pre- to post-CI (p < 0.05). In all three semicircular canals tested by vHIT, there were no statistically significant mean gain changes (p > 0.05). Higher deterioration rates in cVEMP (53.3%) and oVEMP (52.0%) after surgery were observed (p < 0.05). In children with LVAS, cVEMP revealed a higher deterioration rate than superior semicircular canal (SSC) and posterior semicircular canal (PSC) (p < 0.05). In children with normal CT, the deterioration rates in VEMPs were both higher than those in vHIT (p < 0.05). CONCLUSIONS: In general, the otolith organs were the most affected peripheral vestibular sensors in children after cochlear implantation. The variations in otolith function influenced by CI were different between children with LVAS and normal CT. We recommend the use of this vestibular function test battery for children with cochlear implantation.

Audiological and vestibular evaluations in vitiligo patients

The aim of this paper was to investigate audiological abnormalities and potential vestibular injury in a sample of vitiligo subjects. Thirty-five patients with non-segmental vitiligo (NSV) were enrolled in the study. They underwent pure tonal audiometry (PTA), vestibular Fitzgerald-Hallpike caloric test, C-VEM, and O-VEMP testing. The χ2 test and multiple regression analysis were performed. At PTA, 69% of patients presented with bilateral hearing loss, 8% monaural hearing loss, and 23% normal values. Bilateral caloric stimulations were performed and demonstrated that 14% of patients had a monolateral and 9% had a bilateral pathological response. VEMPs analysis showed that 20% of patients had no O-VEMPs response and 3% had no C-VEMPs response. Comparison between the normal values of healthy subjects and NSV patients showed an alteration of VEMPs in 44%. Multiple regression showed no statistical differences. We propose a specific diagnostic protocol employing PTA, bithermal caloric tests, C-VEMP, and O-VEMP testing to evaluate audio-vestibular damage. Our data were concordant with the anatomic-physiological melanocytic distribution and their possible degeneration linked with NSV.

The impact of vestibular symptoms and electronystagmography results on recovery from sudden sensorineural hearing loss

Objectives Idiopathic sudden sensorineural hearing loss (SSNHL) represents a frequently encountered otological entity, of various types and severity, with an array of associated symptoms including vertigo. This is a devastating life-changing condition with a blurry prognosis. The objective of this study was to determine the clinical association of vestibular impairment by electronystagmography (ENG) and caloric tests, and their ability to predict prognosis. Methods An observational, crossectional study was carried out amongst patients admitted with SSNHL. Each consenting patient had an audiometry test performed on admission as well as ENG and caloric tests. Treatment included oral steroids and carbogen with intratympanic steroids used only as salvage treatment. Follow-up was completed after 6 months when hearing gains were evaluated. Finally, an association was sought between the rate of recovery and ENG and caloric test results. Results Of 35 patients included, marked recovery was seen in patients without vertigo when compared to those with vertigo (p=0.003). A statistically significant association was found between the presence of vertigo and hearing deterioration (p=0.008). More so, normal electronystagmography results were associated with marked recovery (p=0.04). Conclusions The vestibular end organs are both subjectively and objectively affected in SSNHL as demonstrated by the abnormal ENG and caloric tests in our study despite the small sample size. Concomitant vestibular involvement carries poorer prognosis and routine identification may help foresee the recovery of patients with SSNHL and as such, aid in patient counseling. ENG and caloric tests are easily available and may be recommended for all patients with SSNHL.

Bilateral vestibulopathy decreases self-motion perception

Objective Current diagnostic criteria for bilateral vestibulopathy (BV) primarily involve measurements of vestibular reflexes. Perceptual self-motion thresholds however, are not routinely measured and their clinical value in this specific population is not yet fully determined. Objectives of this study were (1) to compare perceptual self-motion thresholds between BV patients and control subjects, and (2) to explore patterns of self-motion perception performance and vestibular function in BV patients. Methods Thirty-seven BV patients and 34 control subjects were included in this study. Perceptual self-motion thresholds were measured in both groups using a CAREN platform (Motek Medical BV, Amsterdam, The Netherlands). Vestibular function was evaluated (only in BV patients) by the caloric test, torsion swing test, video head impulse test of all semicircular canals, and cervical- and ocular vestibular-evoked myogenic potentials. Differences in thresholds between both groups were analyzed. Hierarchical cluster analysis was performed to visualize patterns between self-motion perception and vestibular function within the group of BV patients. Results Perceptual self-motion thresholds were significantly higher in BV patients compared to control subjects, regarding nearly all rotations and translations (depending on the age group) (p ≤ 0.001). Cluster analysis showed that within the group of BV patients, higher perceptual self-motion thresholds were generally associated with lower vestibular test results (significant for yaw rotation, caloric test, torsion swing test, and video head impulse test (p ≤ 0.001)). Conclusion Self-motion perception is significantly decreased in BV patients compared to control subjects regarding nearly all rotations and translations. Furthermore, decreased self-motion perception is generally associated with lower residual vestibular function in BV patients. Trial registration Trial registration number NL52768.068.15/METC