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.

The clinical course of vestibular neuritis from the point of view of the ocular vestibular evoked myogenic potential.

BACKGROUND: Studying otolith functions after unilateral vestibular neuritis using ocular vestibular-evoked myogenic potentials and subjective visual vertical tests could give different results. METHOD: A total of 39 patients underwent a vestibular assessment that included the Dizziness Handicap Inventory and horizontal and vertical semicircular canal function testing with video head impulse testing, ocular vestibular-evoked myogenic potential testing, cervical vestibular-evoked myogenic potentials and subjective visual vertical testing. RESULTS: All patients showed a significant alteration (asymmetry ratio more than 40 per cent) for ocular vestibular-evoked myogenic potentials as well as for subjective visual vertical testing (more than -2° to more than +2°) during the acute phase, whereas after 72 hours from the acute vertigo attack normal values (asymmetry ratio less than 40 per cent) were found in 6 out of 39 patients for ocular vestibular-evoked myogenic potentials and 36 out of 39 for the subjective visual vertical (less than -2° to less than +2°). CONCLUSION: Ocular vestibular-evoked myogenic potentials are the most suitable test to evaluate otolith functions in patients with unilateral vestibular neuritis in the acute and sub-acute phase.

Change of gait after unilateral vestibular neuritis: a prospective longitudinal observation study.

Although symptoms of unilateral vestibular neuritis (uVN) resolve spontaneously within several weeks, recovery of gait function has unclearness in gait parameter changes and mediolateral stability improvements. In addition, prospective longitudinal studies on gait parameters after uVN are lacking. This study was conducted to reveal longitudinal change of gait function after acute uVN and to help the precise rehabilitation planning. Twenty three participants with uVN and 20 controls were included. 3D gait analyses were conducted three times after uVN onset at monthly intervals. From the gait analysis data, spatio-temporal parameters, inclination angle (IA) representing the relationship between center of mass (CoM) and center of pressure (CoP) in the frontal plane, and IA variability were obtained. Time effects on gait metrics were tested. Walking speed of participants with uVN improved significantly between the 1st and 3rd tests, but they were not significantly different to that of control, even in the 1st test. The step width of participants with uVN was significantly larger than that of control in the 1st test and improved significantly in the 2nd test. Variability of IA in affected side was significantly larger than that in controls in the 1st test and improved significantly in the 3rd test compared to the 1st test. Improvement of overall gait function and mediolateral stability during gait continued after acute stage of uVN (two months from onset in this study). Rehabilitation intervention should be continued after the acute stage of uVN to enhance appropriate adaptation in gait.

Breaking a dogma: acute anti-inflammatory treatment alters both post-lesional functional recovery and endogenous adaptive plasticity mechanisms in a rodent model of acute peripheral vestibulopathy.

BACKGROUND: Due to their anti-inflammatory action, corticosteroids are the reference treatment for brain injuries and many inflammatory diseases. However, the benefits of acute corticotherapy are now being questioned, particularly in the case of acute peripheral vestibulopathies (APV), characterized by a vestibular syndrome composed of sustained spinning vertigo, spontaneous ocular nystagmus and oscillopsia, perceptual-cognitive, posturo-locomotor, and vegetative disorders. We assessed the effectiveness of acute corticotherapy, and the functional role of acute inflammation observed after sudden unilateral vestibular loss. METHODS: We used the rodent model of unilateral vestibular neurectomy, mimicking the syndrome observed in patients with APV. We treated the animals during the acute phase of the vestibular syndrome, either with placebo or methylprednisolone, an anti-inflammatory corticosteroid. At the cellular level, impacts of methylprednisolone on endogenous plasticity mechanisms were assessed through analysis of cell proliferation and survival, glial reactions, neuron's membrane excitability, and stress marker. At the behavioral level, vestibular and posturo-locomotor functions' recovery were assessed with appropriate qualitative and quantitative evaluations. RESULTS: We observed that acute treatment with methylprednisolone significantly decreases glial reactions, cell proliferation and survival. In addition, stress and excitability markers were significantly impacted by the treatment. Besides, vestibular syndrome's intensity was enhanced, and vestibular compensation delayed under acute methylprednisolone treatment. CONCLUSIONS: We show here, for the first time, that acute anti-inflammatory treatment alters the expression of the adaptive plasticity mechanisms in the deafferented vestibular nuclei and generates enhanced and prolonged vestibular and postural deficits. These results strongly suggest a beneficial role for acute endogenous neuroinflammation in vestibular compensation. They open the way to a change in dogma for the treatment and therapeutic management of vestibular patients.

Stroke Prediction Based on the Spontaneous Nystagmus Suppression Test in Dizzy Patients: A Diagnostic Accuracy Study.

OBJECTIVE: Failure of fixation suppression of spontaneous nystagmus is sometimes seen in patients with vestibular strokes involving the cerebellum or brainstem; however, the accuracy of this test for the discrimination between peripheral and central causes in patients with an acute vestibular syndrome (AVS) is unknown. METHODS: Patients with AVS were screened and recruited (convenience sample) as part of a prospective cross-sectional study in the emergency department between 2015 and 2020. All patients received neuroimaging, which served as a reference standard. We recorded fixation suppression with video-oculography (VOG) for forward, right, and left gaze. The ocular fixation index (OFI) and the spontaneous nystagmus slow velocity reduction was calculated. RESULTS: We screened 1,646 patients reporting dizziness in the emergency department and tested for spontaneous nystagmus in 148 patients with AVS. We analyzed 56 patients with a diagnosed acute unilateral vestibulopathy (vestibular neuritis) and 28 patients with a confirmed stroke. There was a complete nystagmus fixation suppression in 49.5% of patients with AVS, in 40% of patients with vestibular neuritis, and in 62.5% of patients with vestibular strokes. OFI scores had no predictive value for detecting strokes; however, a nystagmus reduction of less than 2 °/s showed a high accuracy of 76.9% (confidence interval 0.59-0.89) with a sensitivity of 62.2% and specificity of 84.8% in detecting strokes. CONCLUSIONS: The presence of fixation suppression does not rule out a central lesion. The magnitude of suppression was lower compared to patients with vestibular neuritis. The nystagmus suppression test predicts vestibular strokes accurately provided that eye movements are recorded with VOG. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that in patients with an AVS, decreased fixation suppression recorded with VOG occurred more often in stroke (76.9%) than in vestibular neuritis (37.8%).

Usefulness of vertebrobasilar artery radiological finding as a predictive and prognostic factor for sudden sensorineural hearing loss.

OBJECTIVE: The association between sudden sensorineural hearing loss (SSNHL) and radiological findings of the vertebrobasilar artery is not well-known and little research has been done. We hypothesized that the radiological features of the vertebrobasilar artery contribute to the incidence and prognosis of SSNHL. METHODS: We retrospectively enrolled patients diagnosed with unilateral SSNHL (SSNHL group) and those with acute vestibular neuritis (AVN; control group) in our hospital. All patients underwent magnetic resonance imaging and computed tomography. We measured the following parameters on the radiological images: basilar artery diameter, direction and distance of basilar artery deviation, direction and distance of vertebral artery deviation, and incidence of vertebral artery obstruction. Pure tone audiometry (PTA) was performed in all patients. Follow up PTA between 1 week and 1 month after treatment was performed in the SSNHL group. RESULTS: A total of 244 SSNHL patients and 62 AVN patients were included in the analysis. Age, body mass index, and basilar artery diameter were found to be significantly associated with SSNHL. In the SSNHL group, patients were divided into three subgroups based on the consistency between the basilar artery deviation site and disease site. No significant difference was noted in initial PTA, final PTA, PTA recovery, and symptom improvement among the three groups. In case of the basilar artery, when the deviation and disease sites were in the opposite direction and the basilar artery diameter was >3.5 mm, diameter of basilar artery was positively correlated with PTA recovery. CONCLUSIONS: The strength of this study is that radiological evaluation of the vertebrobasilar artery was performed. Further research on the association between SSNHL and radiological features of the vertebrobasilar artery should be conducted to emphasize the importance of vascular assessment in SSNHL.

Platform posturography of patients with peripheral vestibular dysfunction in the non-acute phase of vertigo.

OBJECTIVE: Posturography (PG) shows various patterns corresponding to a patient's equilibrium condition; however, PG is not useful for the differential diagnosis of peripheral vestibular diseases (PVDs). The aim of this study was to identify parameters of PG that can distinguish between PVDs. METHODS: The differences in PG parameters between PVDs were evaluated retrospectively. Two hundred and two patients with Ménière's disease (MD), 154 patients with benign paroxysmal positional vertigo (BPPV), 20 patients with sudden sensorineural hearing loss with vertigo (SSNHLwV), and 31 patients with vestibular neuritis (VN) underwent PG during the non-acute phase of vertigo, from January 2010 to March 2017. RESULTS: The velocity of body oscillation of BPPV patients with eyes open and closed were significantly faster than those of MD patients with eyes open (p < 0.001) and closed (p = 0.033). The velocity of body oscillation of VN patients with eyes open was significantly faster than that of MD patients with eyes open (p = 0.0083). There were no significant differences among the other PG parameters between PVDs. Although there were significant differences among the velocity with eyes open and closed between males and females (eye open: p = 0.0009, eye close: p < 0.0001), there was no significant difference in the ratio of males to females among PVDs (p = 0.1834). Therefore, the ratio did not influence the difference in velocity among PVDs. Patient age correlated with the velocity with eyes open (p < 0.001) and with eyes closed (p < 0.001). Post-hoc analysis revealed significant differences in patient age, and comparisons of MD and BPPV, MD and SSNHLwV, BPPV and VN, and VN and SSNHLwV. Therefore, we performed multiple regression analysis to determine whether the significant differences in the velocity of body oscillation among PVDs were caused by the difference in age distribution between PVD groups, rather than by differences in the PVDs themselves. There were correlations between age and the velocity of body oscillation with eyes open (p < 0.001) and with eyes closed (p < 0.001). There also were correlations between MD or VN and the velocity of body oscillation with eyes open (p = 0.0194). CONCLUSION: There were significant differences in the velocity of body oscillation with eyes open between MD and VN patients. The difference between MD and VN was significant regardless of the age distribution. To distinguish between MD and VN, the velocity of body oscillation with eyes open is a useful PG index.

The Impact of the COVID-19 Pandemic on Follow-Ups for Vertigo/Dizziness Outpatients.

OBJECTIVES: In the present report, we aimed to investigate the impact of the coronavirus disease (COVID-19) pandemic on vertigo/dizziness outpatient cancellations in Japan. METHODS: We examined 265 vertigo/dizziness outpatients at the ear, nose, and throat department of the Nara Medical University between March 01, 2020, and May 31, 2020, during the COVID-19 pandemic in Japan. We also focused on 478 vertigo/dizziness outpatients between March 01, 2019, and May 31, 2019, before the COVID-19 pandemic, to compare the number of cancellations between these 2 periods. The reasons for cancellation and noncancellation were investigated using telephone multiple-choice questionnaires (telMCQs), particularly for patients with benign paroxysmal positional vertigo (BPPV) and Meniere's disease (MD). RESULTS: There were many cancellations for medical examinations during the 2020 study period. The total number of vertigo/dizziness outpatients decreased by 44.6% in the 2020 period compared to the same period in 2019. The percent reduction in clinic attendance from 2019 to 2020 (ie, [2019-2020]/2019) for patients with BPPV was higher than that for patients with MD. Compared to the other vertigo-associated conditions, patients with MD exhibited a lower percent reduction in clinic attendance. According to the results of the telMCQs, 75.0% of BPPV cases and 88.2% of MD cases cancelled their appointment and gave up visiting hospitals due to fear of COVID-19 infection, even if they had moderate to severe symptoms. On the contrary, 25.0% and 80.0% patients with BPPV and MD, respectively, did not cancel their appointment; they should not have visited the hospital but stayed at home because they had slight symptoms. CONCLUSIONS: These findings suggest that advanced forms should be prepared for medical care, such as remote medicine. These forms should not only be for the disease itself but also for the mental distress caused by persistent symptoms.

Vestibular mapping in patients with unilateral peripheral-vestibular deficits.

OBJECTIVE: To test the hypothesis that patterns of semicircular canal (SCC) and otolith impairment in unilateral vestibular loss depend on the underlying disorders, we analyzed peripheral-vestibular function of all 5 vestibular sensors. METHODS: For this retrospective case series, we screened the hospital video-head-impulse test database (n = 4,983) for patients with unilaterally impaired SCC function who also received ocular vestibular-evoked myogenic potentials and cervical vestibular-evoked myogenic potentials (n = 302). Frequency of impairment of vestibular end organs (horizontal/anterior/posterior SCC, utriculus/sacculus) was analyzed with hierarchical cluster analysis and correlated with the underlying etiology. RESULTS: Acute vestibular neuropathy (AVN) (37.4%, 113 of 302), vestibular schwannoma (18.2%, 55 of 302), and acute cochleovestibular neuropathy (6.6%, 20 of 302) were most frequent. Horizontal SCC impairment (87.4%, 264 of 302) was more frequent (p < 0.001) than posterior (47.4%, 143 of 302) and anterior (37.8%, 114 of 302) SCC impairment. Utricular damage (58%, 175 of 302) was noted more often (p = 0.003) than saccular impairment (32%, 98 of 302). On average, 2.6 (95% confidence interval 2.48-2.78) vestibular sensors were deficient, with higher numbers (p ≤ 0.017) for acute cochleovestibular neuropathy and vestibular schwannoma than for AVN, Menière disease, and episodic vestibular syndrome. In hierarchical cluster analysis, early mergers (posterior SCC/sacculus; anterior SCC/utriculus) pointed to closer pathophysiologic association of these sensors, whereas the late merger of the horizontal canal indicated a more distinct state. CONCLUSIONS: While the extent and pattern of vestibular impairment critically depended on the underlying disorder, more limited damage in AVN and Menière disease was noted, emphasizing the individual range of loss of function and the value of vestibular mapping. Likely, both the anatomic properties of the different vestibular end organs and their vulnerability to external factors contribute to the relative sparing of the vertical canals and the sacculus.

Separating posterior-circulation stroke from vestibular neuritis with quantitative vestibular testing.

OBJECTIVE: To separate vestibular neuritis (VN) from posteriorcirculation stroke (PCS) using quantitative tests of canal and otolith function. METHODS: Video Head-Impulse tests (vHIT) were used to assess all three semicircular canal pairs; vestibulo-ocular reflex (VOR) gain and saccade metrics were examined. Cervical and ocular-Vestibular-Evoked Myogenic Potentials (c- and oVEMP) and Subjective Visual Horizontal (SVH) were used to assess otolith function. RESULTS: For controls (n = 40), PCS (n = 22), and VN (n = 22), mean horizontal-canal VOR-gains were 0.96 ± 0.1, 0.85 ± 0.3 and 0.40 ± 0.2, refixation-saccade prevalence was 71.9 ± 41, 90.7 ± 57, 209.2 ± 62 per 100 impulses and cumulative-saccade amplitudes were 0.9 ± 0.4°, 2.4 ± 2.2°, 8.0 ± 3.5°. Abnormality-rates for cVEMP, oVEMP and SVH were 38%, 9%, 72% for PCS, and 43%, 50%, 91% for VN. A gain ≤0.68, refixation-saccade prevalence of ≥135% and cumulative-saccade amplitudes ≥5.3° separated VN from PCS with sensitivities of 95.5%, 95.5%, and 81.8%, and specificities of 68.2%, 86.4% and 95.5%. VOR-gain and saccade prevalence when combined, separated VN from PCS with a sensitivity and specificity of 90.9%. Abnormal oVEMP asymmetry-ratios were of low sensitivity (50%) but high specificity (90.9%) for separating VN from PCS. CONCLUSION: vHIT provided the best separation of VN from PCS. VOR-gain, refixation-saccade prevalence and amplitude were effective discriminators of VN from PCS. SIGNIFICANCE: vHIT and oVEMP could assist early identification of the aetiology of Acute Vestibular Syndrome in the Emergency Room.

Cerebellar ataxia, neuropathy, vestibular areflexia syndrome due to RFC1 repeat expansion.

Ataxia, causing imbalance, dizziness and falls, is a leading cause of neurological disability. We have recently identified a biallelic intronic AAGGG repeat expansion in replication factor complex subunit 1 (RFC1) as the cause of cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) and a major cause of late onset ataxia. Here we describe the full spectrum of the disease phenotype in our first 100 genetically confirmed carriers of biallelic repeat expansions in RFC1 and identify the sensory neuropathy as a common feature in all cases to date. All patients were Caucasian and half were sporadic. Patients typically reported progressive unsteadiness starting in the sixth decade. A dry spasmodic cough was also frequently associated and often preceded by decades the onset of walking difficulty. Sensory symptoms, oscillopsia, dysautonomia and dysarthria were also variably associated. The disease seems to follow a pattern of spatial progression from the early involvement of sensory neurons, to the later appearance of vestibular and cerebellar dysfunction. Half of the patients needed walking aids after 10 years of disease duration and a quarter were wheelchair dependent after 15 years. Overall, two-thirds of cases had full CANVAS. Sensory neuropathy was the only manifestation in 15 patients. Sixteen patients additionally showed cerebellar involvement, and six showed vestibular involvement. The disease is very likely to be underdiagnosed. Repeat expansion in RFC1 should be considered in all cases of sensory ataxic neuropathy, particularly, but not only, if cerebellar dysfunction, vestibular involvement and cough coexist.

Results in caloric test, video head impulse test and inner ear MRI in patients with Ménière's disease.

OBJECTIVE: Our aim was to elucidate relationships between results from the caloric test (c-test), video Head Impulse Test (vHIT) and inner ear gadolinium-enhanced MRI (ieMRI) in patients with endolymphatic hydrops (EH), especially patients with Ménière's disease (MD). METHODS: We managed 1789 successive patients at the Vertigo/Dizziness Center in Nara Medical University from May 2014 to December 2018. After providing informed consent for vertigo/dizziness examinations, 281 patients were hospitalized to check their inner ear function for proper diagnosis and treatment. Then 76 participants underwent the c-test, vHIT and ieMRI. Among these 76 cases, 20 were diagnosed with MD (20/76; 26.3%) and 56 were non-MD (56/76; 73.7%) according to the 2015 diagnostic guideline of the International Classification of Vestibular Disorders. The MD group included 15 unilateral and 5 bilateral cases. The non-MD group included 22 benign paroxysmal positional vertigo, 10 vestibular neuritis, 8 sudden deafness with vertigo, 6 orthostatic dysregulation, 4 vestibular neuropathy and 6 others. Results in these examinations in the side of an active lesioned inner ear were representative in each peripheral case. RESULTS: Twenty-nine of the 76 patients (38.1%) showed discrepant results between the c-test (outside of normal range) and vHIT (within normal range). Twenty-two of 76 patients (28.9%) had a positive EH sign on ieMRI. The c-test/vHIT discrepancy percentage in MD (14/20; 70.0%) was significantly higher than that in non-MD (15/56; 26.8%) (p=0.00179). The positive EH sign in ieMRI percentage in MD (15/20; 75.0%) was significantly higher than that in non-MD (7/56; 12.5%) (p=0.0015). There was a significant positive relationship between the c-test/vHIT discrepancy and the positive EH sign (p=0.00058) in all 76 cases combined. However, there was no significant relationship between c-test/vHIT discrepancy and positive EH sign (p=0.13) in the 20 MD cases. Considering the 15 unilateral and 5 bilateral MD cases, the c-test/vHIT discrepancy was observed in 14 of the 25 affected ears. Positive signs of vestibular EH herniation into the cupula in the lateral semicircular canal was seen in 14 of the 25 MD ears. There was significant relationship between the c-test/vHIT discrepancy and EH herniation (p=0.0012) in MD ears. CONCLUSION: The present results suggest that patients with MD could have inner ear EH significantly more often than those with non-MD. In cases with MD, a positive EH sign on ieMRI did not always indicate a c-test/vHIT discrepancy; both findings may occur due to herniation of vestibular EH adjacent to the lateral semicircular canal.

Comparing the Suppression Head Impulse Paradigm and the Head Impulse Paradigm in Vestibular Neuritis.

OBJECTIVE: To compare the results of suppression head impulse paradigm (SHIMP) and head impulse paradigm (HIMP) in acute vestibular neuritis (AVN). STUDY DESIGN: Retrospective study. SETTING: Tertiary otology clinic. PATIENTS AND INTERVENTIONS: We tested 21 patients with AVN with the HIMP, SHIMP, and caloric tests, and we analyzed the relationships between the tests' results. MAIN OUTCOME MEASURES: For this study, we adopted vestibulo-ocular reflex (VOR) gains in the SHIMP and HIMP, peak saccade velocity (PSV) of SHIMP which is another indicator of residual vestibular function, and canal paresis of caloric test. RESULTS: VOR gains showed significant correlation (R = 0.926, p < 0.001) between the SHIMP and HIMP, but VOR gains were slightly lower in the SHIMP than in the HIMP (mean difference 0.07 ±â€Š0.09, p < 0.001). The difference between the HIMP and SHIMP gains was slightly larger on the affected side (0.10 ±â€Š0.09) than on the healthy side (0.03 ±â€Š0.09). The PSV of SHIMP had significant correlation with HIMP gain and canal paresis. Sixteen of 21 patients showed 100% ipsilesional caloric canal paresis, and eight (50%) of them showed no anti-compensatory saccade (direction toward head rotation) in the SHIMP. However, they showed not extremely low VOR gain but variable VOR gain. CONCLUSION: The new parameters of SHIMP might be used as complement for evaluating vestibular function in AVN. However, the clinical impact of the saccades of SHIMP in AVN has not been revealed clearly yet. This question should be investigated in further studies.

Rehabilitation of dynamic visual acuity in patients with unilateral vestibular hypofunction: earlier is better.

PURPOSE: Patients with acute peripheral unilateral hypofunction (UVH) complain of vertigo and dizziness and show posture imbalance and gaze instability. Vestibular rehabilitation therapy (VR) enhances the functional recovery and it has been shown that gaze stabilization exercises improved the dynamic visual acuity (DVA). Whether the effects of VR depend or not on the moment when it is applied remains however unknown, and investigation on how the recovery mechanisms could depend or not on the timing of VR has not yet been tested. METHODS: Our study investigated the recovery of DVA in 28 UVH patients whose unilateral deficit was attested by clinical history and video head impulse test (vHIT). Patients were tested under passive conditions before (pre-tests) and after (post-tests) being subjected to an active DVA rehabilitation protocol. The DVA protocol consisted in active gaze stabilization exercises with two training sessions per week, each lasting 30 min, during four weeks. Patients were sub-divided into three groups depending on the time delay between onset of acute UVH and beginning of VR. The early DVA group (N = 10) was composed of patients receiving the DVA protocol during the first 2 weeks after onset (mean = 8.9 days), the late group 1 (N = 9) between the 3rd and the 4th week (mean = 27.5 days after) and the late group 2 (N = 9) after the 1st month (mean: 82.5 days). We evaluated the DVA score, the angular aVOR gain, the directional preponderance and the percentage of compensatory saccades during the HIT, and the subjective perception of dizziness with the Dizziness Handicap Inventory (DHI). The pre- and post-VR tests were performed with passive head rotations done by the physiotherapist in the plane of the horizontal and vertical canals. RESULTS: The results showed that patients submitted to an early DVA rehab improved significantly their DVA score by increasing their passive aVOR gain and decreasing the percentage of compensatory saccades, while the late 1 and late 2 DVA groups 1 and 2 showed less DVA improvement and an inverse pattern, with no change in the aVOR gain and an increase in the percentage of compensatory saccades. All groups of patients exhibited significant reductions of the DHI score, with higher improvement in subjective perception of dizziness handicap in the patients receiving the DVA rehab protocol in the first month. CONCLUSION: Our data provide the first demonstration in UVH patients that earlier is better to improve DVA and passive aVOR gain. Gaze stabilization exercises would benefit from the plastic events occurring in brain structures during a sensitive period or opportunity time window to elaborate optimal functional reorganizations. This result is potentially very important for the VR programs to restore the aVOR gain instead of recruiting compensatory saccades assisting gaze stability.

Measurement of horizontal ocular deviation on magnetic resonance imaging in various disease with acute vertigo.

In our previous study, we found that horizontal ocular deviation (OD) was significantly increased in patients with unilateral vestibular neuritis (VN). This study is aimed to compare the measurements of horizontal OD in various diseases which can present as acute vertigo in the emergency department. We retrospectively reviewed patients who visited the emergency department and underwent brain MRI due to acute vertigo. We compared them to healthy controls who underwent brain MRI for a regular health examination. Among the study participants, 149 patients who were diagnosed with benign paroxysmal positional vertigo (BPPV), unilateral Ménière's disease (MD), vestibular migraine (VM), unilateral vestibular neuritis (VN), or posterior inferior cerebellar artery (PICA) infarction were enrolled. Absolute angles of horizontal OD were larger in the definite MD (19.1 ± 12.7°), possible and probable MD (15.5 ± 11.7°), and VN (22.2 ± 11.7°) groups compared to the control group (4.3 ± 3.7°). Most VN patients (83.3%) had horizontal OD toward the direction of the lesion. About half of the MD patients (46.2%) and half of the patients with PICA infarction (50.0%) had horizontal OD toward the opposite direction of the lesion. Regarding PICA infarction, horizontal OD was observed only in patients who immediately underwent an MRI after developing the PICA territory vestibulocerebellar infarction. Although the exact mechanism of horizontal OD is unclear, this study suggests that horizontal OD reflects a static vestibular imbalance, and that the eyeball is deviated to the weaker of the two vestibular nuclei during neural resting activity. Therefore, horizontal OD could be helpful in assessing for a prior vestibular imbalance.

Why and when to refer patients for vestibular evoked myogenic potentials: A critical review.

Cervical and ocular vestibular evoked myogenic potentials (cVEMPs and oVEMPs respectively) are now used by an increasing number of laboratories to evaluate otolith inner ear function and their pathways through the central nervous system. However, the literature is incomplete or unclear as to what information both c- and oVEMPs can add beyond what a good clinical examination can provide, and what other paramedical tests can provide also, and the present review aims to clarify what is known so far. The following review will describe what is known with regards to both c- and oVEMPs and their use. MEDLINE (accessed by PubMed, years 1994-2018) was searched with the following string: ("vestibular evoked myogenic potentials" [all fields]). Only articles published in English were evaluated. Both c- and oVEMPs are useful not only for confirming the presence of superior semicircular canal dehiscence (SSCD), but also for confirming the presence of acoustic neuromas when MRI is not available, bilateral vestibulopathies, inferior vestibular neuritis and vestibular dysfunction in inherited neuropathies. Further work is required, especially with respect to oVEMPs. The usefulness of both c- and oVEMPs goes beyond the confirmation of SSCDs, and is useful in many clinical cases.

The functional head impulse test: Comparing gain and percentage of correct answers.

OBJECTIVES: The video head impulse test (vHIT) provides as output a gain value that summarizes the behavior of the vestibulo-ocular reflex as the ratio of a measure of eye movement to the corresponding measure of head movement and is not directly informative of the functional effectiveness of the motor response. The functional HIT (fHIT) is based on the ability to recognize the orientation of a Landolt C optotype that briefly appears on a computer screen during passive head impulses imposed by the examiner over a range of head accelerations; accordingly fHIT is a functional measurement of the vestibular-ocular reflex since it measures the capability to keep clear vision and to read during head movement. METHODS: We compared the results of the fHIT with those of the vHIT and the results of the Dizziness Handicap Inventory (DHI) questionnaire in a group of 27 vestibular neuritis patients recorded acutely and at 3-months follow-up. RESULTS: Both the vHIT and fHIT exams correctly classified all patients as abnormal on the affected side when tested in the acute phase. After a 3-month follow-up, both were able to show that compensation phenomena had occurred. Otherwise the data from the two techniques were not correlated. More specifically, the fHIT detected more abnormalities than the vHIT, for head rotation toward the healthy side, both in the acute phase and after 3 months, and for head rotation toward the affected side after 3 months. The asymmetry indices, that compare the performance of the healthy to the affected side, also were larger for the fHIT than for the vHIT both at onset and after 3 months. There was no significant correlation between the different vHIT and fHIT parameters and indices, or with the DHI values after 3 months. CONCLUSIONS: The fHIT data are able to detect a difference between the healthy and the affected side in the acute phase, and they show an improvement after 3 months. fHIT detects more abnormalities than vHIT, but both these techniques lack a correlation with the DHI score.