1
|
Raciti FM, Morales Y, Snapp HA, Rajguru SM. A reliable and reproducible protocol for sound-evoked vestibular myogenic potentials in rattus norvegicus. Front Integr Neurosci 2023; 17:1236642. [PMID: 37731913 PMCID: PMC10508189 DOI: 10.3389/fnint.2023.1236642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 08/21/2023] [Indexed: 09/22/2023] Open
Abstract
Introduction Cervical vestibular evoked myogenic potentials (cVEMPs) provide an objective measure of the integrity of the sacculo-collic pathway leading to their widespread use as a clinical tool in the diagnostic vestibular test battery. Though the application of cVEMPs in preclinical models to assess vestibular function, as performed in relevant clinical populations, remains limited. The present study aimed to establish a rodent model of cVEMP with standardized methods and protocols, examine the neural basis of the responses, and characterize and validate important features for interpretation and assessment of vestibular function. Methods We compared air-conducted sound (ACS)-evoked VEMPs from the sternocleidomastoid muscles in naïve Brown Norway rats. A custom setup facilitated repeatable and reliable measurements which were carried out at multiple intensities with ACS between 1 and 16 kHz and over 7 days. The myogenic potentials were identified by the presence of a positive (P1)-negative (N1) waveform at 3-5 ms from the stimulus onset. Threshold, amplitude, and latency were compared with intensity- and frequency-matched responses within and between animals. Results cVEMP responses were repeatedly evoked with stimulus intensities between 50-100 dB SPL with excellent test-retest reliability and across multiple measurements over 7 days for all frequencies tested. Suprathreshold, cVEMP responses at 90 dB SPL for 6-10 kHz stimuli demonstrated significantly larger amplitudes (p < 0.01) and shorter latencies (p < 0.001) compared to cVEMP responses for 1-4 kHz stimuli. Latency of cVEMP showed sex-dependent variability, but no significant differences in threshold or amplitude between males and females was observed. Discussion The results provide a replicable and reliable setup, test protocol, and comprehensive characterization of cVEMP responses in a preclinical model which can be used in future studies to elucidate pathophysiological characteristics of vestibular dysfunctions or test efficacy of therapeutics.
Collapse
Affiliation(s)
- Federica M. Raciti
- Department of Otolaryngology, University of Miami, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
| | - Yasniary Morales
- Department of Otolaryngology, University of Miami, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
| | - Hillary A. Snapp
- Department of Otolaryngology, University of Miami, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
| | - Suhrud M. Rajguru
- Department of Otolaryngology, University of Miami, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
- Bruce W. Carter Department of Veterans Affairs Medical Center, Miami, FL, United States
| |
Collapse
|
2
|
Mansour Y, Burchell A, Kulesza R. Abnormal vestibular brainstem structure and function in an animal model of autism spectrum disorder. Brain Res 2022; 1793:148056. [PMID: 35985362 DOI: 10.1016/j.brainres.2022.148056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 08/11/2022] [Indexed: 11/25/2022]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder that includes several key neuropathological changes and behavioral impairments. In utero exposure to the anti-epileptic valproic acid (VPA) increases risk of an ASD diagnosis in human subjects and timed in utero exposure to VPA is a clinically relevant animal model of ASD. Many human subjects with ASD have cerebellar hypoplasia, fewer Purkinje cells, difficulties with balance, ophthalmic dysfunction and abnormal responses to vestibular stimulation and such vestibular difficulties are likely under reported in ASD. We have recently shown that animals exposed to VPA in utero have fewer neurons in their auditory brainstem, reduced axonal projections to the auditory midbrain and thalamus, reduced expression of the calcium binding protein calbindin (CB) in the brainstem and cerebellum, smaller and occasionally ectopic cerebellar Purkinje cells and ataxia on several motor tasks. Based on these findings, we hypothesized that in utero VPA exposure similarly impacts structure and function of the vestibular brainstem. We investigated this hypothesis using quantitative morphometric analyses, immunohistochemistry for CB, a battery of vestibular challenges, recording of vestibular-evoked myogenic potentials and spontaneous eye movements. Our results indicate that VPA exposure results in fewer neurons in the vestibular nuclei, fewer CB-positive puncta, difficulty on certain motor tasks, longer latency VEMPs and significantly more horizontal eye movements. These findings indicate that the vestibular nuclei are impacted by in utero VPA exposure and provide a basis for further study of vestibular circuits in human cases of ASD.
Collapse
Affiliation(s)
- Yusra Mansour
- Department of Anatomy, Lake Erie College of Osteopathic Medicine, Erie, PA, United States; Henry Ford Macomb Hospital, Department of Otolaryngology - Head and Neck Surgery, Clinton Township, MI, United States
| | - Alyson Burchell
- Department of Anatomy, Lake Erie College of Osteopathic Medicine, Erie, PA, United States
| | - Randy Kulesza
- Department of Anatomy, Lake Erie College of Osteopathic Medicine, Erie, PA, United States.
| |
Collapse
|
3
|
Sox10 Gene Is Required for the Survival of Saccular and Utricular Hair Cells in a Porcine Model. Mol Neurobiol 2022; 59:3323-3335. [DOI: 10.1007/s12035-021-02691-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 12/08/2021] [Indexed: 10/18/2022]
|
4
|
Consistent removal of hair cells in vestibular end organs by time-dependent transtympanic administration of gentamicin in guinea pigs. J Neurosci Methods 2021; 351:109049. [PMID: 33359225 DOI: 10.1016/j.jneumeth.2020.109049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 11/24/2020] [Accepted: 12/18/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Vestibular hair cell loss and its role in balance disorders are not yet completely understood due largely to the lack of precise hair cell damage protocols. NEW METHOD Our damage protocol aims to selectively remove type I hair cells in a way that produces consistent and predictable lesions that can be used for reliable inter-animal and inter-group comparison in balance research. This objective is achieved by transtympanic injection of gentamicin on both the round window membrane and oval window over a fixed time period followed by thorough washing. RESULTS We achieved nearly total and consistent loss of type I hair cells at 94 % for the crista ampullaris of the lateral semicircular canal (LSC) and 86 % for the utricular macula with negligible loss of type II hair cells at 4% for the crista ampullaris of the LSC and 6% for the utricular macula. While the vestibular function was compromised in the relevant study group, this group had a zero mortality rate with no significant suppression of body weight gain. COMPARISON WITH EXISTING METHODS Gentamicin is typically administered via intraperitoneal systemic injection or, more recently, transtympanic injection. The intraperitoneal method is simple, but mortality rate is high. The transtympanic injection method produces ototoxic damage but with inconsistent lesion size. This inconsistency prevents reliable comparisons among animals. CONCLUSIONS This protocol employs a transtympanic injection method which selectively targets type I hair cells for removal in the vestibular epithelia in a time-dependent manner, uniformly damages vestibular function, and causes uniform hair cell loss.
Collapse
|
5
|
Yang X, Sun P, Wu JP, Jiang W, Vai MI, Pun SH, Peng C, Chen F. Nondestructive and objective assessment of the vestibular function in rodent models: A review. Neurosci Lett 2020; 717:134608. [PMID: 31743751 DOI: 10.1016/j.neulet.2019.134608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 10/28/2019] [Accepted: 10/31/2019] [Indexed: 11/25/2022]
Abstract
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.
Collapse
Affiliation(s)
- Xiaojie Yang
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Peng Sun
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China; State Key Laboratory of Analog and Mixed-Signal VLSI, University of Macau, Macau, China
| | - Jian-Ping Wu
- Academy of Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Weitao Jiang
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Mang I Vai
- State Key Laboratory of Analog and Mixed-Signal VLSI, University of Macau, Macau, China.
| | - Sio Hang Pun
- State Key Laboratory of Analog and Mixed-Signal VLSI, University of Macau, Macau, China.
| | - Cheng Peng
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
| | - Fangyi Chen
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
| |
Collapse
|
6
|
Negishi-Oshino R, Ohgami N, He T, Li X, Kato M, Kobayashi M, Gu Y, Komuro K, Angelidis CE, Kato M. Heat shock protein 70 is a key molecule to rescue imbalance caused by low-frequency noise. Arch Toxicol 2019; 93:3219-3228. [PMID: 31576414 DOI: 10.1007/s00204-019-02587-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 09/26/2019] [Indexed: 01/27/2023]
Abstract
A previous study showed that people living in urban areas are generally exposed to low-frequency noise (LFN) with frequencies below 100 Hz and sound levels of 60-110 dB in daily and occupational environments. Exposure to LFN has been shown to affect balance in humans and mice. However, there is no information about prevention of LFN-mediated imbalance because of a lack of information about the target region based on health risk assessment of LFN exposure. Here, we show that acute exposure to LFN at 100 Hz, 95 dB, but not at 85 dB or 90 dB, for only 1 h caused imbalance in mice. The exposed mice also had decreased cervical vestibular-evoked myogenic potential (cVEMP) with impaired activity of vestibular hair cells. Since imbalance in the exposed mice was irreversible, morphological damage in the vestibules of the exposed mice was further examined. The exposed mice had breakage of the otoconial membrane in the vestibule. LFN-mediated imbalance and breakage of the otoconial membrane in mice were rescued by overexpression of a stress-reactive molecular chaperone, heat shock protein 70 (Hsp70), which has been shown to be induced by exposure of mice to 12 h per day of LFN at 95 dB for 5 days. Taken together, the results of this study demonstrate that acute exposure to LFN at 100 Hz, 95 dB for only 1 h caused irreversible imbalance in mice with structural damage of the otoconial membrane as the target region for LFN-mediated imbalance, which can be rescued by Hsp70.
Collapse
Affiliation(s)
- Reina Negishi-Oshino
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
| | - Nobutaka Ohgami
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
| | - Tingchao He
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
| | - Xiang Li
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
| | - Masashi Kato
- Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya, 466-8555, Japan
| | - Masayoshi Kobayashi
- EPMA Laboratory, Niigata University Center for Instrumental Analysis, Gakkou-cho-dori 2-5274, Niigata, 951-8514, Japan
| | - Yishuo Gu
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
| | - Kanako Komuro
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
| | | | - Masashi Kato
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan.
| |
Collapse
|
7
|
Yang TH, Young YH. Eradicating Otomycosis with Terbinafine Solution: Basic and Clinical Investigation. Audiol Neurootol 2019; 24:183-190. [PMID: 31454819 DOI: 10.1159/000501540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 06/17/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Otomycosis still remains intractable in clinical practice, likely because topical antifungal agents lack efficacy or are potentially toxic to the inner ear end organs. OBJECTIVES The aim of this study was to investigate whether terbinafine solution is a potential candidate for treating intractable otomycosis in humans. In addition, the toxic effect on the inner ear was also assessed by animal models treated with terbinafine. METHODS Guinea pigs were instilled with 0.1 mL terbinafine (10 and 25 mg/mL) in the left round window membrane. At 2 weeks after treatment, all animals underwent an inner ear test battery and were then sacrificed for morphological study. Clinically, 20 patients with otomycosis were treated with terbinafine solution at a dosage of 0.4 mg. RESULTS All terbinafine-treated animals showed intact inner ear function when total dosage of terbinafine was <2.5 mg, which was further confirmed by morphological study. Subsidence of otomycosis was achieved in all 20 patients 1 week after treatment with terbinafine (0.4 mg) without untoward effect. No evidence of recurrence was noted 1 year after treatment. CONCLUSION The paucity of inner ear toxicity of terbinafine even at a dosage of 2.5 mg was identified in guinea pig models morphologically and physiologically. Topical application of terbinafine solution at a dosage of 0.4 mg may be a potential treatment for otomycosis in humans.
Collapse
Affiliation(s)
- Ting-Hua Yang
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan
| | - Yi-Ho Young
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan,
| |
Collapse
|
8
|
Negishi-Oshino R, Ohgami N, He T, Ohgami K, Li X, Kato M. cVEMP correlated with imbalance in a mouse model of vestibular disorder. Environ Health Prev Med 2019; 24:39. [PMID: 31153359 PMCID: PMC6545207 DOI: 10.1186/s12199-019-0794-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 05/14/2019] [Indexed: 01/16/2023] Open
Abstract
Background Cervical vestibular evoked myogenic potential (cVEMP) testing is a strong tool that enables objective determination of balance functions in humans. However, it remains unknown whether cVEMP correctly expresses vestibular disorder in mice. Objective In this study, correlations of cVEMP with scores for balance-related behavior tests including rotarod, beam, and air-righting reflex tests were determined in ICR mice with vestibular disorder induced by 3,3′-iminodipropiontrile (IDPN) as a mouse model of vestibular disorder. Methods Male ICR mice at 4 weeks of age were orally administered IDPN in saline (28 mmol/kg body weight) once. Rotarod, beam crossing, and air-righting reflex tests were performed before and 3–4 days after oral exposure one time to IDPN to determine balance functions. The saccule and utricles were labeled with fluorescein phalloidin. cVEMP measurements were performed for mice in the control and IDPN groups. Finally, the correlations between the scores of behavior tests and the amplitude or latency of cVEMP were determined with Spearman’s rank correlation coefficient. Two-tailed Student’s t test and Welch’s t test were used to determine a significant difference between the two groups. A difference with p < 0.05 was considered to indicate statistical significance. Results After oral administration of IDPN at 28 mmol/kg, scores of the rotarod, beam, and air-righting reflex tests in the IDPN group were significantly lower than those in the control group. The numbers of hair cells in the saccule, utricle, and cupula were decreased in the IDPN group. cVEMP in the IDPN group was significantly decreased in amplitude and increased in latency compared to those in the control group. cVEMP amplitude had significant correlations with the numbers of hair cells as well as scores for all of the behavior tests in mice. Conclusions This study demonstrated impaired cVEMP and correlations of cVEMP with imbalance determined by behavior tests in a mouse model of vestibular disorder. Electronic supplementary material The online version of this article (10.1186/s12199-019-0794-8) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Reina Negishi-Oshino
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
| | - Nobutaka Ohgami
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
| | - Tingchao He
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
| | - Kyoko Ohgami
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
| | - Xiang Li
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
| | - Masashi Kato
- Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan.
| |
Collapse
|
9
|
Rosengren SM, Colebatch JG. The Contributions of Vestibular Evoked Myogenic Potentials and Acoustic Vestibular Stimulation to Our Understanding of the Vestibular System. Front Neurol 2018; 9:481. [PMID: 30013504 PMCID: PMC6037197 DOI: 10.3389/fneur.2018.00481] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 06/04/2018] [Indexed: 12/16/2022] Open
Abstract
Vestibular-evoked myogenic potentials (VEMPs) are short-latency muscle reflexes typically recorded from the neck or eye muscles with surface electrodes. They are used clinically to assess otolith function, but are also interesting as they can provide information about the vestibular system and its activation by sound and vibration. Since the introduction of VEMPs more than 25 years ago, VEMPs have inspired animal and human research on the effects of acoustic vestibular stimulation on the vestibular organs, their projections and the postural muscles involved in vestibular reflexes. Using a combination of recording techniques, including single motor unit recordings, VEMP studies have enhanced our understanding of the excitability changes underlying the sound-evoked vestibulo-collic and vestibulo-ocular reflexes. Studies in patients with diseases of the vestibular system, such as superior canal dehiscence and Meniere's disease, have shown how acoustic vestibular stimulation is affected by physical changes in the vestibule, and how sound-evoked reflexes can detect these changes and their resolution in clinical contexts. This review outlines the advances in our understanding of the vestibular system that have occurred following the renewed interest in sound and vibration as a result of the VEMP.
Collapse
Affiliation(s)
- Sally M Rosengren
- Neurology Department, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.,Central Clinical School, The University of Sydney, Sydney, NSW, Australia
| | - James G Colebatch
- Prince of Wales Hospital Clinical School and Neuroscience Research Australia, University of New South Wales, Sydney, NSW, Australia
| |
Collapse
|
10
|
Abstract
OBJECTIVE This study reviewed the development of the inner ear test battery comprising auditory brainstem response (ABR), and caloric, ocular vestibular-evoked myogenic potential (oVEMP), and cervical vestibular-evoked myogenic potential (cVEMP) tests in guinea pig models at our laboratory over the last 20 years. Detailed description of the methodology for testing the small animals is also included. METHODS Inner ear disorders, i.e. ototoxicity, noise exposure, or perilymph fistula were established in guinea pig models first. One to four weeks after operation, each animal underwent ABR, oVEMP, cVEMP, and caloric tests. Then, animals were sacrificed for morphological study in the temporal bones. RESULTS Inner ear endorgans can be comprehensively evaluated in guinea pig models via an inner ear test battery, which provides thorough information on the cochlea, saccule, utricle, and semicircular canal function of guinea pigs. Coupled with morphological study in the temporal bones of the animals may help elucidate the mechanism of inner ear disorders in humans. CONCLUSIONS The inner ear test battery in guinea pig models may encourage young researchers to perform basic study in animals and stimulate the progress of experimental otology which is in evolution.
Collapse
Affiliation(s)
- Yi-Ho Young
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan
| |
Collapse
|
11
|
Shi X, Zhang Y, Li Y, Qiu S, Zhang S, Li Y, Yuan N, Qiao Y, Yang S. Vestibular-evoked myogenic potentials in miniature pigs. J Otol 2016; 11:88-93. [PMID: 29937816 PMCID: PMC6002581 DOI: 10.1016/j.joto.2016.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 05/19/2016] [Accepted: 05/20/2016] [Indexed: 11/25/2022] Open
Abstract
Objective To report detection of vestibular-evoked myogenic potentials (VEMPs) in the miniature pig. Methods Potentials evoked by 1000 Hz tone bursts were recorded from neck extensor muscles and the masseter muscles in normal adult Bama miniature pigs anesthetized with 3% pentobarbital sodium and Carbachol II. Results The latency of the first positive wave P from neck extensor muscles was 7.65 ± 0.64 ms, with an amplitude of 1.66 ± 0.34 uv and a rate of successful induction of 75% at 80 dB SPL. The latency of potentials evoked from the masseter muscles was 7.60 ± 0.78 ms, with an amplitude of 1.31 ± 0.28 uv and a rate successful induction of 66% at 80 dB SPL. Conclusion The latencies and thresholds of VEMPs recorded from the neck extensor muscle and the masseter muscle appear to be comparable in normal adult Bama miniature pigs, although the amplitude recorded from the neck extensor muscle seems to be higher than that from the masseter muscle. However, because of their usually relatively superficial and easily accessible location, as well as their large volume and strong contractions, masseter muscles may be better target muscles for recording myogenic potentials.
Collapse
Affiliation(s)
- Xi Shi
- Institute of Audiology and Balance Science, Xuzhou Medical University, China
| | - Yan Zhang
- Department of Otorhinolaryngology Head and Neck Surgery, First Hospital of Jilin University, Changchun, Jilin 130021, China
| | - Ya Li
- Institute of Audiology and Balance Science, Xuzhou Medical University, China
| | - Shiwei Qiu
- Institute of Audiology and Balance Science, Xuzhou Medical University, China
| | - Shili Zhang
- Institute of Audiology and Balance Science, Xuzhou Medical University, China
| | - Yaohan Li
- Institute of Audiology and Balance Science, Xuzhou Medical University, China
| | - Na Yuan
- Institute of Audiology and Balance Science, Xuzhou Medical University, China
| | - Yuehua Qiao
- Institute of Audiology and Balance Science, Xuzhou Medical University, China.,Clinical Hearing Center, Affiliated Hospital of Xuzhou Medical University, China
| | - Shiming Yang
- Department of Otolaryngology-Head & Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General Hospital, Beijing 100853, China
| |
Collapse
|
12
|
Armstrong PA, Wood SJ, Shimizu N, Kuster K, Perachio A, Makishima T. Preserved otolith organ function in caspase-3-deficient mice with impaired horizontal semicircular canal function. Exp Brain Res 2015; 233:1825-35. [PMID: 25827332 DOI: 10.1007/s00221-015-4254-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Accepted: 03/10/2015] [Indexed: 11/30/2022]
Abstract
Genetically engineered mice are valuable models for elucidation of auditory and vestibular pathology. Our goal was to establish a comprehensive vestibular function testing system in mice using: (1) horizontal angular vestibulo-ocular reflex (hVOR) to evaluate semicircular canal function and (2) otolith-ocular reflex (OOR) to evaluate otolith organ function and to validate the system by characterizing mice with vestibular dysfunction. We used pseudo off-vertical axis rotation to induce an otolith-only stimulus using a custom-made centrifuge. For the OOR, horizontal slow-phase eye velocity and vertical eye position were evaluated as a function of acceleration. Using this system, we characterized hVOR and OOR in the caspase-3 (Casp3) mutant mice. Casp3 (-/-) mice had severely impaired hVOR gain, while Casp3 (+/-) mice had an intermediate response compared to WT mice. Evaluation of OOR revealed that at low-to-mid frequencies and stimulus intensity, Casp3 mutants and WT mice had similar responses. At higher frequencies and stimulus intensity, the Casp3 mutants displayed mildly reduced otolith organ-related responses. These findings suggest that the Casp3 gene is important for the proper function of the semicircular canals but less important for the otolith organ function.
Collapse
Affiliation(s)
- Patrick A Armstrong
- Department of Otolaryngology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555-0521, USA
| | | | | | | | | | | |
Collapse
|
13
|
Choi BY, Park G, Gim J, Kim AR, Kim BJ, Kim HS, Park JH, Park T, Oh SH, Han KH, Park WY. Diagnostic application of targeted resequencing for familial nonsyndromic hearing loss. PLoS One 2013; 8:e68692. [PMID: 23990876 PMCID: PMC3750053 DOI: 10.1371/journal.pone.0068692] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 05/31/2013] [Indexed: 01/19/2023] Open
Abstract
Identification of causative genes for hereditary nonsyndromic hearing loss (NSHL) is important to decide treatment modalities and to counsel the patients. Due to the genetic heterogeneity in sensorineural genetic disorders, the high-throughput method can be adapted for the efficient diagnosis. To this end, we designed a new diagnostic pipeline to screen all the reported candidate genes for NSHL. For validation of the diagnostic pipeline, we focused upon familial NSHL cases that are most likely to be genetic, rather than to be infectious or environmental. Among the 32 familial NSHL cases, we were able to make a molecular genetic diagnosis from 12 probands (37.5%) in the first stage by their clinical features, characteristic inheritance pattern and further candidate gene sequencing of GJB2, SLC26A4, POU3F4 or mitochondrial DNA. Next we applied targeted resequencing on 80 NSHL genes in the remaining 20 probands. Each proband carried 4.8 variants that were not synonymous and had the occurring frequency of less than three among the 20 probands. These variants were then filtered out with the inheritance pattern of the family, allele frequency in normal hearing 80 control subjects, clinical features. Finally NSHL-causing candidate mutations were identified in 13(65%) of the 20 probands of multiplex families, bringing the total solve rate (or detection rate) in our familial cases to be 78.1% (25/32) Damaging mutations discovered by the targeted resequencing were distributed in nine genes such as WFS1, COCH, EYA4, MYO6, GJB3, COL11A2, OTOF, STRC and MYO3A, most of which were private. Despite the advent of whole genome and whole exome sequencing, we propose targeted resequencing and filtering strategy as a screening and diagnostic tool at least for familial NSHL to find mutations based upon its efficacy and cost-effectiveness.
Collapse
Affiliation(s)
- Byung Yoon Choi
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Gibeom Park
- Department of Biomedical Sciences, College of Medicine, College of Natural Science, Seoul National University, Seoul, Korea
| | - Jungsoo Gim
- Interdiciplinary Program for Bioinformatics, College of Natural Science, Seoul National University, Seoul, Korea
- Statistics, College of Natural Science, Seoul National University, Seoul, Korea
| | - Ah Reum Kim
- Otorhinolaryngology, Seoul National University Hospital, Seoul, Korea
| | - Bong-Jik Kim
- Otorhinolaryngology, Seoul National University Hospital, Seoul, Korea
| | - Hyo-Sang Kim
- Otorhinolaryngology, Seoul National University Hospital, Seoul, Korea
| | - Joo Hyun Park
- Otorhinolaryngology, Seoul National University Hospital, Seoul, Korea
| | - Taesung Park
- Statistics, College of Natural Science, Seoul National University, Seoul, Korea
| | - Seung-Ha Oh
- Otorhinolaryngology, Seoul National University Hospital, Seoul, Korea
| | - Kyu-Hee Han
- Otorhinolaryngology, Seoul National University Hospital, Seoul, Korea
- * E-mail: (KH); (WP)
| | - Woong-Yang Park
- Department of Molecular and Cellular Biology, Sungkyunkwan University School of Medicine, Suwon, Korea
- Samsung Genome Institute, Samsung Medical Center, Seoul, Korea
- * E-mail: (KH); (WP)
| |
Collapse
|
14
|
Evidence for the utricular origin of the vestibular short-latency-evoked potential (VsEP) to bone-conducted vibration in guinea pig. Exp Brain Res 2013; 229:157-70. [DOI: 10.1007/s00221-013-3602-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 05/29/2013] [Indexed: 10/26/2022]
|
15
|
Young YH. Potential application of ocular and cervical vestibular-evoked myogenic potentials in meniere's disease: A review. Laryngoscope 2012; 123:484-91. [DOI: 10.1002/lary.23640] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2012] [Revised: 06/25/2012] [Accepted: 07/11/2012] [Indexed: 11/10/2022]
|
16
|
Lin CT, Young YH, Cheng PW, Lue JH. Effects of gentamicin on guinea pig vestibular ganglion function and on substance P and neuropeptide Y. J Chem Neuroanat 2010; 40:286-92. [DOI: 10.1016/j.jchemneu.2010.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Revised: 08/05/2010] [Accepted: 08/10/2010] [Indexed: 11/16/2022]
|
17
|
Yang TH, Liu SH, Young YH. Evaluation of guinea pig model for ocular and cervical vestibular-evoked myogenic potentials for vestibular function test. Laryngoscope 2010; 120:1910-7. [DOI: 10.1002/lary.21056] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
18
|
Shanidze N, Kim AH, Raphael Y, King WM. Eye-head coordination in the guinea pig I. Responses to passive whole-body rotations. Exp Brain Res 2010; 205:395-404. [PMID: 20686891 DOI: 10.1007/s00221-010-2374-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 07/15/2010] [Indexed: 11/28/2022]
Abstract
Vestibular reflexes act to stabilize the head and eyes in space during locomotion. Head stability is essential for postural control, whereas retinal image stability enhances visual acuity and may be essential for an animal to distinguish self-motion from that of an object in the environment. Guinea pig eye and head movements were measured during passive whole-body rotation in order to assess the efficacy of vestibular reflexes. The vestibulo-ocular reflex (VOR) produced compensatory eye movements with a latency of approximately 7 ms that compensated for 46% of head movement in the dark and only slightly more in the light (54%). Head movements, in response to abrupt body rotations, also contributed to retinal stability (21% in the dark; 25% in the light) but exhibited significant variability. Although compensatory eye velocity produced by the VOR was well correlated with head-in-space velocity, compensatory head-on-body speed and direction were variable and poorly correlated with body speed. The compensatory head movements appeared to be determined by passive biomechanical (e.g., inertial effects, initial tonus) and active mechanisms (the vestibulo-collic reflex or VCR). Chemically induced, bilateral lesions of the peripheral vestibular system abolished both compensatory head and eye movement responses.
Collapse
Affiliation(s)
- N Shanidze
- Department of Otolaryngology, University of Michigan, Ann Arbor, MI, USA.
| | | | | | | |
Collapse
|
19
|
Yang TH, Liu SH, Wang SJ, Young YH. An animal model of ocular vestibular-evoked myogenic potential in guinea pigs. Exp Brain Res 2010; 205:145-52. [DOI: 10.1007/s00221-010-2346-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Accepted: 06/21/2010] [Indexed: 10/19/2022]
|
20
|
Yang TH, Liu SH, Young YH. A novel inner ear monitoring system for evaluating ototoxicity of gentamicin eardrops in guinea pigs. Laryngoscope 2010; 120:1220-6. [DOI: 10.1002/lary.20923] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
21
|
Assessment of gentamicin-induced vestibulotoxicity by click and galvanic vestibular-evoked myogenic potentials: A guinea pig investigation. Neurotoxicology 2010; 31:121-5. [DOI: 10.1016/j.neuro.2009.10.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Revised: 10/02/2009] [Accepted: 10/15/2009] [Indexed: 02/07/2023]
|
22
|
Curthoys IS. A critical review of the neurophysiological evidence underlying clinical vestibular testing using sound, vibration and galvanic stimuli. Clin Neurophysiol 2009; 121:132-44. [PMID: 19897412 DOI: 10.1016/j.clinph.2009.09.027] [Citation(s) in RCA: 277] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 09/08/2009] [Accepted: 09/12/2009] [Indexed: 12/01/2022]
Abstract
In addition to activating cochlear receptors, air conducted sound (ACS) and bone conducted vibration (BCV) activate vestibular otolithic receptors, as shown by neurophysiological evidence from animal studies--evidence which is the foundation for using ACS and BCV for clinical vestibular testing by means of vestibular-evoked myogenic potentials (VEMPs). Recent research is elaborating the specificity of ACS and BCV on vestibular receptors. The evidence that saccular afferents can be activated by ACS has been mistakenly interpreted as showing that ACS only activates saccular afferents. That is not correct - ACS activates both saccular and utricular afferents, just as BCV activates both saccular and utricular afferents, although the patterns of activation for ACS and BCV do not appear to be identical. The otolithic input to sternocleidomastoid muscle appears to originate predominantly from the saccular macula. The otolithic input to the inferior oblique appears to originate predominantly from the utricular macula. Galvanic stimulation by surface electrodes on the mastoids very generally activates afferents from all vestibular sense organs. This review summarizes the physiological results, the potential artifacts and errors of logic in this area, reconciles apparent disagreements in this field. The neurophysiological results on BCV have led to a new clinical test of utricular function - the n10 of the oVEMP. The cVEMP tests saccular function while the oVEMP tests utricular function.
Collapse
Affiliation(s)
- Ian S Curthoys
- Vestibular Research Laboratory, School of Psychology, A 18, The University of Sydney, Sydney, NSW 2006, Australia.
| |
Collapse
|
23
|
Vestibular evoked myogenic potentials in normal mice and Phex mice with spontaneous endolymphatic hydrops. Otol Neurotol 2009; 30:535-44. [PMID: 19300299 DOI: 10.1097/mao.0b013e31819bda13] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVE AND BACKGROUND Vestibular evoked myogenic potentials (VEMPs) have been recorded from the neck musculature and the cervical spinal cord in humans and a limited number of laboratory animals in response to loud sound. However, the mouse VEMP has yet to be described. Evaluation of the sacculocollic pathway via VEMPs in mice can set the stage for future evaluations of mutant mice that now play an important role in research regarding human auditory and vestibular dysfunction. MATERIALS AND METHODS Sound-evoked potentials were recorded from the neck extensor muscles and the cervical spinal cord in normal adult mice and in circling Phex(Hyp-Duk/y) mice with known vestibular abnormalities, including endolymphatic hydrops (ELH). RESULTS Biphasic potentials were recorded from all normal animals. The mean threshold of the VEMP response in normal adult mice was 60 dB normal hearing level with a mean peak latency of 6.25 +/- 0.46 and 7.95 +/- 0.42 milliseconds for p1 and n1 peaks, respectively. At the maximum sound intensity used (100 dB normal hearing level), 4 of 5 Phex mice did not exhibit VEMP responses, and 1 showed an elevated threshold, but normal response, with regard to peak latency and amplitude. The histologic findings in all of these Phex mice were consistent with distended membranous labyrinth, displaced Reissner membrane, ganglion cell loss, and ELH. CONCLUSION This is the first report of VEMP recordings in mice and the first report of abnormal VEMPs in a mouse model with ELH. The characteristics of these potentials such as higher response threshold in comparison to auditory brainstem response, myogenic nature of the response, and latency correlation with the cervical recording (accessory nerve nucleus) were similar to those of VEMPs in humans, guinea pigs, cats, and rats, suggesting that the mouse may be used as an animal model in the study of VEMPs. The simplicity and reliability of these recordings make the VEMP a uniquely informative test for assessing vestibular function, and these results suggest that they may be informative in mice with various mutations. However, further investigation is necessary.
Collapse
|
24
|
Day AS, Lue JH, Yang TH, Young YH. Effect of Intratympanic Application of Aminoglycosides on Click-Evoked Myogenic Potentials in Guinea Pigs. Ear Hear 2007; 28:18-25. [PMID: 17204896 DOI: 10.1097/01.aud.0000249765.76065.27] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Although numerous studies have identified damage to the cochlear and vestibular end organs as the primary site of aminoglycoside-induced ototoxicity, the effect on the saccule remains poorly understood, possibly due to lack of monitoring saccular function in experimental animals. Therefore, this study applied three kinds of aminoglycosides into the tympanic space of guinea pigs to examine their toxic impact on the saccule by way of click-evoked myogenic potential test coupled with morphologic assessment. DESIGN Albino guinea pigs were treated with saline, gentamicin, tobramycin, or amikacin, with 10 animals assigned to each group. Each compound was injected directly overlying but not through the round window membrane on the left ear, with the right ear serving as a control. One week after injection, each animal underwent auditory brain stem response, caloric test, and click-evoked myogenic potential test. Animals were then killed for morphologic assessment through the use of light and electron microscopic examinations. RESULTS The animals treated with saline, gentamicin, tobramycin, or amikacin exhibited abnormal auditory brain stem response in 0%, 30%, 100%, and 30% of cases; abnormal caloric responses were found in 0%, 100%, 40%, and 40% of cases; absent click-evoked myogenic potentials were found in 0%, 100%, 30%, and 40% of cases, respectively. Gentamicin and other groups differed significantly in abnormal rates of caloric responses and click-evoked myogenic potentials. Morphologic study of the gentamicin-treated animals confirmed that the absence of click-evoked myogenic potential originated from the lesion in the saccular macula. CONCLUSIONS Gentamicin represents the dominant susceptibility of aminoglycoside-induced vestibulotoxicity for eliminating both semicircular canal and saccular functions. This study further confirms the findings of human studies in which the caloric and vestibular evoked myogenic potentials responses were monitored to assess the abolition of vestibular function in patients treated with intratympanic gentamicin injection.
Collapse
Affiliation(s)
- An-Shiou Day
- Department of Otolaryngology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | | | | | | |
Collapse
|
25
|
Abstract
PURPOSE OF REVIEW Vestibular evoked myogenic potential testing is the only clinically feasible way to measure function of the saccule. Interest in this test has exploded in recent years because of its potential utility in diagnosing third-window disorders and in diagnosing and monitoring Ménière's disease. RECENT FINDINGS Recent literature on vestibular evoked myogenic potential covers a wide range of topics. Review articles, method articles and many case reports and uncontrolled case series are seeking new applications for vestibular evoked myogenic potential in diagnosis and monitoring of neurotologic disease, and in shedding light on inner ear diseases by mapping anatomic sites of involvement. The most informative work is still in the areas of superior semicircular canal dehiscence and in Ménière's disease. Also, many aspects of vestibular evoked myogenic potential and its use have not yet been adequately studied or described. SUMMARY Vestibular evoked myogenic potential is a new test of saccular and inferior vestibular nerve integrity. It holds great promise for diagnosing and monitoring Ménière's disease and some other neurotologic disorders. It is still an evolving field, however. The methods, equipment, and applications for vestibular evoked myogenic potential testing are not yet standardized. It is not yet time for this test to be widely applied, but that time is not far off.
Collapse
Affiliation(s)
- Steven D Rauch
- Harvard Medical School at Massachusetts Eye and Ear Infirmary, Boston, Massachusetts 02114, USA.
| |
Collapse
|
26
|
Young YH. Vestibular evoked myogenic potentials: optimal stimulation and clinical application. J Biomed Sci 2006; 13:745-51. [PMID: 16900318 DOI: 10.1007/s11373-006-9106-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Accepted: 07/14/2006] [Indexed: 02/03/2023] Open
Abstract
By easily stimulating the ear with loud sound and recording on tonically contracted neck muscles, vestibular evoked myogenic potential (VEMP) test can reflect inner ear function other than the cochlea and semicircular canal. This expands the test battery for clinicians to explore saccular disease, adding a potential usefulness to the sacculo-collic reflex. The ideal stimulation mode for VEMPs is as follows: 95 dB tone bursts, frequency 500 Hz, stimulation repetition rate 5 Hz, rise/fall time 1 ms, plateau 2 ms, binaural stimulation with bilateral recordings. Animal model using guinea pigs has been established, which sets the stage for useful future studies investigating VEMPs in guinea pigs that would appear to resemble human VEMP responses. Clinically, VEMP test has been widely used in central and peripheral vestibular disorders.
Collapse
Affiliation(s)
- Yi-Ho Young
- Department of Otolaryngology, National Taiwan University Hospital, 1 Chang-Te Street, Taipei, Taiwan.
| |
Collapse
|
27
|
Wit HP, Kingma CM. A simple model for the generation of the vestibular evoked myogenic potential (VEMP). Clin Neurophysiol 2006; 117:1354-8. [PMID: 16678484 DOI: 10.1016/j.clinph.2006.03.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2005] [Revised: 02/23/2006] [Accepted: 03/05/2006] [Indexed: 10/24/2022]
Abstract
OBJECTIVE To describe the mechanism by which the vestibular evoked myogenic potential is generated. METHODS Vestibular evoked myogenic potential generation is modeled by adding a large number of muscle motor unit action potentials. These action potentials occur randomly in time along a 100 ms long time axis. But because between approximately 15 and 20 ms after a loud short sound stimulus (almost) no action potentials are generated during VEMP measurements in human subjects, no action potentials are present in the model during this time. RESULTS The evoked potential is the result of the lack of amplitude cancellation in the averaged surface electromyogram at the edges of this 5 ms long time interval. CONCLUSIONS The relatively simple model describes generation and some properties of the vestibular evoked myogenic potential very well. SIGNIFICANCE It is shown that, in contrast with other evoked potentials (BAEPs, VERs), the vestibular evoked myogenic potential is the result of an interruption of activity and not that of summed synchronized neural action potentials.
Collapse
Affiliation(s)
- Hero P Wit
- Department of Otorhinolaryngology, University Medical Center Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands.
| | | |
Collapse
|