BACKGROUND AND OBJECTIVES: The purpose of this study was to investigate the effects of low level laser for the prevention and treatment of aminoglycoside-induced vestibular ototoxicity. MATERIALS AND METHOD: An organotypic culture of 2 to 4 days old rat utricular maculae was established. Rats were divided into 6 groups according to the treadtment of the utricles: G (gentamicintreated), L (laser-irradiated), LG (laser-irradiated and gentamicin-treated), GL (gentamicin-treated and laser-irradiated), LGL (gentamicin-treated during laser-irradiated) and C (control). After organotypic culture, the utricles of 6 groups were examined by confocal laser scanning electron microscope and scanning electron microscope. The results of each group were compared with each other by statistical methods. RESULTS: The number of vestibular hair cells of the group G was smaller compared to that of the group C. The group L had no difference compared with the group C. The groups LG and GL showed more vestibular hair cells compared with the group G. The group LG showed more vestibular hair cells than the group GL. The group LGL showed most vestibular hair cells compared to that of the groups G, LG, and GL. CONCLUSION: The most effective treatment of aminoglycosideinduced vestibular otoxicity is the irradiation of low level laser before and after the insult of the aminoglycoside. Further clinical studies using low level laser were needed to prevent aminoglycoside-induced ototoxicity and to promote the regeneration of vestibular hair cells.
Animals ; Electrons ; Gentamicins ; Hair Cells, Vestibular ; Rats ; Regeneration ; Saccule and Utricle

Vestibular stimulation by air-conducted sound (ACS), bone-conducted vibration (BCV), or electrical currents (galvanic stimulation) elicits vestibular evoked myogenic potentials (VEMPs) that are now widely used to assess otolith function. Conventional cervical VEMPs, which are a manifestation of the vestibulocollic reflex, measure electromyographic activity from surface electrodes placed over the tonically activated sternocleidomastoid muscles. VEMPs can also be recorded from the extraocular muscles using surface electrodes placed over the inferior oblique and inferior rectus muscles, known as ocular VEMPs (oVEMPs). oVEMPs are a manifestation of the vestibulo-ocular pathways. We describe herein the neurophysiological properties of VEMPs obtained in response to ACS and BCV stimulation, and outline the known characteristics of VEMPs in central and peripheral disorders commonly encountered in neuro-otology clinics.
Electrodes ; Muscles ; Neurotology ; Otolithic Membrane ; Reflex ; Saccule and Utricle ; Vestibular Evoked Myogenic Potentials ; Vibration

BACKGROUND AND OBJECTIVES: Subjective visual vertical (SVV) reflects utricle and superior vestibular neural functions, and cervical vestibular evoked myogenic potentials (cVEMP) reflect saccule and inferior vestibular neural functions. But, origin and characteristics of ocular VEMP (oVEMP) remain controversial, especially in case of evoked by air conducted sound (ACS). Thus, the aim of this study was to identify the origin and characteristics of oVEMP by comparing with various otolith function tests. MATERIALS AND METHODS: Forty vestibular neuritis patients were enrolled from September 2012 to January 2013 in this study. We examined cVEMP, oVEMP using 500 Hz air-counducted sounds. And, we measured static and dynamic SVV. RESULTS: Abnormal cVEMP responses were observed in 6 (15%) patients, and abnormal oVEMP responses were observed in 28 (70%) patients. Abnormal static and dynamic SVV were observed in 18 (45%), 35 (87.5%) patients, respectively. There was strong correlation between oVEMP and dynamic SVV (p=0.009). CONCLUSION: ACS oVEMP responses showed different tendency from cVEMP responses in vestibular neuritis patients, but similar tendency with results of dynamic SVV. The results suggest that origin of oVEMP is different from that of cVEMP and maybe utricle and superior vestibular neuron.
Humans ; Neurons ; Otolithic Membrane ; Saccule and Utricle ; Vestibular Evoked Myogenic Potentials ; Vestibular Neuronitis

Vestibular evoked myogenic potential (VEMP) has developed as a broadly applied vestibular function test in clinics from its introduction in 1992. In the past, there was only one well known VEMP protocol, which is cervical VEMP, however recently ocular VEMP is also popular. Therefore, clarifying the VEMP recording protocol (cervical VEMP or ocular VEMP) before discussing the VEMP result has become essential. There is considerable difference regarding this VEMP test from other vestibular function tests. VEMP is thought to be assessing the functions of the otolith organs (utricle and saccule) which are evoked by acoustic stimulus. Cervical VEMP is valuable since this is the only available test method which could speculate the function of the saccule and inferior vestibular nerve. Still, there's less clearly understood part regarding the central pathway of VEMP. However, many clinicians and researchers participating in vestibular research speculate that this functional test will have a more dominant role in the near future. Here we describe the basic principles and methodological considerations regarding VEMP recording.
Acoustics ; Evoked Potentials ; Otolithic Membrane ; Saccule and Utricle ; Vestibular Evoked Myogenic Potentials ; Vestibular Function Tests ; Vestibular Nerve

BACKGROUND: Cervical (cVEMP) and ocular (oVEMP) vestibular-evoked myogenic potentials are short-latency manifestations of vestibulo-ocular and vestibulocollic reflexes that originate from the utricle and saccule. The aim of this study was to determine whether simultaneously recording cVEMP and oVEMP more reliably detects the reflex responses than when making separate recordings. METHODS: Both simultaneous recordings and conventional separate recordings of the cVEMP and oVEMP responses to air-conducted tone bursts were obtained in 39 healthy subjects. p13 and n10 latencies, and p13-n23 and n10-p16 amplitudes of cVEMP and oVEMP waveforms were measured, respectively. The asymmetry ratios (ARs) of the amplitudes were calculated. RESULTS: In cVEMP testing, the p13 latencies and p13-n23 amplitudes did not differ significantly between simultaneous and conventional separate recordings. In oVEMP testing, the n10 latencies measured in simultaneous recordings showed a small but statistically significant prolongation compared to the results in separate recordings. Moreover, the n10-p16 amplitudes were significantly larger in the simultaneous recordings. The AR of simultaneous recordings of cVEMP and oVEMP did not differ between the two recording methods. CONCLUSIONS: Simultaneously recording cVEMP and oVEMP provides a reliable test and could be a clinically useful and simplified diagnostic tool for evaluating dizzy patients.
Humans ; Reflex ; Saccule and Utricle

BACKGROUND: Cervical (cVEMP) and ocular (oVEMP) vestibular-evoked myogenic potentials are short-latency manifestations of vestibulo-ocular and vestibulocollic reflexes that originate from the utricle and saccule. The aim of this study was to determine whether simultaneously recording cVEMP and oVEMP more reliably detects the reflex responses than when making separate recordings. METHODS: Both simultaneous recordings and conventional separate recordings of the cVEMP and oVEMP responses to air-conducted tone bursts were obtained in 39 healthy subjects. p13 and n10 latencies, and p13-n23 and n10-p16 amplitudes of cVEMP and oVEMP waveforms were measured, respectively. The asymmetry ratios (ARs) of the amplitudes were calculated. RESULTS: In cVEMP testing, the p13 latencies and p13-n23 amplitudes did not differ significantly between simultaneous and conventional separate recordings. In oVEMP testing, the n10 latencies measured in simultaneous recordings showed a small but statistically significant prolongation compared to the results in separate recordings. Moreover, the n10-p16 amplitudes were significantly larger in the simultaneous recordings. The AR of simultaneous recordings of cVEMP and oVEMP did not differ between the two recording methods. CONCLUSIONS: Simultaneously recording cVEMP and oVEMP provides a reliable test and could be a clinically useful and simplified diagnostic tool for evaluating dizzy patients.
Humans ; Reflex ; Saccule and Utricle

BACKGROUND AND OBJECTIVES: Vestibular evoked myogenic potentials (VEMP) test provides a useful method for assessment of saccule function and the functional integrity of the inferior vestibular nerve, and subjective visual vertical (SVV) abnormalities are presumably related to a lesion of the utricle. The aim(s) of this study were to measure otolith function using SVV and VEMP tests, and to define the influence of the otolithic organs in patients suffering from vestibular neuritis. MATERIALS AND METHOD: From September 2005 to January 2006, twelve patients who received treatment in hospital and also had been tested for caloric test, subjective visual vertical (SVV) and vestibular evoked myogenic potential (VEMP) tests with unilateral vestibular neuritis were enrolled. All the tests were done within 8 days after the onset of their symptoms, simultaneously. The SVV was measured in 34 normal subjects as well as in patients. RESULTS: Eight of 12 patients showed abnormal tilt to the lesion side in SVV test, and five of 8 patients showed no VEMP on the affected side. There was no correlation between SVV tilts and unilateral weakness (UW) in caloric tests. Two patients with abnormal UW (54, 82%) showed normal finding in SVV & VEMP tests. One patient with abnormal UW (83%) and SVV tilts (18.04Degree) to the lesion side was normal in VEMP test. Two patients with abnormal UW (28, 37%) and no response in VEMP test were normal in SVV test. CONCLUSION: Our results demonstrate that the incidence of abnormal results were 62.5, 66.7% in VEMP and SVV tests in acute stage of vestibular neuritis, respectively. There was no correlation between the abnormal results of the tests and these findings suggest that impairment of the otolithic function is depending on the extent and/or the localization of vestibular neuritis.
Caloric Tests ; Humans ; Incidence ; Otolithic Membrane* ; Saccule and Utricle ; Vestibular Evoked Myogenic Potentials ; Vestibular Function Tests ; Vestibular Nerve ; Vestibular Neuronitis*

BACKGROUND AND OBJECTIVES: Vestibular evoked myogenic potentials (VEMP) test provides a useful method for assessment of saccule function and the functional integrity of the inferior vestibular nerve, and subjective visual vertical (SVV) abnormalities are presumably related to a lesion of the utricle. The aim(s) of this study were to measure otolith function using SVV and VEMP tests, and to define the influence of the otolithic organs in patients suffering from vestibular neuritis. MATERIALS AND METHOD: From September 2005 to January 2006, twelve patients who received treatment in hospital and also had been tested for caloric test, subjective visual vertical (SVV) and vestibular evoked myogenic potential (VEMP) tests with unilateral vestibular neuritis were enrolled. All the tests were done within 8 days after the onset of their symptoms, simultaneously. The SVV was measured in 34 normal subjects as well as in patients. RESULTS: Eight of 12 patients showed abnormal tilt to the lesion side in SVV test, and five of 8 patients showed no VEMP on the affected side. There was no correlation between SVV tilts and unilateral weakness (UW) in caloric tests. Two patients with abnormal UW (54, 82%) showed normal finding in SVV & VEMP tests. One patient with abnormal UW (83%) and SVV tilts (18.04Degree) to the lesion side was normal in VEMP test. Two patients with abnormal UW (28, 37%) and no response in VEMP test were normal in SVV test. CONCLUSION: Our results demonstrate that the incidence of abnormal results were 62.5, 66.7% in VEMP and SVV tests in acute stage of vestibular neuritis, respectively. There was no correlation between the abnormal results of the tests and these findings suggest that impairment of the otolithic function is depending on the extent and/or the localization of vestibular neuritis.
Caloric Tests ; Humans ; Incidence ; Otolithic Membrane* ; Saccule and Utricle ; Vestibular Evoked Myogenic Potentials ; Vestibular Function Tests ; Vestibular Nerve ; Vestibular Neuronitis*

OBJECTIVE: To explore the roles of otolith organs in the occurrence and recurrence of primary benign paroxysmal positional vertigo (BPPV) by vestibular evoked myogenic potential (VEMP) test. METHOD: We enrolled 17 recurrent primary BPPV patients and 42 non-recurrent primary BPPV patients between September 2014 and November 2014. All patients underwent VEMP tests, including cervical vestibular evoked myogenic potential (cVEMP and ocular vestibular evoked myogenic potential (oVEMP) tests. The abnormal case was defined as non-elicitation or asymmetry rate between bilateral sides is larger than 29%. RESULT: Significant difference was found in abnormal rate between cVEMP and oVEMP (P < 0.05 ) in BPPV patients. The abnormal rate of oVEMP was higher than that of cVEMP. Significant difference was found in abnormal rate in oVEMP test between recurrent and non-recurrent groups (P < 0.01) but not in cVEMP( P > 0.05). No significant difference was found in sex and age between recurrent and non-recurrent groups (P > 0.05). CONCLUSION The impairment of otolith organs, especially the utricle, is related to primary BPPV. Dysfunction of utricle may play a role in recurrence of BPPV. Recurrence of BPPV is not correlated with sex and age.
Benign Paroxysmal Positional Vertigo ; physiopathology ; Humans ; Otolithic Membrane ; physiopathology ; Recurrence ; Saccule and Utricle ; physiopathology ; Vestibular Evoked Myogenic Potentials

BACKGROUND AND OBJECTIVES: To culture and maintain mammalian hair cells is still a big challenge. In this study, long-term organotypic culture of rat utricular maculae was established to study vestibular hair cell. The effects of low level laser on hair cell viability in postnatal organotypic culture of rat utricles were investigated. MATERIALS AND METHOD: Uticular explants were prepared from postnatal 2 to 7 rats and cultured. To improve hair cell survival, the utricles were irradiated daily with low level laser. Whole-mount utricles were stained with FM1-43 which is known to be an efficient marker to identify live hair cells in cultured tissues. Such cells visualized directly through tissue culture dish with cover glass bottom by Confocal laser scanning microscope at specific time points. RESULTS: The explanted utricular hair cells were cultured for up to 31 days in in vitro culture system. In low level laser irradiation group, utricular hair cells were more survived at 24 DIV and 31 DIV. CONCLUSION: These results suggest that low level laser promotes hair cell viability in utricular explants.
Animals ; Cell Survival* ; Glass ; Hair Cells, Vestibular ; Hair* ; Rats* ; Saccule and Utricle*