Objectives: The aim of our study is to examine vestibular-evoked myogenic potentials(VEMPs) elicited by the galvanic vestibular stimulation in the sternocleidomastoid muscle(SCM) in healthy subjects for clinical appli...Objectives: The aim of our study is to examine vestibular-evoked myogenic potentials(VEMPs) elicited by the galvanic vestibular stimulation in the sternocleidomastoid muscle(SCM) in healthy subjects for clinical applications of auditory neuropathy or vestibular neuropathy in the future.Methods: We enrolled sixteen healthy subjects to record the average responses of SCM to galvanic vestibular stimulation(GVS) [current 3 mA;duration 1 ms] by electromyography(EMG). SPSS 18.0 software was used to analyze the obtained data for mean and standard deviation.Results: In all healthy subjects mastoid-forehead galvanic vestibular stimulation produced a positive-negative biphasic EMG responses on SCM ipsilateral to the cathodal electrode. The latency of p13 was 11.7 ± 3.0 ms. The latency of n23 was 17.8 ± 3.4 ms. The amplitude of p13-n23 was147.0 ± 69.0 μV. The interaural asymmetry ratio(AR) of p13, n23 latency and the amplitude was respectively 0.12 ± 0.09, 0.08 ± 0.08 and0.16 ± 0.10.Discussions: Galvanic vestibular stimulation could elicit biphasic EMG responses from SCM via the vestibular nerve but not from the otolith organs. Galvanic stimulation together with air conducted sound(ACS) or bone conducted vibration(BCV) can elicit VEMPs and may enable the differentiation of retrolabyrinthine lesions from labyrinthine lesions in vestibular system.展开更多
Objective Auditory neuropathy(AN)is a unique pattern of hearing loss with preservation of hair cell function.The condition is characterized by the presence of otoacoustic emissions(OAE)or cochlear microphonic(CM)respo...Objective Auditory neuropathy(AN)is a unique pattern of hearing loss with preservation of hair cell function.The condition is characterized by the presence of otoacoustic emissions(OAE)or cochlear microphonic(CM)responses with severe abnormalities of the auditory brainstem response(ABR).The vestibular branches of the VIII cranial nerve and the structures innervated by it can also be affected.However,the precise lesion sites in the vestibular system are not well characterized in patients with AN.Methods The air-conducted sound(ACS)vestibular-evoked myogenic potentials(VEMPs)and galvanic vestibular stimuli(GVS)-VEMPs were examined in 14 patients with AN.Results On examination of VEMPs(n=14,28 ears),the absent rates of ACS-cervical VEMP(cVEMP),ACS-ocular VEMP(oVEMP),GVS-cVEMP,GVS-oVEMP and caloric test were 92.9%(26/28),85.7%(24/28),67.9%(19/28),53.6%(15/28),and 61.5%(8/13),respectively.Impaired functions of the saccule,inferior vestibular nerve,utricle,superior vestibular nerve,and horizontal semicircular canal were found in 25.0%(7/28),67.9%(19/28),32.1%(9/28),53.6%(15/28)and 61.5%(8/13)patients,respectively.On comparing the elicited VEMPs parameters of AN patients with those of normal controls,both ACS-VEMPs and GVS-VEMPs showed abnormal results in AN patients(such as,lower presence rates,elevated thresholds,prolonged latencies,and decreased amplitudes).Conclusion The study suggested that patients with AN often have concomitant vestibular disorders.Retro-labyrinthine lesions were more frequently observed in this study.GVS-VEMPs combined with ACS-VEMPs may help identify the lesion sites and facilitate detection of areas of vestibular dysfunction in these patients.展开更多
Introduction:The masseter vestibular evoked myogenic potential(mVEMP)is a bilaterally generated,electromyographically(EMG)-mediated response innervated by the trigeminal nerve.The purpose of the present investigation ...Introduction:The masseter vestibular evoked myogenic potential(mVEMP)is a bilaterally generated,electromyographically(EMG)-mediated response innervated by the trigeminal nerve.The purpose of the present investigation was to 1)determine whether subjects could accurately achieve and maintain a range of EMG target levels,2)to examine the effects of varied EMG levels on the latencies and amplitudes of the mVEMP,and 3)to investigate the degree of side-to-side asymmetry and any effects of EMG activation.Methods:Subjects were nine neurologically and otologically normal young adults.A high-intensity tone burst was presented monaurally while subjects were seated upright and asked to match a range of EMG target levels by clenching their teeth.Recordings were made from the ipsilateral and contralateral masseter muscles referenced to the ear being monaurally stimulated.Results:We found that the tonic EMG target had no effect on mVEMP latency.Additionally,although mVEMP amplitudes“scaled”to the EMG target,there was a tendency for the subjects’EMG level to“undershoot”the EMG target levels greater than 50 mV.While some individuals did generate differences in EMG activation between sides,there were no significant differences on average EMG activation between sides.Further,while average corrected amplitude asymmetry was similar across EMG targets,some individuals demonstrated large,corrected amplitude asymmetry ratios.Conclusions:The results of this investigation suggest that,as with cVEMP recordings,the underlying EMG activation may vary between subjects and could impact mVEMP amplitudes,yet could be mitigated by amplitude correction techniques.Further it is important to be aware that even young normal subjects have difficulty maintaining large,tonic EMG activity during the mVEMP recording.展开更多
Objective:Patients with dizziness may present with symptoms of tilting,swaying,rocking,floating or with disequilibrium.This may be suggestive of an isolated otolithic dysfunction yet,there is little emphasis on this e...Objective:Patients with dizziness may present with symptoms of tilting,swaying,rocking,floating or with disequilibrium.This may be suggestive of an isolated otolithic dysfunction yet,there is little emphasis on this emerging clinical entity.To characterize and describe the prevalence of isolated otolith dysfunction in a local tertiary hospital and correlate them with clinical diagnosis.Methodology:Retrospective medical chart review of patients who presented with dizziness to the specialist outpatient Otolaryngology clinic,who required vestibular laboratory investigation.Results:Of the 206 patients,more than half of them(52.4%)fulfilled the criteria for either probable or definite isolated otolith dysfunction.When there are clinical symptoms of otolith dysfunction reported,there is a 1.62 odds of a remarkable laboratory otolith finding.The most common clinical finding was“no clear diagnosis”(65.5%)followed by Vestibular Migraine(13.6%).Conclusion:The prevalence of isolated otolith dysfunction is quite high.Laboratory tests of otolith function should be performed more routinely.This can be done in a sequential way to optimize cost effectiveness in countries with no insurance reimbursement.Prospective cohort studies on isolated otolith dysfunction,will lay the groundwork for achieving diagnostic consensus and formulating rehabilitation plans to aid this group of patients。展开更多
Profound sensorineural hearing loss (PSHL) is not uncommonly encountered in otology. In clinics, there is a high incidence of otolithic damage in patients with PSHL, but relevant reports are few. Sharing a continuous ...Profound sensorineural hearing loss (PSHL) is not uncommonly encountered in otology. In clinics, there is a high incidence of otolithic damage in patients with PSHL, but relevant reports are few. Sharing a continuous membranous structure and similar receptor cell ultrastructures, the cochlea and vestibule may be susceptible to the same harmful factors. Disorders of the inner ear may result in a variety of manifestations, including vertigo, spatial disorientation, blurred vision, impaired articulation, and hearing impairment. Considering the diversity of clinical symptoms associated with PSHL with otolithic dysfunction, it may be frequently misdiagnosed, and objective means of testing the function of otolithic organs should be recommended for hearing-impaired patients. Vestibular-evoked myogenic potentials (VEMPs) via air-conducted sound are of great importance for the diagnosis of otolithic function. Hearing devices such as cochlear implants are commonly accepted treatments for PSHL, and early identification and treatment of vestibular disorders may increase the success rate of cochlear implantation. Therefore, it is necessary to increase awareness of otolithic functional states in patients with PSHL.展开更多
This study investigated the relationship among the severity of hearing impairment,vestibular function and balance function in patients with idiopathic sudden sensorineural hearing loss（ISSNHL）.A total of 35 ISSNHL p...This study investigated the relationship among the severity of hearing impairment,vestibular function and balance function in patients with idiopathic sudden sensorineural hearing loss（ISSNHL）.A total of 35 ISSNHL patients（including 21 patients with vertigo） were enrolled.All of the patients underwent audiometry,sensory organization test（SOT）,caloric test,cervical vestibular-evoked myogenic potential（cV EMP） test and ocular vestibular-evoked myogenic potential（o VEMP） test.Significant relationship was found between vertigo and hearing loss grade（P=0.009）,and between SOT VEST grade and hearing loss grade（P=0.001）.The abnormal rate of o VEMP test was the highest,followed by the abnormal rates of caloric and c VEMP tests,not only in patients with vertigo but also in those without vertigo.The vestibular end organs were more susceptible to damage in patients with vertigo（compared with patients without vertigo）.Significant relationship was found between presence of vertigo and SOT VEST grade（P=0.010）.We demonstrated that vestibular end organs may be impaired not only in patients with vertigo but also in patients without vertigo.The cochlear and vestibular impairment could be more serious in patients with vertigo than in those without vertigo.Vertigo does not necessarily bear a causal relationship with the impairment of the vestibular end organs.SOT VEST grade could be used to reflect the presence of vertigo state in the ISSNHL patients.Apart from audiometry,the function of peripheral vestibular end organs and balance function should be evaluated to comprehensively understand ISSNHL.Better assessment of the condition will help us in clinical diagnosis,treatment and prognosis evaluation of ISSNHL.展开更多
基金supported by Japan China Sasakawa Medical Fellowship 2016(YL)
文摘Objectives: The aim of our study is to examine vestibular-evoked myogenic potentials(VEMPs) elicited by the galvanic vestibular stimulation in the sternocleidomastoid muscle(SCM) in healthy subjects for clinical applications of auditory neuropathy or vestibular neuropathy in the future.Methods: We enrolled sixteen healthy subjects to record the average responses of SCM to galvanic vestibular stimulation(GVS) [current 3 mA;duration 1 ms] by electromyography(EMG). SPSS 18.0 software was used to analyze the obtained data for mean and standard deviation.Results: In all healthy subjects mastoid-forehead galvanic vestibular stimulation produced a positive-negative biphasic EMG responses on SCM ipsilateral to the cathodal electrode. The latency of p13 was 11.7 ± 3.0 ms. The latency of n23 was 17.8 ± 3.4 ms. The amplitude of p13-n23 was147.0 ± 69.0 μV. The interaural asymmetry ratio(AR) of p13, n23 latency and the amplitude was respectively 0.12 ± 0.09, 0.08 ± 0.08 and0.16 ± 0.10.Discussions: Galvanic vestibular stimulation could elicit biphasic EMG responses from SCM via the vestibular nerve but not from the otolith organs. Galvanic stimulation together with air conducted sound(ACS) or bone conducted vibration(BCV) can elicit VEMPs and may enable the differentiation of retrolabyrinthine lesions from labyrinthine lesions in vestibular system.
基金supported by grants from the National Natural Science Foundation of China(No.81670945,No.81970891,No.81600809,No.81700915)the Shaanxi Major International Cooperative Project of China(No.2020KWZ-019)the Key R&D Projects in Shaanxi Province,China(No.2018SF-189).
文摘Objective Auditory neuropathy(AN)is a unique pattern of hearing loss with preservation of hair cell function.The condition is characterized by the presence of otoacoustic emissions(OAE)or cochlear microphonic(CM)responses with severe abnormalities of the auditory brainstem response(ABR).The vestibular branches of the VIII cranial nerve and the structures innervated by it can also be affected.However,the precise lesion sites in the vestibular system are not well characterized in patients with AN.Methods The air-conducted sound(ACS)vestibular-evoked myogenic potentials(VEMPs)and galvanic vestibular stimuli(GVS)-VEMPs were examined in 14 patients with AN.Results On examination of VEMPs(n=14,28 ears),the absent rates of ACS-cervical VEMP(cVEMP),ACS-ocular VEMP(oVEMP),GVS-cVEMP,GVS-oVEMP and caloric test were 92.9%(26/28),85.7%(24/28),67.9%(19/28),53.6%(15/28),and 61.5%(8/13),respectively.Impaired functions of the saccule,inferior vestibular nerve,utricle,superior vestibular nerve,and horizontal semicircular canal were found in 25.0%(7/28),67.9%(19/28),32.1%(9/28),53.6%(15/28)and 61.5%(8/13)patients,respectively.On comparing the elicited VEMPs parameters of AN patients with those of normal controls,both ACS-VEMPs and GVS-VEMPs showed abnormal results in AN patients(such as,lower presence rates,elevated thresholds,prolonged latencies,and decreased amplitudes).Conclusion The study suggested that patients with AN often have concomitant vestibular disorders.Retro-labyrinthine lesions were more frequently observed in this study.GVS-VEMPs combined with ACS-VEMPs may help identify the lesion sites and facilitate detection of areas of vestibular dysfunction in these patients.
文摘Introduction:The masseter vestibular evoked myogenic potential(mVEMP)is a bilaterally generated,electromyographically(EMG)-mediated response innervated by the trigeminal nerve.The purpose of the present investigation was to 1)determine whether subjects could accurately achieve and maintain a range of EMG target levels,2)to examine the effects of varied EMG levels on the latencies and amplitudes of the mVEMP,and 3)to investigate the degree of side-to-side asymmetry and any effects of EMG activation.Methods:Subjects were nine neurologically and otologically normal young adults.A high-intensity tone burst was presented monaurally while subjects were seated upright and asked to match a range of EMG target levels by clenching their teeth.Recordings were made from the ipsilateral and contralateral masseter muscles referenced to the ear being monaurally stimulated.Results:We found that the tonic EMG target had no effect on mVEMP latency.Additionally,although mVEMP amplitudes“scaled”to the EMG target,there was a tendency for the subjects’EMG level to“undershoot”the EMG target levels greater than 50 mV.While some individuals did generate differences in EMG activation between sides,there were no significant differences on average EMG activation between sides.Further,while average corrected amplitude asymmetry was similar across EMG targets,some individuals demonstrated large,corrected amplitude asymmetry ratios.Conclusions:The results of this investigation suggest that,as with cVEMP recordings,the underlying EMG activation may vary between subjects and could impact mVEMP amplitudes,yet could be mitigated by amplitude correction techniques.Further it is important to be aware that even young normal subjects have difficulty maintaining large,tonic EMG activity during the mVEMP recording.
文摘Objective:Patients with dizziness may present with symptoms of tilting,swaying,rocking,floating or with disequilibrium.This may be suggestive of an isolated otolithic dysfunction yet,there is little emphasis on this emerging clinical entity.To characterize and describe the prevalence of isolated otolith dysfunction in a local tertiary hospital and correlate them with clinical diagnosis.Methodology:Retrospective medical chart review of patients who presented with dizziness to the specialist outpatient Otolaryngology clinic,who required vestibular laboratory investigation.Results:Of the 206 patients,more than half of them(52.4%)fulfilled the criteria for either probable or definite isolated otolith dysfunction.When there are clinical symptoms of otolith dysfunction reported,there is a 1.62 odds of a remarkable laboratory otolith finding.The most common clinical finding was“no clear diagnosis”(65.5%)followed by Vestibular Migraine(13.6%).Conclusion:The prevalence of isolated otolith dysfunction is quite high.Laboratory tests of otolith function should be performed more routinely.This can be done in a sequential way to optimize cost effectiveness in countries with no insurance reimbursement.Prospective cohort studies on isolated otolith dysfunction,will lay the groundwork for achieving diagnostic consensus and formulating rehabilitation plans to aid this group of patients。
文摘Profound sensorineural hearing loss (PSHL) is not uncommonly encountered in otology. In clinics, there is a high incidence of otolithic damage in patients with PSHL, but relevant reports are few. Sharing a continuous membranous structure and similar receptor cell ultrastructures, the cochlea and vestibule may be susceptible to the same harmful factors. Disorders of the inner ear may result in a variety of manifestations, including vertigo, spatial disorientation, blurred vision, impaired articulation, and hearing impairment. Considering the diversity of clinical symptoms associated with PSHL with otolithic dysfunction, it may be frequently misdiagnosed, and objective means of testing the function of otolithic organs should be recommended for hearing-impaired patients. Vestibular-evoked myogenic potentials (VEMPs) via air-conducted sound are of great importance for the diagnosis of otolithic function. Hearing devices such as cochlear implants are commonly accepted treatments for PSHL, and early identification and treatment of vestibular disorders may increase the success rate of cochlear implantation. Therefore, it is necessary to increase awareness of otolithic functional states in patients with PSHL.
基金supported by grants from the National Twelfth Five-Year Science and Technology Support Program of China(No.2012BAI12B02)the National Eleventh Five-Year Science and Technology Support Program of China(No.2007BAI18B13)
文摘This study investigated the relationship among the severity of hearing impairment,vestibular function and balance function in patients with idiopathic sudden sensorineural hearing loss（ISSNHL）.A total of 35 ISSNHL patients（including 21 patients with vertigo） were enrolled.All of the patients underwent audiometry,sensory organization test（SOT）,caloric test,cervical vestibular-evoked myogenic potential（cV EMP） test and ocular vestibular-evoked myogenic potential（o VEMP） test.Significant relationship was found between vertigo and hearing loss grade（P=0.009）,and between SOT VEST grade and hearing loss grade（P=0.001）.The abnormal rate of o VEMP test was the highest,followed by the abnormal rates of caloric and c VEMP tests,not only in patients with vertigo but also in those without vertigo.The vestibular end organs were more susceptible to damage in patients with vertigo（compared with patients without vertigo）.Significant relationship was found between presence of vertigo and SOT VEST grade（P=0.010）.We demonstrated that vestibular end organs may be impaired not only in patients with vertigo but also in patients without vertigo.The cochlear and vestibular impairment could be more serious in patients with vertigo than in those without vertigo.Vertigo does not necessarily bear a causal relationship with the impairment of the vestibular end organs.SOT VEST grade could be used to reflect the presence of vertigo state in the ISSNHL patients.Apart from audiometry,the function of peripheral vestibular end organs and balance function should be evaluated to comprehensively understand ISSNHL.Better assessment of the condition will help us in clinical diagnosis,treatment and prognosis evaluation of ISSNHL.
