Tactile responses in pure-tone audiometry: a saccule function?

Clinical and Experimental Pharmacology and Physiology, 2014

Extracellular single neuron recording and labelling studies of primary vestibular afferents in Scarpa's ganglion have shown that guinea pig otolithic afferents with irregular resting discharge are preferentially activated by 500Hz bone-conducted vibration (BCV) and manya lso by 500Hz air-conducted sound (ACS) at lowt hreshold and high sensitivity.V ery fewa fferent neurons from any semicircular canal are activated by these stimuli and then only at high intensity. 2. Tracing the origin of the activated neurons shows that these sensitive otolithic afferents originate mainly from aspecialized region-the striola-of both the utricular and saccular maculae. 3. This same 500Hz BCV elicits vestibulardependent eye movements in alert guinea pigs and also in healthyh umans. These stimuli evoke myogenic potentials (VEMPs) which are used to test the function of the utricular and saccular maculae in human patients. 4. Although utricular and saccular afferents can both be activated by BCV and ACS, the differential projection of utricular and saccular afferents to different muscle groups allows for differentiation of the function of these two sensory regions. The basic neural data support the conclusion that in human patients in response to brief 500Hz BCV delivered to Fz (the midline of the forehead at the hairline) the cervical VEMP (cVEMP) indicates predominantly saccular function and the ocular VEMP (oVEMP) indicates predominantly utricular function. 5. The neural, anatomical and behavioural evidence underpins clinical tests of otolith function in humans using sound and vibration.

Hearing Research, 2013

and sharing with colleagues.

The journal of international advanced otology, 2016

The objective of this study was to explore the usefulness of 1000-Hz tone burst (TB) stimuli for detecting cervical vestibular-evoked myogenic potential (cVEMP) abnormalities in patients with a cochlear implant (CI). Thirty asymptomatic patients who received unilateral CI because of severe bilateral sensorineural hearing loss were assessed for cVEMP produced by TB stimuli at two frequencies (500 and 1000 Hz) in the airway. VEMPs were recorded when the devices were switched to the on (CI-on) and off (CI-off) positions. At the CI-on position, the surgical side (SS) 500-Hz response rates (15/30) were significantly higher than the SS 1000-Hz response rates (9/30) (p=0.031), while the non-operated control side (CS) 500-Hz response rates (20/30) were higher than the CS 1000-Hz response rates (18/30), but the difference was not significant (p=0.50). At the CI-on position, the SS 500-Hz response rates (15/30) were lower than the CS 500-Hz response rates (20/30), but the difference was not s...

Hearing, Balance and Communication, 2019

Objectives: To describe the vestibular evoked myogenic potential (VEMP) response to air-conducted sound (ACS) and bone-conducted vibration (BCV) in patients with unilateral definite M eni ere's disease (MD), and the contribution to the usual ACS evaluation of the bone-air index (BAI) and interaural asymmetry ratio (IAR) in the diagnosis. Methods: A case-control study was designed. Fifty-one patients (25 men and 26 women) with an average age of 55 years, and 31 healthy volunteers with no history of vertigo and hearing loss, were included. The BAI was used as a new parameter to describe the amplitude of the response. Results: Only n10 latency ACS evoked was significantly longer than in controls. The ACS cVEMP p13-n23 amplitude of the affected ear of patients with MD was lower than in the non-affected ear (p ¼ .023) and the control group (.001). The IAR was significantly higher in patients with MD both for the ACS and for the BCV cVEMP compared to the control group: p ¼ .004 and .001, respectively. Significant differences were found in oVEMP n10-p16 amplitude between ACS and BCV in the patients with MD (p ¼ .002). The BAI in oVEMP showed a significant increase in the affected ear compared to the control group (p ¼ .001). The acoustic stimulus in cVEMP was the only one that showed significant differences in amplitude according to degree of hearing loss (p ¼ .039). Conclusions: The joint use of an acoustic and vibratory stimulus is an interesting option to characterize the results in this group. The BAI provides useful complementary information, and also turns out to give added value to the traditional VEMP assessment by ACS. We recommend its use when M eni ere's disease is suspected.

https://www.ijrrjournal.com/IJRR_Vol.6_Issue.11_Nov2019/Abstract_IJRR0077.html, 2019

Introduction-Vestibular Myogenic Potential (VEMP) is a newer modality to partially assess otolithic organs by assessing the functions of saccule and its neural connections. Cervical and Ocular VEMP are being studied extensively for its anticipated objective utility in diagnosing vestibulopathies. With the advent of various techniques of conduct and interpretation of VEMP there is a felt need to obtain and standardise the normative data in Indian population. This observational descriptive study peruses three objectives-Comparison of effect of different stimuli i.e. click vs. short tone burst & unilateral vs. bilateral stimulation in generation of cVEMP; to study the effect of mode of muscle contraction on cVEMP i.e. head lift vs. neck torsion, and, to study age & gender related variations in generation of these potentials. Methods-171 healthy adult volunteers between 18-25 years of age with normal hearing were recruited and subjected to cVEMP testing. cVEMP was performed by head lift and neck torsion manoeuvre and with short tone burst (95 dBnHL, 500 Hz) (STB) and clicks and data was recorded and analysed. Results-Statistically significant amplitudes (in µV) for both waveforms, p13 and n23, were recorded with head lift manoeuvre as compared to neck torsion and STB stimulus as compared to clicks. Latencies of waveform p13 and n23 were significantly shorter for click stimuli compare to Short tone burst stimulus. We found no statistically significant variation in amplitudes and latencies of both waveforms among both genders. Conclusion-cVEMP can be reliably obtained by both click and short tone burst stimuli in normal hearing individuals. STB stimulus produces morphologically clearer responses with larger amplitudes than click stimuli while Click stimulus elicits a cVEMP with shorter latencies than STB. Head lift manoeuvre was a reliable means of producing Sternocleidomastoid contraction while neck torsion was not. There was no gender variation in terms of amplitudes and latencies of cVEMP waveforms.

Acta Oto-Laryngologica, 2013

Conclusion: Patients with vestibular neuritis (VN) with complete canal paresis (CP) showed a higher rate of abnormal ocular vestibular evoked myogenic potential (oVEMP) than those with partial CP. From these results, it is speculated that the superior vestibular nerve function mainly affects oVEMP. Significant correlation was found between the grades of the hearing outcome and oVEMP in sudden sensorineural hearing loss (SSHL). Objective: We attempted to correlate the results of oVEMP with the results of cervical VEMP (cVEMP), results of subjective visual vertical (SVV), and clinical course in patients with various vestibular disorders. Methods: Twenty-two patients with VN, 65 with SSHL, and 22 with Meniere's disease (MD), were enrolled in this study. We compared the results of oVEMP with those of cVEMP, SVV, and the caloric test. Furthermore, the oVEMP results were compared with the initial hearing threshold, presence of vertigo, and hearing recovery in the patients with SSHL. Results: The patients with VN with complete CP showed a higher rate of abnormal oVEMP than those with partial CP. In the patients with SSHL, the hearing recovery rate was lower in the patients with abnormal oVEMP than in those with normal oVEMP.

The Journal of the Acoustical Society of America, 1953

Journal of hearing science, 2013

Background: Vestibular evoked myogenic potential (VEMP) is a test to assess the functioning of otolith organs of the inner ear. Cervical VEMPs (cVEMPs) assess the saccule and the inferior vestibular nerve, whereas ocular VEMPs (oVEMPs) assess the utricle and superior vestibular nerve. In individuals with sensorineural hearing loss, disturbances of cochlear function could accompany vestibular impairment since both these parts of the inner ear are anatomically related. The aim of the present study was to find out the prevalence of cVEMPs and oVEMPs in individuals with congenital severe to profound sensorineural hearing loss. Material and methods: There were 46 participants in the present study: 23 with normal hearing and 23 with bilateral severe to profound hearing loss, and cVEMPs and oVEMPs were recorded from all of them. Results: cVEMPs were present in 100% of subjects, both in the control and experimental groups; oVEMPs were present in 100% of the control and 66% of the experimental group. In hearing impaired individuals no correlation was found between cVEMPs and oVEMPs, although a Mann-Whitney test revealed that the amplitude of cVEMPs and oVEMPs were significantly smaller in the hearing impaired group compared to normals. Conclusions: The results indicate impairment of both utricular and saccular function in individuals with severe to profound hearing loss. Also oVEMPs were absent in more individuals compared to cVEMPs, which suggests that utricular function is more linked with the cochlea compared to that of the saccule.

Los determinantes, individualmente o agrupados en un sistema, crean el contexto en el que nacen y compiten las empresas de una nación: la disponibilidad de recursos y técnicas necesarias para la ventaja competitiva en un sector; la información que determina las oportunidades que se detectan y las orientaciones con que se despliegan los recursos y las técnicas; las metas que persiguen los propietarios, directores y empleados que están interesados en la competencia o que la llevan a cabo y, lo que es todavía más importante, las presiones a que se ven sometidas las empresas para invertir e innovar. Según Michael Porter cuatro son los componentes o determinantes de la ventaja competitiva que conforman el diamante, los cuales se ilustran en la gráfica a continuación: Figura 1 Los determinantes de la Ventaja Competitiva Fuente: Michael Porter. La Ventaja Competitiva de las Naciones. 1. Condiciones de los factores. La posición de la nación en lo que concierne a mano de obra especializada o infraestructura necesaria para competir en un sector dado. 2. Condiciones de la demanda. La naturaleza de la demanda interior de los productos o servicios del sector. 3. Sectores afines y de apoyo. La presencia o ausencia en la nación de sectores proveedores y sectores afines que sean internacionalmente competitivos. 4. Estrategia, estructura y rivalidad de la empresa. Las condiciones vigentes en la nación respecto a cómo se crean, organizan y gestionan las compañías, así como la naturaleza de la rivalidad doméstica. ESTRATEGIA, ESTRUCTURA Y RIVALIDAD DE LA EMPRESA CONDICIONES DE LOS FACTORES CONDICIONES DE LA DEMANDA SECTORES CONEXOS Y DE APOYO 1.2.1. Condiciones de los factores.