Assessing the Vestibulo-ocular Reflex of Contralesional Sides According to Head Impulse Velocity Utilizing the Video Head Impulse Test in Patients with Vestibular Neuritis.

There is a lack of comparative studies examining changes in vestibulo-ocular reflex (VOR) gain with head velocity in the video head impulse test (vHIT) of patients with vestibular neuritis (VN). Thus, the purpose of present study was to identify the effect of head impulse velocity on the gain of the VOR during the vHIT in patients with VN. Head impulse velocities ranging from 100%-200°/s [158.08 ± 23.00°/s in the horizontal canal (HC), 124.88 ± 14.80°/s in the anterior canal (AC), and 122.92 ± 14.26°/s in the posterior canal (PC) were used during vHIT trials of 32 patients with VN. Differences in VOR gain on the ipsilesional and contralesional sides according to head velocity were analyzed. The mean VOR gains in ipsilesional side were decreased to 0.47 in the HC and 0.56 in the AC, leading to marked asymmetry compared to the contralesional side; PC gain was relatively preserved at 0.82 in the ipsilesional side. The mean head impulse velocity applied during vHIT trials in each semicircular canal plane did not differ bilaterally. On the contralesional side, VOR gain was negatively correlated with head impulse velocity (R2=0.25, P=.004 in HC; R2=0.17, P=.021 in AC; R2=0.24, P=.005 in PC), while VOR gain on the ipsilesional sides of the HC and AC was not. Head impulse velocity may have a differential impact on VOR gain, depending on the degree of deficit. Increasing head velocity in vHIT may be considered to identify subtle deficits on the contralesional side of patients with VN.

Evaluation of Semicircular Canal Function in Relapsing Polychondritis Patients With Dizziness and Sensorineural Hearing Loss Using Video Head Impulse Test.

OBJECTIVE: To evaluate semicircular canal function using video head impulse test (vHIT) in relapsing polychondritis (RP) patients presenting with dizziness and sensorineural hearing loss. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Three patients with RP underwent vHIT and hearing tests. INTERVENTION: Diagnostic. MAIN OUTCOME MEASURES: The gain in vestibulo-ocular reflex (VOR) and the presence of catch-up saccade were examined, and the correlation between semicircular canal dysfunction and hearing loss was investigated. RESULTS: Of the six ears, five exhibited semicircular canal dysfunction. Among these, one ear showed dysfunction in two semicircular canals, while the remaining four ears demonstrated dysfunction in all three semicircular canals. Sensorineural hearing loss, ranging from moderate to profound, was detected by pure-tone audiometry in all six ears. Furthermore, a significant correlation was observed between VOR gain in the horizontal semicircular canal (HSC) and hearing level. CONCLUSIONS: This study demonstrated semicircular canal dysfunction in RP patients presenting with dizziness and hearing loss using vHIT. Moreover, a significant correlation was found between HSC dysfunction and the severity of hearing loss. While inner ear involvement is a key clinical symptom included in the diagnostic criteria for RP, there have been few reports evaluating vestibular dysfunction, and this is the first report on the evaluation of several cases using vHIT. Accurate assessment of vestibular function by vHIT may facilitate early diagnosis and intervention in RP, potentially improving patient outcomes.

Can Video Head Impulse Testing Be Used to Estimate the Involved Canal in Benign Paroxysmal Positional Vertigo?

BACKGROUND:  There may be confusion about which canal is involved in patients with benign paroxysmal positional vertigo (BPPV), especially with those that have subtle findings. The study aimed to determine if video head impulse testing may be used in such patients as a diagnostic tool. Symptom scoring and treatment efficiency in BPPV are essential parts of the process. Therefore, inventories like "Dizziness Handicap Inventory" may be useful in this regard. METHODS:  Patients with posterior and lateral canal BPPV were included. Video head impulse testing was performed prior to treatment and 1 week after treatment. Vestibuloocular reflex (VOR) gains were noted and compared to the opposite side. The presence of correction saccades was noted as well. Also, pretreatment and posttreatment Dizziness Handicap Inventory scores were compared. RESULTS:  Fifty-seven patients were diagnosed with posterior canal BPPV, and sixteen were with horizontal canal BPPV. In patients with posterior canal BPPV, there was no difference between the involved canal VOR gains and the other canals on the same side (P=.639). The involved horizontal canal did not differ from the opposite horizontal canal. Patients with lateral canal BPPV show more significant improvement after treatment compared to patients with posterior canal BPPV. CONCLUSION:  Video head impulse testing may not be used to estimate the involved canal in BPPV; however, it may be used to evaluate the efficiency of the treatment, especially in the lateral canal.

Extreme Frequency of Benign Paroxysmal Positional Vertigo Recurrences Unexplained by Any Known Risk Factors: A Case Report.

Benign paroxysmal positional vertigo (BPPV) is a common vestibulopathy and involves failed dissolution and dislocation of calcium carbonate crystals into the semicircular canal. This causes short-lasting vertigo during changes in head position. Oftentimes, BPPV can be resolved within a single clinic visit, but secondary to many known risk factors, BPPV can recur. This case report follows a patient with extremely frequent recurrences despite a lack of known risk factors. A 55-year-old female experienced BPPV in December 2022, with successful canalith repositioning treatment from otolaryngology. On having a recurrence in March 2023, the patient underwent videonystagmography including caloric testing, and MRI, all of which showed normal findings besides left posterior-canal BPPV. From December 2022 to February 2024, the patient had 13 recurrences, each treated to resolution, confirmed by repeating positional tests and per subjective report for at least 2 weeks following. The incidence of BPPV recurrence is reported higher in females, however, this could not be interpreted as a causative factor. Though many other risk factors are documented in literature, this patient's history, demographics, imaging, and blood tests were all negative. This case report highlights a gap in knowledge of vestibular pathophysiology, as this patient's high rate of recurrence remains unexplained.

[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.

A Quantitative Study of the Head Pitching Test for Lateral Canal BPPV.

OBJECTIVES: Lateral semicircular canal BPPV (LSC-BPPV) is diagnosed with the Head Yaw Test (HYT) by observing nystagmus direction and comparing the nystagmus intensity on both sides according to Ewald's laws. Head Pitching Test (HPT) is a diagnostic maneuver performed in the upright position by bending the patient's head forward (bowing) and backward (leaning) and observing the evoked nystagmus. We aimed to assess the sensitivity of HPT in correctly diagnosing LSC-BPPV through the quantitative measurement of Bowing and Leaning nystagmus slow-phase velocity (SPV). METHODS: One hundred cases of LSC-BPPV were prospectively enrolled. HPT was performed, looking for pseudospontaneous, bowing, and leaning nystagmus. HYT was considered for the "final diagnosis." HPT was defined as "diagnostic" if the nystagmus was present in at least one position, "undiagnostic" if no nystagmus was detectable. The direction and the SPV of nystagmus in all positions were analyzed and compared to determine the degree of agreement between HPT and HYT. OUTCOMES: Sixty-four geotropic and 36 apogeotropic forms were diagnosed. HPT was diagnostic in 80 cases, with no difference between the two forms. According to Ewald's laws, the direction of stronger nystagmus evoked by HPT agreed with the HYT results in 39/52 (75%) cases in geotropic forms and 21/28 (75%) cases in apogeotropic forms. The agreement between HPT and HYT was "substantial" considering all the cases and "almost complete" considering only the patients with diagnostic HPT. CONCLUSION: Quantitative HPT is a valid test in diagnosing the affected side and form of LSC-BPPV, even if less reliable than HYT.

Association of audiovestibular findings with fluid-attenuated inversion recovery magnetic resonance imaging in patients with vestibular schwannoma.

BACKGROUND: Vestibular schwannoma (VS) is a benign tumor of the vestibular nerve. Flair-attenuated inversion recovery (FLAIR) of magnetic resonance imaging (MRI) images are sensitive in detecting high protein contents of fluids. OBJECTIVES: To investigate the association between signal intensity (SI) on FLAIR images and audiovestibular findings in patients with VS. METHODS: Medical records of twenty-five patients with VS were retrospectively analyzed. RESULTS: Larger tumors were associated with increased FLAIR SI of the cochlea, vestibule, and semicircular canal (SCC) on the affected side compared to those of the unaffected side. Pure-tone audiometry (PTA), and speech audiometry were associated with the SI of the affected cochlea. There was no significant correlation between the SI of the vestibule and vestibular evoked myogenic potential, SI of the SCC, and caloric test or video head impulse test results. CONCLUSION: Our study suggests that tumor size was significantly associated with high SI on FLAIR imaging, and audiological findings were associated with the SI of the affected cochlea. Further studies with larger cohorts are required to confirm the association between vestibular function and FLAIR imaging in VS.

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.

Toward Automating Diagnosis of Middle- and Inner-ear Mechanical Pathologies With a Wideband Absorbance Regression Model.

OBJECTIVES: During an initial diagnostic assessment of an ear with normal otoscopic exam, it can be difficult to determine the specific pathology if there is a mechanical lesion. The audiogram can inform of a conductive hearing loss but not the underlying cause. For example, audiograms can be similar between the inner-ear condition superior canal dehiscence (SCD) and the middle-ear lesion stapes fixation (SF), despite differences in pathologies and sites of lesion. To gain mechanical information, wideband tympanometry (WBT) can be easily performed noninvasively. Absorbance , the most common WBT metric, is related to the absorbed sound energy and can provide information about specific mechanical pathologies. However, absorbance measurements are challenging to analyze and interpret. This study develops a prototype classification method to automate diagnostic estimates. Three predictive models are considered: one to identify ears with SCD versus SF, another to identify SCD versus normal, and finally, a three-way classification model to differentiate among SCD, SF, and normal ears. DESIGN: Absorbance was measured in ears with SCD and SF as well as normal ears at both tympanometric peak pressure (TPP) and 0 daPa. Characteristic impedance was estimated by two methods: the conventional method (based on a constant ear-canal area) and the surge method, which estimates ear-canal area acoustically.Classification models using multivariate logistic regression predicted the probability of each condition. To quantify expected performance, the condition with the highest probability was selected as the likely diagnosis. Model features included: absorbance-only, air-bone gap (ABG)-only, and absorbance+ABG. Absorbance was transformed into principal components of absorbance to reduce the dimensionality of the data and avoid collinearity. To minimize overfitting, regularization, controlled by a parameter lambda, was introduced into the regression. Average ABG across multiple frequencies was a single feature.Model performance was optimized by adjusting the number of principal components, the magnitude of lambda, and the frequencies included in the ABG average. Finally, model performances using absorbance at TPP versus 0 daPa, and using the surge method versus constant ear-canal area were compared. To estimate model performance on a population unknown by the model, the regression model was repeatedly trained on 70% of the data and validated on the remaining 30%. Cross-validation with randomized training/validation splits was repeated 1000 times. RESULTS: The model differentiating between SCD and SF based on absorbance-only feature resulted in sensitivities of 77% for SCD and 82% for SF. Combining absorbance+ABG improved sensitivities to 96% and 97%. Differentiating between SCD and normal using absorbance-only provided SCD sensitivity of 40%, which improved to 89% by absorbance+ABG. A three-way model using absorbance-only correctly classified 31% of SCD, 20% of SF and 81% of normal ears. Absorbance+ABG improved sensitivities to 82% for SCD, 97% for SF and 98% for normal. In general, classification performance was better using absorbance at TPP than at 0 daPa. CONCLUSION: The combination of wideband absorbance and ABG as features for a multivariate logistic regression model can provide good diagnostic estimates for mechanical ear pathologies at initial assessment. Such diagnostic automation can enable faster workup and increase efficiency of resources.

Video head impulse test in subacute and chronic stroke survivors: new perspectives for implementation of assessment in rehabilitation.

INTRODUCTION: The Video Head Impulse Test (vHIT) is a safe and reliable assessment of peripheral vestibular function. Many studies tested its accuracy in clinical settings for differential diagnosis and quantification of the vestibulo-oculomotor reflex (VOR) in various disorders. However, the results of its application after lesions of the CNS are discordant and have never been studied in rehabilitation. This study aims to assess the VOR performance in a sample of stroke survivors. METHODS: This is a cross-sectional study on 36 subacute and chronic stroke survivors; only persons with first-ever stroke and able to walk independently, even with supervision, were included. We performed VOR assessments for each semicircular canal by vHIT and balance assessments by the Berg Balance Scale and the MiniBESTest scale. RESULTS: Two hundred and sixteen semicircular canals were assessed using the Head Impulse paradigm (in both the vertical and horizontal planes), while 72 semicircular canals were assessed using the Suppressed Head Impulse paradigm (horizontal plane). There was a high prevalence of participants with dysfunctional canals, particularly for the left anterior and right posterior canals, which were each prevalent in more than one-third of our sample. Furthermore, 16 persons showed an isolated canal dysfunction. The mean VOR gain for the vertical canals had confidence intervals out of the normal values (0.74-0.91 right anterior; 0.74-0.82 right posterior; 0.73-0.87 left anterior). CONCLUSION: Our findings suggest that peripheral vestibular function may be impaired in people with stroke; a systematic assessment in a rehabilitation setting could allow a more personalized and patient-centred approach.

Gufoni maneuver for treatment of horizontal canal benign paroxysmal positional vertigo: a systematic review of randomized controlled trials.

PURPOSE: This review aims to investigate the effects of the Gufoni maneuver on horizontal semicircular canal benign paroxysmal positional vertigo (HC-BPPV). METHODS: A comprehensive search, including PubMed, PEDro, REHABDATA, SCOPUS, EMBASE, and Web of Science, was conducted to determine randomized clinical trials (RCTs) studying the effects of the Gufoni maneuver for HC-BPPV from inception to March 1, 2024. The quality of the included studies was estimated using the Physiotherapy Evidence Database (PEDro) scale. RESULTS: Ten randomized controlled trials (RCTs) were included in this review with a total of 1025 HC-BPPV patients (mean age = 58.58 years; 63% female; 55% right-side HC-HBPPV; 49% geotropic HC-BPPV). The included RCTs ranged from 4 to 9 out of 10 (median = 6.5) on the PEDro scale. The included studies showed that the Gufoni maneuver revealed efficacy when compared to the sham maneuver but not when compared to other maneuvers such as the Barbecue roll maneuver, the Appiani maneuver, the Mastoid oscillation, the head shaking, and the modified Gufoni maneuver. CONCLUSIONS: The Gufoni maneuver is considered an option for treating patients with geotropic or apogeotropic HC-BPPV. Precise diagnosis of the BPPV, the subtype of HC-BPPV, symptom duration, history of previous BPPV attacks, the applied methods of maneuver and the proficiency of the clinician performing the maneuver, proper diagnosis, presence of any underlying health conditions are critical for successful treatment. Further studies are strongly warranted.

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.

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.

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.

Variants of posterior semicircular canal involvement in benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo is the most common cause of peripheral vertigo. It is characterized by short and recurrent episodes of vertigo, trigged by specific head movements that displace otoconia within the semicircular canals. The movement of dislodge otoconia from the utricle cause abnormal positional endolymphatic currents. Primary treatment involves reposition maneuvers aimed at moving the displaced otoconia out the affected canal, therefore correct identification of the affected canal is essential for the diagnosis. The posterior semicircular canal (PSC) is the most frequently affected due to its spatial orientation and the force of gravity. Recent technological advances have allowed for better assessment of positional nystagmus during diagnostic and therapeutic maneuvers, revealing various possible scenarios of PSC involvement. Regarding the PSC, otoconia may be found in different parts of the canal, and not just in the expected location, floating in the long arm of the canal. The understanding of these variants is crucial, as the prognosis and the disease progression differ in such cases. This review aims to describe the six possible variants of PSC involvement described so far.

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.