Semicircular Canal Research Articles

A Clinical Framework for Video Head Impulse Testing and Vestibular Evoked Myogenic Potential Assessments in Primary School-Aged Children.

This study aimed to offer normative data and age trends of an age-appropriate vestibular test protocol in a large group (n = 140) of school-aged children (6 to 13 years old) as well as to provide a practical and clinical framework for accurate performance and interpretation of vestibular test results in this specific age group. The typically developing participants (mean age of 9.51 ± 2.04 years) were recruited to provide a representative group of 20 children for each of the seven age groups that were composed of children aged from 6 to 13 years in 1-year intervals. Each age group consisted of 10 boys and 10 girls. The protocol comprises the video head impulse test, and cervical and ocular vestibular evoked myogenic potential assessments to provide a child-friendly, noninvasive, short, and portable test battery, which is equally applicable in the hospital and office-practice, and which provides information on the integrity of all five parts of the peripheral vestibular system. The study demonstrates that all included tests and methods, with an overall test duration of 25 min 12 sec ± 5 min 10 sec, were feasible to perform in primary school-aged children, taking into account some practical adaptations. Concerning the video head impulse test, no clinically relevant sex and age effects were noted. However, t tests revealed significant differences for the mean gain of the horizontal (right > left; t[139] = 14.563; p < 0.001) and posterior semicircular canals (left > right; t[139] = -4.823; p < 0.001) between both sides. For the cVEMP assessment, no laterality differences were observed for any of the parameters, but a significantly shorter N1 latencies in the youngest age categories (<8 years), compared with the oldest groups were observed [F(6,118) = 8.336; p < 0.001; partial ƞ² = 0.298]. For all oVEMP parameters, no laterality, sex, or age differences were seen. On the basis of the presented normative data, cutoff criteria were proposed with accompanying clinical recommendations to perform vestibular function testing in this target population. This is the first study in a large group of school-aged children offering normative data and age trends of an age-appropriate vestibular test protocol that evaluates the integrity of all parts of the peripheral vestibular organ. The reported normative values and clinical cutoff values will enable appropriate and age-specific interpretation of clinical and scientific results. Moreover, in combination with extensive history taking, and additional vestibular testing (e.g., rotatory chair test, caloric testing) when needed, the results of this study may support clinicians in the diagnosis of side-specific and location-specific vestibular deficits, which is required for accurate counseling and referral for further follow-up and/or intervention.

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

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

Tỷ lệ và phân loại chóng mặt tư thế kịch phát lành tínhống bán khuyên ngang tại Bệnh viện Quân y 175

Objective: To determine the prevalence of benign paroxysmal positional vertigo (BPPV) in the horizontal semicircular canal and classify the mechanism at Military Hospital 175.Methods: A cross-sectional study conducted at the Department of Neurology, Military Hospital 175, from March 2022 - September 2023, patients were examined and performed positioning tests on the videonystagmography system. Patients with atypical results were examined with imaging and the HINT test. Patients with BPPV were included in the analysis.Results: 466 cases were diagnosed with BPPV. 133 patients had horizontal semicircular canal BPPV, accounting for 28.54% of BPPV cases. In the group of 133 patients with horizontal semicircular canal BPPV, 116 cases were due to otoliths in the semicircular canal (canalithiasis), accounting for 87.22%; 14 cases were due to otoliths on the cupula (cupulothiasis), accounting for 10.53%; 3 cases were due to light cupula mechanism, accounting for 2.26%.Conclusion: The prevalence of horizontal semicircular canal BPPV was 28.54% in BPPV patients, higher than other previous studies in Europe. 87.22% of horizontal semicircular canal BPPV were hii due to stones in the semicircular canal, 10.53% were due to stones in the semicircular canal and 2.26% were due to light cupula mechanism. Performing a positioning head roll test in addition to the Dix-Hallpike test is necessary to avoid missing horizontal semicircular canal BPPV.

Anterior Canal BPPV- A Rare Form of Vertical Canaloliathiasis: Series of 11 Cases.

The most common cause of peripheral vertigo is Benign Paroxysmal Positional Vertigo (BPPV) primarily due to involvement of posterior semicircular canal. BPPV due to anterior canal is rare entity. This is a retrospective study, in which data of 628 patients who underwent vertigo test were analyzed. Amongst which 354 were patients of BPPV. It was found that 305 patients had posterior canal BPPV, 18 patients had lateral canal BPPV and 11 patients had anterior canal BPPV. The VNG data of 11 patients with anterior canal BPPV along with their treatment outcomes was analyzed. Of the eleven patients of anterior canal BPPV, ten patients had torsional nystagmus with or without downbeat nystagmus in Deep Head Hanging test. Only one patient had isolated downbeat nystagmus in Supine Head Hanging Test. Patients were treated with modified Yacovino's maneuver. Eight patients had immediate relief with modified Yacovino's repositioning maneuver. One patient had immediate conversion to left posterior canal BPPV and was treated for the same. Two patients presented with delayed conversion to posterior canal BPPV and were treated for the same. Anterior canal BPPV is rare but existent entity. It has a typical torsional and downbeat Nystagmus which is induced by Dix-Hallpike and Deep head hanging test. There is no reversal of nystagmus on getting up. It can be easily corrected by Yacovino's maneuver in the majority of the cases.

Otic Capsule Dehiscences Simulating Other Inner Ear Diseases: Characterization, Clinical Profile, and Follow-Up-Is Ménière's Disease the Sole Cause of Vertigo and Fluctuating Hearing Loss?

We present a series of six cases whose clinical presentations exhibited audiovestibular manifestations of a third mobile window mechanism, bearing a reasonable resemblance to Ménière's disease and otosclerosis. The occurrence of these cases in such a short period has prompted a review of the underlying causes of its development. Understanding the pathophysiology of third mobile window syndrome and considering these entities in the differential diagnosis of conditions presenting with vertigo and hearing loss with slight air-bone gaps is essential for comprehending this group of pathologies. A descriptive retrospective cohort study of six cases diagnosed at a tertiary center. All of them went through auditive and vestibular examinations before and after a therapeutic strategy was performed. Out of 84 cases of dehiscences described in our center during the period from 2014 to 2024, 78 belonged to superior semicircular canal dehiscence, while 6 were other otic capsule dehiscences. Among these six patients with a mean age of 47.17 years (range: 18-73), all had some form of otic capsule dehiscence with auditory and/or vestibular repercussions, measured through hearing and vestibular tests, with abnormalities in the results in five out of six patients. Two of them were diagnosed with Ménière's disease (MD). Another two had cochleo-vestibular hydrops without meeting the diagnostic criteria for MD. In two cases, the otic capsule dehiscence diagnosis resulted from an intraoperative complication due to a gusher phenomenon, while in one case, it was an accidental radiological finding. All responded well to the proposed treatment, whether medical or surgical, if needed. Otic capsule dehiscences are relatively new and unfamiliar entities that should be considered when faced with cases clinically suggestive of Ménière's disease, with discrepancies in complementary tests or a poor response to treatment. While high-sensitivity and specificity audiovestibular tests exist, completing the study with imaging, especially petrous bone CT scans, is necessary to locate and characterize the otic capsule defect responsible for the clinical presentation.

Evaluation of semicircular canal and otolith graviceptive pathway function in patients diagnosed with motion sickness disorder based on the diagnostic criteria of the Bárány society

Objective: To investigate the altered function of the semicircular canal and otolith graviceptive pathway in patients diagnosed with motion sickness disorder (MSD) based on the diagnostic criteria of the Bárány society, and explore its relevance to the pathogenesis of MSD. Methods: This is a case-control study. Twenty patients with MSD and age-and sex-matched healthy controls without a history of MSD from the Department of Neurology of Aerospace Center Hospital between March and August 2022 were recruited. All subjects completed the motion sickness susceptibility questionnaire-short version (MSSQ-short) and the motion sickness assessment questionnaire (MSAQ). Canal function was evaluated using caloric stimulation test and video head impulse test (vHIT), and subjective visual vertical/horizontal (SVV/SVH) and vestibular evoked myogenic potential (VEMP) were employed to assess otolith graviceptive function. Differences in vestibular function and correlations between the two groups were analyzed. Results: Each group consisted of 20 cases (9 males and 11 females). The mean age of the MSD and control groups was (26.9±3.9) years and (27.0±3.4) years, respectively. The scores of MSSQ-short [27.0 (22.5, 38.8) vs 1.2 (0, 3.2), P<0.001] and MSAQ [70.1 (54.5, 78.1) vs 11.8 (11.1, 13.9), P<0.001] were significantly higher in the MSD group compared with those of the control group. Evaluation of canal function revealed a significantly higher incidence of caloric stimulation intolerance in MSD patients (60.0%, 12/20) compared with that of the control group (20.0%, 4/20) (P=0.010). Evaluation of otolith graviceptive pathway indicated no significant difference in SVV, SVH and cervical VEMP (cVEMP) abnormality rates between the two groups (all P>0.05). The ocular VEMP (oVEMP) abnormality rate was significantly higher in the MSD group (55.0%, 11/20) than that of the control group (10.0%, 2/20) (P=0.002), with a delayed P1-wave latency compared with the control group [(18.4±1.2) ms vs (17.6±0.8) ms, P=0.018]. Further correlation analysis revealed that P1-wave latency in oVEMP was positively correlated with MSSQ-short (r=0.486, P=0.002) and MSAQ (r=0.391, P=0.015) scores, and duration of caloric intolerance symptoms (r=0.377, P=0.004). Conclusion: The presence of hypersensitivity to caloric stimulation and delayed latency of otolith function in patients with MSD suggests a "separation" between semicircular canal and otolithic function, which may be related to sensory conflict.

Clinical features and temporal CT findings in patients with Branchio-Oto-Renal or Branchio-Oto Syndrome

Objective: To assess the clinical features and CT diagnostic characteristics of Branchio-Oto-Renal or Branchio-Oto Syndrome. Methods: The temporal CT findings and clinical features observations of 13 patients with Branchio-Oto-Renal Syndrome (BORS) or Branchio-Oto Syndrome(BOS) confirmed by genetic testing were retrospectively analyzed. There were 8 males and 5 females, aged from 1 to 39 years, with a median age of 9 years, in which 3 pairs (6 cases) were parent-child relationship. Results: All of 13 cases had hearing loss and preauricular fistula, 11 cases accompanied by 2nd branchial fistulas. There were 20 ears of mixed hearing loss, 3 ears of sensorineural hearing loss, and 2 ears of conductive hearing loss. The mutation point of gene testing was located in EYA1 in 12 cases and SIX1 in 1 case. Twenty ears showed gradually narrowing of the diameter of basal turn, with hypoplasia in the second turn and aplasia in apical turn. There were irregular wall of vestibule and horizontal semicircular canal in 10 ears,widened vestibular in 7 ears, and vestibular fusion with horizontal semicircular canal in 3 ears. Three ears had an enlarged vestibular aqueduct, 8 ears showed enlargement of internal auditory canal. Seventeen ears had adhesion of malleolus to tympanic cavity. Six ears could not measured the incudostapedial joint angle by reason of tympanic inflammatory cover, 3 ears could not show incudostapedial joint, and 8 ears showed the incudostapedial joint angle more than 122°. Six ears showed poor oval window, and 1 ear had poor round window. Eighteen ears showed distended eustachian tube, and accompanied by tympanic or mastoiditis in 11 ears. Anterolateral shift of tympanum was found in 22 ears, 17 ears had low middle cranial fossa, and 3 ears had stenotic external auditory canal. Conclusions: Cochlear dysplasia, ossicular chain malformation and distended eustachian tube comprise the characteristic CT signs of BOS/BORS, which possesses versatile and complex CT findings. Temporal CT can accurately assess the important structures such as cochlea, ossicles, vestibule, semicircular canal, vestibular aqueduct and internal auditory canal. Combing with the clinical characteristics of bilateral, mixed hearing loss, preauricular fistula and branchial fistula can provide valuable information for early diagnosis and treatment.

Comparison of Laminectomy with Fusion and Laminoplasty Treating Multilevel Cervical Spondylotic Myelopathy: A Single-Center Retrospective Study

Comparing laminectomy with fusion (LF) and laminoplasty (LP) for treating multilevel cervical spondylotic myelopathy (MCSM) and comparative analysis of neck pain and sagittal cervical parameters. This single-center study retrospectively analyzed MCSM patients treated with LF or LP in our department between June 2018 and January 2023, with at least a 12-month follow-up. T-tests were used to identify operation time, hemoglobin, hospital stay, modified Japanese Orthopaedic Association (mJOA) score, C2-C7 Cobb angle, C2-C7 sagittal vertical axis, T1 slope, cervical range of motion (cROM), and C4/5 anterior and posterior spinal canal diameter (A-P diameter) and area. Nonparametric tests were used to identify visual analog scale (VAS) score (assessing neck pain). Pearson correlation analyses were used to identify the neck pain. Of all 67 patients (LF: 24, LP: 43), both groups' mJOA scores significantly improved (P<0.001). The VAS scores had both significantly decreased, with the LF group exhibiting a more marked reduction (LF: P<0.001, LP: P=0.037). Both groups' C4/5 A-P diameters and areas increased significantly (P<0.001). The cROM had both significantly decreased, with the LF group exhibiting a greater reduction. At the last follow-up, the LF group's T1 slope and C2-C7 Cobb angle considerably increased, and pain VAS scores substantially correlated with the C2-C7 Cobb angle (R=-0.451, P<0.001). LF and LP were efficacious for MCSM. LF relieved neck pain better but caused greater reduction in cervical mobility. Cervical lordosis improvement was significantly correlated with neck pain alleviation.

Topographic Radioanatomical Analysis of the Singular Canal: Computed Tomography Study

Purpose: The singular canal (SC) is where the singular nerve, a branch of the inferior vestibular nerve, which carries afferent information from the posterior semicircular canal (PSCC), passes and is important in the surgical approach of the presigmoid retrolabyrinthine. This study was carried out to evaluate the visibility of the SC on standard computed tomography (CT) images, its distance to the surrounding structures, and to investigate the variations of its anatomy and its relationship with the meatus acusticus internus. Materials and Methods: The study was carried out retrospectively using images of 194 temporal bones on temporal bone CT scans of 44 men and 53 women aged 18–65. In the study, various measurements were made, especially the presence of the SC, its length, its angle with the internal acoustic canal (IAC), and the distance between the internal acoustic pore (IAP) and the singular foramen. In addition, the presence of the high jugular bulb and PSCC dehiscence images were investigated. Results: The SC was detected in 85.1% of the analyzed images. The mean canal length was 3.93 ± 1.22 mm, the angle between the SC and the IAC was 22.68° ±3.60°, and the distance between the SC and the IAP was 7.70 ± 0.83 mm. While no difference was found between the sides, it was determined that the length and diameter of the SC did not differ according to gender. Conclusion: Detailed morphometric analysis of the SC and a thorough understanding of its relationship with the IAC, vestibulum, and PSCC will help to accurately define the posterior and lateral borders of the dissection for this region.

Evaluation of oVEMP and cVEMP in Superior Semicircular Canal Dehiscence Cases

Superior semisircular canal dehiscence (SSCD) is a disease of the audiovestibular system, which occurs as a result of the lack of bone layer covering the superior semisircular canal. The disease forms a third window in the inner ear due to the lack of bone layer. The third window that occurs forms a pseudo conductive type of hearing loss, which has decreased bone thresholds in the audiometry test. Vestibular evoked myogenic potentials are an electrophysiological measurement method in which the responses of the neck or eye muscles to an acoustic stimulus are recorded by means of electrodes. The purpose of use is to evaluate the functions of the urticle and saccule, which are the vestibular end organs. Therefore its primary purpose is to diagnose semicircular canal dehiscence. This review is based on research from the last decade; diagnostic results of ocular vestibular evoked myogenic potentials (oVEMP) and cervical vestibular evoked myogenic potentials (cVEMP) tests were evaluated in cases of superior semicircular canal dehiscence (SSCD). Studies indicate abnormal decreases in cVEMP test thresholds on the affected side in SSCD cases. Additionally, a significant increase in oVEMP amplitude on the affected side has been reported. Results; It shows that evaluating these two tests together will contribute to the diagnosis of semicircular canal dehiscence cases.

Educational simulator for mastoidectomy considering mechanical properties using 3D printing and its usability evaluation

Complex temporal bone anatomy complicates operations; thus, surgeons must engage in practice to mitigate risks, improving patient safety and outcomes. However, existing training methods often involve prohibitive costs and ethical problems. Therefore, we developed an educational mastoidectomy simulator, considering mechanical properties using 3D printing. The mastoidectomy simulator was modeled on computed tomography images of a patient undergoing a mastoidectomy. Infill was modeled for each anatomical part to provide a realistic drilling sensation. Bone and other anatomies appear in assorted colors to enhance the simulator’s educational utility. The mechanical properties of the simulator were evaluated by measuring the screw insertion torque for infill specimens and cadaveric temporal bones and investigating its usability with a five-point Likert-scale questionnaire completed by five otolaryngologists. The maximum insertion torque values of the sigmoid sinus, tegmen, and semicircular canal were 1.08 ± 0.62, 0.44 ± 0.42, and 1.54 ± 0.43 N mm, displaying similar-strength infill specimens of 40%, 30%, and 50%. Otolaryngologists evaluated the quality and usability at 4.25 ± 0.81 and 4.53 ± 0.62. The mastoidectomy simulator could provide realistic bone drilling feedback for educational mastoidectomy training while reinforcing skills and comprehension of anatomical structures.

The Safety and Efficacy of Hydroxyapatite Repair of Cholesteatoma Skull Base Defects.

To investigate the possibility of hydroxyapatite as a safe and effective alternative to currently used bioavailable materials for repair of tegmen defects and labyrinthine fistulas in the setting of cholesteatoma. Retrospective study. Tertiary-level-care hospital. Electronic medical records of patients 18+ years undergoing cholesteatoma-removal surgery between 2013 and 2022 were reviewed. Twenty-two patients diagnosed with cholesteatoma who underwent repair of either a tegmen defect or labyrinthine fistula using hydroxyapatite were evaluated. There were 17 canal wall up (CWU) and 5 canal wall down (CWD) surgeries. The cholesteatoma recidivism rate was 18.2% (n = 4) and the recurrence rate was 4.5% (n = 1). To ensure that these rates were similar to cholesteatoma-removal surgeries in which hydroxyapatite was not used, a 22 age, gender, and operative technique-matched cohort was evaluated. For patients with CWU surgeries, the rate of recurrence and recidivism were identical between both cohorts (0% and 23.5%, respectively; P = 1 for both). While in CWD surgeries, there was a nonstatistically significant difference in the recurrence as there was only 1 patient with recurrence in the hydroxyapatite group (P = 1). Three (13.5%) patients in the hydroxyapatite group had a local infection and 1 (4.5%) had a subacute mastoid infection. All patients with semicircular canal fistulas had consistent bone lines on postoperative audiograms, with no worsening sensorineural hearing loss. In our cohort, hydroxyapatite was safe and successful in repairing skull base defects and inner-ear fistulas in the setting of cholesteatoma with a low rate of postoperative infection and no evidence of a higher rate of cholesteatoma recurrence. Further studies are needed to assess population generalizability.

Clinical features of congenitally enlarged bony portion of Eustachian tube

Objective:To investigate the clinical features of patients with congenitally enlarged bony portions of the Eustachian tube（ET）. Methods:The medical history, physical examination, hearing test, temporal bone high resolution computed tomography（HRCT） of six patients（nine ears） with congenitally enlarged bony portion of the ET were retrospectively analyzed. Results:Four patients were men and two were women. The minimum, maximum, and average ages were 5, 21, and（14.7±6.4） years, respectively. Three malformations were bilateral and three were left-sided. Three ears had conductive hearing loss（average bone and air conduction thresholds were 13.7 dB and 71.3 dB）, three had mixed hearing loss（average bone and air conduction thresholds were 27.7 dB and 83.7 dB）, and one had extremely severe sensorineural hearing loss. The average maximum length and width of the enlarged bony ET on temporal bone HRCT were（22.61±2.94） mm and（6.50±2.33） mm, respectively. The enlargement was combined with an external auditory canal malformation in six ears, narrow tympanic cavity in six, tympanic antrum malformation in five, ossicular chain malformation in seven, cochlear malformation in six, helicotrema malformation in three, vestibule widening in two, semicircular canal malformation in three, vestibular window malformation in six, facial nerve abnormality in five, internal auditory meatus malformation in two, low middle cranial fossa in eight, and severe internal carotid artery malformation in one. Conclusion:Bony ET enlargement is a rare congenital middle ear malformation which could combined with other ear malformations. Patients can have no ET dysfunction but different patterns of hearing loss. The defect is usually found unintentionally during imaging, and the HRCT of temporal bone is significant.

Role of Vestibular Rehabilitation in Patients with Superior Semicircular Canal Dehiscence Syndrome

Superior canal dehiscence syndrome (SCDS) described in 1998 is a disorder characterized by vertigo in response to loud sounds, pulsatile tinnitus, conductive hyperacusis, autophony and chronic disequilibrium. While resurfacing and/or plugging of the superior canal may improve autophony and reduce dizziness handicap, it can result in immediate and long-term deficits in VOR function, necessitating vestibular rehabilitation (VR) during the early post-operative recovery period. Case description: a 34- year-old man with a history of autophony, pulsatile tinnitus and audible eye movements in his right ear. He denied any vertigo or disequilibrium. Immediately after surgical plugging he presented severe vertigo and disequilibrium as well as deterioration of right hearing loss. Due to persistent instability, VR was performed for five months after surgery with improved outcomes. Our purpose is to emphasize and increase awareness in surgeons, especially in Latin America, the importance of VR immediately after surgery. Additionally, we make some comments about the surgical decisions in two patients with otosclerosis and SCDS and the importance of VR.

Pediatric Benign Paroxysmal Positional Vertigo: Degree of Nystagmus and Concurrent Dizziness Differs from Adult BPPV.

Background: Benign paroxysmal positional vertigo (BPPV) is characterized by brief, intense episodes of vertigo triggered by abrupt changes in head position. It is generally accepted as being most common in adults, while it is regarded as rare in children. It is necessary to compare the disease between pediatric and adult patients for a better understanding of the disease's characteristics and its natural history. This study aimed to identify the clinical characteristics of BPPV in children and compare them with those of adult BPPV patients. Methods: All children ≤ 18 years old who were diagnosed with BPPV were selected by searching the electronic database of our hospital. Clinical features were identified by medical record review. For adult patients, we collected data from patients > 19 years of age. Results: A total of 30 pediatric (13.65 ± 4.15 years old) and 264 adult patients (60.86 ± 13.74 years old) were included in the study. Among pediatric patients, the lateral canals were involved in 80% and the posterior canals in 16.67%. In adult patients, the lateral and posterior canals were involved similarly (p = 0.007). The degree of nystagmus in pediatric patients was 6.82 ± 12.09, while in adults it was 15.58 ± 20.90 (p < 0.001). The concurrent dizziness disorder was higher in the pediatric group and recurrence was higher in the adult group. In the regression analysis, it was found that adult patients had a stronger nystagmus with a value of 6.206 deg/sec, and the risk of concurrent dizziness disorder was found to be 5.413 times higher in the pediatric group (p < 0.05). Conclusions: BPPV occurs in pediatric patients with lower prevalence, but it cannot be overlooked. In the pediatric group, a relatively high proportion of patients demonstrated lateral canal involvement, weaker nystagmus, and additional dizziness disorder.

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

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

Semont maneuver for posterior canal benign paroxysmal positional vertigo: a systematic review of randomized controlled trials.

This review aimed to examine the effects of the Semont maneuver on posterior canal benign paroxysmal positional vertigo (BPPV). PubMed, PEDro, SCOPUS, REHABDATA, EMBASE, and Web of Science were searched comprehensively from inception to January 2024. The Physiotherapy Evidence Database (PEDro) scale was employed to evaluate the quality of the selected studies. In total, 18 randomized controlled trials met the eligibility criteria. A total of 2237 participants with BPPV (mean age = 58.10years) were included in this review. Among them, 37.5% were males, and 58% presented with right-sided BPPV. The included studies ranked from 5 to 9 out of 10 (Median = 7), suggesting good to excellent quality on the PEDro scale. The available literature revealed that the Semont maneuver is effective in improving posterior canal BPPV symptoms. The Semont maneuver is considered a standard option for treating posterior canal BPPV, with a high success rate of around 80%. It is suggested as the primary option for managing posterior canal BPPV in individuals who complain of cervical or lumbar problems, severe cardiac or respiratory conditions. Further studies are strongly needed to understand the long-term effects of the Semont maneuver and to identify the recurrence rate.

A retrospective study of posterior canal benign paroxysmal positional vertigo cases in a tertiary care industrial hospital

Background: Balance disorders form a significant proportion of the patients attending ENT OPD. Among the various otologic causes responsible for balance disturbances, BPPV is one of the important causes. The etiological mechanism responsible for BPPV are canalithiasis and cupulolithiasis. Positional maneuver such as Epleys maneuver are used for treating posterior canal BPPV along with medications. Methods: We are retrospectively studying the posterior canal BPPV cases seen in our hospital from January 2022 to January 2024. There were total 192 vertigo cases seen in the vertigo clinic of ENT Department after taking into account inclusion and exclusion criteria. Diagnosed cases of posterior canal BPPV were treated by Epleys maneuver along with pharmacological treatment. Results: Total 50 cases of posterior canal BPPV were diagnosed which constituted 26.04% of the total no of vertigo cases. Regarding the etiology of posterior canal BPPV, 2 cases were posttraumatic while 48 cases were idiopathic. The success rate of Epleys maneuver along with Betahistine was 78% in treating such cases. Conclusions: This retrospective study shows that most of the posterior canal BPPV cases were idiopathic. Epleys maneuver along with Betahistine was effective in the management of BPPV patients in our setup.

Functional neuroanatomy of the vestibular cortex and vestibular stimulation methods for neuroimaging studies

The vestibular cortex is a distributed network of multisensory areas that plays a crucial role in balance, posture, and spatial orientation. The core region of the vestibular cortex is the parietoinsular vestibular cortex (PIVC), which is located at the junction between the posterior insula, parietal operculum, and retroinsular region. The PIVC is connected to other vestibular areas, the primary and secondary somatosensory cortices, and the premotor and posterior parietal cortices. It also sends projections to the vestibular nuclei in the brainstem. The PIVC is a multisensory region that integrates vestibular, visual, and somatosensory information to create a representation of head-in-space motion, which is used to control eye movements, posture, and balance. Other regions of the vestibular cortex include the primary somatosensory, posterior parietal, and frontal cortices. The primary somatosensory cortex is involved in processing information about touch and body position. The posterior parietal cortex is involved in integrating vestibular, visual, and somatosensory information to create a representation of spatial orientation. The frontal cortex is involved in controlling posture, and eye movements. The various methods used to stimulate the vestibular receptors in neuroimaging studies include caloric vestibular stimulation (CVS), galvanic vestibular stimulation (GVS), and auditory vestibular stimulation (AVS). CVS uses warm or cold water or air to stimulate the semicircular canals, GVS uses a weak electrical current to stimulate the vestibular nerve, and AVS uses high-intensity clicks or short tone bursts to stimulate the otolithic receptors.

Posterior Semicircular Canal Dehiscence with Vestibulo-Ocular Reflex Reduction for the Affected Canal at the Video-Head Impulse Test: Considerations to Pathomechanisms.

Posterior semicircular canal dehiscence (PSCD) has been demonstrated to result in a third mobile window mechanism (TMWM) in the inner ear similar to superior semicircular canal dehiscence (SSCD). Typical clinical and instrumental features of TMWM, including low-frequency conductive hearing loss (CHL), autophony, pulsatile tinnitus, sound/pressure-induced vertigo and enhanced vestibular-evoked myogenic potentials, have been widely described in cases with PSCD. Nevertheless, video-head impulse test (vHIT) results have been poorly investigated. Here, we present six patients with PSCD presenting with a clinical scenario consistent with a TMWM and an impaired vestibulo-ocular reflex (VOR) for the affected canal on vHIT. In two cases, an additional dehiscence between the facial nerve and the horizontal semicircular canal (HSC) was detected, leading to a concurrent VOR impairment for the HSC. While in SSCD, a VOR gain reduction could be ascribed to a spontaneous "auto-plugging" process due to a dural prolapse into the canal, the same pathomechanism is difficult to conceive in PSCD due to a different anatomical position, making a dural herniation less likely. Alternative putative pathomechanisms are discussed, including an endolymphatic flow dissipation during head impulses as already hypothesized in SSCD. The association of symptoms/signs consistent with TMWM and a reduced VOR gain for the posterior canal might address the diagnosis toward PSCD.