Effects of Age and Middle Ear on the Frequency Tuning of the cVEMP and oVEMP.

BACKGROUND: Upward shift in the air conducted (AC) frequency tuning of vestibular evoked myogenic potentials (VEMPs) as an effect of aging is hypothesized to be due to the microstructural stiffening changes in the inner ear. However, with an AC stimulus, it may be possible that the shift in the frequency tuning of VEMPs as an effect of aging may also be due to contributions from the middle ear. PURPOSE: The main aim of this study was to examine the effects of age on the frequency tuning of the cervical VEMP (cVEMP) and ocular VEMP (oVEMP) and determine the role of middle ear transmission characteristics in shaping these effects. RESEARCH DESIGN: Standard group comparison. STUDY SAMPLE: One-hundred seven participants divided in three groups: young adult, middle-age, and older adults with "normal" middle ear and negative history of neurological or vestibular complaints. DATA COLLECTION AND ANALYSES: Middle ear measures included static admittance and middle ear resonant frequency. cVEMP and oVEMPs were elicited with AC tone bursts at 500, 750, and 1,000 Hz. RESULTS: No significant effect of age was observed on any of the middle ear measures. There was a significant effect of age on the amplitude of the cVEMP, but this effect was frequency specific. The age-related reduction in cVEMP corrected amplitude was only observed when the eliciting stimulus was 500 or 750 Hz, with no significant effect observed with a 1,000 Hz stimulus. For the oVEMP, the effects of age were apparent at all stimulus frequencies. We also observed a general upward shift in the frequency tuning of both the cVEMP and oVEMP for middle-age and older adults, with 750 and 1,000 Hz yielding higher response rates and larger amplitudes among middle-aged and older adults. Measurements of middle ear did not significantly contribute to the observed findings. CONCLUSIONS: The upward shift in frequency tuning of VEMPs among middle age and older adults could be due to the changes in the vestibular system and not from the middle ear. These results support the use of different frequency stimuli (i.e., 750 or 1,000 Hz) to elicit a VEMP if a response is absent using a 500 Hz stimulus, especially in patients over the age of 40.

Video Head Impulse Test in Persons with Blindness: Feasibility and Outcomes.

BACKGROUND: To achieve balance, persons with blindness (PWB) use proprioceptive and vestibular cues rather than the visual system; however, PWB are equally susceptible to acquire vestibular disorders. Reliable assessments of the vestibular system in PWB are essential to determine the presence or absence of vestibular disorders. PURPOSE: The saccular and the utricular functioning can be assessed using cervical vestibular-evoked myogenic potential and ocular vestibular-evoked myogenic potential, respectively. Evaluation of the functional integrity of the semicircular canals requires an assessment of the vestibular ocular reflex; however, this can be challenging in PWB. Video head impulse test (vHIT) assesses the vestibular ocular reflex (VOR) elicited against the natural high-frequency head movement in the planes of all six semicircular canals. This study aimed to explore the feasibility and outcomes of administering vHIT in PWB. RESEARCH DESIGN: Standard (static) groups comparison. STUDY SAMPLE: Nineteen young PWB and 23 age-matched adults with "normal" vision (control group) were included in the study. DATA COLLECTION AND ANALYSES: PWB underwent vHIT once, while the control group was tested in three conditions; condition 1 was used to simulate blindness for the control group, where vHIT was done in a pitch-dark room without prior instructions; condition 2 included vHIT testing in daylight, without a fixed visual target and any instructions; and condition 3 involved vHIT in daylight in the presence of a set visual target and with standard instructions to maintain visual focus on the visual target. RESULTS: The VOR gain was abnormal in the PWB group for all the canals. Among the PWB, the lateral canals (mean = 0.63) had the best VOR gain, followed by the anterior canals (mean = 0.53) and the posterior canals (mean = 0.31). In the control group, the VOR gain was significantly reduced in condition 1. There was no significant difference between the VOR gain in the PWB group and the control group in condition 1 for the lateral and the anterior canals. A higher proportion of participants in the PWB group had the presence of refixation saccades. CONCLUSION: VOR is significantly reduced in PWB but not completely absent. There may be a need to develop normative data for blind individuals to decide whether or not a person with blindness has a vestibular dysfunction, specifically a VOR deficit.

A Novel Stimulation Paradigm for Obtaining Interfrequency Amplitude Ratio of Ocular Vestibular Evoked Myogenic Potentials.

Purpose Interfrequency amplitude ratio (IFAR), the ratio of amplitude between ocular vestibular evoked myogenic potentials (oVEMPs) for tone bursts of 500 and 1000 Hz, aids in identification of Ménière's disease with high sensitivity and specificity. However, it requires recording of oVEMP for 2 frequencies, which doubles the time of recording. Use of simultaneous recording of responses for both frequencies could potentially bring down testing time. Simultaneous recording might be possible by modifying the oddball paradigm and using a ratio of 1:1 for the 2 frequencies. This might also reduce variation in oVEMP amplitude between frequencies due to changes in gaze angle between the recordings. However, it remains to be explored whether or not the use of modified oddball paradigm to record oVEMP (MoVEMP) will produce comparable responses to conventional sequential recording of oVEMP (CoVEMP) for obtaining IFAR. Hence, the study aimed to compare MoVEMP and CoVEMP on various measures of oVEMP. Method The study included 29 healthy adults in the age range of 18-30 years, 23 of which were used for validation and 6 for finding test-retest reliability. All participants underwent contralateral oVEMP recording using 500- and 1000-Hz tone bursts presented using MoVEMP and CoVEMP paradigms. Results Comparable outcomes on latencies, amplitude, and IFAR were obtained between CoVEMP and MoVEMP. Furthermore, MoVEMP took significantly lesser time per ear and also produced better test-retest reliability than CoVEMP. Conclusion MoVEMP is a quicker and more reliable clinical stimulation paradigm for obtaining IFAR than CoVEMP.

A Novel Grading System for Salpingopharyngeal Fold Hypertrophy in Obstructive Sleep Apnoea.

The present study aimed at reporting the incidence of Salpingopharyngeal Fold (SPF) hypertrophy on Drug Induced Sleep Endoscopy (DISE) in patients with Obstructive Sleep Apnoea (OSA, validate a grading system and analyse the impact of various grades on the clinical presentation while ascertaining its relation with Apnoea-Hypopnoea Index (AHI). A retrospective analysis of 169 patients with polysomnographic confirmation of obstructive sleep apnoea has been done in the study. The DISE video data of 169 patients was evaluated by two ENT surgeons individually and they graded the hypertrophy of the fold as Grade 0 being normal anatomy, Grade 1 being hypertrophy causing partial obstruction and Grade 2 being hypertrophy causing complete obstruction of lateral pharyngeal wall. It was found that the presence of SPF hypertrophy independently adds considerably to the severity of the obstruction, attributing to lateral collapse at the upper retropalatal level and also significantly increases AHI. It is thus advised to consider the grade of SPF hypertrophy while surgically planning the management of patients with OSA.

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.

Altered auditory and vestibular functioning in individuals with low bone mineral density: a systematic review.

Alteration in the process of bone remodelling is associated with falls and fractures due to increased bone fragility and altered calcium functioning. The auditory system consists of skeletal structures and is, therefore, prone to getting affected by altered bone remodelling. In addition, the vestibule consists of huge volumes of calcium (CaCO3) in the form of otoconia crystals and alteration in functioning calcium levels could, therefore, result in vestibular symptoms. Thus, the present study aimed at compiling information from various studies on assessment of auditory or vestibular systems in individuals with reduced bone mineral density (BMD). A total of 1977 articles were searched using various databases and 19 full-length articles which reported auditory and vestibular outcomes in persons with low BMD were reviewed. An intricate relationship between altered BMD and audio-vestibular function was evident from the studies; nonetheless, how one aspect of hearing or balance affects the other is not clear. Significant effect of reduced bone mineral density could probably be due to the metabolic changes at the level of cochlea, secondary to alterations in BMD. One could also conclude that sympathetic remodelling is associated with vestibular problems in individual; however, whether vestibular problems lead to altered BMD cannot be ascertained with confidence. The studies reviewed in the article provide an evidence of possible involvement of hearing and vestibular system abnormalities in individuals with reduced bone mineral density. Hence, the assessment protocol for these individuals must include hearing and balance evaluation as mandatory for planning appropriate management.

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

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.