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Meniere's disease (MD) is a condition of the inner ear with symptoms affecting both vestibular and hearing functions. Some patients with MD experience vestibular drop attacks (VDAs), which are violent falls caused by spurious vestibular signals from the utricle and/or saccule. Recent surgical work has shown that patients who experience VDAs also show disrupted utricular otolithic membranes. The objective of this study is to determine if otolithic membrane damage alone is sufficient to induce spurious vestibular signals, thus potentially eliciting VDAs and the vestibular dysfunction seen in patients with MD. We use a previously developed numerical model to describe the nonlinear dynamics of an array of active, elastically coupled hair cells. We then reduce the coupling strength of a selected region of the membrane to model the effects of tissue damage. As we reduce the coupling strength, we observe large and abrupt spikes in hair bundle position. As bundle displacements from the equilibrium position have been shown to lead to depolarization of the hair-cell soma and hence trigger neural activity, this spontaneous activity could elicit false detection of a vestibular signal. The results of this numerical model suggest that otolithic membrane damage alone may be sufficient to induce VDAs and the vestibular dysfunction seen in patients with MD. Future experimental work is needed to confirm these results in vitro.

Developmental abnormalities in otoliths can impact growth and survival in teleost fishes. Here, we quantified the frequency and severity of developmental anomalies in otoliths of delta smelt (Hypomesus transpacificus), a critically endangered estuarine fish that is endemic to the San Francisco Estuary. Left-right asymmetry and anomalous crystalline polymorphs (i.e., vaterite) were quantified and compared between wild and cultured populations using digital image analysis. Visual estimates of vaterite were validated using X-ray diffraction, Raman spectroscopy, laser ablation ICPMS, and electron probe microanalysis. Results indicated that cultured delta smelt were 80 times more likely to contain a vateritic otolith and 18 times more likely to contain relatively large (≥ 15%) amounts of vaterite. Similarly, cultured fish exhibited 30% greater asymmetry than wild fish. These results indicate that cultured delta smelt exhibit a significantly higher frequency of vestibular abnormalities which are known to reduce fitness and survival. Such hatchery effects on otolith development could have important implications for captive culture practices and the supplementation of wild fish populations with cultured individuals.

Background and Aim: Magnesium is essential for the morphogenesis of otoconia. The imbalance in the chemical composition of otoconia can make people susceptible to Benign Paroxysmal Positional Vertigo (BPPV). The primary outcome was to compare serum magnesium levels in BPPV patients with controls. The Ca/Mg ratios in participants are also recorded and analyzed in the present study. Methods: In this case-control study, we measured the serum Mg, Ca, and vitamin D in BPPV patients and age-, sex-matched subjects without BPPV. The results were adjusted for Ca, vitamin D, hypertension, and body mass index. Results: A total of 123 BPPV patients participated in this study. The mean Mg value was higher in patients than controls (2.01 vs. 1.95 mg/dL, p=0.030). Condition logistic regression analyses showed a higher rate of BPPV among subjects with low Ca/Mg ratio (quartile 1), relative to subjects with medium ratio (quartiles 2 and 3) (adjusted OR: 3.92, p=0.003). Conclusion: The present study demonstrated an imbalance of Ca and Mg in the BPPV patients as significantly higher Mg levels and lower serum Ca/Mg ratio. Although it appears decreased Ca/Mg ratio to be a risk factor for BPPV, this result should be confirmed in confirmatory studies. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to characterise the ipsilateral, contralateral and bilateral masseter vestibular-evoked myogenic potential using clicks and 500 Hz tone burst stimuli in healthy adults. Method: Masseter vestibular-evoked myogenic potential was recorded from 20 healthy participants aged 19–28 years (11 males and 9 females). Masseter vestibular-evoked myogenic potential was recorded using 500 Hz tone burst and click stimuli in ipsilateral, contralateral and bilateral modes. Results: A statistically significant difference was observed between ipsilateral and contralateral stimulation for p11 latency, n21 latency and p11-n21 amplitude for both click and 500 Hz tone burst stimuli. The amplitude of the p11-n21 complex was higher for ipsilateral, contralateral and bilateral stimulations for 500 Hz tone burst than for click stimulus. Conclusion: This study showed a significant difference for p11-n21 amplitude between click and 500 Hz tone burst evoked masseter vestibular-evoked myogenic potential. In addition, bilateral stimulation elicited a larger response than ipsilateral and contralateral stimulation. [ABSTRACT FROM AUTHOR]

Background and Aim: Magnesium is essential for the morphogenesis of otoconia. The imbalance in the chemical composition of otoconia can make people susceptible to Benign Paroxysmal Positional Vertigo (BPPV). The primary outcome was to compare serum magnesium levels in BPPV patients with controls. The Ca/Mg ratios in participants are also recorded and analyzed in the present study. Methods: In this case-control study, we measured the serum Mg, Ca, and vitamin D in BPPV patients and age-, sex-matched subjects without BPPV. The results were adjusted for Ca, vitamin D, hypertension, and body mass index. Results: A total of 123 BPPV patients participated in this study. The mean Mg value was higher in patients than controls (2.01 vs. 1.95 mg/dL, p=0.030). Condition logistic regression analyses showed a higher rate of BPPV among subjects with low Ca/Mg ratio (quartile 1), relative to subjects with medium ratio (quartiles 2 and 3) (adjusted OR: 3.92, p=0.003). Conclusion: The present study demonstrated an imbalance of Ca and Mg in the BPPV patients as significantly higher Mg levels and lower serum Ca/Mg ratio. Although it appears decreased Ca/Mg ratio to be a risk factor for BPPV, this result should be confirmed in confirmatory studies.

Introduction Degenerative changes in the otolithic organs have been theorized to be caused by the mechanical obstruction to endolymphatic flow, possibly resulting in endolymphatic hydrops (ELH). Otolin-1 is an otoconial matrix protein that crosses the blood labyrinth barrier and has been found in the serum of healthy and diseased patients. Objective To measure the serum levels of Otolin-1 in Meniere disease (MD) patients and compared them with the healthy individuals. Methods This pilot, cross-sectional study was performed at our tertiary care referral center to compare the serum Otolin-1 levels of healthy individuals with those of MD patients. The blood samples were obtained during patients' visit to the vertigo clinic following remission of an acute episode. The data was analyzed using the Stata/SE version 12.0 (StataCorp. College Station, TX, USA). Comparison between the serum Otolin-1 levels in the two groups was performed using the unpaired t -test. A p -value of 0.05 was considered to be statistically significant. Results The participants were divided into two groups, with 31 MD patients, and 30 age and gender-matched members of the control group. The serum levels of Otolin-1 in MD patients (247.6, ± 44.2 pg/ml) were not found to be significantly different from those of the control group (236.2, ± 43.5 pg/ml) (p = 0.31). Conclusion The current study reveals that the serum levels of Otolin-1 are not significantly different between the patients with MD in the interictal phase and the control group's healthy ones. [ABSTRACT FROM AUTHOR]

Meniere disease (MD) is a rare disorder of the inner ear defined by sensorineural hearing loss (SNHL) associated with episodes of vertigo and tinnitus. The phenotype is variable, and it may be associated with other comorbidities such as migraine, respiratory allergies, and several autoimmune disorders. The condition has a significant heritability according to epidemiological and familial segregation studies. Familial MD is found in 10% of cases, the most frequently found genes being OTOG, MYO7A, and TECTA, previously associated with autosomal dominant and recessive non-syndromic SNHL. These findings suggest a new hypothesis where proteins involved in the extracellular structures in the apical surface of sensory epithelia (otolithic and tectorial membranes) and proteins in the stereocilia links would be key elements in the pathophysiology of MD. The ionic homeostasis of the otolithic and tectorial membranes could be critical to suppress the innate motility of individual hair cell bundles. Initially, focal detachment of these extracellular membranes may cause random depolarization of hair cells and will explain changes in tinnitus loudness or trigger vertigo attacks in early stages of MD. With the progression of the disease, a larger detachment will lead to an otolithic membrane herniation into the horizontal semicircular canal with dissociation in caloric and head impulse responses. Familial MD shows different types of inheritance, including autosomal dominant and compound recessive patterns and implementation of genetic testing will improve our understanding of the genetic structure of MD. [ABSTRACT FROM AUTHOR]

Slender sole Lyopsetta exilis is an abundant groundfish on the continental shelf and inner waters of British Columbia, Canada, where it reaches a maximum standard length of 44 cm. Benthic image surveys coupled with oxygen measurements in Saanich Inlet document a dense population in bottom conditions near anoxia (0.03 ml l-1 oxygen) where diel migrating zooplankton intersect the bottom; we confirm this species is a planktivore, which limits its depth range to the base of the migration layer. In a comparison with slender sole from a nearby well-oxygenated habitat, several probable effects of living in severe hypoxia emerge: both sexes are significantly smaller in Saanich and the sex ratio is male-skewed. Otoliths from the Saanich fish were difficult to read due to many checks, but both sexes were smaller at age with the largest female (20 cm) from the hypoxia zone registering 17 years. Hypoxia appears to have a direct consequence on growth despite good food supply in this productive basin. Hyperventilation, a low metabolic rate and a very low critical oxygen tension help this fish regulate oxygen uptake in severely hypoxic conditions; it will be particularly resilient as the incidence of hypoxia increases on the continental shelf. Data from small-mesh bottom-trawl surveys over four decades reveal an increase in mean annual catch per unit effort in southern regions of the province, including the outer shelf and the Strait of Georgia. The California Cooperative Oceanic Fisheries Investigations (CalCOFI) ichthyoplankton database records a general decline in fish larvae on the Oregon-California shelf since 1990, but slender sole larvae are increasing there, as they are in the Strait of Georgia. We project that the slender sole will gain relative benefits in the future warming, deoxygenated northeast Pacific Ocean.

Despite the diversity in fish auditory structures, it remains elusive how otolith morphology and swim bladder-inner ear (= otophysic) connections affect otolith motion and inner ear stimulation. A recent study visualized sound-induced otolith motion; but tank acoustics revealed a complex mixture of sound pressure and particle motion. To separate sound pressure and sound-induced particle motion, we constructed a transparent standing wave tube-like tank equipped with an inertial shaker at each end while using X-ray phase contrast imaging. Driving the shakers in phase resulted in maximised sound pressure at the tank centre, whereas particle motion was maximised when shakers were driven out of phase (180°). We studied the effects of two types of otophysic connections-i.e. the Weberian apparatus (Carassius auratus) and anterior swim bladder extensions contacting the inner ears (Etroplus canarensis)-on otolith motion when fish were subjected to a 200 Hz stimulus. Saccular otolith motion was more pronounced when the swim bladder walls oscillated under the maximised sound pressure condition. The otolith motion patterns mainly matched the orientation patterns of ciliary bundles on the sensory epithelia. Our setup enabled the characterization of the interplay between the auditory structures and provided first experimental evidence of how different types of otophysic connections affect otolith motion.

Introduction Degenerative changes in the otolithic organs have been theorized to be caused by the mechanical obstruction to endolymphatic flow, possibly resulting in endolymphatic hydrops (ELH). Otolin-1 is an otoconial matrix protein that crosses the blood labyrinth barrier and has been found in the serum of healthy and diseased patients.

Chronic ototoxicity of β-diketone antibiotics (DKAs) to zebrafish (Danio rerio) was explored in detail by following abnormal expressions of two hearing-related miRNAs. Dose-dependent down-regulation of miR-96 and miR-184 was observed in otoliths during embryonic-larval development. Continuous DKA exposure to 120-hpf larva decreased sensitivity to acoustic stimulation. Development of otolith was delayed in treatment groups, showing unclear boundaries and vacuolization at 72-hpf, and utricular enlargement as well as decreased saccular volume in 96-hpf or latter larval otoliths. If one miRNA was knocked-down and another over-expressed, only a slight influence on morphological development of the otic vesicle occurred, but knocked-down or over-expressed miRNA both significantly affected zebrafish normal development. Injection of miR-96, miR-184 or both micRNA mimics to yolk sac resulted in marked improvement of otic vesicle phenotype. However, hair cell staining showed that only the injected miR-96 mimic restored hair cell numbers after DKA exposure, demonstrating that miR-96 played an important role in otic vesicle development and formation of hearing, while miR-184 was only involved in otic vesicle construction during embryonic development. These observations advance our understanding of hearing loss owing to acute antibiotic exposure and provide theoretical guidance for early intervention and gene therapy for drug-induced diseases.

Effective conservation of endangered species requires knowledge of the full range of life-history strategies used to maximize population resilience within a stochastic and ever-changing environment. California's endemic Delta Smelt (Hypomesus transpacificus) is rapidly approaching extinction in the San Francisco Estuary, placing it in the crossfire between human and environmental uses of limited freshwater resources. Though managed as a semi-anadromous species, recent studies have challenged this lifecycle model for Delta Smelt, suggesting the species is an estuarine resident with several localized "hot-spots" of abundance. Using laser-ablation otolith strontium isotope microchemistry, we discovered three distinct life-history phenotypes including freshwater resident (FWR), brackish-water resident (BWR), and semi-anadromous (SA) fish. We further refined life-history phenotypes using an unsupervised algorithm and hierarchical clustering and found that in the last resilient year-class, the FWR (12%) and BWR (7%) comprised a small portion of the population, while the majority of fish were SA (81%). Furthermore, the semi-anadromous fish could be clustered into at least four additional life-history phenotypes that varied by natal origin, dispersal age and adult salinity history. These diverse life-history strategies should be incorporated into future conservation and management efforts aimed at preventing the extinction of Delta Smelt in the wild.

The IsoFishR application is a data reduction and analysis tool for laser-ablation strontium isotope data, following common best practices and providing reliable and reproducible results. Strontium isotope ratios (87Sr/86Sr) are a powerful geochemical tracer commonly applied in a wide range of scientific fields and laser-ablation inductively coupled mass spectrometry is considered the method of choice to obtain spatially resolved 87Sr/86Sr isotope ratios from a variety of sample materials. However, data reduction and analyses methods are variable between different research groups and research communities limiting reproducibility between studies. IsoFishR provides a platform to standardize these methods and can be used for both spot and time-resolved line transects. Furthermore, it provides advanced data analysis tools and filters for outlier removal, noise reduction, and visualization of time resolved data. The application can be downloaded from GitHub (https://github.com/MalteWillmes/IsoFishR) and the source code is available, encouraging future development and evolution of this software.

European sea bass (Dicentrarchus labrax) is a species of high commercial and recreational value, but it exhibits highly variable recruitment rates and has been subject to recent declines. Emergency management measures put in place to protect spawning stocks include the annual closure of commercial and recreational fisheries over a 2-month, February-March, window. Whether this protection measure is having the desired outcome for this data-poor species remains unclear. Otolith microstructural analyses (counts and widths of daily growth rings and check marks indicative of settlement) were used to estimate (1) spawn timing, (2) pelagic larval duration and settlement timing, (3) growth rate and condition, and (4) the otolith-fish size relationship for juvenile European sea bass caught from two estuaries in Wales (Dwyryd, Y Foryd), located at the northern edge of the species range. We observed a significant mismatch between the timing of fisheries closures and the spawning, with 99.2% of recruits having been spawned after the fishery had reopened (back-calculated median spawn date = May 5 ± 17 days SD), suggesting that the closure may be too early to adequately protect this population. Further, we present the first empirically derived estimates of pelagic larval duration for sea bass recruits settling in UK habitats, which showed a strong negative relationship with spawn date. Finally, we found significant differences in fish condition between the two estuaries, suggesting local variation in habitat quality. The results suggest that the timing of current fisheries closures may not be adequately protecting the spawners supplying these northernmost estuaries, which are likely to become increasingly important as sea bass distributions shift northward in our climate future., (© 2024 The Author(s). Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.)

Anthropogenic deoxygenation of the Baltic Sea caused major declines in demersal and benthic habitat quality with consequent impacts on biodiversity and ecosystem services. Using Baltic cod otolith chemical proxies of hypoxia, salinity, and fish metabolic status and growth, we tracked changes from baseline conditions in the late Neolithic (4500 BP) and early twentieth century to the present, in order to understand how recent, accelerating climate change has affected this key species. Otolith hypoxia proxies (Mn:Mg) increased with expanding anoxic water volumes, but decreased with increasing salinity indexed by otolith Sr:Ca. Metabolic status proxied by otolith Mg:Ca and reconstructed growth were positively related to dissolved oxygen percent saturation, with particularly severe declines since 2010. This long-term record of otolith indicators provides further evidence of a profound state change in oxygen for the worse, in one of the world's largest inland seas. Spreading hypoxia due to climate warming will likely impair fish populations globally and evidence can be tracked with otolith chemical biomarkers., (© 2024. The Author(s).)

Purpose: Assess otolith and canal involvement in patients with Benign Paroxysmal Positional Vertigo (BPPV) during the acute phase., Methods: Ninety patients with BPPV in the acute phase underwent a vestibular assessment that included an assessment with videonistagmography, video Head Impulse Test (vHIT) to evaluate horizontal and vertical semicircular canals, and ocular vestibular evoked myogenic potentials (oVEMPs) for the otolithic function., Results: Ninety patients had an involvement of the posterior canal, fifty-five out of ninety patients presented a BPPV of the right ear. No asymmetry of the otolithic functions was found for the utricular macula. Furthermore, no reduction of the Vestibular Ocular Reflex gain was found for the examined canal functions., Conclusions: The lack of asymmetry suggests that during the acute phase of BPPV, the otolithic function is balanced between the affected and unaffected ears. Moreover, the preserved VOR gain for the examined canal functions suggests that the VOR responses for the examined channels were intact., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: This study aimed to evaluate serum otolin-1 levels in patients with benign paroxysmal positional vertigo and to compare these levels with healthy individuals. Method: This was a case-control study. After obtaining institutional ethical committee clearance, the serum level of otolin-1 was calculated in adult individuals (18–75 years old) who were divided into group 1 (patients presenting with benign paroxysmal positional vertigo) and group 2 (healthy patients without benign paroxysmal positional vertigo as the control group). Data analysis was carried out to compare the serum levels in the cases and controls. A p-value less than 0.05 was considered significant. Results: A total of 70 age-matched individuals (cases, n = 40; controls, n = 30) were included in the study. The mean serum level of otolin-1 was 636.8 pg/ml (range, 259–981 pg/ml) in the group of patients with benign paroxysmal positional vertigo and 236.2 pg/ml (range, 189–370 pg/ml) in the control group. The difference was statistically significant (p = 0.0000). Conclusion: The serum levels of otolin-1 in patients with benign paroxysmal positional vertigo are significantly higher compared with individuals without benign paroxysmal positional vertigo. [ABSTRACT FROM AUTHOR]

A complete understanding of population connectivity via larval dispersal is of great value to the effective design and management of marine protected areas (MPA). However empirical estimates of larval dispersal distance, self-recruitment, and within season variability of population connectivity patterns and their influence on metapopulation structure remain rare. We used high-resolution otolith microchemistry data from the temperate reef fish Hypsypops rubicundus to explore biweekly, seasonal, and annual connectivity patterns in an open-coast MPA network. The three MPAs, spanning 46 km along the southern California coastline were connected by larval dispersal, but the magnitude and direction of connections reversed between 2008 and 2009. Self-recruitment, i.e. spawning, dispersal, and settlement to the same location, was observed at two locations, one of which is a MPA. Self-recruitment to this MPA ranged from 50-84%; within the entire 60 km study region, self-recruitment accounted for 45% of all individuals settling to study reefs. On biweekly time scales we observed directional variability in alongshore current data and larval dispersal trajectories; if viewed in isolation these data suggest the system behaves as a source-sink metapopulation. However aggregate biweekly data over two years reveal a reef network in which H. rubicundus behaves more like a well-mixed metapopulation. As one of the few empirical studies of population connectivity within a temperate open coast reef network, this work can inform the MPA design process, implementation of ecosystem based management plans, and facilitate conservation decisions.

Objective To explore the correct diagnosis and treatment of canal conversion of otolith in the treatment of geotropic nystagmus horizontal semicircular canal benign paroxysmal positional vertigo (BPPV) by Barbecue maneuver. Methods and Results There were 66 patients with geotropic nystagmus horizontal semicircular canal BPPV treated by Barbecue maneuver from January to December 2010 in Guangdong General Hospital. Among 66 cases, 6 cases (9.09%) were transformed to posterior semicircular canal BPPV and 10 cases (15.15% ) were transformed to apogeotropic nystagmus. Among 50 cases (75.76%) who did not show transition, 3 cases (4.55%) were found relapsed on the 30th day of follow-up. The total effective rate was 95.45% (63/66). No one suffered from severe adverse events. Conclusions During the maneuver treatment of geotropic nystagmus horizontal semicircular canal BPPV, canal conversion of otolith could happen. Therefore, characteristics of nystagmus should be concerned, and exact diagnosis and repeated maneuver treatment is the key to success. DOI: 10.3969/j.issn.1672-6731.2019.02.004

Objective To explore the change of serum sex hormones and 25-hydroxycholecalciferol [25-(OH)-D3 ] level in postmenopausal female patients with benign paroxysmal positional vertigo (BPPV). Methods Electrochemiluminescence (ECL) assay was employed to detect the serum levels of estradiol (E2), progesterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), and 25-(OH)-D3 in 63 female postmenopausal BPPV patients with age 50-80 years from September 1, 2015 to February 1, 2017. Spearman rank correlation analysis was used to analyze the relation between age and E2 , E2 and 25-(OH)-D3. Univariate and multivariate stepwise Logistic regression analysis were used to screen the risk factors for BPPV. Results The serum levels of E2 [15.67 (10.96, 22.15) pg/ml] and 25-(OH)-D3 [(24.24 ± 1.05) ng/ml] in BPPV group were lower than those in control group [E2: 31.78 (25.60, 39.50) pg/ml, 25-(OH)-D3: (27.62 ± 0.76) ng/ml], and the differences were statistically significant (Z = -6.768, P = 0.000; t = -2.605, P = 0.010). There was no significant difference on progesterone, LH and FSH between 2 groups. Correlation analysis showed there was no relation between E2 and 25-(OH)-D3 levels in both groups. There was a negative correlation between age and E2 in control group (rs = -0.263, P = 0.038), but no correlation in BPPV group. Multivariate Logistic regression analysis showed decreased serum E2 and 25-(OH)-D3 levels maybe the risk factors for postmenopausal female BPPV patients. Conclusions E2 and 25-(OH)-D3 deficiency are independent risk factors for BPPV in postmenopausal female patients. DOI: 10.3969/j.issn.1672-6731.2019.01.007

Objective To investigate the efficacy of Gufoni maneuver for treating geotropic nystagmus horizontal semicircular canal benign paroxysmal positional vertigo (BPPV). Methods We retrospectively analyzed 87 patients diagnosed as geotropic nystagmus horizontal semicircular canal BPPV from January to December 2016. All patients were treated by Gufoni maneuver twice and examined on the next day to access the status of BPPV. Patients still with geotropic nystagmus or dizziness were treated by Gufoni maneuver twice again and examined after 30 min. The effect was assessed by "Diagnosis basis and curative effect appraisal of benign paroxysmal positional vertigo (2006, Guiyang)". Results The success rate of first treatment by Gufoni maneuver achieved to 71.26% (62/87) and increased to 86.21% (75/87) after the second treatment. Among these patients, 12 patients failed to recover, 8 of whom were treated by forced prolonged position (FPP) and recovered after one week, and 4 of whom turned to be posterior semicircular canal BPPV and were treated by Epley maneuver successfully. Conclusions Gufoni maneuver is proved to be a good treatment for geotropic nystagmus horizontal semicircular canal BPPV and the efficacy increases after repeated treatment. DOI: 10.3969/j.issn.1672-6731.2019.01.008

Objective: To evaluate horizontal semicircular canal (HSC) effects according to Ewald's law and nystagmus characteristics of horizontal semicircular canal benign paroxysmal positional vertigo (HSC-BPPV) in the supine roll test.Methods: Patients with HSC-BPPV (n = 72) and healthy subjects (n = 38) were enrolled. Latency, duration, and intensity of nystagmus elicited by supine roll test were recorded using video nystagmography.Results: In patients with HSC-BPPV, horizontal nystagmus could be elicited by right/left head position (positional nystagmus) and during head-turning (head-turning nystagmus), and nystagmus direction was the same as that of head turning. Mean intensity values of head-turning nystagmus in HSC-BPPV patients were (44.70 ± 18.24)°/s and (44.65 ± 19.27)°/s on the affected and unaffected sides, respectively, which was not a significant difference (p = 0.980), while those for positional nystagmus were (40.81 ± 25.56)°/s and (17.69 ± 9.31)°/s (ratio, 2.59 ± 1.98:1), respectively, representing a significant difference (p < 0.0001). There was no positional nystagmus in 49 HSC-BPPV patients after repositioning treatment, nor in the 38 healthy subjects. No significant difference in head-turning nystagmus was detected in HSC-BPPV patients with or without repositioning.Conclusions: The direction and intensity of nystagmus elicited by supine roll test in patients with HSC-BPPV, was broadly consistent with the physiological nystagmus associated with a same HSC with single factor stimulus. Our findings suggest that HSC-BPPV can be a show of Ewald's law in human body.

Objective: To evaluate horizontal semicircular canal (HSC) effects according to Ewald's law and nystagmus characteristics of horizontal semicircular canal benign paroxysmal positional vertigo (HSC-BPPV) in the supine roll test. Methods: Patients with HSC-BPPV (n = 72) and healthy subjects (n = 38) were enrolled. Latency, duration, and intensity of nystagmus elicited by supine roll test were recorded using video nystagmography. Results: In patients with HSC-BPPV, horizontal nystagmus could be elicited by right/left head position (positional nystagmus) and during head-turning (head-turning nystagmus), and nystagmus direction was the same as that of head turning. Mean intensity values of head-turning nystagmus in HSC-BPPV patients were (44.70 ± 18.24)°/s and (44.65 ± 19.27)°/s on the affected and unaffected sides, respectively, which was not a significant difference (p = 0.980), while those for positional nystagmus were (40.81 ± 25.56)°/s and (17.69 ± 9.31)°/s (ratio, 2.59 ± 1.98:1), respectively, representing a significant difference (p < 0.0001). There was no positional nystagmus in 49 HSC-BPPV patients after repositioning treatment, nor in the 38 healthy subjects. No significant difference in head-turning nystagmus was detected in HSC-BPPV patients with or without repositioning. Conclusions: The direction and intensity of nystagmus elicited by supine roll test in patients with HSC-BPPV, was broadly consistent with the physiological nystagmus associated with a same HSC with single factor stimulus. Our findings suggest that HSC-BPPV can be a show of Ewald's law in human body. [ABSTRACT FROM AUTHOR]

Objective: To compare the clinical efficacy of personalized vestibular rehabilitation and otolith reposition in treating atypical benign paroxysmal positional vertigo (BPPV). Methods: A randomized controlled trial was carried out. Fifty patients diagnosed with atypical BPPV in the Vertigo Clinic of the First Affiliated Hospital of Shandong First Medical University from October 2022 to September 2023 were recruited and randomly divided into manual reduction group (25 cases) and vestibular rehabilitation group (25 cases) according to the random number table. All patients were given flunarizine. Patients in the manual reduction group were treated by Epley maneuver and (or) Barbecue maneuver, while the vestibular rehabilitation group was given personalized vestibular rehabilitation therapy. After two weeks' treatment, the clinical symptoms (positional vertigo/nystagmus) and total dizziness handicap inventory (DHI) score, DHI physical (DHI-P), DHI emotional (DHI-E), and DHI functional (DHI-F) of the two groups were evaluated and compared. Results: A total of 50 patients diagnosed with atypical BPPV were included, including 23 males and 27 females, with an average age of (48.8±14.5) years. There was no statistically significant difference between the two groups in age, gender, disease severity, Romberg, position test abnormality ratio (Dix-hallpike/Roll test), temperature test, and video head impulse test baseline test results (all P >0.05). After 2 weeks of treatment, the effective rates of the treatment in the manual reduction and vestibular rehabilitation groups were 56.0% (14/25) and 88.0% (22/25), respectively, with a statistically significant difference ( P =0.025). The total DHI score, DHI-P, DHI-E, and DHI-F scores in both groups were significantly decreased after treatment (all P <0.001). Compared with the manual reduction group, the total DHI score (23.2±2.7 vs 36.4±15.7, P =0.002), DHI-P (10.2±4.6 vs 13.7±5.3, P =0.016) and DHI-F (6.5±6.4 vs 13.0±7.2, P =0.002) in the vestibular group were lower, however, there was no significant difference in DHI-E score between the two groups (6.6±4.8 vs 9.6±7.3, P =0.087). Conclusion: Compared with otolith reposition, personalized vestibular rehabilitation therapy plays a better role in improving the symptoms and decreasing DHI score for patients with atypical BPPV.

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.

The temporal asynchronies in larvae production from different spawning areas are fundamental components for ensuring stability and resilience of marine metapopulations. Such a concept, named portfolio effect, supposes that diversifying larval dispersal histories should minimize the risk of recruitment failure by increasing the probability that at least some larvae successfully settle in nursery. Here, we used a reconstructive approach based on otolith chemistry to quantify the larval dispersal portfolio of the European seabass, Dicentrarchus labrax, across six estuarine nursery areas of the northeast Atlantic Ocean. The analysis of natal and trajectory signatures indicated that larvae hatch in distinct environments and then dispersed in water masses featured by contrasting chemical signatures. While some trace elements appeared affected by temporal changes (Mn and Sr), others varied spatially during the larval stage but remained poorly affected by temporal fluctuation and fish physiology (Ba, Cu, Rb and Zn). We then proposed two diversity metrics based on richness and variations of chemical signatures among populations to reflect spatio-temporal diversity in natal origins and larval trajectories (i.e., estimates of dispersal portfolio). Along the French coast, the diversity estimates were maximum in nurseries located at proximity of offshore spawning sites and featured by complex offshore hydrodynamic contexts, such as the Mont St-Michel bay. Finally, our findings indicate that the dispersal portfolio was positively related with the local abundance of seabass juveniles, supporting the assumption that heterogeneity in dispersal history contributes to promote recruitment success in nurseries., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

This study assessed the otolith (sagittae, lapilli, and asterisci) increment deposition rate in the range-shifting damselfish, A. vaigiensis, using different concentrations of Alizain Red S and evaluated the impact of staining on increment width. Daily increment deposition was verified in all otolith types and presented clearer fluorescent markings in the lapilli and sagittae than the asterisci, with high stain concentration showing the best clarity. Higher stain concentrations were found to decrease increment width, suggesting care is needed when using stained otoliths as a proxy for growth for this species., (© 2023 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.)

Black ruff (Centrolophus niger) is a rare and poorly studied species found in both the Atlantic and Pacific Oceans and also in the Mediterranean Sea. It is sporadically caught south of Iceland during the annual International Ecosystem Summer Survey of the Nordic Seas. In total, 43 specimens were caught from 2009 to 2021, of which 41 specimens were caught during 2017-2021. All specimens, except one, were caught using a pelagic trawl (cod-end mesh-size: 50 mm) close to the surface (trawl depth: 0-35 m) with in situ temperature ranging from 9 to 13°C. The area south of Iceland is characterized by having warmer temperatures than other areas around the island, which might be indicative of a northern limit for the distribution of black ruff. The fish were primarily in the range of 29-46 cm with a few larger individuals up to 71 cm. Fourteen fish, caught in 2017 and 2021, were dissected to gather biological information on this species. These fish were all juveniles with no obvious sign of gonad development. Correlations between total length, fork length, and standard length are presented. Otoliths were thin and delicate with a length of ~13-16 mm, and otolith size (length, width, and area) was correlated with fish size. Much of the stomach content was at an advanced stage of digestion, but some contents could be identified and consisted of invertebrates, primarily of the orders Amphipoda and Calanoida with some unidentified fish also present., (© 2023 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.)

Humans have long been fascinated by the mysteries surrounding fish migrations and addressing these complex behaviors often requires large data sets. Biogeochemical tags, including trace elements and stable isotopes, are the most accessible biomarkers for tracking fish migrations. However, access to standardized biogeochemical tag data is rarely available for migratory fish, which limits our understanding of the evolutionary origins, drivers, timing, and corridors of migration. This precludes the development of conservation strategies and the implementation of management actions. Here, we present MFishBT, a global, open-access database of Migratory Fish's Biogeochemical Tags. As of April 2023, the MFishBT contains biogeochemical records from 1,305 studies, of which 53% used element-to-calcium (E/Ca) ratios, 34% used isotopic ratios, and 13% used both. The database covers 17,413 field sampling locations (inland 47% vs. marine 53%) around the globe, comprising 490 migratory fish species of four classes, 44 orders/suborders, and 137 families. In total, 77 trace elements and 11 isotope systems were measured across various fish biological archives, including otoliths, scales, eye lenses, and vertebrae. E/Ca ratios were examined more frequently than isotopic ratios, led by Sr/Ca, Mg/Ca, Ba/Ca, and 87 Sr/ 86 Sr, δ 13 C, and δ 18 O. The MFishBT compiles 27,030, 16,222, and 2,481,714 records with biogeochemical data detected in the core, edge, and core-to-edge transects for biological archives of migratory fish. This is the most globally comprehensive open-access database on biogeochemical tags in migratory fish to date, and can serve a variety of needs in scientific research, conservation, and management. We encourage researchers to add more data sets to this database in the future. This database is released for noncommercial use only. There are no copyright restrictions, and please cite this paper when using these data, or a subset of these data, for publication., (© 2023 The Ecological Society of America.)

Background: Vestibular evoked myogenic potentials (VEMPs) are increasingly being used for testing otolith organ function. Objective: This article provides an overview of the anatomical, biomechanical and neurophysiological principles underlying the evidence-based clinical application of ocular and cervical VEMPs (oVEMPs and cVEMPs). Material and methods: Systematic literature search in PubMed until April 2019. Results: Sound and vibration at a frequency of 500 Hz represent selective vestibular stimuli for the otolith organs. The predominant specificity of oVEMPs for contralateral utricular function and of cVEMPs for ipsilateral saccular function is defined by the different central projections of utricular and saccular afferents. VEMPs are particularly useful in the diagnosis of superior canal dehiscence and otolith organ specific vestibular dysfunction and as an alternative diagnostic approach in situations when video oculography is not possible or useful. Conclusion: The use of VEMPs is a simple, safe, reliable and selective test of dynamic function of otolith organs. [ABSTRACT FROM AUTHOR]

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Ocular vestibular evoked myogenic potentials (oVEMP) and cervical VEMP (cVEMP) are newer diagnostic methods, which allow an insight into the otolith senses. Our aim was to determine changes in certain parameters of the VEMP wave complex after successfully performed repositioning procedure, as an indicator of the state of recovery in patients with benign paroxysmal positional vertigo (BPPV). This may confirm the theory of otolith returning into the area of otolithic senses. The study included 48 patients with unilateral posterior semicircular canal BPPV. On their first arrival, otoneurological examinations, oVEMP and cVEMP tests were performed. The same were included in follow up check-ups scheduled at seven days and six months after successful implementation of Epley maneuvers. The initial measurement revealed a significantly reduced amplitude of oVEMP on the affected side. On the 7-day measurement, the amplitude increase was observed on the affected side, with significant reduction in the amplitude ratio (p=0.693), which reached statistical significance on the last measurement at 6 months (p=0.006). These findings confirmed the hypothesis of the return of otoconia into the utricular area.

A recent study based on gonad histology revealed that the existence of the spawning grounds for Gray's grenadier anchovy (Coilia grayii) and Osbeck's grenadier anchovy (C. mystus) in the Min River Estuary, the largest in Fujian Province, southern China. Further confirming their natal sources and migratory patterns is essential to understand their life histories. We used otolith microchemistry to assess the origins and habitat uses of 23 C. grayii and 22 C. mystus, collected the Min River Estuary and the adjacent waters. The results showed that C. grayii spawned in both freshwater (n‍ = 14) and brackish water (n = 9), and C. mystus spawned mainly in brackish water (n‍ = 20) with minor in freshwater (n‍ = 1) and marine water (n‍ = 1). The migratory patterns of C. grayii (four types) and C. mystus (five types) were diverse, mainly exhibiting anadromous and semi-anadromous behaviors. The first migratory behavior of C. grayii and C. mystus occurred within the age of the first year. The findings have significant implications for fishery stock management of the Min River Estuary and its adjacent waters., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The subpopulation and/or contingent structure of Atlantic bluefin tuna (Thunnus thynnus) within the Mediterranean Sea is undefined, leading to uncertainty regarding the best strategy for an effective assessment and management of this highly exploited stock. This study aimed to reconstruct temperatures experienced by Atlantic bluefin tuna during the early life period (<3.5 months) using clumped isotope temperature proxy, an innovative geothermometer for carbonates, that does not require previous knowledge of other environmental parameters such as water oxygen composition. We examined otolith chemistry in fish captured from 3 different areas of the Mediterranean Sea and adjacent waters. We found that mean seasonal temperature estimates from clumped isotopes did not differ significantly from satellite derived and otolith oxygen stable isotopic ratios derived temperatures, except for the central Mediterranean Sea, were clumped isotopes derived temperatures were significantly higher than satellite derived temperatures. However, the sensitivity of the clumped isotope thermometer was found to be lower than that based on oxygen fractionation equation, with high variance observed in the clumped isotopes derived temperature estimates. We also observed that clumped isotope derived temperatures were undistinguishable among bluefin tuna captured in the Gibraltar Strait, the central, and eastern Mediterranean Sea. In this paper, we discuss the major sources of uncertainty in temperature reconstructions using bluefin tuna otoliths., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Iraide Artetxe-Arrate reports financial support was provided by International Commission for the Conservation of Atlantic Tunas., (Copyright © 2023. Published by Elsevier Ltd.)

Here we review the clinical value of a video-oculography test for clinical evaluation of vestibular otolith function. This test is known as the video ocular counter roll (vOCR) and is based on measurement of torsional vestibulo-ocular reflex with a lateral head tilt. The vOCR test consists of a simple maneuver during which the head and torso are tilted en bloc by the examiner. The pattern of vOCR deficit among patients highlights its clinical value in identifying the stage of vestibular loss and recovery. The quick application of vOCR allows examination of otolith-ocular function and assessment of vestibular recovery at the bedside., (© 2023 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Meniere's disease (MD) is a severe inner ear condition known by debilitating symptoms, including spontaneous vertigo, fluctuating and progressive hearing loss, tinnitus, and aural fullness or pressure within the affected ear. Prosper Meniere first described the origins of MD in the 1860s, but its underlying mechanisms remain largely elusive today. Nevertheless, researchers have identified a key histopathological feature called Endolymphatic Hydrops (ELH), which refers to the excessive buildup of endolymph fluid in the membranous labyrinth of the inner ear. The exact root of ELH is not fully understood. Still, it is believed to involve several biological and bioenvironmental etiological factors such as genetics, autoimmunity, infection, trauma, allergy, and new theories, such as saccular otoconia blocking the endolymphatic duct and sac. Regarding treatment, there are no reliable and definitive cures for MD. Most therapies focus on managing symptoms and improving the overall quality of patients' life. To make significant advancements in addressing MD, it is crucial to gain a fundamental understanding of the disease process, laying the groundwork for more effective therapeutic approaches. This paper provides a comprehensive review of the pathophysiology of MD with a focus on old and recent theories. Current treatment strategies and future translational approaches (with low-level evidence but promising results) related to MD are also discussed, including patents, drug delivery, and nanotechnology, that may provide future benefits to patients suffering from MD., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

The three otolithic endorgans of the inner ear are known to be involved in sound detection in different teleost fishes, yet their relative roles for auditory-vestibular functions within the same species remain uncertain. In zebrafish (Danio rerio), the saccule and utricle are thought to play key functions in encoding auditory and vestibular information, respectively, but the biological function of the lagena is not clear. We hypothesized that the zebrafish saccule serves as a primary auditory endorgan, making it more vulnerable to noise exposure, and that the lagena might have an auditory function given its connectivity to the saccule and the dominant vestibular function of the utricle. We compared the impact of acoustic trauma (continuous white noise at 168 dB for 24 h) between the sensory epithelia of the three otolithic endorgans. Noise treatment caused hair cell loss in both the saccule and lagena but not in the utricle. This effect was identified immediately after acoustic treatment and did not increase 24 h post-trauma. Furthermore, hair cell loss was accompanied by a reduction in presynaptic activity measured based on ribeye b presence, but mainly in the saccule, supporting its main contribution for noise-induced hearing loss. Our findings support the hypothesis that the saccule plays a major role in sound detection and that the lagena is also acoustically affected, extending the species hearing dynamic range., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2023. Published by The Company of Biologists Ltd.)