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Introduction: The aim of the study was to evaluate the vestibulo-ocular reflex (VOR) using the video head impulse test (vHIT) as a vestibular function assessment method in patients with unilateral chronic otitis media (COM). Methods: Twenty-eight patients with unilateral COM scheduled for middle ear surgery, including 12 males and 16 females with a mean age of 54.5 years, successfully underwent preoperative vHIT. vHIT variables, including VOR gain, VOR gain asymmetry, and the incidence of corrective saccades, were compared between the ipsilesional and contralesional ears. Results: Ten (35.7%) patients reported varying degrees of disequilibrium or lightheadedness. The VOR gain in the ipsilesional and contralesional ears was 1.01 ± 0.10 and 1.04 ± 0.11, 0.97 ± 0.12 and 0.94 ± 0.13, and 0.97 ± 0.13 and 1.04 ± 0.15 in the horizontal canal (HC), anterior canal, and posterior canal (PC), respectively. The average VOR gains in the ipsilesional ears were within the predefined range of normal values; however, the gains in HC and PC significantly decreased compared with those in contralesional ears (p = 0.038 in HC and p = 0.015 in PC). The prevalence of corrective saccades, including overt and/or covert saccades, did not differ significantly between the two ears. Conclusion: This study assessed the pathophysiology of the inner ear affected by chronic middle ear infection by quantitatively comparing the VOR using vHIT. It demonstrated that vHIT can be a practical assessment of vestibular function in patients with COM. [ABSTRACT FROM AUTHOR]

We report a rare case of isolated malleus dislocation into the external auditory canal with lateralized intact tympanic membrane following a head trauma. The patient was a 63-year-old woman who presented at the outpatient department of our institute with hearing loss of 10 years' duration after a bicycle accident. During physical examination of the patient, total dislocation of the malleus-like bony structure into the external auditory canal on the right side was observed. In the computed tomography scan, an isolated malleus dislocation with intact incus-stapes articulation was identified. The patient was successfully treated with endoscopic exploratory tympanotomy and partial ossicular replacement prosthesis. The isolated malleus dislocation can rarely occur after trauma. A careful diagnostic step through history, physical examination, and temporal bone computed tomography scan are needed to confirm this rare condition. [ABSTRACT FROM AUTHOR]

Objective: Tinnitus is a common symptom of idiopathic sudden sensorineural hearing loss (ISSHL). This study aimed to investigate the characteristics and outcomes of acute tinnitus in patients with ISSHL. Methods: A total of 59 patients with ISSHL and acute tinnitus were enrolled. All patients underwent audiological assessment, tinnitus matching for loudness and frequency, and steroid treatment for sudden hearing loss. Tinnitus‐related distress was assessed using the tinnitus handicap inventory (THI) questionnaire. The outcomes of hearing recovery and tinnitus remission were investigated retrospectively. Results: The loudness and pitch of acute tinnitus were 63.2 ± 22.4 dB HL and 2010.63 ± 2368.99 Hz, respectively. Complete and partial recovery rates of acute tinnitus in ISSHL patients were 32.2% and 39% according to the THI scores. The group with complete recovery of hearing showed significantly greater improvement in tinnitus distress than the group with no improvement in hearing. The loudness and pitch of tinnitus did not correlate with tinnitus remission. Conclusion: Hearing recovery is more important for tinnitus remission than the psychoacoustic characteristics of acute tinnitus. Timely identification and proper treatment of hearing loss are important to improve tinnitus remission in patients with ISSHL. Level of Evidence: Level 4. [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]

Objectives: To evaluate the efficacy of galvanic vestibular stimulation (GVS) for recovering from the locomotor and spatial memory deficits of a murine bilateral vestibular deafferentation (BVD) model. Methods: Male C57BL/6 mice (n = 36) were assigned to three groups: bilateral labyrinthectomy with (BVD_GVS group) and without (BVD_non-GVS group) the GVS intervention, and a control group with the sham operation. We used the open field and Y maze, and Morris water maze (MWM) tests to assess locomotor and visuospatial cognitive performance before (baseline) and 3, 7, and 14 days after surgical bilateral labyrinthectomy. For the GVS group, a sinusoidal current at the frequency at 1 Hz and amplitude 0.1 mA was delivered for 30 min daily from the postoperative day (POD) 0 to 4 via electrodes inserted subcutaneously close to both the bony labyrinths. Results: Short-term spatial memory was significantly impaired in bilaterally labyrinthectomized mice (BVD_non-GVS group), as reflected by decreased spontaneous alternation performance in the place recognition test and time spent in the novel arm and increased same arm return in the Y-maze test, compared with the control. Long-term spatial memory was also impaired, as indicated by a longer escape latency in the hidden platform trial and a lower percentage of time spent in the target quadrant in the probe trial of the MWM. GVS application significantly accelerated the recovery of locomotion and short-term and long-term spatial memory deficits in the BVD mice. Conclusions: Our data demonstrate that locomotion, short-term, and long-term (at least 2 weeks) spatial memory were impaired in BVD mice. The early administration of sinusoidal GVS accelerated the recovery of those locomotion and spatial memory deficiencies. GVS could be applied to patients with BVD to improve their locomotion and vestibular cognitive functioning. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the disparity in locomotor and spatial memory deficits caused by left- or right-sided unilateral vestibular deafferentation (UVD) using a mouse model of unilateral labyrinthectomy (UL) and to examine the effects of galvanic vestibular stimulation (GVS) on the deficits over 14 days. Five experimental groups were established: the left-sided and right-sided UL (Lt.-UL and Rt.-UL) groups, left-sided and right-sided UL with bipolar GVS with the cathode on the lesion side (Lt.-GVS and Rt.-GVS) groups, and a control group with sham surgery. We assessed the locomotor and cognitive-behavioral functions using the open field (OF), Y maze, and Morris water maze (MWM) tests before (baseline) and 3, 7, and 14 days after surgical UL in each group. On postoperative day (POD) 3, locomotion and spatial working memory were more impaired in the Lt.-UL group compared with the Rt.-UL group (p < 0.01, Tamhane test). On POD 7, there was a substantial difference between the groups; the locomotion and spatial navigation of the Lt.-UL group recovered significantly more slowly compared with those of the Rt.-UL group. Although the differences in the short-term spatial cognition and motor coordination were resolved by POD 14, the long-term spatial navigation deficits assessed by the MWM were significantly worse in the Lt.-UL group compared with the Rt.-UL group. GVS intervention accelerated the vestibular compensation in both the Lt.-GVS and Rt.-GVS groups in terms of improvement of locomotion and spatial cognition. The current data imply that right- and left-sided UVD impair spatial cognition and locomotion differently and result in different compensatory patterns. Sequential bipolar GVS when the cathode (stimulating) was assigned to the lesion side accelerated recovery for UVD-induced spatial cognition, which may have implications for managing the patients with spatial cognitive impairment, especially that induced by unilateral peripheral vestibular damage on the dominant side. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the ameliorating effects of sinusoidal galvanic vestibular stimulation (GVS) on vestibular compensation from unilateral vestibular deafferentation (UVD) using a mouse model of unilateral labyrinthectomy (UL). Methods: Sixteen male C57BL/6 mice were allocated into two groups that comprise UL groups with GVS (GVS group, n = 9) and without GVS intervention (non-GVS group, n = 7). In the experimental groups, we assessed vestibulo-ocular reflex (VOR) recovery before (baseline) and at 3, 7, and 14 days after surgical unilateral labyrinthectomy. In the GVS group, stimulation was applied for 30 min daily from postoperative days (PODs) 0–4 via electrodes inserted subcutaneously next to both bony labyrinths. Results: Locomotion and VOR were significantly impaired in the non-GVS group compared to baseline. The mean VOR gain of the non-GVS group was attenuated to 0.23 at POD 3 and recovered continuously to the value of 0.54 at POD 14, but did not reach the baseline values at any frequency. GVS intervention significantly accelerated recovery of locomotion, as assessed by the amount of circling and total path length in the open field tasks compared to the non-GVS groups on PODs 3 (p < 0.001 in both amount of circling and total path length) and 7 (p < 0.01 in amount of circling and p < 0.001 in total path length, Mann–Whitney U -test). GVS also significantly improved VOR gain compared to the non-GVS groups at PODs 3 (p < 0.001), 7 (p < 0.001), and 14 (p < 0.001, independent t -tests) during sinusoidal rotations. In addition, the recovery of the phase responses and asymmetry of the VOR was significantly better in the GVS group than in the non-GVS group until 2 weeks after UVD (phase, p = 0.001; symmetry, p < 0.001 at POD 14). Conclusion: Recoveries for UVD-induced locomotion and VOR deficits were accelerated by an early intervention with GVS, which implies that GVS has the potential to improve vestibular compensation in patients with acute unilateral vestibular failure. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the deficits of spatial memory and navigation from unilateral vestibular deafferentation (UVD) and to determine the efficacy of galvanic vestibular stimulation (GVS) for recovery from these deficits using a mouse model of unilateral labyrinthectomy (UL). Methods: Thirty-six male C57BL/6 mice were allocated into three groups that comprise a control group and two experimental groups, UVD with (GVS group) and without GVS intervention (non-GVS group). In the experimental groups, we assessed the locomotor and cognitive behavioral function before (baseline) and 3, 7, and 14 days after surgical UL, using the open field (OF), Y maze, and Morris water maze (MWM) tests. In the GVS group, the stimulations were applied for 30 min daily from postoperative day (POD) 0–4 via the electrodes inserted subcutaneously close to both bony labyrinths. Results: Locomotion and spatial cognition were significantly impaired in the mice with UVD non-GVS group compared to the control group. GVS significantly accelerated recovery of locomotion compared to the control and non-GVS groups on PODs 3 (p < 0.001) and 7 (p < 0.05, Kruskal–Wallis and Mann–Whitney U tests) in the OF and Y maze tests. The mice in the GVS group were better in spatial working memory assessed with spontaneous alternation performance and spatial reference memory assessed with place recognition during the Y maze test than those in the non-GVS group on POD 3 (p < 0.001). In addition, the recovery of long-term spatial navigation deficits during the MWM, as indicated by the escape latency and the probe trial, was significantly better in the GVS group than in the non-GVS group 2 weeks after UVD (p < 0.01). Conclusions: UVD impairs spatial memory, navigation, and motor coordination. GVS accelerated recoveries in short- and long-term spatial memory and navigation, as well as locomotor function in mice with UVD, and may be applied to the patients with acute unilateral vestibular failure. [ABSTRACT FROM AUTHOR]

Objective: In the present study, we characterized the vestibulo-ocular reflex (VOR) gain and properties of corrective saccades (CS) in patients with posterior inferior cerebellar artery (PICA) stroke and determined the best parameter to differentiate PICA stroke from benign peripheral vestibular neuritis (VN). In particular, we studied CS amplitude and asymmetry in video head impulse tests (vHITs) to discriminate these two less-studied disease conditions. Methods: The vHITs were performed within 1 week from symptom onset in patients with PICA stroke (n = 17), patients with VN (n = 17), and healthy subjects (HS, n = 17). Results: PICA stroke patients had bilaterally reduced VOR gains in the horizontal semicircular canal (HC) and the posterior semicircular canal (PC) compared with HSs. When compared with VN patients, PICA stroke patients showed preserved gains in the HC and anterior semicircular canal (AC) bilaterally (i.e., symmetric VOR gain). Similar to VOR gain, smaller but bilaterally symmetric CS in the HC and AC were observed in PICA stroke patients compared with VN patients; the mean amplitude of CS for the ipsilesional HC was reduced (p < 0.001, Mann–Whitney U -test), but the mean amplitude of CS for the contralesional HC was increased (p < 0.03, Mann–Whitney U -test) in PICA stroke compared with VN. The receiver operating characteristic (ROC) curve showed that CS amplitude asymmetry (CSs) and VOR gain asymmetry (Gs) of HC are excellent parameters to distinguish PICA stroke from VN. Conclusion: In the current study, we quantitatively investigated the VOR gain and CS using vHITs for three semicircular canals in PICA stroke and VN patients. In addition to VOR gain, quantitative assessments of CS using vHITs can provide sensitive and objective parameters to distinguish between peripheral and central vestibulopathies. [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis: To investigate the efficacy of direct implantation of a Vibrant Soundbridge (VSB) implant in the oval window (OW) without the use of an OW coupler in patients with severe mixed hearing loss. Study Design Retrospective chart review Methods: A total of 62 patients underwent VSB implantation between July 2016 and December 2018 at Severance Hospital in Seoul, South Korea. Among them, eight patients (nine ears) with moderate‐to‐severe mixed hearing loss were implanted with a VSB directly in the OW. A floating mass transducer (FMT) was attached to the stapes footplate and covered with tragal cartilage. The outcomes were evaluated using pure‐tone audiogram and speech audiogram preoperatively and postoperatively. Word recognition score (WRS; % correct) were measured at the most comfortable loudness (MCL) level to evaluate speech perception. Results: All cases posed difficulty with round window vibroplasty during surgery, and eventually, an FMT was appropriately placed in the OW without a coupler. Preoperative and postoperative bone conduction thresholds were not different. VSB‐aided threshold improved in terms of functional and effective gains. Interestingly, four cases showed improved air conduction thresholds without the use of a VSB. In addition, MCL level with a VSB was significantly lower than that with a hearing aid, and VSB‐aided WRS improved over time. Conclusions: Direct implantation of a VSB in the OW without the use of a coupler showed favorable hearing outcomes, and the OW vibroplasty was safe. Direct OW vibroplasty without a coupler is a reliable procedure and can be a good option for hearing rehabilitation in patients with severe mixed hearing loss. Level of Evidence: 4 Laryngoscope, 2020 [ABSTRACT FROM AUTHOR]

Vestibular schwannoma (VS) originates from Schwann cells in the superior or inferior vestibular nerve. Identifying the precise origin will help in determining the optimal surgical approach. We retrospectively analyzed the preoperative vestibular function test according to VS origin to determine whether the test is a valuable indicator of tumor origin. Forty-seven patients with VS (male:female = 18:29, mean age: 54.06 ± 13.50 years) underwent the cochleovestibular function test (pure-tone audiometry, caloric test, video head impulse test (vHIT), cervical and ocular vestibular-evoked myogenic potential, and posturography). All patients then underwent surgical removal of VS, and the schwannoma origin was confirmed. The tumor originated from the superior vestibular nerve (SVN group) in 21 patients, the inferior vestibular nerve (IVN group) in 26 patients, and an undetermined site in eight patients. The only value that differed significantly among the groups was the gain of the vestibular-ocular reflex (VOR) in the ipsilesional posterior canal (iPC) during the vHIT. Our results indicate that VOR gain in the iPC may be used to predict the nerve origin in patients with VS. Other cochleovestibular function tests have limited value to discriminate nerve origins, especially in cases of medium to large VS. [ABSTRACT FROM AUTHOR]

Background: Many mutations in the α-tectorin gene (TECTA) have been reported to cause non-syndromic hearing loss (NSHL) in either a dominant or recessive inheritance pattern. Among the identified TECTA mutations, H1400Y has been associated with NSHL in two independent studies. However, its exact role in contributing to genetic hearing loss remains elusive. Case presentation: We herein report the whole-exome sequencing of a proband presenting with prelingual, non-progressive, mild-to-moderate hearing loss in a simplex family. By using trio-based whole-exome sequencing, we found two heterozygous mutations of R1890C and H1400Y in the ZP and ZA domains of TECTA, respectively. R1890C, previously reported as a pathogenic autosomal dominant mutation of genetic hearing loss, was found to be inherited in a de novo pattern, causing hearing loss in the proband. By contrast, H1400Y was not segregated in this family, and one family member with normal hearing also carried the H1400Y mutation. Conclusion: According to the hearing loss-specific American College of Medical Genetics and Genomics (ACMG) guidelines, we conclude that H1400Y should be disqualified as a cause of genetic hearing loss. True pathogenic variants causing genetic hearing loss should be more deliberately reported in accordance with ACMG guidelines. [ABSTRACT FROM AUTHOR]