Otolithic and canal functions assessment during the acute phase of benign paroxysmal positional vertigo.

PURPOSE: Assess otolith and canal involvement in patients with Benign Paroxysmal Positional Vertigo (BPPV) during the acute phase. METHODS: Ninety patients with BPPV in the acute phase underwent a vestibular assessment that included an assessment with videonistagmography, video Head Impulse Test (vHIT) to evaluate horizontal and vertical semicircular canals, and ocular vestibular evoked myogenic potentials (oVEMPs) for the otolithic function. RESULTS: Ninety patients had an involvement of the posterior canal, fifty-five out of ninety patients presented a BPPV of the right ear. No asymmetry of the otolithic functions was found for the utricular macula. Furthermore, no reduction of the Vestibular Ocular Reflex gain was found for the examined canal functions. CONCLUSIONS: The lack of asymmetry suggests that during the acute phase of BPPV, the otolithic function is balanced between the affected and unaffected ears. Moreover, the preserved VOR gain for the examined canal functions suggests that the VOR responses for the examined channels were intact.

Bone conducted cervical vestibular evoked myogenic potentials: comparison of tone burst stimulus vs chirp stimulus.

PURPOSE: Vestibular evoked myogenic potential (VEMP) is a test used to evaluate the function of otolith organs. In healthy individuals, air-conducted (AC) responses are obtained, whereas, in conductive hearing loss, the inability to transmit the signal well enough with AC stimuli has led to the need for bone-conducted (BC) stimuli. This study aimed to compare 500 Hz Chirp and Tone Burst stimuli in terms of latency and amplitude in BC cVEMP. METHODS: This prospective observational case control study included 35 healthy participants (70 ears) between the age of 20-50. Participants underwent VEMP testing with BC 500 Hz Tone Burst stimulus and 500 Hz narrow band Chirp stimulus without changing the position of the bone conducted vibrator. The intensity of the stimuli was 50 dB nHL. RESULTS: Response rate of 500 Hz TB Stimulus was 51.4% and 95.7% in Chirp stimulus. It was observed that significantly more responses were obtained with Chirp stimulus than TB stimulus (p < 0.001). In terms of p1 latency, n1 latency, both latencies were significantly shorter in Chirp stimulus (p < 0.001). p1n1 amplitude was found significantly larger in Chirp stimulus (p < 0.001). CONCLUSION: Compared to 500 Hz TB stimulus, 500 Hz Chirp stimulus results in a higher response rate, larger p1n1 amplitude, and shorter p1 and n1 latency. A higher response rate may provide a more accurate assessment of otolith organs, reducing false negatives due to signal transmission in patients.

[Practical instructions for recording vestibular evoked myogenic potentials]. / Praktische Hinweise zur Messung vestibulär evozierter myogener Potenziale.

Recording of vestibular evoked myogenic potentials (VEMPs) is a well-established method for functional diagnostics of the otolith organs. VEMPs are vestibular reflexes of the sacculus und utriculus to acoustic stimulation by air-conducted sound or bone-conducted vibration and are recorded by surface electrodes from the cervical (cVEMP) and ocular (oVEMP) muscles. The results of VEMP recordings are part of the neuro-otologic test battery and enable diagnosis of various vestibular disorders or differentiation between non-vestibular and peripheral vestibular vertigo. However, the methods for recording VEMPs vary substantially, although recording and stimulation parameters as well as methods of data analysis have a significant influence on the results. This article provides an overview of recommended parameters as well as practical instructions for the recording, analysis, and interpretation of VEMPs.

Inner membrane YfgM-PpiD heterodimer acts as a functional unit that associates with the SecY/E/G translocon and promotes protein translocation.

PpiD and YfgM are inner membrane proteins that are both composed of an N-terminal transmembrane segment and a C-terminal periplasmic domain. Escherichia coli YfgM and PpiD form a stable complex that interacts with the SecY/E/G (Sec) translocon, a channel that allows protein translocation across the cytoplasmic membrane. Although PpiD is known to function in protein translocation, the functional significance of PpiD-YfgM complex formation as well as the molecular mechanisms of PpiD-YfgM and PpiD/YfgM-Sec translocon interactions remain unclear. Here, we conducted genetic and biochemical studies using yfgM and ppiD mutants and demonstrated that a lack of YfgM caused partial PpiD degradation at its C-terminal region and hindered the membrane translocation of Vibrio protein export monitoring polypeptide (VemP), a Vibrio secretory protein, in both E. coli and Vibrio alginolyticus. While ppiD disruption also impaired VemP translocation, we found that the yfgM and ppiD double deletion exhibited no additive or synergistic effects. Together, these results strongly suggest that both PpiD and YfgM are required for efficient VemP translocation. Furthermore, our site-directed in vivo photocrosslinking analysis revealed that the tetratricopeptide repeat domain of YfgM and a conserved structural domain (NC domain) in PpiD interact with each other and that YfgM, like PpiD, directly interacts with the SecG translocon subunit. Crosslinking analysis also suggested that PpiD-YfgM complex formation is required for these proteins to interact with SecG. In summary, we propose that PpiD and YfgM form a functional unit that stimulates protein translocation by facilitating their proper interactions with the Sec translocon.

Head Orientation Modulates Vestibular Cerebellar Evoked Potentials (VsCEPs) and Reflexes Produced by Impulsive Mastoid and Midline Skull Stimulation.

The cerebellum plays a critical role in the modulation of vestibular reflexes, dependent on input from proprioceptive afferents. The mechanism of this cerebellar control is not well understood. In a sample of 11 healthy human subjects, we investigated the effects of head orientation on ocular, cervical, postural and cerebellar short latency potentials evoked by impulsive stimuli applied at both mastoids and midline skull sites. Subjects were instructed to lean backwards with the head positioned straight ahead or held rotated in different degrees of yaw towards the right and left sides. Impulsive mastoid stimulation, a potent method of utricular stimulation, produced localised vestibular cerebellar evoked potentials (VsCEPs: P12-N17) which were strongly modulated by head orientation. The response was larger on the side opposite to the direction of head rotation and with stimulation on the side of rotation. In contrast, ocular VEMPs (oVEMPs: n10-p16) were present but showed little change with head posture, while cervical VEMPs (cVEMPs: p15-n23) were larger with the head held rotated away from the side of the recording. Postural effects with lateral vestibular stimulation were strongly modulated by head rotation, with more powerful effects occurring bilaterally with stimulation on the side of rotation. The duration of the postural EMG changes was similar to the post-excitation inhibition of the electrocerebellogram (ECeG), consistent with cerebellar participation. We conclude that head rotation selectively affects evoked vestibular reflexes towards different targets, consistent with their physiological roles. Changes in VsCEPs may contribute to the modulation of postural reflexes by the cerebellum.

The use of vestibular evoked myogenic potentials (VEMP) in the diagnosis of otolithic dysfunction of patients with obstructive sleep apnea: a survey of awareness and recognition of otorhinolaryngology medical staffs.

PURPOSE: To assess awareness and recognition of vestibular function tests in otorhinolaryngology medical staffs, especially the vestibular evoked myogenic potentials (VEMP) testing in patients with obstructive sleep apnea (OSA). METHODS: A survey was delivered via either email or a social media app. The medical staffs of the Chinese Medical Association of Otolaryngology Head and Neck Surgery from various branches were enrolled. Study data were collected and managed with an online data collection tool. RESULTS: A total of 1781 emails and 623 social media messages were sent to 2404 otorhinolaryngology medical staffs. One hundred and fifty-seven of them participated in the survey, including 24 via emails and 133 via the social media app. Regarding the knowledge of VEMP, only 59 (37.6%) of them agreed that OSA could be related to vertigo/dizziness/imbalance and 28 (17.8%) believed that OSA could result in VEMP abnormalities and would factor this in diagnosing the impairment of the vestibular function of OSA patients. A total of 7.6% of the respondents had never heard of the VEMP tests. Responses regarding the minimum age at which VEMP are possible ranged from younger than 6 months to greater than 18 years of age. Beliefs regarding the utility and reliability of VEMP varied, with 'unsure' being the most frequent response. In addition, only 17.8% of otolaryngologists indicated some access to the VEMP test. CONCLUSIONS: Knowledge and beliefs about the role of VEMP in diagnosing otolithic organ dysfunction caused by OSA in otorhinolaryngology vary widely. It is important for otorhinolaryngology medical staffs to learn the latest literatures and updated knowledge through continuing education.

Cervical and ocular vestibular evoked myogenic potential: A comparison of narrowband chirp, broadband chirp, tone burst and click stimulation.

OBJECTIVES: To compare the response rate and response parameters of cervical and ocular vestibular evoked myogenic potentials (c&oVEMP) elicited by narrowband (NB) and broadband (BB) CE-Chirp, with the more classical tone burst (TB) and click VEMPs. DESIGN: The response rate, latency, amplitude and asymmetry ratio of c&oVEMPs elicited by 95 dB nHL air conducted (AC) 500 Hz NB CE-chirp, BB CE-chirp, 500 Hz TB and click stimuli were recorded bilaterally. STUDY SAMPLE: 20 male and 38 female participants (19-39 years). RESULTS: For the cVEMP, the highest response rate was found for NB chirp (100%), followed by TB (91%), BB chirp (87%) and finally click (85%). A similar order was seen for oVEMP with percentages of 100%; 57%, 57%, and 43%. The 500 Hz NB CE-Chirp elicited significantly shorter cVEMP P1 and N1 latencies and significantly larger c&oVEMP amplitudes compared to all other stimuli. BB CE-Chirp elicited significantly shorter c&oVEMP P1 and N1 latencies with smaller amplitudes compared to TB. Asymmetry ratios were not statistically significant for all comparisons. CONCLUSION: The 500 Hz NB CE-chirp provides the highest response rates, shorter latencies and larger amplitudes, and therefore seem a promising stimulus for reliably measuring c&oVEMPs in clinical practice.

Comparisons of Auditory and Vestibular Functions After Septorhinoplasty Performed with the Micro-compass Saw Technique and the Classical Technique.

AIM: To evaluate hearing and labyrinth functions following different osteotomy types (micro-compass saw, osteotome, and no osteotomy) performed in septorhinoplasty operations. MATERIAL AND METHOD: The study included 74 patients operated between January 2020 and March 2022, separated into 3 groups: Group 1: 24 patients (16 females and 8 males): osteotome was used for the osteotomy; Group 2: 24 patients (12 females and 12 males): micro-saw was used for osteotomy; and Group 3: 26 patients (17 females and 9 males): open technique septoplasty with no osteotomy. At 1 day before and 1 week after the operation, all the patients underwent audiological examination, tympanometry, vestibular evoked myogenic potentials (c-VEMP), video head impulse test (v-HIT), videonystagmography (VNG), and distortion product otoacoustic emission (DPOAE) tests. RESULTS: In the c-VEMP tests, significant differences were determined between the groups in respect of N1, P1, and N1-P1 latencies and N1-P1 amplitudes before and after the operation. In the v-HIT test, the change in right-side posterior gain postoperatively was statistically significant in the micro-saw group (p<0.05). The postoperative right lateral canal values were determined to be statistically significantly increased in the micro-saw group compared to the osteotome group (p<0.05). CONCLUSION: This is the only study in the literature to have determined vestibular effects with the evaluation of such a wide range of techniques. Previous studies in the literature have found no effect of osteotomy technique on the balance and hearing systems. The results of this study demonstrated that the preoperative and postoperative difference between the osteotomy techniques had an effect on the balance system. The change in the balance tests following an operation with classic osteotomy shows a greater predisposition to benign positional vertigo. In this sense, the micro-saw can be considered safer. Level of Evidence II This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Nonlinearity in bone-conducted amplitude-modulated cervical vestibular-evoked myogenic potentials: harmonic distortion products.

Otolith organs of the balance system, the saccule and utricle, encode linear acceleration. Integrity of the saccule is commonly assessed using cervical vestibular-evoked myogenic potentials (cVEMPs) arising from an inhibitory reflex along the vestibulospinal pathway. Conventional approaches to eliciting these responses use brief, transient sounds to elicit onset responses. Here we used long-duration amplitude-modulated (AM) tones to elicit cVEMPs (AMcVEMPs) and analyzed their spectral content for evidence of nonlinear processing consistent with known characteristics of vestibular hair cells. Twelve young adults (ages 21-25) with no hearing or vestibular pathologies participated in this study. AMcVEMPs were elicited by bone-conducted AM tones with a 500-Hz carrier frequency. Eighteen modulation frequencies were used between 7 and 403 Hz. All participants had robust distortion products at harmonics of the modulation frequency. Total harmonic distortion ranged from approximately 10 to 80%. AMcVEMPs contain harmonic distortion products consistent with vestibular hair cell nonlinearities, and this new approach to studying the otolith organs may provide a noninvasive, in vivo method to study nonlinearity of vestibular hair cells in humans.NEW & NOTEWORTHY The otolith balance organs of humans are assessed for basic science and clinical applications by using vestibular-evoked myogenic potentials (VEMPs). Traditionally, VEMPs are elicited with brief, transient sounds to study onset responses. We used long-duration sounds to elicit steady-state VEMPs. This allowed us to measure nonlinear distortion products, consistent with nonlinear processing in vestibular hair cells. This new approach may help to better understand links between otolith organs and balance function.

Prevalence of abnormal vestibular responses in children with sensorineural hearing loss.

PURPOSE: Dysfunction of the vestibular organs has a great deal of influence on children's balance. Children with sensorineural hearing loss (SNHL) may often have accompanying abnormal vestibular responses. Video head impulse test (vHIT) combined with a test battery of cervical and ocular vestibular evoked myogenic potentials (cVEMPs, oVEMPs) make it possible to determine the prevalence of abnormal vestibular response in any of the five paired vestibular organs amongst children with SNHL. METHOD: Prospective cross-sectional study including children aged 3-17 years with uni- or bilateral SNHL (bone-conduction (BC) pure tone average (PTA4) above 20 dB). Assessments included vHIT, cVEMP, and oVEMP. Descriptive data were analyzed. T-tests were performed to detect any correlation between the degree of SNHL and abnormal vestibular responses. RESULTS: 42 children (27 males), a total of 63 ears with SNHL, mean BC PTA4 SNHL of 42.3 dB (32.0; 58.4 IR) were included. 28.6% had at least one ear with abnormal vestibular response. 97.6% (41/42) completed one and 75.0% (27/36) completed all vestibular examinations. Ears with two pathological examinations had significantly more severe SNHL than ears with one pathological or normal vestibular examinations (p = 0.008, p = 0.005). CONCLUSION: All test methods used with this study were easy, fast, and comfortable for children (as young as 3 years of age) to undergo. Even a moderate SNHL might be associated with abnormal vestibular response. Structural damage to the organs is the most likely cause of vestibular deficit. Consensus on criteria defining pathological examinations with both vHIT and VEMPs are required for more accurate comparison with previous studies.

Relative efficacy of veria and mastoidectomy techniques of cochlear implantation in preservation of sound-induced saccular responses.

OBJECTIVE: Cochlear implantation (CI) is a safe technique to give hearing sensation to a person with hearing impairment. The present study aimed to compare the two surgical approaches of CI, mastoidectomy and veria, for their effects on saccular function assessed using cervical vestibular-evoked myogenic potential (cVEMP). DESIGN: Multiple group time series design. STUDY SAMPLE: The study included 63 children (3-8 years old) who underwent CI using veria technique (n = 20) and mastoidectomy approach (n = 43). The 500-Hz tone-burst evoked cVEMP were recorded on three occasions- a day before CI surgery, a day after the device switch-on and 4 months after the switch-on. RESULTS: The post-implant results revealed the absence of cVEMP in nearly 40% of the participants. The amplitudes were significantly lower at the time of the switch-on and at the 4-months follow-up period (p < 0.05). Among the participants undergoing CI using mastoidectomy approach, amplitudes were significantly larger after surgery than those undergoing surgery using veria technique (p < 0.05). CONCLUSIONS: The saccular responses are better preserved with the mastoidectomy technique than the veria technique for CI surgery.

The vestibulo-masseteric reflex and the acoustic-masseteric reflex: a reliability and responsiveness study in healthy subjects.

The vestibulo-masseteric reflex (VMR or p11 wave), the acoustic-masseteric reflex (AMR or p1/n21 wave) and the mixed vestibulo-cochlear p11/n21 potential are responses of masseter muscles to sound that can be employed to evaluate brainstem function. This study was aimed at establishing the test-retest reliability and responsiveness of these reflex parameters according to the type of electrode configuration. Twenty-two healthy volunteers (M:F = 11:11; mean age 25.3 ± 5.2 years) participated in two testing sessions separated by one week. Zygomatic and mandibular montages were compared following unilateral and bilateral stimulations. For reliability purposes, intraclass correlation coefficient (ICC), coefficient of variation of the method error (CVME) and standard error of measurement (SEM) were calculated. The minimal detectable difference (MDD) was also determined as a measure of responsiveness. Both VMR (p11 wave) and AMR could be consistently evoked from test to retest, although the frequency rate was significantly higher (all p values ≤ 0.009) with zygomatic (VMR: 97.7-100%; AMR: 86.9-97.6%) than mandibular montage (VMR: 84.7-89.8%; AMR: 65.0-67.8%), with no significant differences between unilateral and bilateral stimulations. Good-to-excellent reliability and responsiveness (high ICC, low CVME, SEM and MDD scores) were detected for corrected amplitudes and peak latencies for all reflex responses, whereas raw amplitudes were associated to poor reliability. The reliability of the zygomatic montage proved superior to the mandibular montage for all reflex responses. Given their high test-retest consistency and capability to study different features of the reflex arch, both peak latencies and corrected amplitudes should be reported and considered in the interpretation of reflex testing results.

Bone-conducted vestibular and stretch reflexes in human neck muscles.

In normal humans, tapping the forehead produces a neck muscle reflex that is used clinically to test vestibular function, the cervical vestibular evoked myogenic potential (cVEMP). As stretch receptors can also be activated by skull taps, we investigated the origin of the early and late peaks of the bone-conducted cVEMP. In twelve normal participants, we differentially stimulated the vestibular and neck stretch receptors by applying vibration to the forehead (activating both vestibular and stretch receptors) and to the sternum (activating mainly stretch receptors). Patients with bilateral vestibulopathy (BVP; n = 26) and unilateral vestibular loss (uVL; n = 17) were also investigated for comparison. Comparison of peaks in normal subjects suggested that the early peaks were vestibular-dependent, while the later peaks had mixed vestibular and stretch input. The late peaks were present but small (1.1 amplitude ratio) in patients with BVP and absent VEMPs, confirming that they do not strictly depend on vestibular function, and largest in age-matched controls (1.5 amplitude ratio, p = 0.049), suggesting that there is an additional vestibular reflex at this latency (approx. 30 ms). Patients with uVL had larger late peaks on the affected than the normal side (1.4 vs 1.0 amplitude ratio, p = 0.034). The results suggest that the early responses in SCM to skull vibration in humans are vestibular-dependent, while there is a late stretch reflex bilaterally and a late vestibular reflex in the contralateral muscle.

Enhancing research quality of studies on VEMPs in central neurological disorders: a scoping review.

Common pitfalls in vestibular-evoked myogenic potential (VEMP) recording methods have been extensively outlined by several reviews. Conversely, the robustness of research methodology employed for the design and conduct of VEMP studies has never been appraised. To fill this void, we conducted a scoping review to map and evaluate the overall quality of the existing literature on VEMPs in central neurological disorders. Five databases were searched from inception to October 2018 for case-control studies on multiple sclerosis (MS), cerebellar and/or brainstem strokes, Parkinson's disease (PD), migraine, and tumors of the cerebellopontine angle. Study quality was assessed using the Agency for Healthcare Research and Quality criteria (AHRQ). The 11-criteria AHRQ scoring system revealed that PD studies achieved a score of 5/11, migraine and cerebellar and/or brainstem stroke a score of 4/11, MS and tumors of the cerebellopontine angle a score of 3/11. Age was found to be one of the main sources of case-control imbalance: compared with controls, cases were significantly older with a 3.6-yr difference in MS studies, 6 yr in PD, up to 12 yr in stroke and tumors. Regardless of pathological condition, case-control groups were found unmatched also by gender. Post hoc power calculations revealed that 53% of the studies achieved the minimum statistical power of 80%. This scoping review revealed low research quality across the literature on VEMPs in central neurological disorders. Scoping lines are provided on actions to be undertaken in future studies to establish a common methodological platform and enhance the quality of research in this field.NEW & NOTEWORTHY Robust methodology is a prerequisite for any type of research, particularly for observational designs such as those employed in vestibular-evoked myogenic potential (VEMP) research. On these premises, this scoping review provides methodological guidelines to improve validity, accuracy and consistency of clinical outcomes from VEMP studies involving central nervous system disorders. In fact, the high risk for bias that is inherent to poor methodology threatens the validity of the findings of works that are technically sound but methodologically flawed.

Quantitative evaluation of endolymphatic hydrops with MRI through intravenous gadolinium administration and VEMP in unilateral definite Meniere's disease.

PURPOSE: To help clinicians to further understand the significance of vestibular-evoked myogenic potential (VEMP) examinations to diagnose MD and the quantitative relationship between VEMP and MRI in assessing the location and degree of endolymphatic hydrops (EH) in definite Meniere's disease (MD) patients. METHODS: Fifty-six patients with unilateral definite MD participated in this study, which used MRIs through intravenous gadolinium administration (IV-Gd), audiometry, caloric tests and VEMP tests. The VEMP results of 26 healthy volunteers were used as a normal reference value. RESULTS: The participants were found through MRI to have differing degrees of vestibular and cochlear EH. Quantitative comparison of MRI and VEMP results found that the response rates of oVEMP decreased with cochlear EH increasing; the asymmetry ratio (AR) of oVEMP can be used to find whether cochlear EH or not, and the P1-N1 amplitude was lower in the extreme cochlear EH group (P < 0.01). The AR of cVEMP was larger in severe vestibular EH group than that of the mild or no vestibular EH group (P < 0.01). The correlation between the degree of cochlear EH and the mean PTA threshold was statistically significant (P < 0.05). The duration of MD correlated positively with vestibular EH (P < 0.05). The abnormal rate of caloric tests was higher in severe vestibular EH group than that of the mild or no vestibular EH group (P < 0.05). CONCLUSIONS: The advantages of MRIs by IV-Gd administration were obvious in assessing the location and degree of EH. oVEMP and PTA can be indirectly used to evaluate the extent of cochlear EH, cVEMP and caloric tests can be used to assess the extent of vestibular EH on the condition of absent MRIs.

Cervical vestibular evoked myogenic potentials via air conduction delivered by either sequentially or quasi-simultaneously presented narrow-band chirp stimuli.

OBJECTIVE: To produce sound-evoked cervical vestibular evoked myogenic potentials (cVEMPs). These are widely used for the diagnosis of peripheral vestibulopathies and disturbances of the sacculocollic reflexes. The main, sensitive, frequency for eliciting cVEMPs has been shown to be around 500 Hz. DESIGN: Narrow-band chirps in different frequency ranges (middle frequencies of 0.5, 1, 2 and 4 kHz) will be used for sequential and quasi-simultaneous stimulation of the cervical vestibular organ. As benchmarks, peak-to-peak p13 and n23 amplitudes were analysed. Study samples: The pilot study used five normal-hearing subjects (mean age 38.6 years) none of whom have balance disorders. RESULTS: From 40 measurements, p13 and n23 could be identified in a total of 34 detected cVEMPs. As expected, amplitudes were highest at 500 Hz, followed by 1, 2 and 4 kHz. Using the quasi-simultaneous stimulation method led to a slight reduction in cVEMP amplitudes, but these remained in the same order according to magnitude: 0.5, 1, 2 and 4 kHz. CONCLUSION: Sequential and quasi-simultaneous narrow-band chirps are effective for evoking cVEMPs. High amplitudes contribute to fast identification across an extended frequency range (0.5-4 kHz) and also contribute to a reduction in examination time and overall sound exposure.

Recovery of ocular and cervical vestibular evoked myogenic potentials after treatment of inner ear diseases.

Purpose: This study aimed to assess the clinical value of ocular vestibular evoked myogenic potential (oVEMP) and cervical vestibular evoked myogenic potential (cVEMP) for monitoring the rehabilitation of vestibular function in patients treated for peripheral vertigo. Materials and methods: Fifteen patients who had been diagnosed with peripheral vertigo and showed no VEMP response on the affected side but exhibited symptom alleviation and VEMP responses after therapies were retrospectively enrolled. We analyzed the restoration and parameters of their VEMP response. Results: After treatment, six patients with sudden sensorineural hearing loss showed VEMP recovery, including two with both oVEMP and cVEMP recovery, three with oVEMP recovery only, and one with cVEMP recovery only. Two patients with Meniere's disease (MD) showed cVEMP recovery, while the other three MD patients showed oVEMP recovery. Three patients with herpes zoster oticus exhibited cVEMP recovery. One patient with vestibular neuritis exhibited cVEMP recovery. Among the patients with cVEMP and/or oVEMP restoration, most patients presented normal VEMP parameters; however, some patients showed abnormal VEMP parameters after treatment. Conclusion: Combined oVEMP and cVEMP are objective tools for assessing vestibular otolithic end organ function during dynamic functional recovery from vestibular diseases.

Comparison of Vestibular Evoked Myogenic Potential and Dizziness Handicap Inventory in Patient with Peripheral Vestibular Lesions between Pre and Post Vestibular Rehabilitation.

AIM AND OBJECTIVE: VEMP is brief latency electromyography and is elicited by a high-intensity auditory stimulus. The aim of the current study was to compare VEMP and DHI in patients with peripheral vestibular lesions between pre and post vestibular rehabilitation. METHOD: A total of 30 participants with peripheral vestibular lesions were considered, among which 15 were given vestibular rehabilitation, and 15 were not given vestibular rehabilitation. The participants were subjected for cVEMP, oVEMP, and DHI testing before and after vestibular rehabilitation. RESULT: The latency and peak to peak amplitude measures showed no major difference among the training phase and between training and group for both cVEMP and oVEMP responses. However, the DHI scores were found to be significantly improved after vestibular training in the participants with dizzness. The above findings explain that even in the presence of peripheral vestibular lesion, symptomatic relief from vertiginous symptoms is possible. CONCLUSION: These were inculcated by vestibular rehabilitation prompted vestibular compensation. Vestibular rehabilitation should be practiced among individuals with peripheral vestibular lesions, irrespective of age.

Evaluation of saccular and inferior vestibular nerve function in children with auditory neuropathy spectrum disorder.

PURPOSE: The aim of the current work was to evaluate the function of the saccule and inferior vestibular nerve in children with auditory neuropathy spectrum disorder (ANSD) by recording the cervical-evoked myogenic potentials (C-VEMP) on those children and to compare C-VEMP results in ANSD children of pre-lingual onset to those in ANSD children of post-lingual onset. METHODS: The study included 38 ANSD children of pre-lingual onset, 16 ANSD children of post-lingual onset, and 20 control children. All participant children were subjected to C-VEMP testing using 500 Hz tone burst stimuli. RESULTS: The vast majority of ANSD children of pre-lingual onset (35 out of 38; 92.1%) had bilateral intact C-VEMP response with C-VEMP parameters (amplitude, asymmetric ratio, latency, and inter-aural latency difference) that were not statistically different than those in the control children. Only three children had bilateral absent C-VEMP response. On the other hand, the majority of ANSD children of post-lingual onset (11 out of 16; 68.75%) had bilateral absent C-VEMP response. The remaining five children had bilateral intact C-VEMP response with C-VEMP parameters that were not statistically different than those in the control children. CONCLUSIONS: The pathology of ANSD spares the saccule and inferior vestibular nerve in the vast majority of ANSD children of pre-lingual onset, while it involves them in the majority of ANSD of post-lingual onset reflecting different site(s) of lesion between the two ANSD categories. Such results have important clinical implications as regards to the management of ANSD in children.

The inion response revisited: evidence for a possible cerebellar contribution to vestibular-evoked potentials produced by air-conducted sound stimulation.

This study investigated the effect of eye gaze and head position on vestibular-evoked potentials (VsEPs). Head position would be expected to affect myogenic sources, and eye position is known to affect ocular myogenic responses (ocular vestibular-evoked myogenic potentials), whereas a neurogenic source should behave otherwise. Eleven healthy subjects were recruited, and VsEPs, using 72-channel EEG, were recorded at a fixed intensity above the vestibular threshold. Three eye gaze and three head positions were tested (-20°, 0°, and +20° to the horizontal). Short-latency potentials showed that in addition to the expected effect of gaze on infraocular (IO') leads, where up-gaze gives a maximum response, significant changes in amplitude were also observed in electrodes remote from the eyes and in particular, from contralateral parietal-occipital (PO) and neck (CB') leads. Short-latency potentials of similar latency were observed (p10/n17 and n10/p17, respectively). The pattern of change with gaze in the PO leads was distinct from that observed for the IO' leads. For the PO leads, the maximum response was obtained with neutral gaze, and this was also distinct from that observed for CB' electrodes, where a maximal response was observed with head flexion in the second wave but not the first. Evidence of modulation of N42 and N1 potentials with both eye and head position was also observed. Head- and eye-position manipulation thus suggests that the inion response consists of an early neurogenic component, as well as myogenic responses. The p10/n17 at PO, in particular, may be an indicator of vestibulocerebellar projections.NEW & NOTEWORTHY Loud sounds were used to activate vestibular receptors in human volunteers and the effects of head and eye position studied for short-latency responses. A potential (p10/n17) recorded in the parieto-occipital leads showed behavior not expected for a response with a myogenic origin. Source modeling suggested a possible origin from the cerebellum. It may represent a new indicator of human vestibulocerebellar function.