[Correlation between parameters of suppression head impulse paradigm and changesin DHI score in acute vestibular neuritis].

Objective:To explore the correlation between the parameters of suppression head impulse paradigm（SHIMP） and changes in dizziness handicap inventory（DHI） scores. Additionally, to evaluate the degree of vertigo and prognosis of patients with acute vestibular neuritis through SHIMP parameters. Methods:Thirty-three patients with acute vestibular neuritis were enrolled for DHI evaluation, vHIT and SHIMP. A secondary DHI score were evaluated after after two weeks, once patients no longer exhibited spontaneous nystagmus. The decrease in the second DHI score was used as the efficacy index（EI）. All patients were divided into significantly effective group, effective group and ineffective group based on EI. Differences of the VOR gain values of SHIMP and the anti-compensatory saccade were compared among the three groups. Results:There were 13 cases in the significant effective group, 11 cases in the effective group, and 9 cases in the ineffective group. ①The mean gain of the horizontal semicircular canal in the significant effective group, the effective group, and the ineffective group was（0.50±0.11）, （0.44±0.12）, and（0.34±0.08）, respectively. The difference between the significant effective group and the ineffective group was statistically significant（P<0.01）. The gain of horizontal semicircular canal was positively correlated with EI（r=0.538 5, P<0.01） 。②The occurrence rate of the anti-compensatory saccade in the significant effective group, the effective group, and the ineffective group was（51.23±19.59）, （33.64±17.68）, and（13.78±11.81）, respectively. Pairwise comparisons between each group showed statistical significance（P<0.05）. The occurrence rate of anti-compensatory saccade was positively correlated with EI（r=0.658 2, P<0.01）. Conclusion:The horizontal semicircular canal gain and the occurrence rate of the anti-compensatory saccade in SHIMP for patients with acute vestibular neuritis were closely correlated with decrease in DHI score.

Vertical saccades during horizontal head impulses: a sign of posterior semicircular canal hypofunction.

Objective: We describe an uncharacteristic vestibular-ocular reflex (VOR) pattern, studied by video head impulse tests (VHIT) in patients suffering from unilateral isolated posterior semicircular canal (PSC) hypofunction. In these patients, we found an upward sliding of the eyes, followed by an oblique downward catch-up saccade during horizontal head impulse to the healthy side. Methods: We present a retrospective study of all VHIT exams presenting isolated PSC hypofunction between May 2020 and November 2022. Results: We found 37 patients, which led to the discovery of such incongruent eye movement in 19 cases; their gain data are shown and compared to the remaining 18 cases in which such an anomaly was absent. A control group of 31 healthy subjects was recruited to define the reference criteria for VHIT gain values. The correlation between the amplitude of the vertical saccade and the relative functional imbalance of the vertical semicircular canals was studied. Conclusions: We have observed that in approximately half of the subjects with isolated CSP deficiency, there is a VOR anomaly. A possible pathophysiological explanation of the unbalanced effect of vertical semicircular canal stimulation of a labyrinth during horizontal head thrust toward the opposite side is proposed. The planar incongruity of the response of the VOR described here appears more evident at the onset of the CSP deficit. Current VHIT systems do not detect this incongruent eye reflex. They can lead to an error in gain evaluation (pseudo-deficit) of the lateral semicircular canal of the healthy side and problems in performing the test (trace rejected). In the future, software for VHIT should take into account the possibility of non-coplanar ocular responses to cephalic stimuli.

Individualized repositioning with a mechanical rotational chair facilitates successful treatment of patients with very retractable benign paroxysmal positional vertigo.

BACKGROUND: About 12.5 % of patients diagnosed with benign paroxysmal positional vertigo (BPPV), experience persistent BPPV where it is unknown why some BPPV cases are very refractory (vrBPPV) to treatment. OBJECTIVES: The primary objective was to investigate if patients with vrBPPV could be successfully treated with a mechanical rotation chair (MRC) adjusted to the exact vertical semicircular canal (SCC) angles of the individual patient. Secondary endpoint was to determine if inner ear anomalies were predominant in these patients. METHODS: This prospective clinical trial included 20 patients (main group) who underwent computed tomography (CT) with measurements of the bony island and the width between the SCC walls of the posterior leg of the lateral SCCs. The inter-SCC angles, the angles between the sagittal plane and the vertical SCCs were compared to the presumed mean standard angles of the SCCs. Of these, 14 patients (subgroup) underwent individualized treatment with the Rotundum® repositioning chair according to their measured SCC angles. RESULTS: All measured SCC angles differed significantly (p < 0.05) from the presumed mean standard SCC angles, except the angle between the sagittal plane and the left posterior SCC (p-SCC). Three out of 14 patients experienced subjective and objective remission after treatment with this MRC. Six out of 14 patients experienced either subjective remission or objective remission. CONCLUSIONS: Patients with vrBPPV have vertical SCC angles that differ significantly from the presumed mean standard SCC angles. Individualized treatment with this MRC successfully treated 21.4 % of the patients with vrBPPV and provided subjective relief for 42.9 %.

A new roll test to diagnose posterior semicircular canal benign paroxysmal positional vertigo.

BACKGROUND: The Dix-Hallpike (DH) test is a gold standard for diagnosing benign paroxysmal positional vertigo (BPPV). However, lateral semicircular canal BPPV is not rare. We have been performing the new roll test that begins from the sitting position and contains a head-hanging position, in order not to overlook lateral canal BPPV. We noticed that transient vertical/torsional nystagmus sometimes occurs during the new roll test. OBJECTIVE: To clarify the value of the new roll test in diagnosing posterior canal BPPV and elucidate the position that elicits nystagmus. MATERIALS AND METHODS: The subjects were 100 consecutive patients (79 were female, 21 were male) with posterior canal BPPV. We classified the patients into four types based on a position that induced nystagmus. RESULTS: The patient's position that elicited nystagmus varied. The supine type accounted for 24 %, the lateral type accounted for 62 %, the head-hanging type accounted for 9 %, and the DH type accounted for 5 %. CONCLUSION: The new roll test is valuable for diagnosing posterior canalolithiasis cases. Most patients reveal vertical/torsional nystagmus in the supine or lateral position. Therefore, performing the new roll test first is efficient at the initial visit.

[Discussion and analysis the value of supine median³ nystagmus in the diagnosis and treatment of HC-BPPV].

Objective:To explore the clinical value of supine median³ nystagmus in the accurate diagnosis of horizontal semicircular canal benign paroxysmal positional vertigo（HC-BPPV）. Methods:A total of 187 patients with HC-BPPV admitted to the First Affiliated Hospital of Xi'an Jiaotong University from June 2020 to March 2021 were selected. Among them 42 cases of Cupulolithiasis and 145 cases of Canalithiasis. The nystagmus parameters of patients left and right supine position and supine median³ position were recorded in detail by RART. According to the direction of supine median³ nystagmus, patients were divided into three groups: group A（nystagmus to weak side）, group B（nystagmus to strong side）, group C（negative nystagmus）. The canalith repositioning manoeuvres（CRM） was carried out by utility of an automatic vestibular function diagnosis and therapy system（SRM-IV）. The cure rate of CRM in three groups of HC-BPPV patients was compared, Multivariate logistic regression analysis was performed to analyze the influencing factors of CRM for HC-BPPV. Results:The cure rates of group A, group B and group C were 81.58%, 16.13% and 56.25%, respectively. The difference among the three groups was statistically significant. Then a pairwise comparison of group A, B and C, the difference was statistically significant（χ²A-B=40.294,P<0.001,χ²B-C=14.528, P<0.001,χ²A-C=11.606, P=0.001）; the results of multivariate logistic regression analysis showed that the direction of supine median³ nystagmus and BMI were the influencing factors of CRM for HC-BPPV. Conclusion:The direction, intensity and duration of supine median³ nystagmus play an important role in determining the responsibility semicircular canal of HC-BPPV.

Evaluation of the reliability and validity of the upright head roll test for lateral semicircular canal benign paroxysmal positional vertigo.

BACKGROUND: The upright head roll test (UHRT) is a recently introduced diagnostic maneuver for lateral semicircular canal benign paroxysmal positional vertigo (LSC-BPPV). OBJECTIVE: This study aimed to evaluate the reliability and validity of the UHRT. METHODS: Two separate studies were conducted. Study 1 analyzed 827 results of videonystagmography (VNG) to assess UHRT reliability, and Study 2 analyzed 130 LSC-BPPV cases to evaluate UHRT validity. RESULTS: The inter-test reliability between UHRT and the supine head roll test (SHRT) showed substantial agreement (Cohen's kappa = 0.753) in direction-changing positional nystagmus (DCPN) and almost perfect agreement (Cohen's kappa = 0.836) in distinguishing the direction of DCPN. The validity assessment of UHRT showed high accuracy in diagnosing LSC-BPPV (80.0%) and in differentiating the variant types (74.6%). UHRT was highly accurate in diagnosing the canalolithiasis type in LSC-BPPV patients (Cohen's kappa = 0.835); however, it showed only moderate accuracy in diagnosing the cupulolithiasis type (Cohen's kappa = 0.415). The intensity of nystagmus in UHRT was relatively weaker than that in SHRT (P < 0.05). CONCLUSION: UHRT is a reliable test for diagnosing LSC-BPPV and distinguishing subtypes. However, UHRT has a limitation in discriminating the affected side owing to a weaker intensity of nystagmus than SHRT.

Pre- and post-operative semicircular canal function evaluated by video head impulse test in patients with vestibular schwannoma.

OBJECTIVES: To evaluate pre- and post-operative semicircular canal function in patients with vestibular schwannoma (VS) by the video Head Impulse Test (vHIT). METHODS: Nineteen patients with VS who underwent surgery were enrolled in this study. The gain in vestibulo-ocular reflex (VOR) and the degree of scatter in catch-up saccades were examined pre- and post-operatively for the semicircular canals in VS patients. RESULTS: Ten of 19 cases (52.6 %) with VS were defined as demonstrating both superior vestibular nerve (SVN) and inferior vestibular nerve (IVN) impairment from the results of pre-operative vHIT. Hearing level and subjective vestibular symptoms showed significant correlations with pre-operative semicircular canal function. Compared to pre-operative vHIT results, VOR gains within 1 month after surgery were significantly reduced in all three canals; however, significant differences had disappeared in the anterior and posterior semicircular canals at 6 months after surgery. Cases of unknown origin had a significantly greater reduction in posterior semicircular canal function after surgery compared with those with disease of IVN origin. CONCLUSIONS: As vHIT could evaluate pre-operative vestibular nerve impairment, post-operative VOR gain reduction and the degree of vestibular compensation, semicircular canal function evaluated by vHIT provides a good deal of useful information regarding VS patients undergoing surgery compared to caloric testing, and vHIT should be performed pre- and post-operatively for patients with VS.

Differences in semicircular canal function in the video head impulse test in patients in the chronic stage of sudden sensorineural hearing loss with vertigo and vestibular neuritis.

BACKGROUND: Sudden sensorineural hearing loss with vertigo (SHLV) and vestibular neuritis (VN) can result in prolonged dizziness. OBJECTIVES: This study aimed to compare the video head impulse test (vHIT) of patients with SHLV and VN. METHODS: Fifteen patients with SHLV and 21 patients with VN who visited the Vertigo/Dizziness Center of our hospital between December 2016 and February 2023 were included. vHIT was performed at the time of admission, and the VOR gain and catch up saccade (CUS) in the three types of semicircular canals (SCCs) were analyzed. RESULTS: Pathologic vHIT results were observed most frequently in the posterior SCC (73%), followed by lateral (53%) and anterior (13%) SCCs in the SHLV group. In contrast, pathologic vHIT results were observed most frequently in the lateral SCC (100%), followed by the anterior (43%) and posterior SCC (24%) SCCs in the VN group. Pathological vHIT results in the lateral and posterior SCC showed significant differences between the two groups, but for anterior SCC, no significant differences were found. CONCLUSIONS AND SIGNIFICANCE: Comparison of the two vHIT results revealed differences in the SCC dysfunction patterns. This may be due to the different pathophysiological mechanisms of the two vestibular disorders, which may result in prolonged vertigo.

Preliminary Evidence for the Effects of Gentamicin on Vertical Semicircular Canals.

INTRODUCTION: Gentamicin is a vestibulotoxic antibiotic often used in patients with Ménière's disease for its vestibular ablative effects. Gentamicin's effect on the horizontal semicircular canal does not always correlate with the degree of vertigo control achieved by patients; its effect on the vertical semicircular canals remains unknown. We sought to examine the effect of intratympanic gentamicin on vertical semicircular canal function in patients with Ménière's disease using video head impulse testing. METHODS: A retrospective case series was carried out at a tertiary academic center. Patients with Ménière's disease who received ≥1 intratympanic gentamicin injection from 2019-2022 and had video head impulse testing performed were included. Outcomes of interest were vertical semicircular canal function following intratympanic gentamicin, correlations between vertical semicircular canal function and horizontal semicircular canal function, and residual symptoms following injection. RESULTS: Ten patients met inclusion criteria. Twenty percent had abnormal V-SCC function prior to any injection and 40% following the first injection. There was an association between abnormal vertical and horizontal semicircular canal function following the first intratympanic gentamicin injection, though the relationship did not reach statistical significance (p = 0.058). While patients with abnormal vertical semicircular canal function following the first injection were less likely to report ongoing vertigo attacks, the relationship was not statistically significant (p = 0.260). CONCLUSIONS: Intratympanic gentamicin leads to changes in vertical semicircular canal function in at least a proportion of patients with Ménière's disease. Further study is required to better assess correlations between vertical semicircular canal function and symptom control following intratympanic gentamicin.

Triple semicircular canal occlusion: a surgical perspective with short- and long-term outcomes.

OBJECTIVE: To determine the short- and long-term outcomes of triple semicircular canal occlusion as a potential alternative for patients with intractable Ménière's disease. METHODS: A retrospective case series was performed in university settings, enrolling patients with intractable Ménière's disease with previous maximum treatment, who underwent transmastoid, triple semicircular canal occlusion. The study documented: pre- and post-operative Dizziness Handicap Inventory scores at six weeks and one year post-treatment, pure tone audiometry, and surgical aspects. RESULTS: Two female patients, aged 42 and 65 years, underwent unilateral three-semicircular-canal occlusion. Their respective Dizziness Handicap Inventory scores improved from 88 to 68 and 54 to 30 at six weeks post-operatively, with scores of 66 and 0 at one year post-treatment. The one patient with pre-existing functional hearing maintained her hearing threshold post-operatively. CONCLUSION: Triple semicircular canal occlusion is a safe, hearing-preserving, extracranial alternative technique that can control rotatory vertigo in patients with intractable Ménière's disease, when other measures have failed.

Evaluation on Effectiveness of a New System as well as Analysis on Optimal Horizontal Eye Position for Vertical Video Head Impulse Test.

OBJECTIVE: To compare the performances among three different systems for video head impulse test (vHIT), and to identify an optimal target angle for precisely evaluating the function of vertical semicircular canals in vHIT. METHODS: A two-center prospective study was done. Participants were sit 1.2 m away from the wall in a noise-proved room that dedicated for vHIT experiments. During the comparison experiments, similar settings were ensured in both hospitals, with the same distance to wall and angle of staring. For each equipment, the procedures followed the developers' recommendations. The same examiner performed the comparison between two systems in one location. For the eye-position projects, targets were placed on the wall sequentially at the pre-marked lines for different angles. For the comparison projects, 9 and 13 participants were recruited, respectively. Any participant with otologic or vestibular disorders was excluded. A total of 26 healthy participants were recruited in the eye-position experiments, 16 of which were further involved in inter-examiner tests. RESULTS: Our evaluations of three different systems showed that a new vHIT system, VertiGoggles® ZT-VNG-I (VG) performed as good as the long-tested Otometrics® ICS impulse (Oto) and EyeSeeCam® (ESC). During the comparison, we validated 25-degree, instead of right ahead at 0 degree, is a better place to set the targets when torsion was applied at vertical semicircular canal planes. CONCLUSION: The new VG system is good for clinical practices. Furthermore, we proposed a new protocol to set the targets 25 degrees from right ahead after tilting head 45 degrees to evaluate vertical canals during vHIT.

Five subtypes of benign paroxysmal positional vertigo.

BACKGROUND: Benign paroxysmal positional vertigo is classified into five subtypes according to the features of positional nystagmus: lateral canalolithiasis, lateral light cupula, lateral heavy cupula, posterior canalolithiasis and posterior heavy cupula. OBJECTIVES: The first aim of the study was to clarify whether the lateral canal type or posterior canal type was more common. The second aim of the study was to assess the aetiology of benign paroxysmal positional vertigo by investigating the onset time of each subtype. METHODS: The subjects were 512 consecutive patients with benign paroxysmal positional vertigo. The patients were prospectively aggregated, and interviews were used to evaluate onset time. RESULTS: The lateral canal type (55.5 per cent) was more common than the posterior canal type (44.5 per cent). Time of awakening was the most common onset time in every subtype. CONCLUSION: The incidence of lateral canal type is higher than that of posterior canal type. The aetiology of benign paroxysmal positional vertigo is closely related to sleep.

[Vertigo and dizziness].

Pathophysiology of vertigo/dizziness can be understood by eye deviation (nystagmus). In benign paroxysmal positional vertigo, eye deviation of causative semicircular canal stimulation is directly observed. In other peripheral vestibular disorders, eye deviation results from the sum of unilateral all semicircular canal disorders. The central vestibular pathway is controlled by the cerebellum. Thus, in vertigo/dizziness of central origin, not only eye deviation due to impairment of the central vestibular pathway but also deviation due to disinhibition of the pathway from the cerebellum is observed. The cerebellar control on the central vestibular pathway also plays an important role in vestibular compensation. When treating vertigo/dizziness, it is necessary to understand the pathophysiology of the vertigo/dizziness, to set the treatment target based on the pathophysiology, and to intervene for the target.

Do otosclerosis and stapedotomy affect semicircular canal functions? Preliminary results of video head impulse test.

BACKGROUND: Otosclerosis and stapedotomy have some effects on the vestibular system, but there are very limited data on their effects on semicircular canals (SCCs). OBJECTIVE: The aim of the study is to investigate if otosclerosis and stapedotomy have an effect on SCCs and video head impulse test (vHIT). MATERIAL AND METHODS: This retrospective study included 11 otosclerosis patients who had undergone stapedotomy and 30 healthy participants. Twenty-two ears of 11 patients with otosclerosis were divided into two groups based on whether the ear had been operated (12 ears) or not (10 ears). All participants underwent vHIT. We compared gains of all SCCs, presence of saccades among the operated ears, unoperated ears and control ears. RESULTS: Significant difference (p<.05) was noted in comparisons of gain of lateral SCCs among all groups. Control group had the highest gain, followed by unoperated and operated groups, respectively. Comparison of incidence of covert saccade showed significant difference (p<.05) for lateral and posterior SCCs. CONCLUSIONS AND SIGNIFICANCE: Otosclerosis and otosclerosis surgery may have some effects on SCC functions and thereby vHIT. Lateral SCC is the most affected SCC in terms of gain. These findings appear to add important contributions to our knowledge.

Vestibular and cochlear nerve enhancement on MRI and its correlation with vestibulocochlear functional deficits in patients with Ramsay Hunt syndrome.

OBJECTIVE: The correlation between enhancement of the vestibulocochlear nerves on gadolinium-enhanced magnetic resonance imaging (MRI) and vestibulocochlear functional deficits was examined in patients with Ramsay Hunt syndrome (RHS). METHODS: Nineteen patients with RHS who showed herpes zoster oticus, peripheral facial palsy, and vertigo were enrolled. Canal paresis (CP) in the caloric test, abnormal response to ocular and cervical vestibular myogenic potentials (oVEMP and cVEMP), and refractory sensorineural hearing loss were evaluated. MRI images perpendicular to the internal auditory canal were reconstructed to identify the superior (SVN) and inferior vestibular nerves (IVN) and the cochlear nerve (CV). The signal intensity increase (SIinc) of the four-nerve enhancement was calculated as an index. RESULTS: Among RHS patients, 79%, 53%, 17% and 26% showed CP in the caloric test, abnormal responses to oVEMP and cVEMP, and refractory sensorineural hearing loss, respectively. SIinc rates of the SVN were significantly increased in RHS patients with CP in the caloric test, and with abnormal responses to oVEMP and cVEMP. SIinc rates of the SVN tended to increase in RHS patients with refractory sensorineural hearing loss (p = 0.052). SIinc rates of the IVN were significantly increased in RHS patients with abnormal responses to oVEMP and cVEMP, and refractory sensorineural hearing loss, but not in those with CP in the caloric test. SIinc rates of the CN were significantly increased in RHS patients with CP in the caloric test, abnormal response to oVEMP and refractory sensorineural hearing loss, but not in those with abnormal response to cVEMP. CONCLUSION: In patients with RHS, the origin of vertigo may be superior vestibular neuritis, which is affected by reactive varicella-zoster virus from the geniculate ganglion of the facial nerve through the faciovestibular anastomosis. The results also suggested that in some RHS patients, inferior vestibular neuritis contributes to the development of vertigo and that the origin of refractory sensorineural hearing loss is cochlear neuritis.

The characteristics of vHIT gain and PR score in peripheral vestibular disorders.

BACKGROUND: Clinical application of vHIT is limited due to a lack of interpretation of vHIT gain and saccades. OBJECTIVES: This research focuses on comparing common vertigo diseases on vHIT gain and saccade divergence(PR score). MATERIAL AND METHODS: We retrospectively reviewed 165 patients who have one definite diagnosis, good data quality, and can be read by MATLAB software. All patients were grouped into unilateral vestibular dysfunction (UVD), Meniere's disease (MD), vestibular migraine (VM), Ramsay Hunt Syndrome (RHS), bilateral vestibular hypofunction (BVH), benign paroxysmal positional vertigo (BPPV), and acoustic neuroma (AN). PR score was calculated by an open-source software HitCal. RESULTS: The saccade detection rate is higher than the abnormal vHIT gain on UVD, MD, VM, RHS, BVH and BPPV. PR score combined with vHIT gain could separate the affected side in UVD and RHS. In the MD group, both vHIT gain and PR score have inconspicuous performance. We also found that different compensation levels and hearing loss status affect results. CONCLUSIONS AND SIGNIFICANCE: vHIT gain combined with PR score enables a proper distinction among common vertigo diseases. PR score is more sensitive than the gain value on evaluating the physiological situation, vestibular compensation and disease progression.

Assessment of the effects of menopause on semicircular canal using the video head impulse test.

This cross-sectional study included early menopausal and late menopausal women aged between 40 and 60 years to evaluate the effects of menopause on semicircular canal function. A video head impulse test (vHIT) was performed for all subjects. Vestibulo-ocular reflex (VOR) mean gains of each semicircular canal and gain asymmetry were compared between groups. Of the 87 subjects, 37(42.5%) were reproductive age 28(32.5%) were early menopausal and 22(25.3%) were late menopausal patients. VOR gain of semicircular canals or gain asymmetry values did not differ between groups. In postmenopausal women, presence of vasomotor symptoms was associated with higher gain asymmetry of the left anterior-right posterior (LARP) plane (p = .01), and presence of balance problems was associated with lower right anterior (RA) VOR gain (p = .01). In conclusion semicircular canal function in postmenopausal women was similar to that in women of reproductive age.IMPACT STATEMENTWhat is already known on this subject? During menopause, women face potential risks such as dizziness, balance problems, falls and fractures. Postmenopausal patients were tested with dynamic posturography to measure balance before and after oestrogen treatment, and it was shown that balance problems significantly improved with oestrogen treatment. Healthy vestibular system is one of the components for sustaining normal balance.What do the results of this study add? In postmenopausal women the function of the semicircular canals is normal and the balance deficit in postmenopausal women may not be caused by the vestibular system. In this study changes within normal limits were observed in vestibular system of postmenopausal women.What are the implications of these findings for clinical practice and/or further research? Reported balance deficits might have been due to central origin. Further research to differentiate origin of balance deficits are needed. Specific research on symptomatic postmenopausal patients would reveal more information.

Effects of Occlusion and Conductive Hearing Loss on Bone-Conducted cVEMP.

OBJECTIVE: To evaluate the effects of conductive hearing loss and occlusion on bone-conducted cervical vestibular evoked myogenic potentials (cVEMPs). STUDY DESIGN: Prospective cohort study conducted in the year 2018. The right ear of each volunteer was evaluated under 3 conditions by using bone-conducted cVEMPs: normal (open external auditory canal), occluded (conductive hearing loss with occlusion effect), and closed (conductive hearing loss without the occlusion effect). SETTING: Single academic center. SUBJECTS AND METHODS: The study comprised 30 healthy volunteers aged 20 to 35 years (16 women, 14 men). All had normal hearing and no vestibular or auditory pathologies. The thresholds and amplitudes of cVEMP responses were recorded for the 3 conditions. The results of each condition for a particular participant were compared. RESULTS: As compared with the open condition, the conductive condition increased thresholds by 2.8 dB (P = .01), and the occluded condition decreased thresholds by 3.8 dB (P = .008). The amplitude in the occluded condition was larger than the normal condition and the conductive condition (mean difference: 20.64 [P = .009] and 31.76 [P < .001], respectively). CONCLUSION: The occlusion effect is present in cVEMP responses. The mechanism is not due to the conductive hearing loss induced. Clinical implications include potentially altering vestibular function with sealed hearing aids and in the surgically modified ears (ie, obliterated ears and open cavity mastoidectomy).

Pseudo-spontaneous nystagmus in lateral semicircular canal benign paroxysmal positional vertigo: Correlation with bow and lean test in a pitch plane.

OBJECTIVES: We investigated the incidence and characteristics of pseudo-spontaneous nystagmus (PSN) in benign paroxysmal positional vertigo involving the lateral semicircular canal (LC-BPPV) and evaluated the correlation between PSN and the bow and lean test. METHODS: We examined nystagmus in the sitting position using video-oculography goggles in 131 LC-BPPV patients. The positioning test and bow and lean test were also performed. Patients were divided into canalolithiasis and cupulolithiasis groups according to the character of nystagmus. In each group, the incidence and direction of PSN, correlation with the bow and lean test, and treatment outcome were analyzed. RESULTS: PSN was observed in 25 cases (19.1%) in LC-BPPV patients, 7 of which were canalolithiasis and 18 of which were cupulolithiasis (p = 0.098). Of the 25 patients with PSN, 21 (84%) exhibited nystagmus consistent with the lean test whereas 4 (16%) exhibited nystagmus consistent with the bow test. In patients with PSN, nystagmus was observed in the bow and lean test in all cases (23/23), but in patients without PSN, no nystagmus was observed in 13 cases (13/87) in the bow and lean test (p = 0.048). The number of barbecue maneuvers performed until the end of treatment was 1.4 ± 0.7 in patients with PSN and 1.4 ± 0.9 in those without PSN (p = 0.976). CONCLUSION: We identified PSN in patients with LC-BPPV irrelevant of subtype. Moreover, all patients with PSN showed nystagmus in the bow and lean test. The direction of PSN was mostly consistent with that of the lean test (21/25, 84%). The presence of PSN was not related to the treatment outcome in this study.