Live Imaging of the Dehydration Effect of Isosorbide on the Normal and Hydropic Guinea Pig Cochleae Using Optical Coherence Tomography.

OBJECTIVE: To investigate the isosorbide-induced dehydration effect on the endolymphatic space by intratympanic administration of isosorbide. BACKGROUND: Isosorbide, an osmotic diuretic, is used orally as a typical conservative therapy for Menière's disease (MD) in Japan. The dehydration effect occurs 6 hours after isosorbide ingestion. Intratympanic administration of isosorbide resolves endolymphatic hydrops faster than oral ingestion. In addition, the dehydration effect has never been shown directly. Therefore, we investigated the dehydration effect of intratympanic administration of isosorbide on endolymphatic hydrops using optical coherence tomography. METHODS: We used eight Hartley guinea pigs, divided into normal and hydrops groups. In the hydrops group, the animals underwent endolymphatic sac obliteration to create endolymphatic hydrops. We obtained midmodiolar section images of the cochleae using optical coherence tomography. Then, 50 to 70% isosorbide was sequentially administered intratympanically for 5 minutes, and the apical turn of the cochlea was observed. The relative midmodiolar cross-sectional area of the scala media was calculated for quantitative assessment of the endolymphatic space. RESULTS: In the normal group, 50% isosorbide had a slight but significant dehydration effect on the scala media; at 55 to 70%, Reissner's membrane became flat. In the hydrops group, 50% isosorbide slightly reduced endolymphatic hydrops; 65% flattened Reissner's membrane, and 70% slightly concaved it toward the basilar membrane. CONCLUSION: The results suggest that we could select the concentration of isosorbide according to the stage or severity of MD and relief from acute attack. Intratympanic administration of isosorbide may be a promising treatment for patients with MD.

Live imaging and functional changes of the inner ear in an animal model of Meniere's disease.

The symptoms of Meniere's disease (MD) are generally considered to be related to endolymphatic hydrops (EH). There are many recent reports supporting the possibility that vasopressin (VP) is closely linked to the formation of EH in Meniere's disease. Based on this, we developed a clinically relevant animal model of Meniere's disease in which a VP type 2 receptor agonist was administered after electrocauterization of the endolymphatic sac. We report live imaging of the internal structure, and functional changes of the inner ear after electrocauterization of the endolymphatic sac and administration of a VP type 2 receptor agonist. In this model, the development of EH was visualized in vivo using optical coherence tomography, there was no rupture of Reissner's membrane, and low-tone hearing loss and vertiginous attacks were observed. This study suggested that acute attacks are caused by the abrupt development of EH. This is the first report of live imaging of the development of EH induced by the administration of a VP type 2 receptor agonist.

Noisy galvanic vestibular stimulation has a greater ameliorating effect on posture in unstable subjects: a feasibility study.

Ameliorating effect of noisy galvanic vestibular stimulation (nGVS) on posture varies among subjects. In this feasibility study, we investigated the association between original postural instability and the ameliorating effect of nGVS on posture. Data were collected in a previously published study. Thirty healthy elderly were recruited. Two nGVS sessions (30 min or 3 h) were performed in a randomised order. The optimal intensity of nGVS, the most effective intensity for improving posture, was determined before each session. Posture was measured for 30 s during and after nGVS in the eyes-closed/foam rubber condition. The velocity, envelopment area, and root mean square of the centre of pressure movement without nGVS were significantly larger in the group with an optimal intensity than those in the group without an optimal intensity. There was a significant positive correlation between these values and the long-term ameliorating effects. The ratio of the values in the eyes-closed/foam rubber condition to those in the eyes-open condition was significantly larger in the group with an optimal intensity, and had a significant correlation with the long-term ameliorating effects. The ameliorating effects are greater in subjects who were originally unstable and in those whose postural stability was relatively independent of vestibular input.

Noisy Galvanic Vestibular Stimulation Sustainably Improves Posture in Bilateral Vestibulopathy.

Patients with bilateral vestibulopathy (BV) suffer from persistent postural imbalance, leading to a marked decrease in quality of life and a higher risk of falls. However, so far, the effective treatments for BV are very limited. We examined whether long-term noisy galvanic vestibular stimulation (nGVS) keeps improving body balance after the cessation of the stimulus in BV patients. Thirteen BV patients received nGVS for 30 min with a lower intensity than the intensity at which they feel any cutaneous sensations, and their postural movement was monitored for 6 h after the stimuli. The same session was repeated at 14-day intervals. Stance tasks on two legs were performed with eyes closed. The velocity of the center of pressure (COP) movement, the area enclosed by the COP movement, and the root mean square of the displacement of the COP were measured. The power spectrum of the COP movement was assessed. Subjective improvement of body balance was graded as worsened (-2), slightly worsened (-1), unchanged (0), slightly improved (+1) and improved (+2) in comparison with that without nGVS. In each session, the velocity of the COP movement was significantly improved for 6 h after the stimulus had ceased (P < 0.01). Concomitantly, the mean frequency of the COP power spectrum was significantly reduced in the anterior-posterior axis (P < 0.05). Subjective symptoms of imbalance were improved during the post-stimulation effect (P < 0.05). nGVS leads to an improvement in body balance that lasts for several hours after the end of the stimulus in BV patients with a reduction in the high-frequency components of their postural movement. This trial was registered with the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMINCTR: UMIN000028054).

Noisy vestibular stimulation increases gait speed in normals and in bilateral vestibulopathy.

BACKGROUND: Galvanic vestibular stimulation delivered as zero-mean current noise (noisy GVS) has been shown to improve static and dynamic postural stability probably by enhancing vestibular information. OBJECTIVE: /Hypothesis: To examine the effect of an imperceptible level of noisy GVS on dynamic locomotion in normal subjects as well as in patients with bilateral vestibulopathy. METHODS: Walking performance of 19 healthy subjects and 12 patients with bilateral vestibulopathy at their preferred speed was examined during application of noisy GVS with an amplitude ranging from 0 to 1000 µA. The gait velocity, stride length and stride time were analyzed. RESULTS: Noisy GVS had significant effects on gait velocity, stride length and stride time in healthy subjects as well as in patients with bilateral vestibulopathy (p < 0.05). The optimal amplitude of noisy GVS improved gait velocity by 10.9 ±â€¯1.2%, stride length by 5.7 ±â€¯1.2% and stride time by 4.6 ±â€¯7% (p < 0.0001) compared to the control session in healthy subjects. The optimal stimulus improved gait velocity by 12.8 ±â€¯1.3%, stride length by 8.3 ±â€¯1.1% and stride time by 3.7 ±â€¯7% (p < 0.0001) in patients with bilateral vestibulopathy. The improved values of these parameters of locomotion by noisy GVS in the patients were not significantly different from those in healthy subjects in the control condition (p > 0.4). CONCLUSION: Noisy GVS is effective in improving gait performance in healthy subjects as well as in patients with bilateral vestibulopathy.

Clinical features of otolith organ-specific vestibular dysfunction.

OBJECTIVE: To elucidate the clinical features and vestibular symptoms of patients with otolith organ dysfunction in the presence of normal function of the semicircular canals. METHODS: We reviewed the clinical records of 277 consecutive new patients with balance disorders who underwent testing of cervical and ocular vestibular evoked myogenic potentials (cVEMPs and oVEMPs) as well as caloric testing and video head impulse testing (vHIT). RESULTS: We identified 76 patients who showed normal caloric responses and normal vHIT findings in each SCC plane, but abnormal responses in cVEMP and/or oVEMP testing. Benign paroxysmal positional vertigo (BPPV) was the most common diagnosis. 37% of patients could not be categorized into any of the established clinical entities that could cause a balance disorder and did not show sensorineural hearing loss. The most common clinical manifestation in the idiopathic cases was recurrent rotatory vertigo with a duration of 1-12 h. CONCLUSIONS: The most common diagnosis of otolith organ-specific vestibular dysfunction was BPPV. The most common clinical manifestation in the idiopathic cases was recurrent rotatory vertigo. SIGNIFICANCE: Specific dysfunction of the otolith organs occurs in association with some of the undiagnosed patients with recurrent rotatory vertigo.

Effects of Peripheral Vestibular Dysfunction on Dynamic Postural Stability Measured by the Functional Reach Test and Timed Up and Go Test.

OBJECTIVE: To investigate the influence of vestibular function on dynamic postural stability assessed by the functional reach test (FRT) and the timed up and go test (TUG). STUDY DESIGN: Retrospective study. SETTING: Tertiary referral center. SUBJECTS AND METHODS: The FRT and TUG were performed in 399 patients with dizziness. The effects of peripheral vestibular dysfunction assessed by the caloric test and cervical vestibular evoked myogenic potentials (cVEMPs) to air-conducted sound (500 Hz, tone burst) on the results of FRT and TUG were analyzed. RESULTS: Neither FRT nor TUG scores showed significant differences in relation to the results of the caloric test ( P > .3). The FRT scores in patients who showed abnormal cVEMP responses on both sides were significantly smaller than those in patients who showed normal cVEMP responses ( P < .01). The TUG scores in patients who showed abnormal cVEMP responses on both sides were significantly greater than those in patients who showed normal cVEMP responses ( P < .05). CONCLUSION: The vestibulo-spinal reflex mediated by the saccule and its afferents is one of the factors that influence the maintenance of dynamic postural stability as measured by FRT and TUG.

Tumor-induced Osteomalacia Caused by a Parotid Tumor.

A 77-year-old man was suspected of having tumor-induced osteomalacia (TIO) because of hypophosphatemia (1.9 mg/dL) and elevated serum fibroblast growth factor 23 (FGF23) level (186.9 pg/mL). We detected a tumor in his left parotid gland, and the FGF23 level in the left external jugular vein indicated that the tumor overproduced FGF23. After the removal of the tumor, the serum FGF23 level rapidly decreased, and the serum phosphate normalized. This is the first case of TIO caused by a tumor in a parotid gland. This case indicates that the responsible tumors for TIO can be quite diverse.

Noisy galvanic vestibular stimulation induces a sustained improvement in body balance in elderly adults.

Vestibular dysfunction causes postural instability, which is prevalent in the elderly. We previously showed that an imperceptible level of noisy galvanic vestibular stimulation (nGVS) can improve postural stability in patients with bilateral vestibulopathy during the stimulus, presumably by enhancing vestibular information processing. In this study, we investigated the after-effects of an imperceptible long-duration nGVS on body balance in elderly adults. Thirty elderly participants underwent two nGVS sessions in a randomised order. In Session 1, participants received nGVS for 30 min twice with a 4-h interval. In Session 2, participants received nGVS for 3 h. Two-legged stance tasks were performed with eyes closed while participants stood on a foam rubber surface, with and without nGVS, and parameters related to postural stability were measured using posturography. In both sessions, the postural stability was markedly improved for more than 2 h after the cessation of the stimulus and tended to decrease thereafter. The second stimulation in Session 1 caused a moderate additional improvement in body balance and promoted the sustainability of the improvement. These results suggest that nGVS can lead to a postural stability improvement in elderly adults that lasts for several hours after the cessation of the stimulus, probably via vestibular neuroplasticity.

Vestibular Evoked Myogenic Potentials in Vestibular Migraine: Do They Help Differentiating From Menière's Disease?

OBJECTIVE: To investigate whether both cervical and ocular vestibular myogenic potentials (cVEMPs and oVEMPs) to air-conducted sound (ACS) and bone-conducted vibration (BCV) can help to differentiate vestibular migraine (VM) and Menière's disease (MD). STUDY DESIGN: Retrospective study. SETTINGS: A tertiary referral center. SUBJECTS AND METHODS: Twenty-eight patients with VM, 28 patients with definite unilateral MD, and 28 age-matched controls were included. Cervical VEMPs to 500 Hz ACS (cVEMPs-air) and 500 Hz BCV (cVEMPs-bone), oVEMPs to 500 Hz ACS (oVEMPs-air) and 500 Hz BCV (oVEMPs-bone), and caloric tests were performed. Results of these vestibular function tests were compared between the groups. RESULTS: The prevalence of abnormality was significantly higher in VM than in controls only for the caloric test (P < .05). Asymmetry ratios (ARs) for cVEMPs-air and oVEMPs-air were significantly larger in VM than in controls (P < .05). Between VM and MD, the prevalence of abnormality was significantly different only for oVEMPs-air. The ARs for oVEMPs-air and caloric test asymmetries were significantly smaller in VM than in MD (P < .05). CONCLUSIONS: Among the vestibular function tests, oVEMPs-air may be most helpful for the differentiation of VM from MD as a group.

Dehydration effects of a V2 antagonist on endolymphatic hydrops in guinea pigs.

We investigated the influence of vasopressin type 2 receptor antagonist (OPC-41061; Tolvaptan) on experimentally induced endolymphatic hydrops (EH) in guinea pigs. In the first series, the endolymphatic sac (ES) of the left ear of all animals was electrocauterized. Four weeks after surgery, the animals were allocated to four groups: three systemic applications groups (saline, OPC 10 and 100 mg/kg) and a local round window (RW) OPC 1 mg/body application group. We examined the histopathology of the temporal bones and assessed volumetric changes of the endolymphatic space in the cochlea and saccule. In the second series, we investigated the effects of systemic and topical applications of OPC on plasma vasopressin (p-VP) concentrations and plasma osmolality (p-OSM). In the first series, we found that EH was reduced in the OPC 10 mg/kg systemic and OPC RW application groups. In contrast, EH increased in the OPC 100 mg/kg systemic application group. In the second series, neither p-VP levels nor p-OSM were significantly different among the non-OPC, OPC 10 mg/kg systemic, and OPC RW application groups. However, in the OPC 100 mg/kg systemic application group, the p-VP level was significantly higher than that in other groups, and p-OSM was higher than that in the non-OPC group. The systemic application of a low dose of OPC and topical application of OPC resulted in reduced EH in the face of minimal systemic effects (p-VP and p-OSM). These findings suggest that OPC-41061 may be one useful treatment option for EH.

Characteristics of vertigo and the affected vestibular nerve systems in idiopathic bilateral vestibulopathy.

CONCLUSION: Vertigo attacks in IBV patients involving both the superior and inferior vestibular nerve systems were significantly more severe than vertigo attacks in patients with selective involvement of the inferior vestibular nerve system alone. OBJECTIVE: To investigate the relationship between the frequency and duration of vertigo and the affected vestibular nerve system in idiopathic bilateral vestibulopathy (IBV). METHODS: This study categorized 44 IBV patients into the following three sub-groups according to the affected vestibular nerve system: superior, inferior, and mixed type. These patients were also categorized into the following three sub-groups according to their clinical time course: progressive type showing no episodes of vertigo, sequential type showing recurrent vertigo attacks and single-attack type showing a single episode of vertigo. RESULTS: Ten, 11 and 23 patients were classified as the superior, the inferior, and the mixed type, respectively. Seventeen, 23, and four patients were classified as the progressive, the sequential, and the single-attack type, respectively. For the patients having one or more vertigo attacks, the duration of the vertigo attack was longer than 24 h in 69% of the mixed type, and the duration of vertigo in the mixed type was significantly longer than that in the inferior type (p < 0.05).

The effect of aging on the center-of-pressure power spectrum in foam posturography.

To assess age-related frequency-domain characteristics of the sway of center of pressure (COP) in foam posturography, two-legged stance tasks were performed by 163 controls in 4 conditions: eyes open with and without foam rubber, and eyes closed with and without foam rubber. The areas under the curve (AUCs) of power spectral density of the COP were calculated across low frequency (≥0.02 Hz and <0.1 Hz, LF-AUC), middle frequency (≥0.1 Hz and <1 Hz, MF-AUC) and high frequency (≥1 Hz and <10 Hz, HF-AUC) ranges. We categorized the controls into 7 age groups and analyzed each AUC in the 4 conditions. MF- and HF-AUCs tended to show a difference between younger and older age-groups in all 4 conditions. Comparing the number of pairs in which a significant difference was shown, the condition with foam rubber, especially with eyes open, tended to highlight age-related changes. In the medial-lateral axis in the eyes open/foam rubber condition, the MF-AUC of the ≥ 75 years group was significantly larger than that of the 65-74 years group, and the MF-AUC of the 65-74 years group was significantly higher than that of the 55-64 years group, although there were no significant differences of MF-AUC among age groups under 54 years. In this condition, although HF-AUC did not change in groups over 35 years old, HF-AUC of each age group over 35 years old was significantly larger than that of the group under 24 years old. This result suggests that, in the medial-lateral axis in the eyes open/foam rubber condition, MF-AUC is specifically affected by age in late-middle-aged (ages 55-64) and older subjects, while HF-AUC is specifically affected by age in early-middle-aged (ages 35-44) subjects.

Clinical characteristics of patients with abnormal ocular/cervical vestibular evoked myogenic potentials in the presence of normal caloric responses.

OBJECTIVE: To investigate the clinical features and vestibular symptoms of patients with abnormal ocular vestibular evoked myogenic potentials (oVEMPs) and/or cervical VEMPs (cVEMPs) in the presence of normal caloric responses. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. METHODS: One thousand five hundred twenty-one consecutive patients with balance problems who underwent the caloric, cVEMP, and oVEMP tests were included, and patients who showed abnormal oVEMPs and/or cVEMPs in the presence of normal caloric responses were selected. Clinical characteristics, diagnoses, and vestibular symptoms of the patients were analyzed. RESULTS: Of the 1521 patients, 227 (15%) were found to have abnormal oVEMPs and/or cVEMP responses with normal caloric responses. Benign paroxysmal positional vertigo (BBPV), Meniere's disease, and vestibular migraine were the common diagnoses of these patients. Eighty-one patients (36%) could not be diagnosed with a recognizable disease. Multiple episodes of spinning vertigo with a duration of seconds to hours were their most common vestibular symptoms. CONCLUSION: BPPV, Meniere's disease, and vestibular migraine are the most frequent diagnoses showing abnormal oVEMP and/or cVEMPs without canal paresis. Apart from these clinical entities, a portion of undiagnosed patients with multiple episodes of vertigo might have a disease that involves the otolith organs only.

Idiopathic latent vestibulopathy: a clinical entity as a cause of chronic postural instability.

The objective of this study is to describe a new clinical entity of idiopathic latent vestibulopathy (ILV), in which patients have unilateral or bilateral vestibulopathy combined with unsteadiness but without episodic vertigo, auditory disturbance, or a medical history suggesting the presence of vestibulopathy. A retrospective study of 1,233 consecutive new outpatients was conducted. Two-legged stance tasks were performed by 11 patients identified as having ILV in four conditions: eyes open with and without foam rubber, and eyes closed with and without foam rubber. We examined six parameters: the velocity of movement of the center of pressure (COP) with eyes closed/foam rubber, the envelopment area traced by the movement of the COP with eyes closed/foam rubber, Romberg's ratio of velocity and area with foam rubber, and the foam ratios of velocity and area with eyes closed. Multiple regression analyses were performed in order to explore the relationship between the presence of ILV and the six parameters recorded during foam posturography, while adjusting for the subjects' gender and age. The presence of ILV had a significantly positive relationship with the values of 4 of the 6 parameters. Even though six patients showed only unilateral vestibulopathy, their median value in all 6 parameters was greater than that of healthy controls. ILV could be a clinical entity accountable for postural instability.

Involvement of vestibular organs in idiopathic sudden hearing loss with vertigo: an analysis using oVEMP and cVEMP testing.

OBJECTIVE: To investigate the extent of vestibular lesions in idiopathic sudden hearing loss (ISHL) with vertigo. METHOD: We reviewed the clinical records of 25 consecutive new patients with ISHL with vertigo. We classified patients based on their pattern of vestibular dysfunction. All patients showed cochlear damage and were labeled C (cochlear) type. If a patient showed abnormal cervical vestibular evoked myogenic potential (cVEMP), ocular VEMP (oVEMP) or caloric responses, an S (saccule), U (utricule) or L (lateral semicircular canal) respectively was added to their label. RESULTS: All patients underwent cVEMPs and caloric tests. Sixteen (64%) and 13 (52%) showed abnormal cVEMPs and caloric responses, respectively, on the affected side. Among the 23 patients who underwent oVEMPs, 10 (43%) showed abnormal oVEMPs on the affected side. Of these 23 patients, 6 (26%) were classified as C type, 4 (17%) as CS type, 1 (4%) as CL type, 1 (4%) as CSU type, 2 (9%) as CSL type, 1 (4%) as CUL type, 8 (35%) as CSUL type. CONCLUSION: The vestibular end organs close to the cochlea tended to be preferentially affected. SIGNIFICANCE: It is likely that vestibular dysfunction extends from organs close to the cochlea to those further from the cochlea.

Power spectral analysis of postural sway during foam posturography in patients with peripheral vestibular dysfunction.

OBJECTIVE: To assess the frequency-domain characteristics of postural instability caused by peripheral vestibular dysfunction by performing a power spectral analysis of the center of pressure (COP) sway during foam posturography. METHODS: Data were obtained from 78 patients and 163 controls. Two-legged stance tasks were performed in 4 conditions: eyes open with and without foam rubber, and eyes closed with and without foam rubber. We estimated the power spectrum of the acceleration signal using the maximum entropy method. The areas under the curve (AUCs) of power spectral density of the COP were calculated across low-frequency (0.02 to 0.1 Hz, LF-AUC), middle-frequency (0.1 to 1Hz, MF-AUC), and high-frequency (1 to 10 Hz, HF-AUC) ranges. We performed binomial logistic regression analyses to see whether the AUCs of selected bandwidths of COP have a stronger association with the presence of peripheral vestibular dysfunction in comparison with the velocity and area in the eyes closed/foam rubber condition. RESULTS: In both the controls and patients, the MF-AUC was significantly larger than the LF-AUC or HF-AUC in the eyes closed/foam rubber condition. In this condition, the presence of peripheral vestibular dysfunction had a significantly positive relationship with MF-AUC and HF-AUC (p < 0.05) and the MF-AUC of the anterior-posterior axis showed a stronger association with the presence of peripheral vestibular dysfunction than area. CONCLUSION: An increase in activity at middle frequency movements could be characteristic of peripheral vestibular dysfunction when standing on foam rubber with the eyes closed.

Type 1 allergy-induced endolymphatic hydrops and the suppressive effect of H1-receptor antagonist (olopatadine hydrochloride).

OBJECTIVE: To investigate whether endolymphatic hydrops (EH) is experimentally induced by type 1 (or immediate) hypersensitivity allergic reaction and to investigate the inhibitory action of a histamine H(1)-receptor antagonist (olopatadine hydrochloride [OLO-Hy]) on allergic EH induced by systemic immune challenge with 2,4-dinitrophenylated-Ascaris (DNP-As). METHODS: The experimental animals were actively sensitized with DNP-As twice at a 4-week interval and were provoked by an injection of DNP-BSA including DNP-As 1 week after the second sensitization. The OLO-Hy (+) group received oral administration of OLO-Hy (30 mg/kg) 1 hour before the provocation, whereas the OLO-Hy (-) group received distilled water. The temporal bones in all animals were light microscopically examined to assess the degree of EH quantitatively and the expression of degranulated mast cells in the endolymphatic sac. RESULTS: Endolymphatic hydrops was observed 1, 6, 12, and 24 hours after the last sensitization in the OLO-Hy (-) group but was not observed in the OLO-Hy (+) group. Quantitative analysis of the increase ratios (IRs) of the cross-sectional area of the scala media revealed that the IRs of the OLO-Hy (-) group were significantly greater compared with those of the control group (p < 0.001). There was also a significant difference in the IRs between the OLO-Hy (-) and OLO-Hy (+) groups (p < 0.001). CONCLUSION: The systemic sensitization with DNP-As produced allergy-induced experimental EH by type 1 hypersensitivity allergic reaction, and the development of this EH was prevented by histamine H(1)-receptor antagonists.

Postural stability in vestibular neuritis: age, disease duration, and residual vestibular function.

OBJECTIVES/HYPOTHESIS: To assess the influence of factors that can affect postural instability in vestibular neuritis (VN). STUDY DESIGN: Retrospective data collection study. METHODS: Foam posturography was performed in 58 VN patients. We examined six variables: the velocity of movement of the center of pressure and the envelopment area in eyes closed/foam rubber condition, Romberg's ratios of velocity and area with foam rubber, and the foam ratios of velocity and area with eyes closed. Multiple regression analyses were performed to explore the relationship between these variables and the following independent variables: gender, age, canal paresis (CP) percentage, and disease duration. RESULTS: All six variables were positively associated with age, CP percentage, and a disease duration of 10 days or less (P < .05) except for Romberg's ratio of velocity with foam rubber, which was positively associated with CP percentage and a disease duration of 10 days or less (P < .05), but not with age (P > .05). CONCLUSIONS: VN patients show poor postural performance, which is affected by age, residual vestibular function, and disease duration. Once a VN patient passes the acute phase of the vertigo attack, it is likely that age and residual vestibular function make a greater contribution to postural control. LEVEL OF EVIDENCE: 3b.

The diagnostic value of vestibular evoked myogenic potentials in patients with Meniere's disease.

OBJECTIVE: To estimate the sensitivity and specificity of vestibular evoked myogenic potentials (VEMPs) in comparison with caloric test in diagnosing Meniere's disease (MD) among patients with dizziness. METHODS: Data were retrospectively collected from 1,170 consecutive patients who underwent vestibular tests. Among them, 114 patients were diagnosed as having unilateral definite MD. VEMPs in response to clicks and short tone burst stimulation as well as caloric tests were performed. The sensitivity and specificity of each test were evaluated. The results of each test were compared with hearing level and staging of MD. RESULTS: The sensitivity and specificity of VEMPs were 50.0% and 48.9%, while those of the caloric test were 37.7% and 51.2%, respectively. There was no significant difference in hearing level between patients appropriately or inappropriately identified by VEMPs, whereas there was a significant difference in those of the caloric test. Combined use of VEMP and caloric test increased the sensitivity to 65.8%. CONCLUSION: Although the sensitivity and specificity of VEMPs in diagnosing MD were not high, they were comparable to those of caloric test. VEMPs as well as caloric testing may give additional information as part of a diagnostic test battery for detecting vestibular abnormalities in MD.