Otolithic and canal functions assessment during the acute phase of benign paroxysmal positional vertigo.

PURPOSE: Assess otolith and canal involvement in patients with Benign Paroxysmal Positional Vertigo (BPPV) during the acute phase. METHODS: Ninety patients with BPPV in the acute phase underwent a vestibular assessment that included an assessment with videonistagmography, video Head Impulse Test (vHIT) to evaluate horizontal and vertical semicircular canals, and ocular vestibular evoked myogenic potentials (oVEMPs) for the otolithic function. RESULTS: Ninety patients had an involvement of the posterior canal, fifty-five out of ninety patients presented a BPPV of the right ear. No asymmetry of the otolithic functions was found for the utricular macula. Furthermore, no reduction of the Vestibular Ocular Reflex gain was found for the examined canal functions. CONCLUSIONS: The lack of asymmetry suggests that during the acute phase of BPPV, the otolithic function is balanced between the affected and unaffected ears. Moreover, the preserved VOR gain for the examined canal functions suggests that the VOR responses for the examined channels were intact.

Paediatric vestibular assessment in French cochlear implant centres: Challenges and improvement areas.

OBJECTIVE: Survey of paediatric vestibular activity in all 30 French paediatric cochlear implant (CI) centres to identify challenges and areas of improvement. METHOD: All 30 French CI centres answered a 29-question questionnaire about their paediatric vestibular activity, equipment, and management in different clinical situations (e.g. vestibular assessment before a cochlear implantation or in cases of vertigo) at different ages. RESULTS: Eighteen CI centres had dedicated paediatric vestibular clinics and 12 did not. Minimum age required for vestibular testing was 3 years in eight centres. Four vestibular tests stood out: caloric tests, video Head Impulse Test (vHIT), rotating chair, vestibular evoked myogenic potentials (VEMP). Depending on the centre's experience, the use of vestibular tests in clinical routine was very heterogeneous. Expert centres mostly used vHIT and cervical VEMP (in bone conduction) for assessments before the first cochlear implantation in 1-year-old children. Dizziness assessment in 4-year children was based on the use of vHIT, cervical VEMP on bone conduction, rotatory test, and caloric test. Ocular VEMP was rarely used. CONCLUSIONS: Paediatric vestibular assessment requires specific expertise compared to adults. Due to a lack of specialised human resources, some centres may be unable to follow French paediatric CI guidelines. International recommendations could help standardise paediatric vestibular management and public health policies should be discussed to improve training and access for children.

Assessment of the Clinical Use of Vestibular Evoked Myogenic Potentials and the Video Head Impulse Test in the Diagnosis of Early-Stage Parkinson's Disease.

OBJECTIVES: To explore the usefulness of vestibular tests including "vestibular evoked myogenic potentials" (VEMPs) and the video head impulse test (vHIT) in the early diagnosis of "idiopathic Parkinson's disease" (PD). MATERIALS AND METHODS: The study involved 80 participants including 40 patients (24 males, 16 females; age average 63.20 ± 7.94 years) with PD and 40 healthy individuals (18 males and 22 females; age average of 60.36 ± 7.68 years). The Modified Hoehn and Yahr (H&Y) scale was used to measure how Parkinson's symptoms progress and the level of disability. Patients with PD underwent cVEMPs, oVEMPs, and vHIT and the results were compared with those of 40 age-matched healthy control (HC) subjects. vHIT results and VEMP responses were registered in all patients and HCs. RESULTS: One-sided absent cVEMP responses were found in 6 (15%) patients with PD and 8 (20%) patients had bilaterally absent responses. Five (12.5%) patients had 1-sided absent oVEMP responses and it was bilateral in 6 (15%). Patients with PD had significantly shorter cVEMP P1, N1 latency, lower cVEMP amplitudes, and oVEMP amplitudes than the HC group. The cVEMP and oVEMP amplitude asymmetry ratio was significantly higher in the PD group (P < .05). Evaluation of vHIT results and vestibular-ocular reflex (VOR) gain between the groups revealed that anterior canal and posterior canal VOR gains results were remarkably lower in the PD group than in the HCs (P < .05). There was no difference in right and left lateral canal VOR gains between the groups (P > .05). CONCLUSION: The results of this study suggest that cVEMP and vHIT can be used to evaluate the vestibular system in patients with early-stage Parkinson's disease.

Pediatric Vestibular Assessment: Clinical Framework.

OBJECTIVES: Although vestibular deficits can have severe repercussions on the early motor development in children, vestibular assessment in young children has not yet been routinely integrated in clinical practice and clear diagnostic criteria to detect early vestibular deficits are lacking. In young children, specific adjustments of the test protocol are needed, and normative data are age-dependent as the vestibular pathways mature through childhood. Therefore, this study aims to demonstrate the feasibility of an extensive age-dependent vestibular test battery, to provide pediatric normative data with the concurrent age trends, and to offer a clinical framework for pediatric vestibular testing. DESIGN: This normative study included 133 healthy children below the age of 4 years (mean: 22 mo, standard deviation: 12.3 mo, range: 5-47 mo) without history of hearing loss or vestibular symptoms. Children were divided into four age categories: 38 children younger than 1 year old, 37 one-year olds, 33 two-year olds, and 25 three-year olds. Children younger than 3 years of age were examined with the video Head Impulse Test (vHIT) of the horizontal semicircular canals, cervical vestibular evoked myogenic potentials (cVEMP) with bone conduction stimuli, and the rotatory test at 0.16, 0.04, and 0.01 Hz. In 3-year old children, the vHIT of the vertical semicircular canals and ocular vestibular evoked myogenic potentials (oVEMP) using a minishaker were added to the protocol. RESULTS: The horizontal vHIT appeared to be the most feasible test across age categories, except for children younger than 1-year old in which the success rate was the highest for the cVEMP. Success rates of the rotatory test varied the most across age categories. Age trends were found for the vHIT as the mean vestibulo-ocular reflex (VOR) gain increased significantly with age (r = 0.446, p < 0.001). Concerning the cVEMP, a significant increase with age was found for latency P1 (r = 0.420, p < 0.001), rectified interpeak amplitude P1-N1 (r = 0.574, p < 0.001), and averaged electromyographic (EMG) activity (r = 0.430, p < 0.001), whereas age trends for the latency N1 were less pronounced (r = 0.264, p = 0.004). Overall, the response parameters of the rotatory test did not show significant age effects ( p > 0.01), except for the phase at 0.01 Hz (r = 0.578, p < 0.001). Based on the reported success rates and age-dependent normative vestibular data, straightforward cutoff criteria were proposed (vHIT VOR gain < 0.7, cVEMP rectified interpeak amplitude < 1.3, oVEMP interpeak amplitude < 10 µV) with accompanying clinical recommendations to diagnose early vestibular impairment. CONCLUSIONS: In this large cohort of typically developing children below the age of 4 years, the vHIT and cVEMP were the most feasible vestibular tests. Moreover, the age-dependent normative vestibular data could specify age trends in this group of young children. Finally, based on the current results and clinical experience of more than ten years at the Ghent University Hospital (Belgium), a clinical framework to diagnose early vestibular deficits in young patients is proposed.

Vestibular assessment in children aged zero to twelve years: an integrative review.

OBJECTIVE: To describe the main vestibular assessment tests performed in children aged zero to twelve years and the main causes of referral for vestibular assessment. METHODS: The review was guided by the following question: What are the main vestibular assessment tests performed in children aged zero to twelve years and the main causes of referral for vestibular assessment? The PVO strategy was used, being defined as: Population (P) - newborns and children; study Variable (V) - causes of referral for vestibular assessment; study Outcome (O): the main vestibular assessment tests and the main findings. This study was carried out using the main available databases in the months of July, August and September 2021, with no restrictions regarding language and publication date, namely: PubMed, Web of Science, Scientific Electronic Library Online (SciELO), Latin-American and Caribbean Literature in Health Sciences (LILACS), ScienceDirect, Cochrane Library and Embase. The descriptors were obtained from the MeSH database: newborn, infant, child, children, vestibular screening, vestibular infant screening, vestibular newborn screening, test, vestibular function, vestibular function test. RESULTS: A total of 7,078 studies were identified. After reading the titles and abstracts, 107 of them were selected, with 101 remaining after the exclusion of duplicates. After the full-text reading, 31 articles were included. It was observed that the most frequently used tests were: rotational tests, caloric stimulation and cervical vestibular evoked myogenic potential and the main causes of referral for vestibular evaluation were hearing loss and vestibular screening. CONCLUSION: The main tests for vestibular screening and/or assessment of children aged zero to twelve years are the rotary chair testing, caloric stimulation and cervical-vestibular evoked myogenic potential. Consequently, performing these procedures is extremely important, since the presence of vestibular dysfunction is quite common in the studied population.

Vestibular function assessment in sudden hearing loss.

OBJECTIVES: To perform vestibular assessment using cervical and ocular vestibular evoked myogenic potential, video head impulse test and caloric testing in patients with sudden hearing loss. Moreover, to evaluate the correlation of dizziness with vestibular tests and the correlation of vestibular tests with hearing prognosis. METHODS: This is an observational, longitudinal and prospective study, including participants diagnosed with sudden hearing loss. The participants underwent cervical and ocular vestibular evoked myogenic potential, video head impulse test and caloric testing. The audiometric assessment was performed at the beginning and at the end of the follow-up. A value of p≤0.05 was considered statistically significant. RESULTS: Seventeen patients were included in the study sample, with a mean age of 45.4±11.1 years. Five participants (29.41%) had dizziness and 15 (88.23%) had tinnitus. All participants underwent vestibular evaluation through cervical and ocular vestibular evoked myogenic potential and video head impulse test, and 13 of them were evaluated through caloric testing. The cervical vestibular evoked myogenic potential was considered altered in five (29.41%) participants, while 11 (64.71%) showed alterations at the ocular vestibular evoked myogenic potential. The video head impulse test and the caloric testing were considered altered in seven (41.18%) and five (38.46%) participants, respectively. There was no statistically significant correlation between the clinical data and the results of vestibular tests or hearing recovery, nor between the results of vestibular tests and hearing recovery. CONCLUSION: The assessment through vestibular evoked myogenic potential, video head impulse test and caloric testing showed vestibular involvement in some participants. However, it cannot be stated that the results of the vestibular tests are related to the hearing prognosis of sudden hearing loss.

Assessment of otolith function using vestibular evoked myogenic potential in women during pregnancy.

INTRODUCTION: More than 50% of pregnant women experience dizziness frequently in the first two gestational trimesters. During pregnancy, the changes in the metabolism of hormones are responsible for the ovarian cycle resulting in either peripheral or central vestibular alterations. The need for the study is to focus on the effect of changes during pregnancy on the vestibular evoked myogenic potential, an electrophysiological measure that investigates functions of the otolith structures. OBJECTIVES: The aim is to investigate the vestibular evoked myogenic potential responses during the first trimester of pregnancy. METHODS: A total of 17 pregnant women and 17 non-pregnant women with age matched took part in this study. The cervical vestibular evoked myogenic potential were recorded from the ipsilateral sternocleridomastoid muscle and the ocular vestibular evoked myogenic potential were recorded from contralateral extraocular muscle in both groups. RESULTS: Peak to peak amplitude of cervical vestibular evoked myogenic potential and ocular vestibular evoked myogenic potential was found to be significantly reduced in the responses obtained from first-trimester pregnant women when compared to that of non-pregnant women. CONCLUSIONS: Vestibular evoked myogenic potential tests exhibits a clinically significant reduced peak to peak amplitude in the first trimester of pregnancy, which indicates dysfunction in the otolith reflex pathway.

Vestibular mapping assessment in idiopathic sudden sensorineural hearing loss.

OBJECTIVE: The aim of this study was to investigate patterns of semicircular canal (SCC) and otolith organ dysfunction by vestibular mapping, and to determine the clinical implications of treatment outcomes in idiopathic sudden sensorineural hearing loss (ISSNHL). METHODS: We retrospectively reviewed 135 consecutive patients diagnosed with ISSNHL from January 2016 to December 2020. Patients underwent video-head impulse tests (vHIT) for each SCC, cervical vestibular-evoked myogenic potential test for the saccules, ocular vestibular-evoked myogenic potential test for the utricles, and hearing tests. Hearing outcomes were evaluated according to the American Academy of Otolaryngology-Head and Neck Surgery criteria and factors associated with prognosis were assessed. We also conducted vestibular mapping assessments and hierarchical cluster analysis. RESULTS: Overall, utricular impairment (76, 56.3%) was the most frequent diagnosis in the 135 ISSNHL patients, followed by saccular impairment (59, 43.7%) and posterior SCC impairment (30, 22.2%). The mean number of affected end organs was 1.37 ± 1.24, with higher numbers in the complete recovery group than in the partial/no recovery groups. In a multivariate analysis, higher initial hearing level and abnormal vHIT results in the posterior SCC were associated with poor prognosis in ISSNHL. In hierarchical cluster analysis, horizontal SCC and anterior SCC showed the highest similarity but were in different clusters than posterior SCC, and the saccule and utricle were in separate clusters from the three SCCs. CONCLUSIONS: The vestibular end organ showed various patterns of dysfunction in patients with ISSNHL. Of the five vestibular end organs, only abnormal posterior SCC was associated with poor prognosis for hearing recovery.

Assessment of balance after recovery from Covid-19 disease.

OBJECTIVE: To answer the question whether balance related systems have been affected in adults who recovered from Covid-19 disease. This is the first case-control study to assess balance objectively and quantitatively in Covid-19 disease. METHODS: Thirty-seven patients who recovered from Covid-19 disease and 30 healthy controls were compared using Dizziness Handicap Inventory (DHI), Computerized Dynamic Posturography (CDP), Vestibular Evoked Myogenic Potentials(VEMP) and Video Head Impulse Test (v-HIT). RESULTS: On CDP, the composite and visual general scores of the patients were significantly lower than controls (p<0.01). The v-HIT gains of the patients significantly decreased in the vertical semicircular canals compared to controls (p<0.01).There was a significant difference between the patients and controls regarding the absence of o-VEMPs (p<0.01) while the amplitudes and latencies were similar between the groups (p>0.05). Decreased P1/N1 amplitudes and elongated N1 latencies were found on c-VEMP testing (p<0.05). Anosmia, taste disorder and gender were not associated with subjective and objective test results (p>0.05). CONCLUSION: The Covid-19 disease can cause dizziness rather that incapacitating vertigo. Dizziness can be seen in almost one-fifth of the adult covid19 out-patients, which may be due to involvement of vestibular and visual systems,ortheir central connections. The squeals created in the balance related systems may be irreversible as they have persisted after the recovery of the patients. It is also plausible to anticipate more severe condition in the older patients who were treated in the intensive care units. In the long term follow up of the survivors, the need for balance rehabilitation programs should be remembered in order to minimize risks of falling down.

Differentiating neurodegenerative parkinsonian syndromes using vestibular evoked myogenic potentials and balance assessment.

OBJECTIVE: Vestibular evoked myogenic potentials (VEMP) were investigated to differentiate between parkinsonian syndromes. We correlated balance and VEMP parameters to investigate the VEMP brainstem circuits as possible origin for postural instability. METHODS: We assessed clinical status, ocular and cervical VEMP (oVEMP, cVEMP) and conducted a balance assessment (posturography, Activities-specific Balance Confidence Scale, Berg Balance Scale, modified Barthel Index) in 76 subjects: 30 with Parkinson's disease (PD), 16 with atypical parkinsonism (AP) and 30 healthy controls. VEMP were elicited by using a mini-shaker on the forehead. RESULTS: Patients with PD had a prolonged oVEMP n10 in comparison to controls and prolonged p15 compared to controls and AP. Patients with AP showed reduced oVEMP amplitudes compared to PD and controls. CVEMP did not differ between groups. Postural impairment was higher in AP compared to controls and PD, particularly in the rating scales. No correlations between VEMP and posturography were found. A support vector machine classifier was able to automatically classify controls and patient subgroups with moderate to good accuracy based on oVEMP latencies and balance questionnaires. CONCLUSIONS: Both oVEMP and posturography, but not cVEMP, may be differentially affected in PD and AP. We did not find evidence that impairment of the cVEMP or oVEMP pathways is directly related to postural impairment. SIGNIFICANCE: OVEMP and balance assessment could be implemented in the differential diagnostic work-up of parkinsonian syndromes.

Preoperative Differences in Intracranial Facial Versus Vestibular Schwannomas: A Four Nerve Assessment.

OBJECTIVES: Assesses whether preoperative functional testing can distinguish vestibular schwannomas from facial nerve schwannomas medial to the labyrinthine segment. STUDY DESIGN: Retrospective cohort. METHODS: Retrospectively review surgically managed intracranial facial and vestibular schwannomas between January 2015 and December 2019 at two tertiary care centers. Patients with neurofibromatosis 2 and surgery for recurrence were excluded. Preoperative functional testing to include House-Brackmann scores, electroneuronography (ENoG), cervical vestibular evoked myogenic potentials (cVEMP), caloric testing, acoustic brainstem responses (ABRs), acoustic reflexes, and audiograms was compared between the two groups of schwannomas. RESULTS: Twelve facial and 128 vestibular schwannomas met inclusion criteria. In only one case was a facial schwannoma diagnosed preoperatively from imaging. No statistically significant difference was found in preoperative House-Brackmann scores, ENoG, cVEMP, caloric testing, ABRs, or acoustic reflexes. Pure tone average was worse in the vestibular schwannoma group (63 dB [95% CI: 58-68 dB] vs. 46 dB [95% CI: 34-58 dB], P = .01), and the difference was more apparent in the lower frequencies. Word recognition score was better in the facial schwannoma group (66% [95% CI: 45-86%] vs. 41% [95% CI: 34-47%], P = .02). CONCLUSION: Specialized preoperative functional evaluation of the nerves of the internal auditory canal cannot reliably predict the presence of an intracranial facial schwannoma. Hearing is better in facial schwannomas, particularly in the lower frequencies. This should raise the index of suspicion for an intracranial facial schwannoma, especially in candidates for hearing preservation vestibular schwannoma surgery. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:2098-2105, 2021.

Vestibular function assessment of Susac syndrome patients by the video head impulse test and cervical vestibular-evoked myogenic potentials.

BACKGROUND: Susac syndrome (retino-cochleo-cerebral vasculopathy, SuS) is an autoimmune endotheliopathy characterized by the clinical triad of encephalopathy, branch retinal artery occlusions and sensorineural hearing loss. In contrast to data regarding auditory function, data measuring vestibular function is sparse and the cervical vestibular-evoked myogenic potentials (cVEMPs). OBJECTIVE: To determine whether the video head impulse test (vHIT) can serve as a confirmatory assessment of vestibulocochlear dysfunction in cases of suspected SuS. METHODS: Seven patients diagnosed with SuS underwent pure tone audiometry, a word recognition test, cVEMPs and the vHIT. RESULTS: Five patients were diagnosed with definite SuS, and two with probable SuS. Two patients were asymptomatic for hearing loss or tinnitus, and no sensorineural hearing loss was detected by audiograms. Four patients complained of tinnitus, and three patients reported experiencing vertigo. Three patients had abnormal cVEMPs results. All seven patients' vHIT results were normal, except for patient #2, who was one of the three who complained of vertigo. The calculated gain of her left anterior semicircular canal was 0.5, without saccades. CONCLUSIONS: This is the first study to describe the results of the vHIT and cVEMPs among a group of patients with SuS. The results suggest that the vHIT should not be the only exam used to assess the function of the vestibular system of SuS patients.

The feasibility, validity and reliability of a child friendly vestibular assessment in infants and children candidates to cochlear implant.

OBJECTIVES: The pediatric vestibular assessment has developed significantly in the past two decades, especially in terms of assessment of cochlear implant (CI) candidates. Different methods and test protocols have been applied, however without a general consensus. We present here the feasibility, validity and reliability of a child friendly vestibular testing in use at our department for the assessment of pediatric CI candidates. METHODS: The test battery consisted of head impulse test (HIT), video head impulse test (vHIT), cervical evoked myogenic potentials (cVEMP) and mini ice water caloric test (mIWC), all adapted from previous methods, mentioned in literature. We defined specific criteria for test feasibility, for test validity and test positivity (i.e. indicating vestibular insufficiency). The reliability of the whole protocol was assessed with test agreement analysis. RESULTS: Complete data from 35 children, all CI candidates, age ranging 4-79 months (67% under 2 years) and recruited over two years, were obtained. All but one child could complete at least one test with valid responses bilaterally, with the best compliance for HIT (97,1%) and least for cVEMP (68,6%). Feasibility did not appear to be affected by age or hearing loss etiology. Among the valid responses there was a substantial test agreement between HIT and vHIT, moderate agreement between vHIT/HIT and mIWC and no apparent agreement between the canal tests and cVEMP. Simple clinical guidelines were introduced to solve the tests' disagreement and to improve the protocol reliability: a) a pathological response had to be confirmed in at least two different canal tests and in at least three cVEMP trials; b) a canal/otolith disagreement was interpreted as a partial vestibular loss to be opposed to a complete vestibular insufficiency. CONCLUSIONS: The search for vestibular insufficiency in infants and young children can be attained with an opportunely adapted vestibular assessment, such the test battery proposed here. That assessment resulted easy to conduct and to interpret in a representative sample of CI candidates in preschool age, the most of whom were younger than 2 years. This method appears to particularly suit the demands of a vestibular assessment in young children CI candidates.

Assessment of Vestibular Function in Adults with Prelingual Hearing Loss Using c/oVEMP Tests.

OBJECTIVES: The aim of the present study was to compare the vestibular system integrity of individuals with normal hearing with that of prelingual hearing impaired individuals. It is well known that ocular vestibular evoked myogenic potentials (oVEMPs) reflect utricular function, whereas cervical vestibular evoked myogenic potentials (cVEMPs) reflect saccular function. Therefore, oVEMP and cVEMP tests were applied to evaluate the vestibular system integrity of hearing impaired individuals participating in the research. MATERIALS AND METHODS: The study group consisted of sensorineural prelingual hearing-loss volunteers aged from 18 to 60 years, whereas the control group consisted of age- and gender-matched healthy volunteers. cVEMP and oVEMP tests were performed to evaluate the integrity of the vestibular system, and the results were compared with those of the control group. RESULTS: The study included 20 (76.9%) women and 6 (23.1%) men in the study group; on the other hand, the control group consisted of 19 (73.1%) women and 7 (26.9%) men. There was a difference between the study group and the control group when oVEMP and cVEMP responses were compared, and the response percentage was higher in the control group. The response rates of oVEMP and cVEMP in patients with prelingual hearing loss were 44.2% and 59.6%, respectively. There was also a statistically significant difference between the groups for oVEMP amplitude and cVEMP P1 latency (p≤0.05). CONCLUSION: These findings suggest that prelingual hearing loss is related to both utricular and saccular dysfunctions. However, oVEMPs were more often abnormal in prelingual deaf patients than cVEMPs, suggesting that utricular dysfunction may be more common than saccular dysfunction.

Early Assessment of Vestibular Function after Unilateral Cochlear Implant Surgery.

INTRODUCTION: Cochlear implantation (CI) has been reported to negatively affect vestibular function. The study of vestibular function has variably been conducted using different types of diagnostic tools. The combined use of modern, rapidly performing diagnostic tools could prove useful for standardization of the evaluation protocol. METHODS: In a group of 28 subjects undergoing CI, the video head impulse test (vHIT), the cervical vestibular evoked myogenic potentials (cVEMP) and the short form of the Dizziness Handicap Inventory (DHI) questionnaire were investigated preoperatively and postoperatively (implant on and off) in both the implanted and the contralateral, nonimplanted ear. All surgeries were performed with a round window approach (RWA), except for 3 otosclerosis cases in which the extended RWA (eRWA) was used. RESULTS: The vHIT of the lateral semicircular canal showed preoperative vestibular involvement in nearly 50% of the cases, while the 3 canals were contemporarily affected in only 14% of the cases. In all the hypofunctional subjects, cVEMP were absent. A low VOR gain in all of the investigated superior semicircular canals was found in 4 subjects (14%). In those subjects (21.7%) in whom cVEMP were preoperatively present and normal on the operated side, the absence of a response was postoperatively recorded. DISCUSSION/CONCLUSION: The vestibular protocol applied in this study was found to be appropriate for distinguishing between the CI-operated ear and the nonoperated ear. In this regard, cVEMP was found to be more sensitive than vHIT for revealing a vestibular sufferance after CI, though without statistical significance. Finally, the use of RWA surgery apparently did not reduce the occurrence of signs of vestibular impairment.

Nondestructive and objective assessment of the vestibular function in rodent models: A review.

The normal function of the vestibular system is crucial for the sense of balance. The techniques used to assess the vestibular function plays a vital role in the research of the vestibular system. In this article, we have systematically reviewed some popular methods employing vestibular reflexes and vestibular evoked potentials for assessing the vestibular function in rodent models. These vestibular reflexes and vestibular evoked potentials to effective stimuli have been used as nondestructive and objective functional measures. The main types of vestibular reflexes include the vestibulo-ocular reflex (VOR), vestibulocollic reflex (VCR), and vestibulo-sympathetic reflex (VSR). They are all capable of indicating the functions of the semicircular canals and otoliths. However, the VOR assessment is much more prevalently used because of the relatively stereotypical inputoutput relationship and simple motion pattern of the ocular response. In contrast, the complicated motion pattern and small gain of the VCR response, as well as the undesired component possibly contributed from the acceleration receptors outside the labyrinths in the VSR response, restrict the widespread applications of VCR and VSR in the assessment of the vestibular system. The vestibular evoked myogenic potentials (VEMPs) and vestibular sensory evoked potentials (VsEPs) are the two typical evoked potentials that have been also employed for evaluating the vestibular function. Through exploiting different types of the VEMPs, the saccular and utricular functions can be evaluated separately. The sound-induced VEMPs, moreover, are capable of noninvasively assessing the unilateral vestibular function. The VsEPs, via the morphology of their signal waveforms, enable the access to the location-specific information that indicates the functional statuses of different components within the vestibular neural pathway.

Behavioural and objective vestibular assessment in persons with osteoporosis and osteopenia: a preliminary investigation / Behavioural and objective vestibular assessment in persons with osteoporosis and osteopenia: a preliminary investigation

Abstract Introduction: Calcium is vital for the functioning of the inner ear hair cells as well as for the neurotransmitter release that triggers the generation of a nerve impulse. A reduction in calcium level could therefore impair the peripheric vestibular functioning. However, the outcome of balance assessment has rarely been explored in cases with osteopenia and osteoporosis, the medical conditions associated with reduction in calcium levels. Objective: The present study aimed to investigate the impact of osteopenia and osteoporosis on the outcomes of behavioural and objective vestibular assessment tests. Methods: The study included 12 individuals each in the healthy control group and osteopenia group, and 11 individuals were included in the osteoporosis group. The groups were divided based on the findings of bone mineral density. All the participants underwent behavioural tests (Fukuda stepping, tandem gait and subjective visual vertical) and objective assessment using cervical and ocular vestibular evoked myogenic potentials. Results: A significantly higher proportion of the individuals in the two clinical groups' demonstrated abnormal results on the behavioural balance assessment tests (p < 0.05) than the control group. However, there was no significant difference in latencies or amplitude of cervical vestibular evoked myogenic potential and oVEMP between the groups. The proportion of individuals with absence of ocular vestibular evoked myogenic potential was significantly higher in the osteoporosis group than the other two groups (p < 0.05). Conclusion: The findings of the present study confirm the presence of balance-related deficits in individuals with osteopenia and osteoporosis. Hence the clinical evaluations should include balance assessment as a mandatory aspect of the overall audiological assessment of individuals with osteopenia and osteoporosis.

Resumo: Introdução: O cálcio é vital para o funcionamento das células ciliadas, assim como para a liberação dos neurotransmissores que desencadeiam um impulso nervoso. Uma redução nos níveis de cálcio poderia, portanto, prejudicar o funcionamento vestibular periférico. No entanto, a avaliação do equilíbrio tem sido raramente explorada em casos de osteopenia e osteoporose, condições médicas associadas à redução dos níveis de cálcio. Objetivo: O presente estudo teve como objetivo investigar o impacto da osteopenia e da osteoporose nos resultados dos testes de avaliação comportamental e vestibular objetiva. Método: O estudo incluiu 12 indivíduos nos grupos controle e grupo de osteopenia e 11 indivíduos no grupo da osteoporose. Os grupos foram divididos com base nos achados da densidade mineral óssea. Todos os participantes foram submetidos a testes comportamentais (Prova dos Passos de Fukuda, Marcha em tandem e Vertical Visual Subjetiva) e à avaliação objetiva com o uso de potenciais evocados miogênicos vestibulares cervical e ocular (cVEMP e oVEMP). Resultados: Uma proporção significativamente maior de indivíduos nos dois grupos com condições clínicas mostrou resultados anormais nos testes de avaliação comportamental e do equilíbrio (p < 0,05) do que o grupo controle. Embora não tenha havido diferença significativa nas latências ou na amplitude de cVEMP e oVEMP entre os grupos, a proporção de indivíduos com ausência de oVEMP foi significativamente maior no grupo da osteoporose do que nos outros dois grupos (p < 0,05). Conclusão: Os resultados do presente estudo demonstram a presença de déficits de equilíbrio em indivíduos com osteopenia e osteoporose. Assim, as avaliações clínicas gerais e audiológicas de indivíduos com osteopenia e osteoporose deveriam incluir a avaliação do equilíbrio como um aspecto obrigatório.

Preoperative Assessment of Cervical Vestibular Evoked Myogenic Potentials (cVEMPs) Help in Predicting Hearing Preservation After Removal of Vestibular Schwannomas Through a Middle Fossa Craniotomy.

OBJECTIVE: To determine whether cervical vestibular evoked myogenic potentials (cVEMPs) are predictive of hearing preservation in patients undergoing vestibular schwannoma removal through middle fossa craniotomy approach. STUDY DESIGN: Retrospective case study. SETTING: Tertiary referral center. PATIENTS: Eighteen patients who underwent a middle fossa craniotomy for vestibular schwannoma (stage I or II of Koos classification) with attempted hearing preservation from January 2008 to February 2016 were retrospectively reviewed. INTERVENTION: Pre-surgical cVEMPs test, videonystagmography (caloric test), and magnetic resonance imaging (MRI) as well as a pre- and post-surgical audiometry test. MAIN OUTCOME MEASURES: cVEMPs parameters including amplitude asymmetry ratio (AR), P13, and N23 latencies and peak-to-peak amplitude between P13 and N23 waves were calculated. Hearing data were classified according to the AAO-HNS hearing classes. The nerve of origin of the tumor was specified during surgery and the largest tumor diameter was measure on MRI axial plane on T2-CISS weighed images. RESULTS: Preoperative amplitude asymmetry ratio was lower (n = 15, Mann-Whitney U test, p < 0.001) in the group with postoperative hearing preservation (n = 11) compared with the group with postoperative hearing preservation failure (n = 4). The positive predictive value of an AR less than 24% to assess postoperative hearing preservation is 91.6%. Tumor size and localization were not correlated with cVEMPs, nor with caloric testing in this group of small-sized intracanalicular vestibular schwannomas. CONCLUSIONS: Our data suggest that cVEMPs may help predict hearing preservation outcome in vestibular schwannoma surgery via the middle fossa craniotomy approach.

Assessment of vestibular function in elderly patients.

PURPOSE OF REVIEW: Individuals over the age of 60 are at an increased risk of falls, even if they do not have an isolated dysfunction of the vestibular system. The aim of this article is to review the various vestibular testing currently available and its usefulness in determining the presence of vestibular dysfunction in the elderly population. The primary vestibular tests to be reviewed include: balance function testing, vestibular evoked myogenic potentials (VEMPs), and video head impulse testing (vHIT). RECENT FINDINGS: Balance function testing is important as it evaluates the integration of vestibular information along with sensory and visual information, which may also be impaired. VEMP testing provides a small diagnostic yield as most elderly patients have absent or reduced responses. vHIT gain is reduced in this population, but will still be within the normal range for individuals with normal balance function. SUMMARY: The combination of various vestibular tests provides complimentary information instead of redundant information on the patient's balance function. Each test evaluates various aspects of the vestibular system which are all needed to determine stable balance in the elderly population.