Lateral Canal Research Articles

Changes in Vestibular Function Following Pediatric Cochlear Implantation: a Prospective Study.

Given the close interconnection between the auditory and vestibular end organs, the increasingly broad application of (bilateral) cochlear implantation (CI) in children raises concern about its impact on the vestibular function. Unfortunately, literature on this matter is inconclusive and subject to several limitations. Therefore, this study aimed to elucidate the impact of pediatric CI on the vestibular function in a large sample of children, representative for the current CI population. Fifty hearing-impaired children followed in the Ghent University Hospital were included in this prospective study. Twenty-seven patients underwent unilateral CI, and 23 were bilaterally implanted (9 sequentially, 14 simultaneously), adding up to 73 implanted ears. Children's median age at first implantation was 29 (range 8 to 194) months. Vestibular assessment was scheduled on average 2.8 months (SD: 3.6) before and 4.6 (SD: 4.0) months after implantation and consisted of video Head Impulse Testing of the lateral semicircular canals, rotatory testing (0.16, 0.04, and 0.01 Hz) and cervical vestibular evoked myogenic potential (cVEMP) testing with bone conduction stimulation. Caloric testing was added in children older than 3 years of age. Overall, group analysis in our sample of 73 CI-ears did not reveal any significant impact on the vestibular function, except for a significantly shortened ipsilateral N1 latency of the cVEMP responses (p = 0.027) after CI. Complete ipsilateral loss of function after implantation was seen in 5% (3/54) of all CI-ears on the video head impulse testing, in 0% (0/10) on the caloric test and in 2% (1/52) on the cVEMP, notably all patients deafened by a congenital cytomegalovirus infection. The impact of CI on the vestibular function in our dataset was limited. Therefore, the many advantages of simultaneous bilateral implantation may outweigh the risk for vestibular damage postoperatively. However, the impact on the vestibular function may be dependent on various factors (e.g., etiology of the hearing loss), and the clinical outcome is still difficult to predict. Vestibular assessment remains thus an important aspect in the pediatric CI population; first because the vestibular function should be considered in the decision-making process on (simultaneous or sequential bilateral) CI and second because it is essential to reveal a possible additional sensory deficit, allowing an opportunity for rehabilitation to improve the overall outcome of these children.

Akutní závrať v pohotovostní službě ORL lékaře

Summary Introduction: Acute vertigo ranks among the common reasons for visiting the emergency department. The aim of this study was to evaluate the rate of peripheral vestibular syndrome (PVS) in patients with acute vertigo examined at the ENT emergency department and to compare the agreement of physical ENT examination with video-assisted vestibular testing. Methods: Patients eamined at the ENT emergency department from January to December 2019 were evaluated retrospectively. The patients who underwent basic ENT examination without video-assisted vestibular testing form group A. The patients who underwent basic ENT examination which was followed by video head impulse test (vHIT) and videonystagmography in the next four days form group B. Results: A total of 117 patients with acute vertigo were included in group A, PVS was found in 31 patients (27%). In total, 50 patients were included in group B; PVS was found in 15 patients (30%), vestibular neuronitis was dia­gnosed most often (10 patients). The difference in the dia­gnosis of PVS by basic ENT examination (27 patients, 54%) and by video-assisted vestibular testing (15 patients, 30%) was statistically significant (P = 0.0030). The gain of the lateral (P = 0.0101) and superior (P = 0.0043) semicircular canal proved to be statistically significant, while vHIT was lower in PVS in comparison to other causes of vertigo. Conclusion: After basic ENT examination, PVS as a cause of acute vertigo was dia­gnosed in 27%. Video-assisted vestibular testing proved a statistically significant lower incidence of PVS in comparison to basic ENT examination. Accessibility of video- -assisted vestibular testing in the emergency department might allow for higher accuracy in the dia­gnosis of acute vertigo. Key words acute vertigo – vestibular function tests – video head impulse test – videonystagmography

Measurement of Human Semicircular Canal Spatial Attitude.

Located deep in the temporal bone, the semicircular canal is a subtle structure that requires a spatial coordinate system for measurement and observation. In this study, 55 semicircular canal and eyeball models were obtained by segmentation of MRI data. The spatial coordinate system was established by taking the top of the common crus and the bottom of the eyeball as the horizontal plane. First, the plane equation was established according to the centerline of the semicircular canals. Then, according to the parameters of the plane equation, the plane normal vectors were obtained. Finally, the average unit normal vector of each semicircular canal plane was obtained by calculating the average value of the vectors. The standard normal vectors of the and left posterior semicircular canal, superior semicircular canal and lateral semicircular canal were [−0.651, 0.702, 0.287], [0.749, 0.577, 0.324], [−0.017, −0.299, 0.954], [0.660, 0.702, 0.266], [−0.739, 0.588, 0.329], [0.025, −0.279, 0.960]. The different angles for the different ways of calculating the standard normal vectors of the right and left posterior semicircular canal, superior semicircular canal and lateral semicircular canal were 0.011, 0.028, 0.008, 0.011, 0.024, and 0.006 degrees. The technology for measuring the semicircular canal spatial attitudes in this study are reliable, and the measurement results can guide vestibular function examinations and help with guiding the diagnosis and treatment of BPPV.

Lateral Lingual Foramina and Canals in the Mandible: CBCT Evaluation of 506 Patients in North China.

To assess the prevalence, location, diameter, course and anastomosis of the lateral lingual foramina (LLF) and canals (LLCs) in a northern Chinese population using CBCT. CBCT images of 506 patients (181 male and 325 female, mean age 21.03 ± 8.11 years) were collected. The prevalence, location, diameter, length, angle and anastomosis of the LLF and LLCs were assessed. The measurement variables were analysed by sex and age. Statistical analysis was performed using SPSS (v. 25, IBM, Armonk, NY, USA). A total of 461 LLF were detected in 307 (60.7%) subjects, 175 (57.0%) of whom had unilateral LLF and 132 (43.0%) of whom had bilateral LLF, with each lateral having one to four LLF. The majority of LLF (375/461, 81.3%) were located below the premolars, particularly the first premolar. The mean diameter of the LLF was 0.58 ± 0.20 mm. The mean vertical distance from the LLF to the inferior border and the alveolar crest was 6.68 ± 1.43 mm and 23.65 ± 2.89 mm, respectively. In total, 197 LLCs were visible in the cancellous bone and evaluated. The mean length of LLCs was 6.26 ± 1.29 mm, and the mean angle of LLCs was 140.64° ± 17.29°. The overwhelming majority (93.4%) of LLCs communicated with the mandibular incisive canal and the rest connected with the mandibular canal. The prevalence of LLCs was high in the northern Chinese population. The presence of LLCs is a significant predictor of communication with the mandibular incisive canal.

Validation of inner ear MRI in patients with M\xe9ni\xe8re\u2019s disease by comparing endolymphatic hydrops from histopathologic specimens

Intravenous gadolinium-enhanced inner-ear magnetic resonance imaging (IV-Gd inner-ear MRI) has been used to visualize endolymphatic hydrops (EH) in clinical diagnosis of Ménière’s disease (MD). However, lack of histological validation has led to several concerns regarding how best to interpret the resulting images. Here, we compared hydropic changes in temporal bone specimens with the results of IV-Gd inner-ear MRI in patients with MD. Histopathologic images of temporal bones from 37 patients with MD and 10 healthy controls were collected from the National Temporal Bone Bank of the Massachusetts Eye and Ear Infirmary in the United States. The EH ratios in the vestibule and cochlea were calculated from temporal bones using the methods used for IV-Gd inner-ear MRI, and the degree to which the saccular and utricular hydrops contributed to vestibular hydrops was measured. The presence of hydropic change in each semicircular canal was assessed using temporal bone images and compared with IV-Gd inner-ear MRI scans of 74 patients with MD. Based on human temporal bone imagery, the EH ratios in the cochlea and the vestibule on the affected side were 0.314 and 0.757, respectively. In the healthy control group, the ratio was 0.064 for the cochlea and 0.289 for the vestibule; these values were significantly different from those for the affected side of MD patients. The values for the affected ear were similar to the ratios from the IV-Gd inner-ear MRI scans in MD patients. In the vestibule, saccular hydrops were more common than utricular hydrops. The average EH ratios in the saccule and utricle were 0.513 and 0.242, respectively. No significant hydropic change from each of three semicircular canals was evident in temporal bone histopathology. However, herniation of otolithic organs (saccule or utricle) into the lateral semicircular canal was found in 44.4% of the patients, with saccular herniation (24.8%) more common than utricular herniation (16.7%). Although IV-Gd inner-ear MRI might not reflect fully the results of actual histopathology due to the limited resolution of MRI and image-processing techniques, the measured EH ratios from temporal bone specimens and IV-Gd inner-ear MRI scans were similar. Hydropic change in the three semicircular canals was not significant at either the ampullated or nonampullated end. Canal invasion of vestibular hydrops seen on MRI also appeared in temporal bone histopathology, and saccular invasion was dominant.

Short Communication: Morphological study of the scales of Barbodes cf. binotatus (Cyprinidae) from Toba Lake, Indonesia by using Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS)

Abstract. Lubis K, Sudibyo M, Siregar EH, Laili N. 2021. Short Communication: Morphological study of the scales of Barbodes cf. binotatus (Cyprinidae) from Toba Lake, Indonesia by using Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS). Biodiversitas 22: 3821-3828. Spotted barb (Barbodes cf binotatus) is a freshwater fish of Sumatra Island, especially found in the Toba. The study of morphological characteristics of the scales of Spotted barb (B. cf binotatus) is necessary in fish taxonomy. Therefore, the present study investigated the morphology and the chemical elements of the scales located between the dorsal fin and lateral line and those on the lateral line using SEM-EDS (Scanning Electron Microscope (SEM)- Energy Dispersive X-ray Spectroscopy (EDS). We found that the scales of Spotted barb (B. cf binotatus) have the general morphological characteristics of cycloid scales. The morphologies of the scales between the dorsal fin and lateral line and those on the lateral line are slightly different. Lateral line scales of Spotted barb (B. cf binotatus) have no focus area, replaced by a lateral line canal located along the anterior-posterior axis of the scales with two openings. The anterior opening is bigger and wider in compared to the posterior opening. The circuli of the dorsal fin scale is orientated towards the focus. However, the circuli of the lateral scale faces the lateral line canal. The scales contain some elements such as Ca, K, O, Mg, Na, and P.

Transmastoid exposure of the labyrinthine segment of the facial nerve: an anatomical study

IntroductionCompression of the labyrinthine segment of the facial nerve by edema has been considered as an important pathology in the majority of the cases of idiopathic facial nerve paralysis. Hence, it is suggested that total decompression of the facial nerve should also include the labyrinthine segment by a middle fossa approach. However, the middle fossa approach requires craniotomy and temporal lobe retraction, which increases the morbidity. The labyrinthine segment of the facial nerve can also be reached through mastoidectomy. However, many ear surgeons are not familiar with this approach due to the lack of anatomical data on this surgical area. ObjectiveTo study the anatomical limitations of decompression of the labyrinthine segment via transmastoid approach. MethodsComplete mastoidectomy was performed in six adult cadavers heads. Dissection was extended in the zygomatic root and posterior bony wall of the external auditory canal to visualize the incudomallear joint completely. The bone between tympanic segment, lateral and superior semicircular canal’s ampullas and middle fossa dural plate was removed. Fine dissection was carried out over tympanic segment of the facial nerve in an anterosuperomedial direction the labyrinthine segment was reached. ResultsAll the mastoids were well pneumatized. Distances between the labyrinthine segment and middle fossa dura, and between the labyrinthine segment and superior semicircular canal, were 2.5 and 4.5 mm on average, respectively. In addition, distances between the middle fossa dura and dome of the lateral semicircular canal, and between the middle fossa dura and tympanic segment were 4.6 mm and 4.3 mm on average, respectively. ConclusionIt is possible to expose the labyrinthine segment of the facial nerve through mastoidectomy by dissecting the bone in the area between the tympanic segment of the facial nerve, middle fossa dural plate and ampullary ends of the lateral and superior semicircular canals.

Braincase and Inner Ear Anatomy of the Late Carboniferous Tetrapod Limnoscelis dynatis (Diadectomorpha) Revealed by High-Resolution X-ray Microcomputed Tomography

The braincase anatomy of the Pennsylvanian diadectomorphLimnoscelis dynatisis described in detail, based upon high-resolution X-ray microcomputed tomography. Both supraoccipitals and most of the prootics and opisthotics are preserved. The known portions of the left prootic, opisthotic, and supraoccipital enclose complete sections of the endosseous labyrinth, including the anterior, posterior, and lateral semicircular canals, the vestibule, the cochlear recess, and the canal for the endolymphatic duct. The fossa subarcuata is visible anteromedial to the anterior semicircular canal. The presumed endolymphatic fossae occur in the dorsal wall of the posteromedial portion of the supraoccipital. Both the fossa subarcuata and the fossa endolymphatica lie in the cerebellar portion of the cranial cavity. In order to investigate the phylogenetic position ofL. dynatiswe used a recently published data matrix, including characters of the braincase, and subjected it to maximum parsimony analyses under a variety of character weighting schemes and to a Bayesian analysis.Limnoscelis dynatisemerges as sister taxon toL. paludis, and both species form the sister group to remaining diadectomorphs. Synapsids and diadectomorphs are resolved as sister clades in ∼90% of all the most parsimonious trees from the unweighted analysis, in the single trees from both the reweighted and the implied weights analyses, as well in the Bayesian tree.

Percutaneous Transforaminal Endoscopic Decompression for Lumbar Lateral Recess Stenosis.

Objective: The aim of this study was to evaluate the treatment efficacy of lateral spinal stenosis through the decompression of the nerve root under a multiple planar endoscope.Methods: From January 2017 to March 2019, 52 patients with lumbar spinal stenosis or lumbar spinal stenosis combined with intervertebral disc herniation had been treated via transforaminal approach spinal endoscopy. Our study retrospectively analyzed the treatment outcome. All patients experienced complications with different degrees of facet joint hyperplasia and ligamentum flavum hyperplasia and hypertrophy. Some patients suffered disc herniation. All patients were treated with percutaneous transforaminal approach multiple planar endoscopic decompression. The visual analog scale (VAS) and the Oswestry Disability Index (ODI) were compared before and after the operation, as were the horizontal foramen areas of the medial margins of the upper and lower pedicles of the vertebral arch. The treatment effectiveness was evaluated.Results: VAS and ODI scores were significantly improved at postoperative 3 days, 3 months, 6 months, and the last follow-up (P < 0.05). The area of the intervertebral foramen was 422.5 ± 159.2 mm2 preoperatively and 890.8 ± 367.7 mm2 postoperatively, the difference was statistically significant (P < 0.05).Conclusion: Percutaneous transforaminal approach multiple planar endoscopic decompression could achieve an accurate and effective decompression of the lumbar lateral spinal canal. This procedure has good short-term effects, and is especially suitable for elderly patients.

Five subtypes of benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo is classified into five subtypes according to the features of positional nystagmus: lateral canalolithiasis, lateral light cupula, lateral heavy cupula, posterior canalolithiasis and posterior heavy cupula. The first aim of the study was to clarify whether the lateral canal type or posterior canal type was more common. The second aim of the study was to assess the aetiology of benign paroxysmal positional vertigo by investigating the onset time of each subtype. The subjects were 512 consecutive patients with benign paroxysmal positional vertigo. The patients were prospectively aggregated, and interviews were used to evaluate onset time. The lateral canal type (55.5 per cent) was more common than the posterior canal type (44.5 per cent). Time of awakening was the most common onset time in every subtype. The incidence of lateral canal type is higher than that of posterior canal type. The aetiology of benign paroxysmal positional vertigo is closely related to sleep.

Results of surgical treatment of degenerative stenosis of the lumbar spine in elderly and old patients

Aim. To evaluate the results of surgical treatment in older patients with lumbar spinal stenosis.Materials and methods. The study is based on the results of a comprehensive examination and surgical treatment of 20 patients who were hospitalized in the neurosurgery department of the SI NMC “Shifobakhsh” in the Department of Neurosurgery and Combined Trauma of the ATSMU with stenosis of the lumbar spine with various options for the clinical course. Assessment of the neurological status in degenerative spinal disease was conducted using a visual analog scale (VAS.)Results. When comparing subgroups, it was noted that decompressive interventions show the best results for lumbar spinal stenosis in the older age group.Conclusion. The use of differentiated microsurgical decompression techniques in older patients with degenerative lateral and central spinal canal stenosis provides an improvement in quality of life.

Clinical case: second mandibular premolar with three root canals

Successful and predictable endodontic treatment requires knowledge of root canal anatomy and morphology variations. In cases where X-ray images do not help to clarify the anatomy of the root canals, it is recommended to use magnifying devices. The second premolar of the lower jaw is one of the most diffcult teeth for endodontic treatment due to variations in internal morphology, additional root canals, apical deltas, and lateral canals. Diagnostic radiographs in different projections are important for getting an idea of the number of existing root canals. The purpose of root canal treatment is to clean the root canal of pathogenic microbes and infected pulp, prevent the formation of toxic products, and protect the periapical tissue. The presence of root canal variability increases the complexity of endodontic treatment. The complex anatomy of the root canals, the presence of additional channels, unnoticed by the dentist, can cause the failure of endodontic treatment.

A Novel Instrument for Endoscopic Ear Surgery With a Steerable Flexible Tip: A Pediatric Anatomical Validation Study.

This study compares the reaching ability of two classes of transcanal endoscopic ear surgery (TEES) instruments when operating on difficult to access anatomical targets; two novel instruments with steerable flexible tips (SFT-A and SFT-B) and suction capability are compared with standard commercially available tools. TEES surgeons identified the need for a new surgical instrument that can enable accessibility of all areas visualized by the endoscope. This motivated the development of the two instrument prototypes. Six temporal bone models were 3D printed based on CT data from five cholesteatoma patients. Four anatomical targets were marked on each model. Using these targets, the reaching ability while using four standard TEES instruments were compared with the SFT-A and SFT-B prototypes by five surgeon participants. Results were analysed to compare success rates of contacting each target using each tool by fitting four Firth's logistic regression models. This calculated the statistically significant differences (p < 0.05) in tool success rate. Using SFT-A to contact the sinus tympani (100%) was significantly more successful than the Panetti suction dissector for atticus (PAT) (77%) and to contact the sinodural angle (0%) was less successful than the PAT (10%) and SFT-B (93%). Using SFT-B to contact the lateral semicircular canal (90%) was significantly more successful than all current tools and to contact the sinodural angle (93%) was significantly more successful than all tools. Using SFT-B enables enhanced accessibility of anatomical structures during TEES which may lead to less extensive bone removal to facilitate minimally invasive TEES.

Comparative Analysis of the Filling Capacity of Simulated Lateral Canals of Two Bioactive Root Canal Sealers Using Warm Gutta-Percha Technique

The aim of this study was to evaluate ex vivo the sealing achieved at simulated lateral canals (SLC) and the quality of filling according to their position in the root canal after using the same filling technique. SLC were created at three levels in 55 teeth and divided into two groups depending on the root canal sealer used (1: BioRoot® RCS, 2: GuttaFlow® bioseal). They filled them with the continuous wave technique and submitted to a diaphanization technique. The samples were analyzed using a magnifying lens (20×), pictures were taken, which proceeded to linear measurement with the ImageJ® program and used a filling score system with five grades (0 to 4, 0 and 1 not acceptable, 2 to 4 acceptable); BioRoot® RCS has got a greater proportion than GuttaFlow® bioseal for SLC filled acceptably at 10 mm from the apex (p &lt; 0.05). The highest proportion of SLC filled acceptably was found in the middle third (6 mm) (p &lt; 0.05), followed by the apical third (3 mm) and the coronal third (10 mm). The difference between apical and coronal third could be significant; BioRoot® RCS has been better than GuttaFlow® bioseal for filling SLC in the coronal third of the teeth. Studies on the characteristics of these cements are missing to explain these differences.

Effect of different head impulse procedures on vestibulo-ocular reflex gain

Objectiveto study the effects on vestibulo-ocular reflex (VOR) gain using both video head impulse test (vHIT) and Suppression Head impulse test (SHIMP) either using the outward or the inwards head impulse. MethodsTwenty healthy subjects were enrolled in the study. They were examined using otometric vHIT and SHIMP test lateral plane using the lateral outwards head impulse ten impulses for each side and the inwards head impulse ten impulses for each side. The VOR gain resulting from the outwards versus inwards head impulse during the vHIT and SHIMP were statistically compared. ResultsTwenty healthy subjects, 10 Males and 10 females with a mean age 35±11.7. Paired t- test showed no statistical significance difference in the mean VOR gain of right lateral semicircular canal (1.1±.12) using outwards versus (1.03 ± .22) inwards head impulses, nor for the left lateral semicircular canal mean VOR gain (1.1 ± .22) using outwards head impulse (1.1 ± .3) for inwards head impulse in vHIT. Paired t- test showed no statistical significance difference in the mean VOR gain of right lateral semicircular canal (0.96 ± 0.2)using outwards versus (1.04 ± 0.2) inwards head impulses, nor for the left lateral semicircular canal mean VOR gain (0.98 ± 0.25) using outwards head impulse (1.1 ± 0.28) for inwards head impulse in SHIMP test. No statistical significant difference was found between the VOR gain resulting from the right versus the left semicircular canal. ConclusionThe starting head position does not affect the VOR gain using both vHIT and SHIMP tests.

Comparison of two systems for the video head impulse test (vHIT) for the lateral semicircular canal: description of results from normal and pathological subjects.

The video head impulse test (vHIT) is a recent technique for functional evaluation of semicircular canals (SSCs). The vHIT examines eye movements at high frequencies of stimulation and provides an objective assessment of the functioning of the high-frequency domain of the vestibular system. To describe the results from vHIT performed using two systems. All subjects were evaluated through an audiological and otoneurological battery of tests and were diagnosed as normal or abnormal by an otorhinolaryngologist. The results from two systems: 1. ICS Impulse (Otometrics/Natus, Denmark) and 2. EyeSeeCam (InterAcoustics, Denmark) were recorded. The same operator delivered every impulse to every subject. The head impulses were performed while the operator was standing behind the subject, using both hands on the top of the subject's head, well away from the goggles strap and forehead skin. Two calibrations were completed in each system, prior to beginning the test. Test parameters were recorded through both systems for healthy subjects with no history or complaint of any vestibular disorder (N = 12; M/F = 5/7; age 35.1 ± 13.5 y) and for pathological subjects with a diagnosis of unilateral or bilateral vestibular disorder (N = 15; M/F = 7/8; age 53.4 ± 16.7 y). The vHIT is an important tool for otoneurological complementary evaluation. Both systems are reliable for vestibular disorders. The EyeSeeCam seems to reject fewer data and provides more information to include in diagnostics. Because of the small sample, there is a need for further in-depth comparison of both systems.

Morphological variability of permanent mandibular first premolar teeth in Manipuri population: An In vitro study

Aim: To investigate anatomical and morphological variability of permanent mandibular first premolar teeth in the population of Manipur state of Indian subcontinent. Materials and Methods: Four hundred and eighty teeth from a pool of Manipuri population were studied for anatomical and morphological variability using staining and clearing technique. All samples were evaluated for the number of roots, root canals, root canal configuration, presence of lateral canals, intercanal communications, and apical deltas. Results: Single root with one canal was present in 81.25% (390/480) and single root with two canals in 18.75% (90/480) of samples. Root canal configuration according to Vertucci's classification was as follows: Type I (43.7%) followed by Type V (25%), Type VI (12.5%), and Type II, III, and VII (6.25%). Intercanal communications in the apical third were 12.5% (60/480) and 6.25% (30/480) in the middle third of the root. Occurrence of lateral canals in the apical third was 18.75% (90/480). Apical delta was found in 37.75% (180/480) of samples. Conclusion: The results of this study highlight the variability patterns of mandibular first premolar tooth existent in the population of the state of Manipur. Single-rooted teeth are most common with predominantly Vertucci's Type I root canal configuration and significant presence of lateral canals and apical ramifications. Clinical Significance: Sound knowledge of anatomy of the root canal and possible variations can contribute to a successful treatment outcome.

Transcanal Endoscopic Ear Surgery for Epitympanic Cholesteatoma With Obliteration Using Bioglass.

Transcanal Endoscopic Ear Surgery for Epitympanic Cholesteatoma With Obliteration Using Bioglass.

The Impact of Optical Illusions on the Vestibular System.

Background and ObjectivesBalance control is maintained in stationary and dynamic conditions, with coordinated muscle responses generated by somatosensory, vestibular, and visual inputs. This study aimed to investigate how the vestibular system is affected in the presence of an optical illusion to better understand the interconnected pathways of the visual and vestibular systems.Subjects and MethodsThe study involved 54 young adults (27 males and 27 females) aged 18-25 years. The recruited participants were subjected to the cervical vestibular evoked myogenic potentials (cVEMP) test and video head impulse test (vHIT). The cVEMP and vHIT tests were performed once each in the absence and presence of an optical illusion. In addition, after each test, whether the individuals felt balanced was determined using a questionnaire.ResultscVEMP results in the presence of the optical illusion showed shortened latencies and increased amplitudes for the left side in comparison to the results in the absence of the optical illusion (p≤0.05). When vHIT results were compared, it was seen that the right lateral and bilateral anterior canal gains were increased, almost to 1.0 (p<0.05).ConclusionsIt is thought that when the visual-vestibular inputs are incompatible with each other, the sensory reweighting mechanism is activated, and this mechanism strengthens the more reliable (vestibular) inputs, while suppressing the less reliable (visual) inputs. As long as the incompatible condition persists, the sensory reweighting mechanism will continue to operate, thanks to the feedback loop from the efferent vestibular system.

Characteristics of bone metabolism in postmenopausal female patients with different types of idiopathic benign paroxysmal positional vertigo: A single-centre retrospective study

ObjectiveThe association between benign paroxysmal positional vertigo (BPPV) and impaired calcium metabolism has attracted widespread interest. Several studies have suggested that decreased bone mineral density (BMD) and serum 25-hydroxyvitamin D (25(OH)D) level are related to the occurrence and/or recurrence of BPPV; however, the characteristics of bone metabolism in patients with BPPV subtypes have not been fully investigated, and conclusions have been controversial. This study aimed to evaluate BMD and serum levels of 25(OH)D and bone turnover markers to clarify the characteristics of bone metabolism in patients with different types of BPPV. MethodWe retrospectively analysed the data of new-onset idiopathic postmenopausal female patients with BPPV at our institution from January 2016 to January 2020. The patients' demographic data including age, medication history, concomitant diseases, onset time, clinical form, laboratory indicators, such as serum levels of 25(OH)D, bone formation markers, namely, amino-terminal propeptide of type I procollagen (PINP) and osteocalcin (OC), bone resorption marker, namely, β-isomerized carboxy-terminal telopeptide of type I collagen (β-CTX), and BMD were collected and analysed. ResultsThis study included 201 consecutive postmenopausal female patients with BPPV. Among them, 138 were diagnosed with posterior semicircular canal BPPV, 42 were diagnosed with lateral semicircular canal canalolithiasis, and 21 were diagnosed with lateral semicircular canal cupulolithiasis. There were no significant differences in age distribution, body mass index, clinical history, levels of albumin, globulin, uric acid, creatinine, or blood urea nitrogen, lipid profiles (except high-density lipoprotein cholesterol) and routine blood parameters among these groups (P > 0.05). There were no significant differences in the mean T-score and BMD values of different sites or in the serum levels of 25(OH)D and bone turnover markers (PINP, OC and β-CTX) among the subgroups (P > 0.05). The proportion of reduction in BMD (T-score < −1 SD) and decreased serum vitamin D level (< 20 ng/ml) were not significantly different between the subgroups (P > 0.05). ConclusionThere were no significant differences in bone metabolism in postmenopausal female patients with different types of idiopathic BPPV.