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Background: The vestibular phenotypes of patients with genetic hearing loss are poorly understood. Methods: we performed genetic testing including exome sequencing and vestibular function tests to investigate vestibular phenotypes and functions in patients with genetic hearing loss. Results: Among 627 patients, 143 (22.8%) had vestibular symptoms. Genetic variations were confirmed in 45 (31.5%) of the 143 patients. Nineteen deafness genes were linked with vestibular symptoms; the most frequent genes in autosomal dominant and recessive individuals were COCH and SLC26A4, respectively. Vestibular symptoms were mostly of the vertigo type, recurrent, and persisted for hours in the genetically confirmed and unconfirmed groups. Decreased vestibular function in the caloric test, video head impulse test, cervical vestibular-evoked myogenic potential, and ocular vestibular-evoked myogenic potential was observed in 42.0%, 16.3%, 57.8%, and 85.0% of the patients, respectively. The caloric test revealed a significantly higher incidence of abnormal results in autosomal recessive individuals than in autosomal dominant individuals (p = 0.011). The genes, including SLC26A4, COCH, KCNQ4, MYH9, NLRP3, EYA4, MYO7A, MYO15A, and MYH9, were heterogeneously associated with abnormalities in the vestibular function test. Conclusions: In conclusion, diverse vestibular symptoms are commonly concomitant with genetic hearing loss and are easily overlooked. [ABSTRACT FROM AUTHOR]

After unilateral peripheral vestibular lesions, the neural activity of neurons in the ipsi-lesional medial vestibular nucleus (ipsi-MVe) are markedly decreased, resulting in static and dynamic asymmetries of the vestibulo-ocular and vestibulo-spinal reflexes. Consequently, static vestibular symptoms such as spontaneous nystagmus and postural deviation and dynamic vestibular symptoms such as oscillopsia and swaying gait are induced. However, these behavioral asymmetries gradually recover after the lesion. Progressive balance restoration is termed vestibular compensation, which is divided into two phases: static and dynamic. Static vestibular compensation is further divided into initial and late processes. In the initial process of static vestibular compensation after unilateral labyrinthectomy (UL) in rats, plastic changes in the cerebello-vestibular and vestibular commissural inhibitory pathways suppress neurons in the contra-lesional MVe (contra-MVe), resulting in the restoration of symmetrical resting activity of MVe neurons on both sides at low levels. The declining frequency of spontaneous nystagmus after UL is an index of the initial process, and short-term administration of diazepam, a GABA A receptor agonist, has been shown to accelerate the initial process in rats. Accordingly, short-term administration of diazepam is recommended for the treatment of acute vertigo in patients with unilateral vestibular dysfunction. In the late process of static vestibular compensation after UL in rats, the resting activity of ipsi-MVe neurons gradually recovers due to changes in cell membrane properties, resulting in the reinforcement of balanced intervestibular nuclear activities to nearly normal levels without the suppression of contra-MVe neurons. The declining number of MK801-induced Fos-positive neurons in contra-MVe after UL is an index of the late process, and long-term administration of betahistine, a histamine H 3 receptor antagonist, has been shown to accelerate the late process in rats. Accordingly, long-term administration of betahistine is recommended for the treatment of subacute vertigo in patients who were not compensated for unilateral vestibular dysfunction. In the process of dynamic vestibular compensation after UL, the sensitivity of ipsi-MVe neurons to head velocity and acceleration is restored due to synaptic changes such as long-term potentiation and sprouting of commissures, resulting in the restoration of the dynamic vestibulo-ocular and vestibulo-spinal reflexes. To facilitate dynamic vestibular compensation, early ambulation and subsequent vestibular rehabilitation exercise are recommended for the treatment of chronic vertigo in patients with uncompensated unilateral vestibular dysfunction. Although vestibular compensation after bilateral vestibular loss is not expected, vestibular rehabilitation with a sensory-substitution strategy can improve imbalance in patients with bilateral vestibular lesions. [ABSTRACT FROM AUTHOR]

The aim was to evaluate the vestibular system of children who had undergone cochlear implant surgery and to compare them with the healthy population by vestibulo-ocular reflex (VOR) gains in unilateral and bilateral implant users, with the implants both on and off. Patients older than 5 years who had undergone cochlear implant surgery between 2012 and 2020 and who were cochlear implant users for at least one year were included. After consent was obtained, a video head impulse test (VHIT) was performed to evaluate the three semicircular canals, with devices on and off, and VOR gains were evaluated. VHIT was also used to assess VOR gains in the control group. The VOR gains of the study and control groups, VOR gains of unilateral and bilateral implant users, and VOR gains with implants on and off were compared. When the VOR gains of 24 unilateral and 13 bilateral cochlear implant users and the control group (n = 30) were compared, a significant difference was found only in the anterior semicircular canal, although the VOR gains were found to be low in all three semicircular canals in the implant users (p < 0.05). There was no significant difference between the VOR gains of unilateral and bilateral implant users. There was no significant difference between the VOR gains when either on or off. There was no correlation between cochlear implant usage time, implant insertion age, patient age and VOR gain. The effects of cochlear implant surgery on the vestibular system continue in the late period, but no correlation was observed between implant usage time and VOR gain after the first year. It was observed that having the cochlear implant on or off had no effect on VOR gain. Furthermore, bilateral implant surgery did not lead to additional vestibular dysfunction compared to unilateral implant surgery. [ABSTRACT FROM AUTHOR]

BACKGROUND: Hyperventilation-induced nystagmus test (HINT) is capable of generating a response in 77.2% of cases of acute unilateral vestibulopathy (AUVP); both nystagmus toward the affected side (excitatory pattern) and toward the healthy side (inhibitory pattern) have been described. The aim of the study is to investigate the clinical and prognostic role of the test by evaluating its correlation with vestibulo-ocular reflex (VOR) gain. METHODS: We evaluated 33 AUVP patients by performing the HINT and video head impulse test (V-HIT) during the acute phase and then at 15 and 90 days after the onset of the symptoms. The correlation between the VOR gain of the affected side and test responses was evaluated first, phase by phase, and then considering the pattern shown during the first assessments. RESULTS: Patients with a negative HINT had a higher mean VOR gain than patients with a positive test at both 15 and 90 days. Patients who showed an inhibitory pattern at the first assessment had a continuous improvement in V-HIT performance, while patients with an initial excitatory response had a transient decrease in gain at the subsequent evaluation (P=.001). No difference between these 2 groups emerged at 90 days (P=.09). CONCLUSION: The finding of a negative HINT during the follow-up correlates with good V-HIT performance and could be an indicator of good recovery. The inhibitory pattern is associated with a subsequent improvement; and it would be indicative of compensation. but, despite this, the prognostic value of the test is limited [ABSTRACT FROM AUTHOR]

BACKGROUND: Machado Joseph Disease (MJD) is an autosomal dominant neurodegenerative disease. In previous studies, we described significant bilateral horizontal Vestibulo-Ocular Reflex (VOR) deficit within this population without any reference to the presence of vestibular symptomatology. OBJECTIVE: To evaluate whether, beyond cerebellar ataxia complaints, MJD patients have typical vestibular symptomatology corresponding to the accepted diagnostic criteria of Bilateral Vestibulopathy (BVP) according to the definition of the International Barany Society of Neuro-Otology. METHODS: Twenty-one MJD, 12 clinically stable chronic Unilateral Vestibulopathy (UVP), 15 clinically stable chronic BVP, and 22 healthy Controls underwent the video Head Impulse Test (vHIT) evaluating VOR gain and filled out the following questionnaires related to vestibular symptomatology: The Dizziness Handicap Inventory (DHI), the Activities-specific Balance Confidence Scale (ABC), the Vertigo Visual Scale (VVS) and the Beck Anxiety Inventory (BAI). RESULTS: The MJD group demonstrated significant bilateral vestibular impairment with horizontal gain less than 0.6 in 71% of patients (0.54±0.17). Similar to UVP and BVP, MJD patients reported a significantly higher level of symptoms than Controls in the DHI, ABC, VVS, and BAI questionnaires. CONCLUSIONS: MJD demonstrated significant VOR impairment and clinical symptoms typical of BVP. We suggest that in a future version of the International Classification of Vestibular Disorders (ICVD), MJD should be categorized under a separate section of central vestibulopathy with the heading of bilateral vestibulopathy. The present findings are of importance regarding the clinical diagnosis process and possible treatment based on vestibular rehabilitation. [ABSTRACT FROM AUTHOR]

Background: The current pandemic of COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in significant morbidity and mortality primarily associated with respiratory failure. However, it has also been reported that COVID-19 can evolve into a nervous system infection. The direct and indirect mechanisms of damage associated with SARS-CoV-2 neuropathogenesis could affect our sensory functionality, including hearing and balance. Summary: In order to investigate a possible association between SARS-CoV-2 viral infection and possible damage to the vestibular system, this review describes the main findings related to diagnosing and evaluating otoneurological pathologies. Key Messages: The clinical evidence shows that SARS-CoV-2 causes acute damage to the vestibular system that would not leave significant sequelae. Recovery is similar to vestibular pathologies such as vestibular neuronitis and benign paroxysmal positional vertigo. Further basic science, clinical, and translational research is needed to verify and understand the short- and long-term effects of COVID-19 on vestibular function. [ABSTRACT FROM AUTHOR]

Sudden sensorineural hearing loss with vertigo (SHLV) and vestibular neuritis (VN) can result in prolonged dizziness. This study aimed to compare the video head impulse test (vHIT) of patients with SHLV and VN. 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. 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. 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. [ABSTRACT FROM AUTHOR]

The results of video head impulse tests (video-HITs) may be confounded by data artifacts of various origins, including pupil size and eyelid obstruction of the pupil. This study aimed to determine the effect of these factors on the results of video-HITs. We simulated ptosis by adopting pharmacological dilatation of the pupil in 21 healthy participants (11 women; age 24–58 years). Each participant underwent video-HITs before and after pupillary dilatation using 0.5% tropicamide. We assessed the changes in the vestibulo-ocular reflex (VOR) gain, corrective saccade amplitude, and frequency of eyelid flicks. After pupillary dilatation, the VOR gain decreased for both right (RAC; 1.12 ± 0.12 vs. 1.01 ± 0.16, p = 0.011) and left anterior canals (LACs; 1.15 ± 0.13 vs. 0.96 ± 0.14, p < 0.001), and right posterior canal (RPC, 1.10 ± 0.13 vs. 0.98 ± 0.09, p = 0.001). The corrective saccade amplitudes also decreased significantly for all four vertical canals. The frequency of eyelid flicks, however, did not change. The changes of VOR gain were positively correlated with the lid excursion in RPC (r = 0.629, p = 0.002) and LPC (r = 0.549, p = 0.010). Our study indicates that eyelid position and pupil size should be considered when interpreting the results of video-HITs, especially for the vertical canals. Pupils should be shrunk in a very well-lit room, and artifacts should be prevented by taping or lifting the eyelids as required during video-HITs. [ABSTRACT FROM AUTHOR]

While age-related auditory deficits and cochlear alterations are well described, those affecting the vestibular sensory organs and more broadly the central vestibular pathways are much less documented. Although there is inter-individual heterogeneity in the phenomenon of vestibular ageing, common tissue alterations, such as losses of sensory hair cells or primary and secondary neurons during the ageing process, can be noted. In this review, we document the cellular and molecular processes that occur during ageing in the peripheral and central vestibular system and relate them to the impact of age-related vestibular deficits based on current knowledge. [ABSTRACT FROM AUTHOR]

Purpose: The video Head Impulse Test is routinely used to assess semicircular canal function in adults, but to date, pediatric reference values are scarce. This study aimed to explore the vestibulo-ocular reflex (VOR) in healthy children at different development stages and to compare the obtained gain values with reference to those in an adult population. Methods: This prospective, single-center study recruited 187 children from among patients without otoneurological diseases, healthy relatives of these patients, and staff families from a tertiary hospital. Patients were divided into three groups by age: 3–6 years, 7–10 years, and 11–16 years. The vestibulo-ocular reflex was assessed by video Head Impulse Test, using a device with a high-speed infrared camera and accelerometer (EyeSeeCam®; Interacoustics, Denmark). Results: We found a lower vestibulo-ocular reflex gain of both horizontal canals in the 3–6-year-old group when compared with the other age groups. No increasing trend was found in the horizontal canals from age 7–10 years to age 11–16 years, and no differences were found by sex. Conclusion: Gain values in the horizontal canals increased with age until children reached age 7–10 years and matched the normal values for adults. [ABSTRACT FROM AUTHOR]

Objective: To expand our understanding of the pathophysiological mechanisms underlying vestibular neuritis and labyrinthitis by identifying any difference in the vestibulo‐ocular reflex for each semicircular canal. Study Design: Retrospective analysis. Setting: The Department of Otorhinolaryngology – Head and Neck Surgery, Chosun University Hospital, from January 2015 to December 2021. Methods: We included 23 vestibular neuritis and 27 labyrinthitis patients who had been hospitalized. Pure‐tone audiometry, a bithermal caloric test, and a video head‐impulse test were performed within 5 days of symptom onset. Results: In the vestibular neuritis group, mean vestibulo‐ocular reflex gains were decreased to 0.51 in the ipsilesional horizontal canal and 0.55 in anterior canal, leading to marked asymmetry, whereas the gain of the ipsilesional posterior canal was relatively preserved at 0.85. In the labyrinthitis group, the mean vestibulo‐ocular reflex gain was 0.72 in the ipsilesional horizontal canal, 0.73 in the ipsilesional anterior canal, and 0.55 in the ipsilesional posterior canal. We observed statistical differences in the vestibulo‐ocular reflex gain and incidence of corrective saccades on the ipsilesional side in three semicircular canals between the groups (p =.002 for horizontal canal, p =.003 for anterior canal, and p <.001 for posterior canal). The receiver operating characteristic curve showed that pure‐tone audiometry, ipsilesional posterior canal gain, and gain asymmetry of posterior canal were excellent parameters for distinguishing labyrinthitis from vestibular neuritis. Conclusion: Vestibular neuritis and labyrinthitis patients have different degrees and patterns of video head‐impulse test involvement in the three semicircular canals, suggesting that the two distinct disorders may have different etiologies. [ABSTRACT FROM AUTHOR]

Introduction: Current clinical practice considers the vestibulo-ocular reflex (VOR) gain as registered by the video head impulse test (vHIT) as the primary measure for semicircular canal function, while the role of the re-fixation saccades (RSs) is still under evaluation. The goal of the study was to appraise the added benefit of RS towards the improvement of vHIT diagnostic accuracy in cases of suspected left horizontal semicircular canal dysfunction. Methods: The vHIT recordings of 40 patients with left-sided horizontal VOR gains <0.8 were retrospectively evaluated for the presence of RS. The study groups included 20 patients with a final diagnosis of left horizontal semicircular canal dysfunction and 20 patients for whom vestibular dysfunction was ruled out. Results: Gain values >0.72 were found in all patients with no vestibular disease and in 4 (20%) patients having vestibulopathy. Significantly higher average left-sided RS velocity and frequency were found among the vestibular patients. VOR gain <0.72 was found to be highly specific for the diagnosis of vestibular dysfunction. However, for gain values in the range of 0.72–0.79, the presence of RS with frequency >80% largely improved vHIT diagnostic accuracy. Conclusions: Although VOR gain <0.8 is considered to reflect dysfunction, a significant false-positive rate for left-sided horizontal vHIT was found for gains in the range of 0.72–0.79. The presence of RS with frequency >80% could improve vHIT diagnostic ability in these patients. [ABSTRACT FROM AUTHOR]

Background: Abnormal gains in six-canal video head impulse test are attributed to semi-circular canal deficits. However, as video head impulse test responses are linked to the vestibulo-ocular reflex, it was hypothesised that abnormal gains can be caused by vestibulo-ocular reflex pathway deficits. Methods: This study compared video head impulse test gains in 20 patients with superior semi-circular canal dehiscence (labyrinthine cause) and 20 side- and gender-matched patients with vestibular schwannomas (retrolabyrinthine cause), and investigated correlations between them (Mann–Kendall trend test). Results: Vestibular schwannoma but not superior semi-circular canal dehiscence was significantly associated with abnormal lateral (odds ratio = 9.00 (95 per cent confidence interval = 1.638–49.44), p = 0.011) and posterior (odds ratio = 9.00 (95 per cent confidence interval = 2.151–37.659), p = 0.003) canal status. In vestibular schwannoma patients, there was a statistically significant degree of dependence between all ipsilesional canal video head impulse test gains; such dependence was not observed in superior semi-circular canal dehiscence. Conclusion: Vestibulo-ocular reflex gains differ in patients with labyrinthine and retrolabyrinthine disease; this suggests that abnormal gains can indicate deficits not only in the semi-circular canals but also elsewhere along the vestibulo-ocular reflex pathway. [ABSTRACT FROM AUTHOR]

Caloric irrigation (CI) is the gold standard to investigate peripheral vestibular dysfunction. The video head impulse test (vHIT) is faster and more accessible and may be useful during acute vertigo stroke risk differentiation. Comparative studies between the two methods are needed. The objective of this study was to compare vestibular function data derived from caloric irrigation with that from vHIT. This study included 80 patients with acute onset vertigo who underwent caloric irrigation and vHIT. CI derived sum of slow phase velocities (SPVs) and unilateral weakness (UW) were compared with vHIT vestibulo-ocular reflex (VOR) gain and gain asymmetry (GA) using correlation analyses. Optimal cut offs for vHIT VOR gain and GA were calculated using Youden indexes. There was a strong positive correlation between the asymmetry measures UW and GA whereas the correlation between the sum of SPVs and VOR gain was weaker. The optimal cut offs to diagnose unilateral vestibular weakness were 0.80 for VOR gain and 28% for GA; with specificities for predicting normal caloric irrigation results of 55% and 93%, respectively. In one third of cases the results from caloric irrigation and vHIT dissociated. The results from vHIT correlated with those from CI, still neither test seem to have the accuracy to replace the other. GA appears as an attractive measure in acute vertigo as the high specificity can be used to identify those with a substantial probability of normal vestibular function in need of more comprehensive work-up for central causes. To diagnose vestibular dysfunction, CI remains gold standard. [ABSTRACT FROM AUTHOR]

Objective: To evaluate how often the positive sign of HINTS (Head-Impulse, Gaze Evoked Nystagmus, Test of Skew) appears in patients with acute peripheral vestibular lesion, HINTS findings were quantitatively measured and analyzed in patients with peripheral vestibulopathy accompanying spontaneous nystagmus.Methods: HINTS was evaluated in 14 vertigo patients with spontaneous nystagmus. Horizontal vestibulo-ocular reflex (VOR) gain was measured using the video head impulse test (vHIT). To evaluate gaze-evoked nystagmus (GEN), slow-phase velocities at different points of lateral gaze were measured and plotted, then the slope and its inverse value, the neural integrator time constant, were calculated. Skew deviation was tested using anaglyph filters to simulate the alternate cover test, and the degree and latency of vertical eyeball deviation were measured. The ABCD2 score was calculated to evaluate the risk of stroke.Results: Among 13 patients of peripheral vestibulopathy, 7 showed positive signs in HINTS (normal vHIT: 5, direction-changing GEN: 0, skew deviation: 3). One patient with a cerebellopontine angle tumor presented with both a peripheral and central pattern and showed positive HINTS findings (presence of direction-changing GEN). The mean VOR gain of patients with abnormal vHIT was 0.58±0.29 and 1.10±0.11 in the affected and contralateral side, respectively, while those in patients with normal vHIT were 1.04±0.21 and 1.13±0.12, respectively. The neural integrator time constant calculated from the mean slope of horizontal slow-phase velocity according to horizontal eye position was 42.9 s. The mean vertical eyeball deviation of patients with positive skew was 2.14±1.18° while uncovering the eye on the affected side, and -1.97±1.59° while uncovering the eye on the unaffected side. The median ABCD2 score of 14 patients was 2 (range, 1-3).Conclusions: HINTS findings were objectively measured in vertigo patients with spontaneous nystagmus. Although positive findings of HINTS have been recognized as a central sign, 54% (7/13) of cases with peripheral vestibulopathy showed positive HINTS signs. HINTS results should be interpreted carefully considering that a substantial proportion of peripheral vestibulopathy shows a positive HINTS sign. [ABSTRACT FROM AUTHOR]

This paper describes the diagnostic criteria for Acute Unilateral Vestibulopathy (AUVP), a synonym for vestibular neuritis, as defined by the Committee for the Classification of Vestibular Disorders of the Bárány Society. AUVP manifests as an acute vestibular syndrome due to an acute unilateral loss of peripheral vestibular function without evidence for acute central or acute audiological symptoms or signs. This implies that the diagnosis of AUVP is based on the patient history, bedside examination, and, if necessary, laboratory evaluation. The leading symptom is an acute or rarely subacute onset of spinning or non-spinning vertigo with unsteadiness, nausea/vomiting and/or oscillopsia. A leading clinical sign is a spontaneous peripheral vestibular nystagmus, which is direction-fixed and enhanced by removal of visual fixation with a trajectory appropriate to the semicircular canal afferents involved (generally horizontal-torsional). The diagnostic criteria were classified by the committee for four categories: 1. "Acute Unilateral Vestibulopathy", 2. "Acute Unilateral Vestibulopathy in Evolution", 3. "Probable Acute Unilateral Vestibulopathy" and 4. "History of Acute Unilateral Vestibulopathy". The specific diagnostic criteria for these are as follows: "Acute Unilateral Vestibulopathy": A) Acute or subacute onset of sustained spinning or non-spinning vertigo (i.e., an acute vestibular syndrome) of moderate to severe intensity with symptoms lasting for at least 24 hours. B) Spontaneous peripheral vestibular nystagmus with a trajectory appropriate to the semicircular canal afferents involved, generally horizontal-torsional, direction-fixed, and enhanced by removal of visual fixation. C) Unambiguous evidence of reduced VOR function on the side opposite the direction of the fast phase of the spontaneous nystagmus. D) No evidence for acute central neurological, otological or audiological symptoms. E) No acute central neurological signs, namely no central ocular motor or central vestibular signs, in particular no pronounced skew deviation, no gaze-evoked nystagmus, and no acute audiologic or otological signs. F) Not better accounted for by another disease or disorder. "Acute Unilateral Vestibulopathy in Evolution": A) Acute or subacute onset of sustained spinning or non-spinning vertigo with continuous symptoms for more than 3 hours, but not yet lasting for at least 24 h hours, when patient is seen; B) - F) as above. This category is useful for diagnostic reasons to differentiate from acute central vestibular syndromes, to initiate specific treatments, and for research to include patients in clinical studies. "Probable Acute Unilateral Vestibulopathy": Identical to AUVP except that the unilateral VOR deficit is not clearly observed or documented. "History of acute unilateral vestibulopathy": A) History of acute or subacute onset of vertigo lasting at least 24 hours and slowly decreasing in intensity. B) No history of simultaneous acute audiological or central neurological symptoms. C) Unambiguous evidence of unilaterally reduced VOR function. D) No history of simultaneous acute central neurological signs, namely no central ocular motor or central vestibular signs and no acute audiological or otological signs. E) Not better accounted for by another disease or disorder. This category allows a diagnosis in patients presenting with a unilateral peripheral vestibular deficit and a history of an acute vestibular syndrome who are examined well after the acute phase. It is important to note that there is no definite test for AUVP. Therefore, its diagnosis requires the exclusion of central lesions as well as a variety of other peripheral vestibular disorders. Finally, this consensus paper will discuss other aspects of AUVP such as etiology, pathophysiology and laboratory examinations if they are directly relevant to the classification criteria. [ABSTRACT FROM AUTHOR]

This study aimed to determine the incidence, pattern, and etiology of dissociated vestibulo-ocular reflex (VOR) function according to the stimulus frequency in dizzy patients. We retrospectively evaluated the results of bithermal caloric tests and video-head impulse tests (vHITs) in 1022 patients with dizziness or vertigo between July 2016 and April 2021. Patients were classified into concordant group (normal or abnormal results on both tests) and discordant group (dissociated results between two tests). Of 1022 patients, discordant group had 159 (16%), comprising abnormal horizontal vHITs with normal caloric responses (n = 36, 23%) and abnormal caloric tests with normal horizontal vHITs (n = 123, 77%). The former group showed similar frequency of peripheral (44%) and central (42%) causes, and more common involvement of bilateral horizontal semicircular canals in central than peripheral causes (86.7 vs 37.5%, p = 0.005). The most common peripheral causes were Meniere's disease and chronic vestibular neuritis, while central causes were variable, but mainly affecting the cerebellum. In the latter group, peripheral causes were common (67%), with the main etiologies being Meniere's disease and vestibular neuritis, whereas central causes were found in only 5%. The degree of canal paresis did not differ significantly between patients with central and peripheral causes. Discordant VOR function according to the stimulus frequency was not uncommon in dizzy patients. Specific patterns of VOR dissociation according to the disease etiologies may offer insight into underlying pathophysiology. [ABSTRACT FROM AUTHOR]

The article discusses a case study of a 57-year-old man with multiple system atrophy (MSA) presenting with ocular flutter triggered specifically by vestibular stimulation, alongside various neurological symptoms including gait difficulty, oscillopsia, and dysarthria. It highlights the diagnostic challenges and neurological manifestations associated with MSA, emphasizing the role of vestibular and ocular motor deficits in differentiating this condition from other neurodegenerative disorders.

Fixation nystagmus refers to the nystagmus that appears or markedly increases with fixation. While relatively common in infantile (congenital) nystagmus, acquired fixation nystagmus is unusual and has been ascribed to lesions involving the cerebellar nuclei or the fibers projecting from the cerebellum to the brainstem. We aimed to report the clinical features of patients with acquired fixation nystagmus and discuss possible mechanisms using a model simulation and diagnostic significance. We describe four patients with acquired fixation nystagmus that appears or markedly increases with visual fixation. All patients had lesions involving the cerebellum or dorsal medulla. All patients showed direction-changing gaze-evoked nystagmus, impaired smooth pursuit, and decreased vestibular responses on head-impulse tests. The clinical implication of fixation nystagmus is that it may occur in central lesions that impair both smooth pursuit and the vestibulo-ocular reflex (VOR) but without creating a spontaneous nystagmus in the dark. We develop a mathematical model that hypothesizes that fixation nystagmus reflects a central tone imbalance due to abnormal function in cerebellar circuits that normally optimize the interaction between visual following (pursuit) and VOR during attempted fixation. Patients with fixation nystagmus have central lesions involving the cerebellar circuits that are involved in visual–vestibular interactions and normally eliminate biases that cause a spontaneous nystagmus. [ABSTRACT FROM AUTHOR]

Objective: Some studies have suggested that the human immunodeficiency virus causes dizziness and other balance problems; however, the exact effects on the vestibular system in acute and chronic phases of the disease are not clear. In this study, we aimed to evaluate the effect of the human immunodeficiency virus on semicircular canals using a video head impulse test. Materials and Methods: Seventy-two cases were included in the study. Twenty-six of the cases had positive human immunodeficiency virus RNA (group A) and 22 had negative human immunodeficiency virus RNA with positive anti-human immunodeficiency virus (group B) laboratory results. Twenty-four of the cases were healthy individuals (group C). The vestibular system was evaluated with a video head impulse test in all cases. Results: In the evaluation of overt/covert saccades, a statistically significant difference was detected for the left posterior semicircular canal between group B and the other 2 groups. However, this was considered an incidental finding and not a clinically significant result. There was no other significant difference in the catchup saccades for other canals. In addition, there was no statistically significant difference between the groups for the vestibulo-ocular reflex gain. Conclusion: Although the human immunodeficiency virus has been reported to be vestibulotoxic in previous studies, we found that the video head impulse test findings were not affected in our patient groups. Because the video head impulse test is considered a high-frequency test of vestibulo-ocular reflex, it is possible that vestibular effects of the human immunodeficiency virus can be confined to low frequencies. It is also possible that HIV affects the central structures while sparing the peripheral vestibular pathways. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to assess the functional head impulse test on migraine patients without vertigo. fHIT is a new vestibular test which evaluates the ability to see and read clearly during head movement as a functional measurement of the vestibulo-ocular reflex. Materials and methods: The study included 20 patients suffering from migraine without vertigo between the ages of 20 and 30-years-old who were diagnosed by a neurologist and 20 individuals with non-migraine headaches (control group), with similar demographic characteristics. The functional head impulse test was applied to both groups, and the migraine disability assessment test was applied to migraine patients. Results: There was no statistically significant difference in the general fHIT results between the migraine group and the control group (p > 0.05). However, a statistically significant decrease was obtained in migraine patients in the left lateral (p = 0.018) and right posterior (p = 0.029) semicircular canals at 4000 Hz and the right anterior semicircular canal at 6000 Hz (p = 0.019). When compared by the degree of migraine disability assessment test, no significant difference in the fHIT results were observed (p > 0.05). Conclusion: The semicircular canals may be affected at high head acceleration (4000–6000 Hz) in migraine patients without a history of vertigo. It should be considered that fHIT results between 4000 and 6000 Hz in migraine patients without vertigo can be pathologic. [ABSTRACT FROM AUTHOR]

Similarly, cerebral lesions can also present with spontaneous or positional nystagmus especially when the lesions involve the hippocampus and parahippocampal gyrus that are part of the multisensory vestibular cortices [[3]-[5]]. Dear Sirs, A small punctuate lesion in the hippocampus can cause acute amnesia, confabulation, and altered consciousness, and it represents a typical radiologic finding of transient global amnesia (TGA). Accordingly, 40% of patients having a punctuate lesion in this area reported vertigo and dizziness in an MRI-based patient series [[1]]. [Extracted from the article]

BACKGROUND: Self-motion misperception has been observed in vestibular patients during asymmetric body oscillations. This misperception is correlated with the patient's vestibular discomfort. OBJECTIVE: To investigate whether or not self-motion misperception persists in post-ictal patients with Ménière's disease (MD). METHODS: Twenty-eight MD patients were investigated while in the post-ictal interval. Self-motion perception was studied by examining the displacement of a memorized visual target after sequences of opposite directed fast-slow asymmetric whole body rotations in the dark. The difference in target representation was analyzed and correlated with the Dizziness Handicap Inventory (DHI) score. The vestibulo-ocular reflex (VOR) and clinical tests for ocular reflex were also evaluated. RESULTS: All MD patients showed a noticeable difference in target representation after asymmetric rotation depending on the direction of the fast/slow rotations. This side difference suggests disruption of motion perception. The DHI score was correlated with the amount of motion misperception. In contrast, VOR and clinical trials were altered in only half of these patients. CONCLUSIONS: Asymmetric rotation reveals disruption of self-motion perception in MD patients during the post-ictal interval, even in the absence of ocular reflex impairment. Motion misperception may cause persistent vestibular discomfort in these patients. [ABSTRACT FROM AUTHOR]

To identify the etiology of vertigo/dizziness and determine the effectiveness of the video-head impulse test (vHIT) and the suppression head impulse paradigm (SHIMP) tests in distinguishing between peripheral and non-peripheral etiologies in children who presented to the otolaryngology department with complaints of vertigo/dizziness. The vHIT and SHIMP tests were applied to the children. The vestibulo-ocular reflex (VOR) gain and saccade parameters were compared. In 27 children presenting with vertigo/dizziness, the most common etiological factor was inner ear malformation (IEM) (n = 6/27, 22.2%), followed by cochlear implant surgery (11.1%) and migraine (11.1%). Vestibular hypofunction was indicated by the vHIT results at a rate of 60% (9/15 children) and SHIMP results at 73.3% (11/15 children) among the children with a peripheral etiology, while these rates were 8.3% (1/12 children) and 25% (3/12 children), respectively, in the non-peripheral etiology group. SHIMP-VOR and vHIT-VOR gain values had a moderate positive correlation (p = 0.01, r = 0.349). While there were overt/covert saccades in the vHIT, anti-compensatory saccade (ACSs) were not observed in the SHIMP test (p = 0.041). The rates of abnormal vHIT-VOR gain (p = 0.001), over/covert saccades (p = 0.019), abnormal vHIT response (p = 0.014), ACSs (p = 0.001), and abnormal SHIMP response (p = 0.035) were significantly higher in the peripheral etiology group. IEM was the most common etiological cause, and the rate of vestibular hypofunction was higher in these children with peripheral vertigo. vHIT and SHIMP are effective and useful vestibular tests for distinguishing peripheral etiology from non-peripheral etiology in the pediatric population with vertigo/dizziness. These tests can be used together or alone, but the first choice should be the SHIMP test, considering its short application time (approximately 4–5 min) and simplicity. [ABSTRACT FROM AUTHOR]

Background: Peripheral vestibular vertigo is a common cause of vertigo especially in the elderly. The neutrophil to lymphocyte ratio (NLR) is a rapid and cost-effective inflammatory marker that has been assessed previously in peripheral vestibular disorders. However, its relation to the severity of peripheral vertigo has not been previously investigated. The aim of this study is to assess the levels of NLR in peripheral vestibular vertigo of various severity categories. This was a cross-sectional study at the Wahidin Sudirohusodo Hospital and Hasanuddin University Teaching Hospital in Makassar. The NLR was measured among subjects with periphel vestibular vertigo with severity categorised using the Dizziness Handicap Inventory (DHI) questionnaire. Results: A total of 39 participants with peripheral vestibular vertigo were recruited. A statistically significant difference was found (p = 0.002, Kruskal–Wallis ANOVA) between the mean NLR for the mild, moderate, and severe DHI categories were 2.47 ± 1.66, 2.64 ± 0.96, and 5.15 ± 2.59 respectively. Conclusion: A significant difference in the NLR was found between the three different vertigo severity groups, wherein NLR values rise with increase in vertigo severity. This warrants further exploration on the role of inflammatory biomarkers in vertigo pathophysiology and clinical assessment. [ABSTRACT FROM AUTHOR]

Objective: To compare video head impulse test (vHIT) and caloric test efficacy in decompensated and compensated vertigo patients and to further investigate whether vHIT alone can be used as a diagnostic tool in vertigo. Methods: This study included 25 patients diagnosed with vertigo and without any previous history of vertigo or hearing loss before their admission to our clinic. The control group consisted of 16 healthy adult volunteers. Patients were classified into 2 groups, compensated and decompensated. Video head impulse test and caloric tests were performed and the results were compared between the groups. Results: The difference of caloric test values between control-compensated groups and compensated-decompensated groups was statistically significant (P <.001, Pearson χ2). However, there was no statistically significant difference between the compensated and control groups according to vHIT gain asymmetry values (P =.087). In the very early stages of the disease with spontaneous nystagmus, the diagnostic significance of vHIT was similar to that of the caloric test. When both sides were compared, vHIT gain asymmetry values were close to the caloric test asymmetry values. In the compensated stage, caloric test was superior to vHIT in differentiating compensated vestibular pathologies. When vHIT sensitivity was evaluated according to the bi-thermal caloric test results, the sensitivity of the vHIT gain asymmetry value was 85.71% and 23.08% for decompensated and compensated patients respectively. Conclusion: In the early decompensated stages of the disease with spontaneous nystagmus, vHIT shows similar diagnostic accuracy to that of the caloric test. Since patients can tolerate vHIT more easily, our results suggest that vHIT can be considered as a primary evaluation method in the early (decompensated) period of the disease and should be preferred over the caloric test during the acute phase. Caloric test is more reliable at the compensated stage. Video head impulse test is inadequate in evaluating the compensated vestibular hypofunctional states after compensation has been restored. Level of Evidence: Level 2b [ABSTRACT FROM AUTHOR]

OBJECTIVES: This cross-sectional study aims to describe the features of the suppression head impulse paradigm (SHIMP) in acute unilateral vestibulopathy (AUV) and to define its role in predicting the recovery of patients. METHODS: Thirty patients diagnosed with AUV were retrospectively analyzed. The dizziness handicap inventory score and video head impulse test parameters performed 4–8 weeks from the AUV onset constituted the main outcome measures. Patients with a worse recovery (Group 1) and patients who recovered spontaneously (Group 2) were compared. RESULTS: The SHIMP vestibulo-ocular reflex (VOR) gain was statistically significantly lower than the conventional head impulse paradigm (HIMP) VOR gain (P < 0.001). The SHIMP VOR gain was negatively correlated with the DHI (P < 0.001) and was positively correlated with the HIMP VOR gain (P < 0.001) and the SHIMP overt saccades (%) (P < 0.001). Patients with a worse recovery exhibited the following: higher DHI (P < 0.001), lower SHIMP and HIMP VOR gain (P < 0.001 and P = 0.007, respectively), and lower SHIMP and greater HIMP overt saccade prevalence values (P = 0.007 and P = 0.032, respectively). CONCLUSIONS: The SHIMP and HIMP help in improving our approach to AUV. SHIMP appears to better identify the extent of the vestibular damage in patient suffering from AUV than HIMP and could provide interesting information about the course of the disease. Particularly, the analysis of SHIMP VOR gain and overt saccade prevalence would provide useful information about the recovery of patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: The crucial role of early vestibular rehabilitation (VR) to recover a dynamic semicircular canal function was recently highlighted in patients with unilateral vestibular hypofunction (UVH). However, wide inter-individual differences were observed, suggesting that parameters other than early rehabilitation are involved. OBJECTIVE: The aim of the study was to determine to what extent the degree of vestibular loss assessed by the angular vestibulo-ocular reflex (aVOR) gain could be an additional parameter interfering with rehabilitation in the recovery process. And to examine whether different VR protocols have the same effectiveness with regard to the aVOR recovery. METHODS: The aVOR gain and the percentage of compensatory saccades were recorded in 81 UVH patients with the passive head impulse test before and after early VR (first two weeks after vertigo onset: N = 43) or late VR (third to sixth week after onset: N = 38) performed twice a week for four weeks. VR was performed either with the unidirectional rotation paradigm or gaze stability exercises. Supplementary outcomes were the dizziness handicap inventory (DHI) score, and the static and dynamic subjective visual vertical. RESULTS: The cluster analysis differentiated two distinct populations of UVH patients with pre-rehab aVOR gain values on the hypofunction side below 0.20 (N = 42) or above 0.20 (N = 39). The mean gain values were respectively 0.07±0.05 and 0.34±0.12 for the lateral canal (p < 0.0001), 0.09±0.06 and 0.44±0.19 for the anterior canal (p < 0.0001). Patients with aVOR gains above 0.20 and early rehab fully recovered dynamic horizontal canal function (0.84±0.14) and showed very few compensatory saccades (18.7% ±20.1%) while those with gains below 0.20 and late rehab did not improve their aVOR gain value (0.16±0.09) and showed compensatory saccades only (82.9% ±23.7%). Similar results were found for the anterior canal function. Recovery of the dynamic function of the lateral canal was found with both VR protocols while it was observed with the gaze stability exercises only for the anterior canal. All the patients reduced their DHI score, normalized their static SVV, and exhibited uncompensated dynamic SVV. CONCLUSIONS: Early rehab is a necessary but not sufficient condition to fully recover dynamic canal function. The degree of vestibular loss plays a crucial role too, and to be effective rehabilitation protocols must be carried out in the plane of the semicircular canals. [ABSTRACT FROM AUTHOR]

The syndrome of cerebellar ataxia with neuropathy and bilateral vestibular areflexia (CANVAS) has emerged progressively during the last 30 years. It was first outlined by the neurootology/neurophysiology community in the vestibular areflexic patients, through the description of patients slowly developing late-onset cerebellar ataxia and bilateral vestibulopathy. The characteristic deficit of visuo-vestibulo-ocular reflex (VVOR) due to the impaired slow stabilizing eye movements was put forward and a specific disease subtending this syndrome was suggested. The association to a peripheral sensory axonal neuropathy was described later on, with neuropathological studies demonstrating that both sensory neuropathy and vestibular areflexia were diffuse ganglionopathy. Clinical and electrophysiological criteria of CANVAS were then proposed in 2016. Besides the classical triad, frequent chronic cough, signs of dysautonomia and neurogenic pains were frequently observed. From the beginning of published cohorts, sporadic as well as familial cases were reported, the last suggestive of an autosomal recessive mode of transmission. The genetic disorder was discovered in 2019, under the form of abnormal biallelic expansion in the replication factor C subunit 1 (RFC1) in a population of late-onset ataxia. This pathological expansion was found in 100% of the familial form and 92% of sporadic ones when the triad was complete. But using the genetic criteria, the phenotype of CANVAS seems to expand, for exemple including patients with isolated neuronopathy. We propose here to review the clinical, electrophysiological, anatomical, genetic aspect of CANVAS in light of the recent discovery of the genetic aetiology, and discuss differential diagnosis, neuropathology and physiopathology. [ABSTRACT FROM AUTHOR]

The bedside examination associated with their clinical history remains the most critical means to accurately diagnose the cause for most of the signs and symptoms related to pathology of the cerebellum and vestibular system in patients presenting with dizziness and imbalance. This paper focuses on those critical bedside examinations, suggests when laboratory testing might be useful to confirm the clinical suspicion, and considers the shared neural circuitry within the visual and vestibular systems to offer an algorithmic approach in conducting the clinical bedside examination. [ABSTRACT FROM AUTHOR]

Background: In multiple sclerosis (MS), even in the presence of clinical brainstem symptoms, the brainstem does not always show gross lesions on magnetic resonance imaging (MRI). However, MS may impair vestibular-evoked myogenic potential (VEMP) responses. Material and methods: This study included 70 participants, 40 who were MS patients and 30 healthy adult volunteers as controls. All participants were subjected to history taking, otological examination, basic audiological evaluation, bedside examination of the dizzy patient, cervical VEMP (cVEMP), and ocular VEMP (oVEMP). Results: Of the 40 MS patients, 37.5% had abnormal cVEMP and 67.5% had abnormal oVEMP. Some 23% of the 21 MS patients without brainstem lesions on MRI had abnormal cVEMP and oVEMP, including 69% of those who had vertigo. MS patients with brainstem lesions on MRI had significantly greater oVEMP latency than patients without similar MRI findings. Conclusions: MS patients showed dysfunction in the vestibulo-ocular and vestibulo-spinal reflexes. This dysfunction is reflected in impaired oVEMP and cVEMP respectively despite the absence of structural brainstem abnormalities. Thus, VEMP, especially oVEMP, can be used as an early indicator of brainstem involvement in MS before radiological signs appear on MRI. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Purpose: There is a paucity of age- and vascular risk factor-stratified video head impulse test (vHIT) vestibulo-ocular reflex (VOR) data in the literature. The aim of this study was to investigate the vHIT VOR properties in healthy subjects of different ages and subjects with vascular risk factors. Methods: This was a prospective observational single-center study at a tertiary referral university hospital in northern Sweden. Healthy participants and subjects with vascular risk factors were investigated with a floor standing external camera vHIT device. Age-stratified mean VOR gain among healthy adults and between group gain and gain asymmetry differences were calculated. Results: We included eighty-eight healthy adults with a mean (range) age of 50 (22–85) years and n = 48 stroke ward patients with vascular risk factors (but without vestibular disease) with a mean (range) age of 74 (42–92) years. The mean VOR gain of horizontal canals decreased at higher ages in healthy subjects (r = − 0.32, p < 0.01, n = 167 canals). The age-stratified mean (SD) VOR gains were < 30 years: 0.98 (0.07), 30–39 years: 0.97 (0.07), 40–49 years: 0.98 (0.06), 50–59 years: 0.99 (0.06), 60–69 years: 0.93 (0.08), ≥ 70 years: 0.89 (0.15). No consistent differences between healthy subjects and subjects with vascular risk factors were seen except for a trend towards more pronounced gain asymmetries in the latter group. Conclusions: Age, but not vascular risk factors influence VOR gain. Age-adjusted vHIT-measurements may be useful in acute vertigo stroke risk differentiation. [ABSTRACT FROM AUTHOR]

The bilateral lateral medullary lesions disrupt both the inhibitory Purkinje outflow to bilateral vestibular nuclei and the climbing fibers participating in the cerebellar VOR adaptation, resulting in phenotypically identical HIS compared to the global cerebellar lesions. During vertical HITs for left or bilateral anterior canal semicircular canals, the VOR gain was slightly increased and small corrective saccades were followed in the anti-compensatory direction (Fig. Normally, vertical eye movements derived from each vertical canal are offset but not when the anterior canal gain is increased due to the vestibulocerebellar lesions [[9]]. [Extracted from the article]

Conversely, the involved SC function could likely be impaired in patients with BPPV presenting with persistent/long-lasting positional nystagmus, as in this condition otoconia might be partially entrapped in stenotic tracts of the membranous canal acting as an "incomplete" canalith jam [[2], [4]]. Letter to the editor regarding "Clinical significance of video head impulse test in benign paroxysmal positional vertigo: a meta-analysis" by Elsherif M et al. Therefore, we suggest that vHIT data of the affected canal might change depending on how and where otoconia are disposed within the canal [[4]] rather than on the affected canal itself. [Extracted from the article]

The video head impulse test (vHIT) assesses the vestibulo-ocular reflex (VOR) during a rapid high-velocity low amplitude (10°–20°) head rotation. Patients with peripheral vestibulopathy have a reduced VOR gain with corrective catch-up saccades during the head turn. There are several pitfalls, mainly technical, which may interfere with interpretation of vHIT data. In addition, intrusive eye movement disorders such as spontaneous nystagmus that affect normal eye position and tracking can affect the vHIT results. To date there has been little study of neurological saccadic eye movements that may interfere with the interpretation of vHIT data. Here, in ten patients with a range of central neurological disorders, we describe oculomotor abnormalities on vHIT in the presence of normal range VOR gain values, recorded at a tertiary vestibular neurology service. • Certain apparent catch-up saccades visible on the vHIT data may be due to the gaze-evoked nystagmus, induced by the head turn and transient eccentric positioning of the eyes. • Saccadic oscillations may affect the vHIT by appearing immediately after the head impulse and may be indistinguishable from an overt saccade if seen without clinical correlation. • Our cases highlight that oculomotor abnormalities can interfere with quantitative recording of the head impulse VOR responses and may impact the clinical diagnosis. [ABSTRACT FROM AUTHOR]

Benign Paroxysmal Positional Vertigo (BPPV) is among the most common vestibular disorders, characterized by brief vertigo spells triggered by head position changes with abrupt onset and rapid decrease. BPPV is ascribed to otoconial matter dislodged from utricular macula and attached to the cupula of the affected semicircular canal (cupulolithiasis) or free-floating within its lumen (canalolithiasis). According to the vestibulo-ocular reflex pathophysiology, each cupular deflection, either exciting or inhibiting the corresponding ampullary afferents, generates the contraction of specific extraocular muscles couples leading to pathognomonic nystagmus. The Upright BPPV Protocol (UBP) is a diagnostic approach to BPPV conducted in the sitting position slowly bending the patient's head along the spatial axes, aiming to move canaliths by gravity within the involved semicircular canal, under continuous nystagmus monitoring by video-Frenzel goggles. UBP starts with the evaluation of pseudo-spontaneous nystagmus in the primary gaze position and continues with the upright Head Pitch Test (uHPT) by forward and backward head bendings along the pitch plane. The uHPT can indicate whether horizontal or vertical semicircular canal is involved. If horizontal canal is suspected, the upright Head Roll Test (uHRT) usually provides the diagnosis of the involved side and arm by tilting the patient's head rightward and leftward along the roll plane. Conversely, canalolithiasis involving the posterior semicircular canal can be diagnosed with the uHPT alone. Nevertheless, if necessary, the diagnostic sensitivity can be increased by head movements along the right anterior – left posterior (RALP) and left anterior – right posterior (LARP) canal planes (uRALP/uLARP test). Following the UBP, most BPPV form can be diagnosed in upright position, allowing clinicians to proceed immediately with proper physical treatment and avoiding unpleasant maneuvers to patients. • BPPV diagnosis should be based on the step-by-step observation of the evoked nystagmus. • The Minimum Stimulus Strategy aims to minimize the patient's discomfort. • The Upright BPPV Protocol is performed in the sitting position through head movements along the spatial planes. • The sensitivity of the head pitch test for horizontal canal-BPPV is increased by the upright head roll test. • The sensitivity of the head pitch test for posterior canal-BPPV is increased by the upright RALP/LARP test. [ABSTRACT FROM AUTHOR]

Both Pendred syndrome (PS) and nonsyndromic hearing loss with an enlarged vestibular aqueduct (EVA) are autosomal recessive disorders caused by SLC26A4 pathogenic variants. The spectrum of SLC26A4 pathogenic variants varies with the ethnic background. Among the patients with EVA in Okinawa, 94% had some combination of NM_000441.2(SLC26A4):c.1707+5G>A and NM_000441.2(SLC26A4):c.2168A>G(p.His723Arg), the two SLC26A4 pathogenic variants that are the most common in this population. We identified these two pathogenic variants using a novel genotyping method that employed an allele-specific polymerase chain reaction (PCR) from a gDNA and single-stranded tag hybridization chromatographic printed-array strip (STH-PAS) in DNA samples obtained from 48 samples in Okinawa, including 34 patients with EVA and 14 carriers of c.1707+5G>A or c.2168A>G. In addition, whole blood and saliva samples were used for analysis in this genotyping method with direct PCR. The results of STH-PAS genotyping were consistent with those obtained using standard Sanger sequencing for all samples. The accuracy of the STH-PAS method is 100% under the optimized conditions. STH-PAS genotyping provided a diagnosis in 30 out of 34 patients (88%) in Okinawan patients with EVA in under 3 h. The turn-around time for STH-PAS genotyping used with direct PCR was 2 h as a result of the omission of the DNA extraction and purification steps. Using information about the ethnic distribution of pathogenic variants in the SLC26A4 gene, STH-PAS genotyping performs a rapid genetic diagnosis that is simple and has a considerably improved efficiency. [ABSTRACT FROM AUTHOR]

To evaluate the clinical and genetic features of children with hearing loss associated with one of the most common malformations of the inner ear: bilateral enlargement of vestibular aqueducts (EVA). Clinical and genetic features were investigated in 28 children with hearing loss diagnosed with bilateral EVA by computed tomography from January 2008 to September 2019. Fourteen subjects had undergone newborn hearing screening (NHS). Nine subjects (64.3%) were referred in both ears, 4 subjects (28.6%) were referred in one ear, and one subject (7.1%) passed in both ears. Nineteen of 26 subjects (73.1%) who were followed for more than 3 years had hearing fluctuations, while 17 (65.4%) had hearing loss progression. Eleven of 28 subjects (39.2%) had vertigo attacks. Pathogenic variants were identified in two alleles of the SLC26A4 gene in 24 of 27 subjects (88.9%) by sequencing of all exons and flanking introns, leading to genetic diagnosis of Pendred syndrome/DFNB4. Our results indicate that genetic screening for specific SLC26A4 variants using a commercial clinical laboratory test in Japan would have achieved genetic diagnoses in 13 of the 27 subjects (54.2%). Although there was no statistically significance in the frequency of hearing fluctuation or progression depending on the presence or absence of the gene variant, mean hearing level was severe in subjects with two pathogenic variants in SLC26A4 gene. The most common variant detected in our subjects was p.His723Arg (13 alleles, 27.1%), followed by c. 919-2A > G (four alleles, 8.3%). Two novel variants were detected in this study: c.1544+1G > T and c.1614+5G > A. Our data suggest that some subjects may present with bilateral EVA that cannot be detected by NHS. We estimated that genetic diagnosis for SLC264 gene would not have been made in almost half subjects with the commercial genetic screening approach used in the present study in Japan. Although there were some limitations in this study, the subjects with pathogenic variants in two alleles of the SLC26A4 gene could have more severe hearing loss. [ABSTRACT FROM AUTHOR]