Vestibular System Research Articles

Improving sensory integration in Chinese children with moderate sensory integration challenges through engaging basketball training

ObjectiveThis study aimed to evaluate the effectiveness of combining basketball training with a traditional sensory integration therapy (SIT) vs. a SIT alone in enhancing sensory integration capability among Chinese children diagnosed with mild challenges in sensory integration and sensory processing (CSISP).MethodsThis study comprised a Control group and an Experimental group, both undergoing a 10-week intervention (4 sessions/week, 45 min/session). The Control group exclusively participated in traditional SIT for all sessions. In contrast, the Experimental group engaged in traditional SIT for two sessions per week and Basketball training for the remaining two sessions weekly. Three sensory integration measures (vestibular sensation, tactile perception, proprioception) and five gross motor performance measures (balance beam walking speed, single-leg standing with eyes closed, tennis ball throw, two-legged jump speed, 10-m shuttle run) were assessed before and after the 10-week training period. Separate 2 (Group) × 2 (Test Phases) Analysis of Variance (ANOVA) with repeated measures on the second factor were conducted for each measure. Interaction effects were further explored using Tukey's HSD test to clarify their nature.ResultsBoth groups demonstrated significant improvements in all sensory integration and gross motor performance measures following the 10-week training sessions (p < 0.001). Importantly, the group receiving the combination of basketball training and traditional SIT significantly outperformed the group undergoing SIT alone in all assessed areas.ConclusionThese results indicate that combining basketball training with traditional SIT enhances sensory integration capabilities more effectively among Chinese children aged 4–6 years with moderate CSISP compared to utilizing SIT alone.

A rare haplotype of the GJD3 gene segregating in familial Meniere’s disease interferes with connexin assembly

BackgroundFamilial Meniere’s disease (FMD) is a rare polygenic disorder of the inner ear. Mutations in the connexin gene family, which encodes gap junction proteins, can also cause hearing loss, but their role in FMD is largely unknown.MethodsWe retrieved exome sequencing data from 94 individuals in 70 Meniere's disease (MD) families. Through gene burden analysis, we calculated the enrichment of rare variants (allele frequency < 0.05) in connexins genes in FMD individuals compared with the reference population. The connexin monomer and the homomeric connexon structural models were predicted using AlphaFold2 and HDOCK. RT-qPCR and immunofluorescence were done in mice cochleae to identify expression of the mouse ortholog candidate gene Gjd3.ResultsWe found an enrichment of rare missense variants in the GJD3 gene when comparing allelic frequencies in FMD (N = 94) with the Spanish reference population (OR = 3.9[1.92–7.91], FDR = 2.36E-03). In the GJD3 sequence, we identified a rare haplotype (TGAGT) composed of two missense, two synonymous, and one downstream variant. This haplotype was found in five individuals with FMD, segregating in three unrelated families with a total of ten individuals; and in another eight MD individuals. GJD3 encodes the gap junction protein delta 3, also known as human connexin 31.9 (Cx31.9). The protein model predicted that the NP_689343.3:p.(His175Tyr) missense variant could modify the interaction between connexins and the connexon assembly, affecting the homotypic GJD3 gap junction between cells. Our studies in mice revealed that Gjd3—encoding Gjd3 or mouse connexin 30.2 (Cx30.2)—was expressed in the organ of Corti and vestibular organs, particularly in the tectorial membrane, the base of inner and outer hair cells and the nerve fibers.ConclusionsThe present results describe a novel association between GJD3 and FMD, providing evidence that FMD is related to changes in the inner ear channels, and supporting a new role of tectorial membrane proteins in MD.

Balance recovery and its link to vestibular agnosia in traumatic brain injury: a longitudinal behavioural and neuro-imaging study

BackgroundVestibular dysfunction causing imbalance affects c. 80% of acute hospitalized traumatic brain injury (TBI) cases. Poor balance recovery is linked to worse return-to-work rates and reduced longevity. We previously showed that white matter network disruption, particularly of right inferior longitudinal fasciculus, mediates the overlap between imbalance and impaired vestibular perception of self-motion (i.e., vestibular agnosia) in acute hospitalized TBI. However, there are no prior reports tracking the acute-longitudinal trajectory of objectively measured vestibular function for hospitalized TBI patients. We hypothesized that recovery of vestibular agnosia and imbalance is linked and mediated by overlapping brain networks.MethodsWe screened 918 acute major trauma in-patients, assessed 146, recruited 39 acutely, and retested 34 at 6 months. Inclusion criteria were 18–65-year-old adults hospitalized for TBI with laboratory-confirmed preserved peripheral vestibular function. Benign paroxysmal positional vertigo and migraine were treated prior to testing. Vestibular agnosia was quantified by participants’ ability to perceive whole-body yaw plane rotations via an automated rotating-chair algorithm. Subjective symptoms of imbalance (via questionnaires) and objective imbalance (via posturography) were also assessed.ResultsAcute vestibular agnosia predicted poor balance recovery at 6 months. Recovery of vestibular agnosia and linked imbalance was mediated by bihemispheric fronto-posterior cortical circuits. Recovery of subjective symptoms of imbalance and objective imbalance were not correlated.ConclusionVestibular agnosia mediates balance recovery post-TBI. The link between subjective dizziness and brain injury recovery, although important, is unclear. Therapeutic trials of vestibular recovery post-TBI should target enhancing bi-hemispheric connectivity and linked objective clinical measures (e.g., posturography).

Hearing loss rather than vestibular loss identifies patient subgroups with different outcomes in Meniere’s disease

Objective This study investigates the relationship between Meniere’s disease (MD) duration and both hearing thresholds and vestibular dysfunction. Design Retrospective cohort study. First, the relationships between MD duration and pure-tone audiometry thresholds for each frequency, the canal paresis (CP) ratio, and the vestibulo-ocular reflex (VOR) gain were analysed. Second, clinical characteristics, CP values, and VOR gains were compared between patient groups with low and high hearing thresholds to determine whether they exhibited different clinical presentations. Study sample The study included 69 patients diagnosed with unilateral MD within a duration of 10 years. A hearing dataset from 306 MD Spanish patients was used to cluster patients according to the hearing profile overtime. Results The thresholds at 250–2000 Hz frequencies increased with the duration of the disease. Conversely, vestibular function tests were not related to the duration of MD. Additionally, no statistically significant differences were observed in clinical characteristics, CP values, or VOR gain between patient groups with low and high hearing thresholds. Conclusions Hearing loss involves all frequencies in most patients and hearing outcome, rather than vestibular loss, may define patient subgroups in MD. Moreover, not all patients with MD experience hearing loss progression as the duration of the disease increases.

Post-operative vestibular function outcomes evaluated by video Head Impulse Test in patients with non-vestibular schwannoma cerebellopontine angle tumors.

To evaluate post-operative semicircular canal function in patients with non-vestibular schwannoma (VS) cerebellopontine angle (CPA) tumors by video Head Impulse Test (vHIT). Fourteen patients with non-VS CPA tumors who underwent surgery. The gain in vestibulo-ocular reflex (VOR) was examined pre- and post-operatively for the semicircular canals in patients with non-VS CPA tumors. Ten of 14 patients showed semicircular canal dysfunction in one or more of the semicircular canals pre-operatively and VOR gain was significantly correlated with hearing function. Two patients showed improvement in one or more semicircular canals at 1 month after surgery compared to the pre-operative results. Significant improvements in VOR gain were observed when comparing VOR gain at 1 month and 6 months after surgery. Detailed evaluation of semicircular canal function was achieved by using vHIT in patients with non-VS CPA tumors. The good prognosis for vestibular function as evaluated by vHIT post-operatively was confirmed in patients with non-VS CPA tumors when compared to those in patients with VS. As improvement may occur post-operatively, surgical approaches that preserve the vestibular nerves and semicircular canals should be chosen for patients with non-VS CPA tumors, regardless of preoperative vestibular function. Even if vestibular function deteriorates immediately after surgery, it may improve over time if the nerve is preserved.

Evolutionary analysis of genes associated with the sense of balance in semi-aquatic mammals

BackgroundSemi-aquatic mammals represent a transitional phase in the evolutionary spectrum between terrestrial and aquatic mammals. The sense of balance is crucial for mammalian locomotion, and in semi-aquatic mammals, the structural foundation of this sense (the vestibular system) shows distinct morphological adaptations to both aquatic and terrestrial environments compared to their terrestrial counterparts. Despite this, the precise molecular mechanisms driving these adaptations remain elusive. Our study endeavors to unravel the genetic components associated with the sense of balance in semi-aquatic mammals and to examine the evolutionary trajectories of these genes, shed light on the molecular mechanisms underlying the adaptive evolution of balance perception in semi-aquatic mammals.ResultsWe selected 42 mammal species across 20 orders, 38 families, and 42 genera for analysis. We analyzed a comprehensive set of 116 genes related to the vestibular system's development or function. Our findings indicate that 27 of these genes likely experienced adaptive evolution in semi-aquatic mammals. Particularly, genes such as SLC26A2, SOX10, MYCN, and OTX1 are implicated in collectively orchestrating morphological adaptations in the semicircular canals to suit semi-aquatic environments. Additionally, genes associated with otolith development, including SLC26A2, OC90, and OTOP1, likely regulate otolith sensitivity across various locomotor modes. Moreover, genes linked to vestibular disorders, such as GJB2, GJB6, and USH1C, may provide a molecular foundation for averting vertigo amidst intricate locomotor scenarios in semi-aquatic mammals.ConclusionsOur research offers insights into the molecular mechanisms underlying the evolution of the sense of balance in semi-aquatic mammals, while also providing a new research direction for the adaptive evolution of mammals undergoing a secondary transition to an aquatic lifestyle.

Notch1 is required to maintain supporting cell identity and vestibular function during maturation of the mammalian balance organs.

The inner ear houses both hearing and balance sensory modalities. The hearing and balance organs consist of similar cell types, including sensory hair cells and associated supporting cells. Previously we showed that Notch1 is required for maintaining supporting cell survival during cochlear maturation. To understand the role of Notch during vestibular maturation, we deleted Notch1 from the vestibular organs of both male and female mice at birth. Histological analyses showed a reduction of supporting cells accompanied by an increase in type II hair cells, indicating a conversion of supporting cells to hair cells. Analysis of mature sensory organs indicate the converted hair cells survive, despite a severe reduction of supporting cells. Vestibular sensory evoked potentials (VsEPs), thought to be generated within the striola regions of the maculae, were absent, indicating that NOTCH1 is critical for striolar function. Specialized type I hair cells in the striola failed to develop the complex calyces typical of these cells. Notch1 mutants did not exhibit vestibular behaviors such as circling and head shaking, but showed difficulties with tests of balance and swimming. These results indicate that, unlike the cochlea, supporting cells in balance organs retain the plasticity to convert to hair cells which can survive into adulthood. Despite hair cell survival, vestibular function is compromised likely due to the loss of supporting cells and altered innervation.Significance Statement While the role of Notch has been investigated thoroughly during cochlear development and maturation, less is known about how Notch regulates vestibular maturation. Here, we show that deletion of Notch1 results in vestibular physiological and behavioral dysfunction by 3 months of age. In contrast to the cochlea, vestibular supporting cells retained the ability to convert to hair cells, and survived into adulthood. However, some specialized hair cells in the central region of the vestibular organs were reduced and not innervated properly. These results show that vestibular supporting cells retain the ability to convert to hair cells during maturation and can be manipulated by altering Notch signaling.

Complexes of vertebrate TMC1/2 and CIB2/3 proteins form hair-cell mechanotransduction cation channels.

Calcium and integrin-binding protein 2 (CIB2) and CIB3 bind to transmembrane channel-like 1 (TMC1) and TMC2, the pore-forming subunits of the inner-ear mechano-electrical transduction (MET) apparatus. These interactions have been proposed to be functionally relevant across mechanosensory organs and vertebrate species. Here, we show that both CIB2 and CIB3 can form heteromeric complexes with TMC1 and TMC2 and are integral for MET function in mouse cochlea and vestibular end organs as well as in zebrafish inner ear and lateral line. Our AlphaFold 2 models suggest that vertebrate CIB proteins can simultaneously interact with at least two cytoplasmic domains of TMC1 and TMC2 as validated using nuclear magnetic resonance spectroscopy of TMC1 fragments interacting with CIB2 and CIB3. Molecular dynamics simulations of TMC1/2 complexes with CIB2/3 predict that TMCs are structurally stabilized by CIB proteins to form cation channels. Overall, our work demonstrates that intact CIB2/3 and TMC1/2 complexes are integral to hair-cell MET function in vertebrate mechanosensory epithelia.

Age-related changes in the vestibulothalamic pathway: association with balance ability and subjective visual vertical of vestibular function.

The thalamus regulates various sensory information to each related brain area. The vestibular nucleus transmits information of motor control to the thalamus regulating coordination function. The vestibulothalamic tract (VTT) is a neural pathway between the vestibular nucleus and thalamus that processes vestibular information for postural balance and spatial perception. Therefore, this study analyzed ipsilateral VTT to compare the neural pathway and the differences in vestibular and balance functions according to aging. Eleven elderly and 12 young healthy adults were recruited. This study measured subjective visual vertical (SVV) for vestibular function and body sway during one-leg standing. The ipsilateral VTT were reconstructed to investigate changes of neural pathway between two groups using diffusion tensor imaging. Track volume of left and right VTTs was significantly more in the young healthy adults. In eyes-open (EO) condition during one-leg standing, the body sway demonstrated significant differences between two groups. In the eyes-closed (EC) condition, the degree of hip sway was decreased in the young healthy adults. In the EO condition, the body sway except for antero-posterior direction was significantly correlated with VTT. Meanwhile, in the EC condition, hip sway and all values of body sway were negatively correlated with VTT. In addition, the VTT revealed a negative correlation with SVV. The tract volume of VTT and static balance decreased according to aging. The changes of VTT also affected verticality perception and static balance. Therefore, the study could be helpful in providing the data for patients with thalamus or vestibular injury.

Effects of cochlear implantation on vestibular function in patients with large vestibular aqueduct syndrome

Objective:This study aimed to compare the effects of cochlear implantation（CI） on vestibular function in patients with large vestibular aqueduct syndrome（LVAS） and in patients with extremely severe deafness with normal inner ear structure. Methods:A total of 28 LVAS patients and 28 patients with normal inner ear structure who suffered from extremely severe deafness were selected. The parameters of caloric tests, bone conduction evoked cervical vestibular-evoked myogenic potentials（cVEMP）, bone conduction evoked ocular vestibular-evoked myogenic potentials（oVEMP） and video head impulse tests（v-HIT） were compared between the two groups before and after CI. The data were analyzed using SPSS 26.0 software. Results:There was no significant difference in the results of the preoperative caloric test, v-HIT, and oVEMP（P1, N1） between the LVAS group and the control group（P>0.05）. Compared to the control group, the LVAS group exhibited a shorter cVEMP P1[（13.41±0.71）ms vs （16.28±0.89）ms, P<0.000 1], shorter N1[（19.83±0.54）ms vs （28.18±1.56）ms, P<0.000 1], higher amplitude[（123.60±83.80）μV vs （73.92±79.85）μV, P=0.049 4] and higher oVEMP amplitude[（16.60±13.87）μV vs （9.96±10.47）μV, P=0.028 5] before CI. The abnormal rate of caloric test increased in both groups after CI（25.00% vs 57.14%, P=0.028 8, 32.14% vs 82.14%, P=0.000 3, respectively）. There was no significant difference in the v-HIT parameters in both groups before and after the operation. As for the LVAS group, there was no statistically significant difference in cVEMP and oVEMP induction rates before and after operation. In the control group, there was a decrease in cVEMP induction rate（96.42% vs 64.28%, P=0.005 2） and oVEMP induction rate（96.42% vs 57.14%, P=0.000 9） after CI. LVAS group showed a shorter cVEMP P1[（13.41±0.71）ms vs （10.30±0.60）ms, P<0.000 1]; shorter cVEMP N1[（19.86±0.53）ms vs （18.97±1.33）ms, P=0.004 7]; decreased amplitude[（124.50±84.86）μV vs （64.35±61.57）μV, P=0.001 0] and shorter oVEMP amplitude[（15.92±13.03）μV vs （9.16±9.20）μV, P=0.009 9] after CI. The oVEMP N1 in the control group was longer than that before operation[（11.73 ± 0.91）ms vs （13.35 ± 2.60）ms, P=0.019 6], whereas there was no significant difference in other VEMP parameters after CI. Conclusion:Before CI, there was no significant difference in the results of the caloric test and v-HIT between the LVAS group and the control group, but the LVAS group exhibited increased sensitivity to acoustic stimulation-induced myogenic potentials. After CI, the function of the semicircular canal was impaired in both groups in the low-frequency area, and remained largely unaffected in the high-frequency area. Additionally, the function of the otolith in the LVAS group was less affected than that in the control group after CI, which may be related to the fact that the enlarged vestibular aqueduct of the LVAS patients acted as the third window of the inner ear.

Hearing loss and vestibular dysfunction in congenital CMV infection: could it be due to endolymphatic pressure anomaly? A preliminary study

ObjectivesTo describe the inner ear sectors after an inner ear MRI protocol and search for the presence of endolymphatic pressure anomaly in patients presenting with a congenital CMV infection and audio-vestibular dysfunction. MethodsA 3D FLAIR MRI sequence, 4 hours after gadolinium injection, was performed in patients with sensory-neural hearing loss secondary to a congenital CMV infection in order to analyse the morphology of the endolymphatic space. ResultsTwo patients presented with a unilateral SNHL and 4 patients a bilateral SNHL. Seven ears with SNHL demonstrated an endolymphatic hydrops on MRI images and 2 showed a membranous labyrinth atelectasis. All ears but two had a marked enhancement in the perilymph of the basal turn of the cochlea. One ear, with a normal hearing threshold but altered vestibular function, demonstrated cochlear and saccular hydrops. Two ears with normal or near normal hearing and normal vestibular function were radiologically normal on the MRI. ConclusionThe compartmental endolymphatic study using delayed contrast-enhanced MRI sequences in children with cCMV infection suggests a relationship between inner ear involvement and endolymphatic pressure anomaly.

A retrospective analysis of the clinical characteristics of 63 patients with vestibular neuritis

Objective:To retrospectively analyze the results of auditory examination,vestibular function examination and laboratory examination of 63 patients diagnosed as vestibular neuritis.Methods:A total of 63 patients diagnosed with vestibular neuritis hospitalized in the Department of Otolaryngology, Head and Neck Surgery of the Third Affiliated Hospital of Sun Yat-sen University, from October 2012 to December 2022 were recruited. All patients met the diagnostic criteria for the 2022 Bárány association vestibular neuritis. Clinical data and the results of pure tone audiometry, electrocochleogram, video electronystagmogram, caloric test, cervical vestibuloevoked myogenic potential（cVEMP）, ocular vestibuloevoked myogenic potential（oVEMP）, video head impulse test（vHIT） was collected.A total of 63 age-and sex-matched healthy subjects in the physical examination center were randomly selected as the control group. The differences of blood indexs and lipid metabolism indexes between the two groups were compared. Results:In patients with vestibular neuritis, 50 out of 63 patients presented normal threshold in pure tone audiometry, 8 out of 63 patients had bilateral high-frequency sensorineural hearing loss and 5 out of 63 patients had unilateral mild high-frequency sensorineural hearing loss, 56 out of 63 cases completed the electrocochleogram, of which 3 cases had a binaural-SP/AP amplitude ratio≥0.4, 5 cases had monaural amplitude ratio ≥0.4. Fifty-five out of 63 patients completed the caloric test with CP values greater than 30% in all. The ratio of patients completed cVEMP, oVEMP and vHIT were 46 cases, 22 cases and 30 cases, respectively. 17 out of 63 cases completed all the four vestibular function tests. According to these tests, 49 patients could determine the extent of injury，including 27 cases with unilateral superior vestibular nerve injury, 21 cases with unilateral superior and inferior vestibular nerve injury and 1 case with unilateral inferior vestibular nerve injury. There were significant differences in neutrophil value（P<0.001）, lymphocyte value（P<0.005）, neutrophil/lymphocyte ratio（P<0.001） and apolipoprotein A1（P<0.001） between patient group and control group. Inflammatory markers were risk factors for patients with vestibular neuritis. The OR values of neutrophil value and blood neutrophil/lymphocyte ratio were 1.81（1.38-2.37, P<0.001） and 2.11（1.41-3.16, P<0.001）, respectively. Apolipoprotein A1 was a protective factor for patients with vestibular neuritis, and the OR value was 0.004（0.001-0.042, P<0.001）. Conclusion:Electrocochleogram could be used in vestibular neuritis patients with normal pure tone threshold to test whether there is hidden hearing loss in these patients. Neutrophil value, lymphocyte value, neutrophil/lymphocyte ratio and apolipoprotein A1 were correlated with vestibular neuritis. The Neutrophil value and neutrophil/lymphocyte ratio were risk factors for morbidity.

Ocular Vestibular-Evoked Myogenic Potentials in Individuals with Diabetes Mellitus: A Systematic Review and Meta-Analysis

Studies on ocular vestibular evoked myogenic potentials (VEMPs) in individuals with diabetes mellitus (DM) are inconsistent. The current study aimed to systematically review and report on existing studies on oVEMPs in DM. We performed a systematic review following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. To be included in the review and subsequent meta-analysis, the study had to report on ocular VEMPs (oVEMP) in DM individuals with and/or without peripheral neuropathy (PN). A search strategy for each of the major electronic databases was developed using the key words "diabetes mellitus" and "vestibular evoked myogenic potential" or "VEMP." A three-phase selection process was used for the final inclusion of studies, and the methodological quality of these studies was assessed using the Newcastle Ottawa scale (NCOS). Meta-analysis was performed using a random-effects model, and the statistical heterogeneity was computed using the &lt;i&gt;I&lt;/i&gt;&lt;sup&gt;2&lt;/sup&gt; index. For comparisons between DM and healthy controls, a significant difference was observed for oVEMP p1 latency (&lt;i&gt;P&lt;/i&gt; &amp;#61; 0.03), and amplitude (&lt;i&gt;P&lt;/i&gt; &amp;#61; 0.03). The nature of vestibular dysfunction in DM remains inconclusive. The results of our meta-analysis suggest that both central and peripheral vestibular dysfunction can be observed in DM. It appears that VEMPs may be useful in the early detection of neuropathy in DM. Prospective, well-designed studies are needed to investigate vestibular (dys)function in DM.

Effect of vestibular training on cognitive functions in people with multiple sclerosis: A randomized controlled trial.

Cognitive dysfunction is prevalent but inadequately treated in people with multiple sclerosis (PwMS). Central vestibular functions are associated with multiple cognitive domains in PwMS, even when controlling for disability status. To our knowledge, the effectiveness of vestibular training on cognition in PwMS has never been explored. The study's purpose was to determine the effect of vestibular training on PwMS's cognitive functions. Forty PwMS with relapsing-remitting MS, primarily fatigued, were randomly divided into two equal groups. The control group (GI) was treated with aerobic endurance exercises using stationary bicycle training. The study group (GII) was treated with aerobic endurance exercises as GI in addition to a designed vestibular training program. Outcome measures of cognition were assessed pre- and post-treatment using the Arabic version of Brief International Cognitive Assessment for MS (BICAMS-A) and serum Brain-derived neurotrophic factor (BDNF). Post-treatment, there was a significant increase of oral Symbol Digit Modalities Test (SDMT), California Verbal Learning Test II (CVLT-II), revised Brief Visuospatial retention Test (BVRT-R) of BICAMS-A and serum BDNF in both study and control groups. There was a significant increase in CVLT-II, BVRT-R of BICAMS-A and serum BDNF in the study group compared to the control group (P < 0.05). Vestibular training is an effective and innovative approach for improving cognitive functions in PwMS. PACTR202311670782148.

Effects of Age on the Bone-Conduction Amplitude-Modulated cVEMP Temporal Modulation Transfer Function.

Cervical vestibular evoked myogenic potentials (cVEMPs) reflect saccular stimulation that results in an inhibitory muscle reflex recorded over the sternocleidomastoid muscle. These responses are utilized to study basic vestibular functions and are also applied clinically. Traditionally, cVEMPs have utilized transient stimuli such as clicks and tonebursts to evoke onset responses. Recently, amplitude-modulated tones have been used to elicit cVEMPs (AMcVEMPs). These AMcVEMP responses can provide information about the magnitude, phase synchrony, and nonlinearities from the vestibulo-collic reflexes that cannot be captured using other existing testing techniques. Although temporal modulation transfer functions (TMTFs) of AMcVEMPs for young, healthy adults have been established using different analysis techniques, there is currently no information regarding the effects of age on these responses. Thus, the current study aimed to examine the effects of age on AMcVEMPs across a broad range of modulation frequencies (MFs) using various AMcVEMP metrics including amplitude, signal to noise ratio (SNR), and phase coherence (PC). The study included 16 (aged 20 to 39 years) young, 17 (aged 40 to 59 years) mid-age, and 16 (60 to 75 years) older adults with no history of neurological, vestibular, or middle-ear complaints. The stimuli consisted of amplitude-modulated tones with a carrier frequency of 500 Hz and 10 MFs ranging from 11 to 397 Hz. These stimuli were presented using a B81 transducer at 123 dB FL. AMcVEMPs were recorded from the sternocleidomastoid muscle (ipsilateral to the stimulating mastoid) using surface electrodes. Response analysis was performed using an FFT-based approach with analyses including amplitude, SNR, and PC. AMcVEMP waveforms exhibited periodicity corresponding to the stimulus MF, consistent with previous observations. Furthermore, significant age-related degradation in AMcVEMP amplitude, SNR, and PC measures were observed across a broad range of MFs. While AMcVEMPs were elicited across a wide range of MFs (11 to 263 Hz) for young adults, in mid-age and older adults, these metrics were robust only across a narrower range of MFs, resulting in a reduced TMTF. In addition, the MF eliciting the most robust AMcVEMP varied across different AMcVEMP analysis metrics and age groups. A significant decline in the AMcVEMP response is seen as an effect of aging; however, the effect of aging is not uniform across measures or across MFs. The TMTF of AMcVEMP gets flatter, and the overall range is reduced as an effect of aging. Results from this study enhance our understanding of age-related changes in the vestibular system. Expansion of AMcVEMP to clinical populations may lead to a deeper understanding of the pathophysiology of vestibular disorders.

Changes in oral microbiota at different stages of active orthodontic treatment

INTRODUCTION: There are no sufficient numbers of studies in the modern literature devoted to investigation of the relationship between the use of fixed orthodontic appliances and changes in the qualitative and quantitative bacterial composition at certain periods of orthodontic treatment. AIM: To identify changes in the qualitative and quantitative composition of the microbiocenosis in the area of installed fixed appliances at different periods of orthodontic treatment. MATERIALS AND METHODS: The study included 40 participants aged 18–44 years. All patients had a history of occlusion pathologies, dento-alveolar anomalies, and needed orthodontic treatment with use of fixed metal bracket systems. Before installing a fixed ligature vestibular metal bracket system (OC Orthodontics, USA), all patients underwent sanitation by a dental therapist, professional oral hygiene (removal of hard and soft dental deposits, tooth polishing), and, if necessary, extraction of wisdom teeth/wisdom tooth germs. The microbiocenosis was assessed in the area of intended placement of braces before orthodontic treatment, in the area of installation of braces in the period of adaptation to the fixed appliance (at 1 month after fixing the appliance) and in the period of active treatment (at 6 months after fixing the appliance). RESULTS: On the initial examination, the frequency of detection of stabilizing microflora was 81.25%, periodontopathogenic microflora — 18.75%. In the period of adaptation, the frequency of detection of stabilizing microflora was 56.25%, the frequency of detection of periodontopathogens increased to 43.75% (p = 0.052). In the phase of active orthodontic treatment, a decrease in the frequency of detection of periodontopathogenic bacteria to 40.96% was observed, and the frequency of detection of stabilizing microflora was 59.04% (p = 0.007). The microbial number before the installation of fixed orthodontic appliances was 105 ± 102 CFU/cm2, in the adaptation phase — 107 ± 102 CFU/cm2, in the period of active treatment — 105 ± 102 CFU/cm2 (p = 0.008). CONCLUSION: In the course of clinical and laboratory study, species and quantitative composition of the oral microbiocenosis was found to have characteristic features at different stages of the orthodontic treatment: before installation of fixed orthodontic appliances, the so-called ‘stabilizing’ microorganisms prevail over representatives of the group of periodontopathogens, in the period of adaptation, the proportion of periodontopathogens increases significantly with a decrease in the proportion of stabilizing microflora, in the phase of active orthodontic treatment their ratio normalizes.

Dizziness and unstable gait in the older adults are associated with vestibular hypofunction, muscle dysfunction and sleep disturbance: impact on prevention of accidental falls

BackgroundDizziness and unstable gait with resultant falls are common symptoms among the older adults. Most of studies have focused on statistical analysis regarding single factor related to dizziness and unstable gait. On the other hand, there are very few comprehensive studies using a large number of patients except several review papers.MethodsWe retrospectively analyzed a total of 164 aged patients with dizziness and unstable gait. The patients underwent description of the Japanese version of the Dizziness Handicap Inventory (DHI), measurements of vestibular function, handgrip muscle strength, physical performance, height-adjusted appendicular skeletal muscle mass, and vitamin B1 and B12, a full-night polysomnography study, cognition test and visual test.ResultsAverage age was 80.5 ± 6.1 years and ranged from 59 to 91 years. Forty-eight were males and 116 females. Three causative factors, namely vestibular hypofunction, muscle dysfunction and sleep disturbance, were independently and combinedly associated with dizziness and unstable gait in over 93% of the patients. Patients with higher scores defined by these three causative factors had higher scores of DHI. 23% of the patients showed vitamin B1 and/or B12 deficiency, which was highly associated with sarcopenia/frailty. Cognitive and visual impairment were recognized in 4.9% and 5.0%, respectively.ConclusionDizziness and unstable gait were mainly associated with vestibular hypofunction, muscle dysfunction and sleep disturbance. In addition, vitamin B1 and B12 deficiency, and cognitive and visual impairment secondarily contribute to dizziness and unstable gait. Appropriate selection of treatment according to the underlying causes would prevent accidental falls among the older adults.

Morphological studies of labyrinthine tissue in patients affected with Meniere's disease and vestibular schwannoma following labyrinthectomy.

Meniere's disease (MD) is a disabling disease of the inner ear, having a substantial effect on a patient's quality of life. While various postulations regarding its aetiology exists, due to the difficulty with accessing inner ear tissue, there have been limited histological studies in patients with active MD. Tissue was collected during labyrinthectomy from 8 patients with intractable MD who had failed medical therapy (22 samples), and 9 patients undergoing translabyrinthine resection of vestibular schwannoma (19 samples). 20 additional samples were obtained from 2 cadavers without a history of inner ear disease. Samples were assessed with routine histology and a panel of immunohistochemical markers to assess any differences between the groups. No MD samples demonstrated significant inflammatory infiltrate, evidence of denervation of the sensory epithelium, fibrosis, or thickening of blood vessel wall stroma. Novel findings included confirmation that no lymphatic channels of usual type were present and that the subepithelial stromal cells are strongly positive for S100, suggesting possible perineurial origin. There were no consistent differences in expression of Claudin or Aquaporin between the MD and VS patient samples. This is one of the largest comparative histological study utilising operative samples from inner ear of living donors with active intractable MD and control patients with VS. There were no significant morphological differences between the two groups, suggesting that the aetiology lies elsewhere within the vestibular system. Examination of endolymphatic sac tissue is therefore a priority for future work.

Problem of low-frequency motion cueing along roll on flight simulators

An innovative approach to improve the fidelity of low-frequency lateral motion cueing within full-flight simulators for non-maneuvering aircraft is presented. On the basis of the perception peculiarities by the human vestibular system of movement along the roll, the problem of low-frequency motion cueing of lateral movement by motion systems of flight simulators was formulated and solved. The critical challenge of simulating the set of angular motion cues that pilots perceive during flights is decided. This research highlights two key outcomes. The fourth-order low-pass filter effectively extracts low-frequency motion cues from aircraft motion kinematic parameters, enhancing simulation accuracy. Secondly, proposed method significantly expands the range of simulated motion cues while ensuring their synchronization with high-frequency motion cues along relevant degrees of freedom. This formulation of the problem increases the range of simulated motion cues to ±0,3nz, which practically corresponds to the range of simulated motion cues of a transport aircraft, and thus increases the quality of motion cueing. The implementation of the developed method on the An-72TK-200 full flight simulator confirmed its effectiveness. In conclusion, this study introduces a promising methodology that enhances the quality of motion cueing, thus rendering flight simulations more realistic and beneficial for both pilots and aerospace engineering researchers in the real of non-maneuvering aircraft flight simulators

Emotional and Motor Improvements in Children With ADHD Following Equine-Assisted Occupational Therapy

Attention deficit/hyperactivity disorder (ADHD) is characterized by inattention, hyperactivity, and impulsivity, as children may present developmental and chronic impairments in cognitive–emotional and sensory-motor aspects. This study examined the changes in self-efficacy, muscle tone, and mood following a single session of Equine-Assisted Occupational Therapy (EAOT) within Attention Skills Therapy (ASTride) intervention, designed to improve emotional and cognitive functions. Notably, 31 children diagnosed with ADHD aged 6–12 (mean age 10.06) years. A preliminary study of pre- and post-single 45-min session was performed, using the New General Self-efficacy Scale (NGSE), the Moos Scale Questionnaire (MSQ), and the prone extension test. A significant improvement in self-efficacy and in positive mood, and a decrease in negative mood were found, along with a significant improvement in core muscles. This study provides preliminary evidence supporting the effectiveness of EAOT for children with ADHD regarding emotional and sensory-motor (vestibular) functions.