Immunohistochemical staining with CD117 and PGP9.5 of excised vestibular tissue from patients with neuroproliferative vestibulodynia

BACKGROUND

Neuroproliferative vestibulodynia (NPV), a provoked genital pain characterized by severe allodynia and hyperalgesia, is confirmed in excised vestibular tissue by immunohistochemical staining (>8 CD117-positive immunostained cells/100× microscopic field) rather than by hematoxylin and eosin staining.

AIM

In this study we sought to assess immunostaining of tissue samples obtained during vestibulectomy surgery and to correlate results with patient outcomes.

METHODS

Patients (n = 65) meeting criteria for NPV who underwent vestibulectomy during the period from June 2019 through December 2022 formed the study cohort. We performed assessment of pathology of vestibular tissues by use of immunohistochemical staining, including quantitation of mast cells by CD117 (mast cell marker) and nerve fibers by protein gene product (PGP) 9.5 (neuronal marker). We analyzed 725 photomicrographs of immunostained tissue sections (100× and 200×) by manual counting and computer-assisted histometry and correlated these data to clinical assessments.

OUTCOMES

Outcomes included density of CD117 and PGP9.5 immunostaining in the 1:00-11:00 o'clock and 12:00 o'clock vestibular regions, and patient-reported outcomes assessing sexual function, pain, distress, and symptom improvement.

RESULTS

All 65 NPV patients (median age 26 years), 45 with lifelong and 20 with acquired NPV, had severe pain documented by PROs and vulvoscopy and had >8 CD117-immunopositive cells/100× microscopic field. Median cell count values were similar in the 1:00-11:00 o'clock and 12:00 vestibular regions (28.5 and 29.5/100× field, respectively). Likewise, the marker) and nerve fibers by protein gene product (PGP) 9.5 (neuronal marker). We analyzed 725 photomicrographs of immunostained tissue sections (100× and 200×) by manual counting and computer-assisted histometry and correlated these data to clinical assessments.

OUTCOMES

Outcomes included density of CD117 and PGP9.5 immunostaining in the 1:00-11:00 o'clock and 12:00 o'clock vestibular regions, and patient-reported outcomes assessing sexual function, pain, distress, and symptom improvement.

RESULTS

All 65 NPV patients (median age 26 years), 45 with lifelong and 20 with acquired NPV, had severe pain documented by PROs and vulvoscopy and had >8 CD117-immunopositive cells/100× microscopic field. Median cell count values were similar in the 1:00-11:00 o'clock and 12:00 vestibular regions (28.5 and 29.5/100× field, respectively). Likewise, the median area of CD117 immunostaining was similar in both regions (0.69% and 0.73%). The median area of PGP9.5 immunostaining was 0.47% and 0.31% in these same regions. Pain scores determined with cotton-tipped swab testing were nominally higher in lifelong vs acquired NPV patients, reaching statistical significance in the 1:00-11:00 o'clock region (P < .001). The median score for the McGill Pain Questionnaire affective subscale dimension was also significantly higher in lifelong vs acquired NPV patients (P = .011). No correlations were observed between hematoxylin and eosin results and density of mast cells or neuronal markers. Of note, 63% of the patient cohort reported having additional conditions associated with aberrant mast cell activity.

CLINICAL IMPLICATIONS

The pathology of NPV is primarily localized to the vestibular epithelial basement membrane and subepithelial stroma with no visible vulvoscopic findings, making clinical diagnosis challenging.

STRENGTHS AND LIMITATIONS

Strengths of this study include the large number of tissues examined with what is to our knowledge the first-ever assessment of the 12:00 vestibule. Major limitations are specimens from a single timepoint within the disease state and lack of control tissues.

CONCLUSIONS

Performing immunohistochemical staining of excised vestibular tissue with CD117 and PGP9.5 led to histometric confirmation of NPV, indications that NPV is a field disease involving all vestibular regions, validation for patients whose pain had been ignored and who had experienced negative psychosocial impact, and appreciation that such staining can advance knowledge.

Corrigendum: Precision medicine: a new era for inner ear diseases

[This corrects the article DOI: 10.3389/fphar.2024.1328460.].

Age-Related Changes in Temporal Binding Involving Auditory and Vestibular Inputs

Maintaining balance involves the combination of sensory signals from the visual, vestibular, proprioceptive, and auditory systems. However, physical and biological constraints ensure that these signals are perceived slightly asynchronously. The brain only recognizes them as simultaneous when they occur within a period of time called the temporal binding window (TBW). Aging can prolong the TBW, leading to temporal uncertainty during multisensory integration. This effect might contribute to imbalance in the elderly but has not been examined with respect to vestibular inputs. Here, we compared the vestibular-related TBW in 13 younger and 12 older subjects undergoing 0.5 Hz sinusoidal rotations about the earth-vertical axis. An alternating dichotic auditory stimulus was presented at the same frequency but with the phase varied to determine the temporal range over which the two stimuli were perceived as simultaneous at least 75% of the time, defined as the TBW. The mean TBW among younger subjects was 286 ms (SEM ± 56 ms) and among older subjects was 560 ms (SEM ± 52 ms). TBW was related to vestibular sensitivity among younger but not older subjects, suggesting that a prolonged TBW could be a mechanism for imbalance in the elderly person independent of changes in peripheral vestibular function.

Precision medicine: a new era for inner ear diseases

The inner ear is the organ responsible for hearing and balance. Inner ear dysfunction can be the result of infection, trauma, ototoxic drugs, genetic mutation or predisposition. Often, like for Ménière disease, the cause is unknown. Due to the complex access to the inner ear as a fluid-filled cavity within the temporal bone of the skull, effective diagnosis of inner ear pathologies and targeted drug delivery pose significant challenges. Samples of inner ear fluids can only be collected during surgery because the available procedures damage the tiny and fragile structures of the inner ear. Concerning drug administration, the final dose, kinetics, and targets cannot be controlled. Overcoming these limitations is crucial for successful inner ear precision medicine. Recently, notable advancements in microneedle technologies offer the potential for safe sampling of inner ear fluids and local treatment. Ultrasharp microneedles can reach the inner ear fluids with minimal damage to the organ, collect μl amounts of perilymph, and deliver therapeutic agents in loco. This review highlights the potential of ultrasharp microneedles, combined with nano vectors and gene therapy, to effectively treat inner ear diseases of different etiology on an individual basis. Though further research is necessary to translate these innovative approaches into clinical practice, these technologies may represent a true breakthrough in the clinical approach to inner ear diseases, ushering in a new era of personalized medicine.

Endolymphatic hydrops asymmetry distinguishes patients with Meniere's disease from normal controls with high sensitivity and specificity

Background

Many endolymphatic hydrops (EH) MRI studies in the literature do not include a normal control group. Consequently, it remains unclear which outcome measure in EH MRI can most effectively distinguish between MD patients and normal controls.

Methods

Gadolinium-enhanced EH imaging was performed to quantitatively evaluate the extents of hydrops in MD patients and age-/sex-matched normal controls. Four hours after intravenous injection of contrast agent, MRI was performed using a 3-T MR platform fitted with a 32-channel phased-array coil receptor. MR images (10-15 slices) covering an inner ear were 3D-stacked. Analyses of all images that included the vestibule or the cochlea yielded the volumes (in μL) of the endolymphatic and perilymphatic spaces.

Results

For the vestibule, they were significantly greater EH% in ipsilateral (52.4 ± 12.5) than in contralateral MD ears (40.4 ± 8.5, p = 0.001) and in ipsilateral MD ears than in control ears (42.4 ± 13.7, p = 0.025). For the cochlea, the values were slightly higher EH% in ipsilateral MD ears (49.7 ± 10.4, p = 0.061) but did not significantly differ from contralateral (41.3 ± 12.6) or control ears (39.6 ± 18.9, p = 0.858). In the MD group, the EH asymmetries were 12.0 ± 10.2% (vestibule) and 8.4 ± 8.6% (cochlea), significantly larger than those of controls.

Conclusion

Compared to conventional semiquantitative grading or quantitative EH% analysis, EH asymmetry may better distinguish MD patients from normal controls. Quantitative hydrops volumetric analysis yields clinically relevant information on inner ear function.

Vestibular tissue changes following administration of intravaginal prasterone: a vulvoscopic open-label pilot study in menopausal women with dyspareunia

Background

Prasterone, an intravaginal dyspareunia treatment in menopausal women, improves vaginal health through intracellular conversion of dehydroepiandrosterone into androgens and estrogens. Phase 3 trials for prasterone showed significant improvement in vaginal tissue health and reduction of pain.

Aim

To assess vestibular changes with daily use of intravaginal prasterone in menopausal women with moderate to severe dyspareunia.

Methods

This open-label prospective pilot study was conducted over 20 weeks. It included 11 menopausal women (median age, 56 years) who were treated daily with intravaginal inserts of 6.5-mg prasterone and assessed monthly. During vulvoscopy, vestibular pain was assessed by cotton-tipped swab testing, and vestibular and vaginal health was independently assessed with the Visual Scale (VS). In addition, vulvoscopic photographs were obtained and assessed via the Vulvoscopic Genital Tissue Appearance (VGTA) scale to evaluate overall genital tissue health. Mean changes from baseline for genital tissue health and pain assessments were analyzed by repeated measures 1-way analysis of variance, followed by a Dunnett post hoc test. Sexual event diaries were completed and adverse events recorded.

Outcomes

Outcomes included indices of genital tissue health: pain assessment by cotton-tipped swab testing, VS of the vestibule and vagina, VGTA, and sexual event diary.

Results

Aggregate scores from the cotton-tipped swab test progressively improved, reaching statistical significance at week 16, which was maintained through week 20 (-7.27, P = .019). VS scores significantly improved from baseline by week 4 and were maintained through week 20 for the vestibule (-3.00, P = .004) and vagina (-4.00, P = .002). An overall 1607 vulvoscopic photographs were examined; all showed reduction in vestibular erythema and pallor at the end of the study. The mean change from baseline at week 20 for the VGTA score was -7.9 (P = .0016). Intercourse associated with pain was reduced from 81.3% of initiated events during the first month of the study to 8.3% during the last month. Sexual activities that were discontinued due to discomfort were reduced from 45.8% to 6.3%. No prasterone-related serious adverse events were reported.

Clinical Implications

Prasterone, a safe and effective intravaginal hormone treatment, significantly improves vestibular health parameters.

Strengths and Limitations

Strengths are the prospective study design and the use of multiple outcome measures to assess vestibular tissue health and pain associated with sexual activity. Limitations are the small study cohort and use of nonvalidated outcome measures.

Conclusion

Our findings suggest that intravaginal prasterone exerts biologic activity on the androgenic endodermal vestibule, as the medication passes from vagina to vestibule, resulting in amelioration of pain associated with sexual activity.

Oral Administration of TrkB Agonist, 7, 8-Dihydroxyflavone Regenerates Hair Cells and Restores Function after Gentamicin-Induced Vestibular Injury in Guinea Pig

The causes of vestibular dysfunction include the loss of hair cells (HCs), synapses beneath the HCs, and nerve fibers. 7, 8-dihydroxyflavone (DHF) mimics the physiological functions of brain-derived neurotrophic factor. We investigated the effects of the orally-administered DHF in the guinea pig crista ampullaris after gentamicin (GM)-induced injury. Twenty animals treated with GM received daily administration of DHF or saline for 14 or 28 days (DHF (+) or DHF (-) group; N = 5, each). At 14 days after GM treatment, almost all of the HCs had disappeared in both groups. At 28 days, the HCs number in DHF (+) and DHF (-) groups was 74% and 49%, respectively, compared to GM-untreated control. In the ampullary nerves, neurofilament 200 positive rate in the DHF (+) group was 91% at 28 days, which was significantly higher than 42% in DHF (-). On day 28, the synaptic connections observed between C-terminal-binding protein 2-positive and postsynaptic density protein-95-positive puncta were restored, and caloric response was significantly improved in DHF (+) group (canal paresis: 57.4% in DHF (+) and 100% in DHF (-)). Taken together, the oral administration of DHF may be a novel therapeutic approach for treating vestibular dysfunction in humans.

Galvanic vestibular stimulation-induced activation of C1 neurons in medulla oblongata protects against acute lung injury

Autonomic nerves, including the sympathetic and parasympathetic nerves, control the immune system along with their physiological functions. On the peripheral side, the interaction between the splenic sympathetic nerves and immune cells is important for the anti-inflammatory effects. However, the central mechanism underlying these anti-inflammatory effects remains unclear. C1 neurons respond to stressors and subsequently determine the outflow of the autonomic nervous system. We have previously shown that C1 neurons protect against acute kidney injury and found a signaling connection between peripheral vestibular organs and C1 neurons. Thus, we hypothesized that hypergravity load or galvanic vestibular stimulation (GVS) might protect against acute lung injury. We showed that C1 neurons are histologically and functionally activated by stimulating the peripheral vestibular organs. Protection against acute lung injury that was induced by a 2 G load disappeared due to vestibular lesions or the deletion of C1 neurons. This GVS-induced protective effect was also eliminated by the deletion of the C1 neurons. Furthermore, GVS increased splenic sympathetic nerve activity in conscious mice, and splenic sympathetic denervation abolished the GVS-induced protection against acute lung injury. Therefore, the activated pathway between C1 neurons and splenic sympathetic nerves is indispensable for GVS-induced protection against acute lung injury.

Mechanisms driving vestibular lamina formation and opening in the mouse

The vestibular lamina (VL) forms as an epithelial outgrowth parallel to the dental lamina (DL) in the oral cavity. During late development, it opens to create a furrow that divides the dental tissue from the cheeks and lips and is known as the vestibule. Defects in this process lead to failure in the separation of the teeth from the lips and cheeks, including the presence of multiple frenula. In this paper, the development of the VL is followed in the mouse, from epithelial placode in the embryo to postnatal opening and vestibule formation. During early outgrowth, differential proliferation controls the curvature of the VL as it extends under the forming incisors. Apoptosis plays a role in thinning the deepest part of the lamina, while terminal differentiation of the epithelium, highlighted by the expression of loricrin and flattening of the nuclei, predates the division of the VL into two to create the vestibule. Development in the mouse is compared to the human VL, with respect to the relationship of the VL to the DL, VL morphology and mechanisms of opening. Overall, this paper provides insight into an understudied part of the oral anatomy, shedding light on how defects could form in this region.

Penetration of the Vestibule Following a History of Stapedectomy

This case study describes a 72-year-old female with a history of stapedectomy 40 years prior. She presented experiencing vertigo, fogginess, and imbalance for 9 months. Computed tomography (CT) imaging revealed that the prosthesis was displaced into the vestibule by approximately 2.1 to 2.4 mm. The patient was presented with treatment options, including observation, removal, replacement of the prosthesis, and an oval window patch. The patient opted for observation as the symptoms she was experiencing did not significantly impact her quality of life. Although a stapedectomy may fail for a multitude of reasons, some of the most common causes are prosthesis displacement, especially out of the oval window into the middle ear or away from the incus. Incus necrosis may also play a substantial role in failure.

[To address on the refined and individualized comprehensive evaluation of inner ear function]

Auditory and vestibular function detection technology is the premise and key to the diagnosis and management for inner ear diseases. Concurrent damage to the auditory and vestibular system occurs in many inner ear diseases. The general points and issues on hearing and vestibular function tests, as well as the clinical significance of refined and individualized comprehensive evaluation of inner ear function are described in this paper.

The Effectiveness of the Anteroom (Vestibule) Area on Hospital Infection Control and Health Staff Safety: A Systematic Review

The emergence of SARS-CoV2 in 2019 showed again that the world's healthcare system is not fully equipped and well-designed for preventing the transmission of nosocomial respiratory infections. One of the great tools for preventing the spread of infectious organisms in hospitals is the anteroom. Several articles have investigated the role of the anteroom in disease control but the lack of a comprehensive study in this field prompted us to provide more in-depth information to fill this gap. Also, this study aimed to assess the necessity to construct an anteroom area for hospital staff members at the entrance of each ward of the hospital, and specify the equipment and facilities which make the anteroom more efficient. Articles were identified through searches of Scopus, Web of Sciences, PubMed, and Embase for studies published in English until May 2020 reporting data on the effect of the anteroom (vestibule) area in controlling hospital infections. Data from eligible articles were extracted and presented according to PRISMA's evidence-based data evaluation search strategy. Also, details around the review aims and methods were registered with the PROSPERO. From the database, 209 articles were identified, of which 25 studies met the study criteria. Most studies demonstrated that an anteroom significantly enhances practical system efficiency. The results showed that the equipment such as ventilation system, high-efficiency particulate absorption filter, hand dispensers, alcohol-based disinfection, sink, mirror, transparent panel, UVC disinfection, and zone for PPE change, and parameters like temperature, door type, pressure, and size of the anteroom are factors that are effective on the safety of the hospital environment. Studies demonstrated that providing an anteroom for changing clothing and storing equipment may be useful in reducing the transmission of airborne infections in hospitals. Since the transmission route of SARS-CoV2 is common with other respiratory infectious agents, it can be concluded that a well-designed anteroom could potentially decrease the risk of SARS-CoV2 transmission during hospitalization as well.

Complications of Trans-oral Endoscopic Thyroidectomy Vestibular Approach: A Systematic Review

This review focuses on complications linked to trans-oral endoscopic thyroidectomy via vestibular approach (TOETVA) and aimed to elucidate the procedure's initial safety profile. According to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA), Pubmed, Embase, and the Cochrane databases were screened till May 2021. Twenty-eight articles, nine cohorts and nineteen case series, met the inclusion criteria. Procedure-related complications were analyzed, the most important being hypoparathyroidism: transient (range=0.94-22.2%), permanent (range=1.33-2.22%), and recurrent laryngeal nerve injury: transient (range=1.9-8.8%) and permanent (range=0.59-1.42%). Surgical trauma related complications, the most prevalent being seroma, emphysema, and hematoma accounted for 2.91%. Null mortality was reported. Although current evolving experience indicates that TOETVA is safe and linked to acceptable complication rates, the method needs to be compared with the gold standard of traditional thyroidectomy in the context of sufficiently numbered cohorts and ultimately randomized controlled trials.

Examination of inner ear structures: a micro-CT study

BACKGROUND

We investigated the inner ear anatomy accurately in detail by microcomputed tomography (micro-CT) to contribute to the data related to the inner ear anatomy and the potential clinical contribution of these data in the treatment of the inner ear's pathologies.

AIMS/OBJECTIVES

This study aimed to define a range for normal measurements of the VA, vestibule, lateral semicircular canal, and cochlea. We scanned temporal dry bone samples at high resolution using micro-CT.

MATERIAL AND METHODS

Forty dry temporal bones used in anatomy student education were included in this study with a micro-CT device. All measurements were made on sections in the axial plane with micro-CT programs.

RESULTS

The operculum and the vestibular aqueduct middle diameters median values were 0.487 mm and 0.294 mm, respectively. The median value of middle diameters for the nonampullated section of lateral semicircular canal was 1.103 mm. The mean height of the cochlea was 3.417 mm and the width of the cochlea was 5.615 mm. The mean length of the vestibule was 6.085 mm and the width of the vestibule was 3.002 mm.

CONCLUSIONS AND SIGNIFICANCE

We present a database that clinicians can consider in their studies by creating normal anatomical values measured with high precision for the bone labyrinth.

Diagnostic value of three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) magnetic resonance imaging sequences at 1.5 Tesla in management of sudden sensorineural hearing loss: Our experience in 20 patients

3D-FLAIR 1.5-Tesla MRI sequences can detect abnormalities that show as signal hyperintensity in patients with unilateral SSHL. We propose a simple objective method to detect these abnormalities based on the quantitative calculation of affected versus healthy contralateral ear signal intensity ratios. This signal hyperintensity may involve the cochlea, vestibule or the entire inner ear of affected ears. Such abnormalities were found in 45% of patients with SSHL, and hyperintensity was associated with lower initial and final hearing levels, as well as a lower ≥ 10 dB hearing recovery and more vertigo. We put hyperintensity itself forward as a marker of poor prognosis for patients with SSHL.

Advanced Imaging of the Vestibular Endolymphatic Space in Ménière's Disease

The diagnosis of "definite" Méniére's disease (MD) relies upon its clinical manifestations. MD has been related with Endolymphatic Hydrops (EH), an enlargement of the endolymphatic spaces (ES) (cochlear duct, posterior labyrinth, or both). Recent advances in Magnetic Resonance (MR) imaging justify its increasing role in the diagnostic workup: EH can be consistently recognized in living human subjects by means of 3-dimensional Fluid-Attenuated Inversion-Recovery sequences (3D-FLAIR) acquired 4 h post-injection of intra-venous (i.v.) Gadolinium-based contrast medium, or 24 h after an intratympanic (i.t.) injection. Different criteria to assess EH include: the comparison of the area of the vestibular ES with the whole vestibule on an axial section; the saccule-to-utricle ratio ("SURI"); and the bulging of the vestibular organs toward the inferior 1/3 of the vestibule, in contact with the stapedial platina ("VESCO"). An absolute link between MD and EH has been questioned, since not all patients with hydrops manifest MD symptoms. In this literature review, we report the technical refinements of the imaging methods proposed with either i.t. or i.v. delivery routes, and we browse the outcomes of MR imaging of the ES in both MD and non-MD patients. Finally, we summarize the following imaging findings observed by different researchers: blood-labyrinthine-barrier (BLB) breakdown, the extent and grading of EH, its correlation with clinical symptoms, otoneurological tests, and stage and progression of the disease.

Gender differences in audio-vestibular disorders

In the last years, the attention to the role of gender in physiopathology and pharmacology of diseases in several medical disciplines is rising; however, the data on the relationship between gender and audio-vestibular disorders are still inconclusive and sometimes confusing. With this letter to the editor, we would like to review the role of gender in audio-vestibular disorders. Literature data show that anatomic variances of the inner ear do exist in men and women and that the different physiology and/or hormonal influence between genders could produce different clinical outcome of routine audiological and vestibular tests. Beyond the epidemiological gender-related differences, the clinical data suggest that the gender has a potential role as an etiopathogenetic factor in audio-vestibular disorders and it is probably responsible for the different clinical features observed between male and female subjects.

Laparoscopic Nephroureterectomy for Nonfunctioning Ectopic Pelvic Kidney with Ectopic Ureter and Lower Ureteral Stricture Opening in the Vestibule of the Vagina But No Incontinence: Challenges in Diagnosis and Surgical Dissection

Failure of mature kidney to reach its natural location in renal fossa is termed as renal ectopia. Ectopic kidney can be found in pelvic, iliac, abdominal, and thoracic location. Pelvic ectopia has been estimated to occur in 1 of 2100 to 3000 autopsies. In contrast, ectopic ureters are commonly associated with complete renal duplication. Commonest presentation in females in continuous urinary incontinence with normal voiding habits as ectopic ureter open below the bladder neck in urethra or vagina. An ectopic kidney with ectopic ureter is extremely rare congenital anomaly. We report a 36-year-old woman presenting with left lower abdomen pain with no history of fever, dysuria, or urinary incontinence. On evaluation, she was found to have left nonfunctioning ectopic pelvic kidney with ectopic ureter opening in the vestibule of the vagina, which was managed with laparoscopic nephroureterectomy. One should suspect an ectopic ureter in a female presenting with continuous urinary incontinence since birth. However, diagnosis is challenging when clinical presentation is unusual with no urinary incontinence as seen in the index case. Detailed local examination in correlation with imaging is key for diagnosis and rule out other congenital anomalies. Laparoscopic approach in such clinical scenario is a safe and feasible option.

Endolymphatic Potential Measured From Developing and Adult Mouse Inner Ear

The mammalian inner ear has two major parts, the cochlea is responsible for hearing and the vestibular organ is responsible for balance. The cochlea and vestibular organs are connected by a series of canals in the temporal bone and two distinct extracellular fluids, endolymph and perilymph, fill different compartments of the inner ear. Stereocilia of mechanosensitive hair cells in the cochlea and vestibular end organs are bathed in the endolymph, which contains high K+ ions and possesses a positive potential termed endolymphatic potential (ELP). Compartmentalization of the fluids provides an electrochemical gradient for hair cell mechanotransduction. In this study, we measured ELP from adult and neonatal C57BL/6J mice to determine how ELP varies and develops in the cochlear and vestibular endolymph. We measured ELP and vestibular microphonic response from saccules of neonatal mice to determine when vestibular function is mature. We show that ELP varies considerably in the cochlear and vestibular endolymph of adult mice, ranging from +95 mV in the basal turn to +87 mV in the apical turn of the cochlea, +9 mV in the saccule and utricle, and +3 mV in the semicircular canal. This suggests that ELP is indeed a local potential, despite the fact that endolymph composition is similar. We further show that vestibular ELP reaches adult-like magnitude around post-natal day 6, ~12 days earlier than maturation of cochlear ELP (i.e., endocochlear potential). Maturation of vestibular ELP coincides with the maturation of vestibular microphonic response recorded from the saccular macula, suggesting that maturation of vestibular function occurs much earlier than maturation of hearing in mice.

Association between vestibular dysfunction and findings of horizontal head-shaking and vibration-induced nystagmus

BACKGROUND

The association between vestibular function and findings of horizontal head-shaking nystagmus (HHSN) and vibration-induced nystagmus (VIN) tests is not well understood.

OBJECTIVE

To investigate the association between function in the five distinct vestibular end organs and findings of these nystagmus tests.

METHODS

We retrospectively reviewed the medical records of 50 patients with vestibular diseases who underwent HHSN testing, VIN testing, video head impulse testing (vHIT), cervical vestibular evoked myogenic potential testing to air-conducted sound (ACS cVEMP) and ocular VEMP testing to ACS (ACS oVEMP). We performed mixed-effects logistic regression analyses to see whether age, sex or the presence of nystagmus in HHSN or VIN have an association with the presence of peripheral vestibular dysfunction on the opposite side to the direction of nystagmus.

RESULTS

The presence of HHSN had a significant association with abnormal vHIT in the lateral semicircular canal (LSCC) on the opposite side to the direction of nystagmus. The presence of VIN had a significant association with abnormal vHIT in all the SCCs and abnormal ACS oVEMP on the opposite side to the direction of nystagmus.

CONCLUSIONS

HHSN had an association with LSCC dysfunction alone. VIN had an association with dysfunction in all the SCCs and the utricle.

Dhh-expressing Schwann cell precursors contribute to skin and cochlear melanocytes, but not to vestibular melanocytes

For a long time, melanocytes were believed to be exclusively derived from neural crest cells migrating from the neural tube toward the developing skin. This notion was then challenged by studies suggesting that melanocytes could also be made from neural crest-derived Schwann cell precursors (SCPs) on peripheral nerves. A SCP origin was inferred from lineage tracing studies in mice using a Plp1 promoter-controlled Cre driver transgene (Plp1-CreERT2) and a fluorescent Rosa26 locus-controlled Cre reporter allele (Rosa26^FloxSTOP-YFP ). However, doubts were raised in part because another SCP-directed Cre driver controlled by the Dhh promoter (Dhh-Cre) was apparently unable to label melanocytes when used with a non-fluorescent Rosa26 locus-controlled Cre reporter (Rosa26^{FloxSTOP-LacZ} ). Here, we report that the same Dhh-Cre driver line can efficiently label melanocytes when used in a pure FVB/N background together with the fluorescent instead of the non-fluorescent Rosa26 locus-controlled Cre reporter. Our data further suggest that the vast majority of skin melanocytes are SCP-derived. Interestingly, we also discovered that SCPs contribute inner ear melanocytes in a region-specific manner, extensively contributing to the cochlea but not to the vestibule.

Live imaging of hair bundle polarity acquisition demonstrates a critical timeline for transcription factor Emx2

Directional sensitivity of hair cells (HCs) is conferred by the aymmetric apical hair bundle, comprised of a kinocilium and stereocilia staircase. The mother centriole (MC) forms the base of the kinocilium and the stereocilia develop adjacent to it. Previously, we showed that transcription factor Emx2 reverses hair bundle orientation and its expression in the mouse vestibular utricle is restricted, resulting in two regions of opposite bundle orientation (Jiang et al., 2017). Here, we investigated establishment of opposite bundle orientation in embryonic utricles by live-imaging GFP-labeled centrioles in HCs. The daughter centriole invariably migrated ahead of the MC from the center to their respective peripheral locations in HCs. Comparing HCs between utricular regions, centriole trajectories were similar but they migrated toward opposite directions, suggesting that Emx2 pre-patterned HCs prior to centriole migration. Ectopic Emx2, however, reversed centriole trajectory within hours during a critical time-window when centriole trajectory was responsive to Emx2.

Inverted Papilloma Completely Obstructing Anterior Nasal Orifice

Sinonasal inverted papilloma is a benign lesion that occurs in the nasal cavity and paranasal sinuses. Fungiform papillomas have been described as arising from the septum or the nasal vestibule, while inverted and cylindrical papillomas have been characterized as developing from an attachment site on the lateral nasal wall or a mucosal surface in the paranasal sinuses. Here, we present a rare case of an inverted papilloma that completely obstructed the anterior nasal orifice.

A new method with an explant culture of the utricle for assessing the influence of exposure to low-frequency noise on the vestibule

Health risks attributed to low-frequency noise (LFN) exposure are a serious global issue. Therefore, the development of a method for a prevention based upon risk assessments for LFN is important. Previously in vivo exposure of mice to LFN at 100 Hz, 95 dB for 1 hr produced imbalance with breakage of the otoconial membrane, which covers hair cells as well as impaired activity of hair cells in the vestibule. However, methods for inhibition of LFN-mediated imbalance have not been developed. At present, there are no apparent techniques available with in vitro or ex vivo assessments to evaluate LFN-mediated imbalance by direct administration of preventive chemicals into the vestibule. Our findings demonstrated the usefulness of an explant culture of the utricle with a fluorescent styryl dye, FM1-43FX. In addition, examination of the morphology of the otoconial membrane with explant cultures of utricles was conducted to determine the risk of LFN. Ex vivo exposure of the utricle to LFN at 100 Hz, 95 dB for 1 hr induced breaks in the otoconial membrane as well as decreased uptake of FM1-43FX in hair cells. Taken together, the results of this study provide a novel technique for assessing the risk of LFN exposure using an ex vivo experiment.

Increased Type I and Decreased Type II Hair Cells after Deletion of Sox2 in the Developing Mouse Utricle

The vestibular system of the inner ear contains Type I and Type II hair cells (HCs) generated from sensory progenitor cells; however, little is known about how the HC subtypes are formed. Sox2 (encoding SRY-box 2) is expressed in Type II, but not in Type I, HCs. The present study aimed to investigate the role of SOX2 in cell fate determination in Type I vs. Type II HCs. First, we confirmed that Type I HCs developed from Sox2-expressing cells through lineage tracing of Sox2-positive cells using a CAG-tdTomato reporter mouse crossed with a Sox2-CreER mouse. Then, Sox2 loss of function was induced in HCs, using Sox2flox transgenic mice crossed with a Gfi1-Cre driver mouse. Knockout of Sox2 in HCs increased the number of Type I HCs and decreased the number of Type II HCs, while the total number of HCs and Sox2-positive supporting cells did not change. In addition, the effect of Sox2-knockout persisted into adulthood, resulting in an increased number of Type I HCs. These results demonstrate that SOX2 plays a critical role in the determination of Type II vs. Type I HC fate. The results suggested that Sox2 is a potential target for generating Type I HCs, which may be important for regenerative strategies for balance disorders.

The effect of noise exposure on the vestibular systems of dental technicians

BACKGROUND

Noise exposure is the primary cause of acquired hearing loss in several occupational settings, including dental laboratories and clinics. However, the impact of noise exposure on the vestibular system is not as well researched.

PURPOSE

To investigate the nature of vestibular damage caused by working in dental laboratories and clinics with high levels of noise exposure due to loud dental equipment.

RESEARCH DESIGN

A descriptive, case study design was used to evaluate the vestibular function of dental technicians.

STUDY SAMPLE

Out of 30 dental technicians, 5 males who had been working for several years in dental settings were selected based on their reports of severe symptoms of imbalance.

DATA COLLECTION

Audiologic evaluations were conducted in the vestibular unit of the Doctor Tarek Khrais Center in Amman, Jordan, for one year. Each subject underwent several hearing tests, which included otoscopic examination, pure tone audiometry (PTA), impedance measurements, and speech testing. Assessment of vestibular function was then conducted using a diagnostic test battery which included electrocochleography, ocular vestibular evoked myogenic potentials (oVEMP), cervical vestibular evoked myogenic potentials (cVEMP), positional testing using the Thomas Richard-Vitton (TRV) chair, and standing stability testing.

RESULTS

All test subjects experienced some form of vestibular impairment, including benign paroxysmal positional vertigo (BPPV), endolymphatic hydrops (Meniere disease), or a combination of both. Three out of five cases displayed little or no hearing loss, indicating that vestibular function is more at risk than hearing acuity to continuous noise exposure in dental settings.

CONCLUSIONS

Exposure to loud noise in dental laboratories severely impacts the functioning of the vestibular system of the inner ear more than the cochlea. The main clinical implication of this study is that regular vestibular assessments are a necessity for dental technicians.

Alteration of Musashi1 Intra-cellular Distribution During Regeneration Following Gentamicin-Induced Hair Cell Loss in the Guinea Pig Crista Ampullaris

The mechanism underlying hair cell (HC) regeneration in the mammalian inner ear is still under debate. Understanding what molecules regulate the HC regeneration in mature mammals will be the key to the treatment of the inner ear disorder. Musashi1 (MSI1) is an RNA binding protein associated with asymmetric division and maintenance of stem cell function as a modulator of the Notch-1 signaling pathway. In this study, we investigated the cellular proliferative activity and changes in spatiotemporal pattern of MSI1 expression in the gentamicin (GM)-treated crista ampullaris (CA) in guinea pigs. Although the vestibular HCs in the CA almost disappeared at 14 days after injecting GM in the inner ear, the density of vestibular HCs spontaneously increased by up to 50% relative to controls at 56 days post-GM treatment (PT). The number of the type II HCs was significantly increased at 28 days PT relative to 14 days PT (p < 0.01) while that of type I HCs or supporting cells (SCs) did not change. The number of SCs did not change through the observational period. Administration of bromodeoxyuridine with the same GM treatment showed that the cell proliferation activity was high in SCs between 14 and 28 days PT. The changes in spatiotemporal patterns of MSI1 expression during spontaneous HC regeneration following GM treatment showed that MSI1-immunoreactivity was diffusely spread into the cytoplasm of the SCs during 7–21 days PT whereas the expression of MSI1 was confined to the nucleus of SCs in the other period. The MSI1/MYO7A double-positive cells were observed at 21 days PT. These results suggest that regeneration of vestibular HCs might originate in the asymmetric cell division and differentiation of SCs and that MSI1 might be involved in controlling the process of vestibular HC regeneration.

Positron emission tomography visualized stimulation of the vestibular organ is localized in Heschl's gyrus

The existence of a human primary vestibular cortex is still debated. Current knowledge mainly derives from functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) acquisitions during artificial vestibular stimulation. This may be problematic as artificial vestibular stimulation entails coactivation of other sensory receptors. The use of fMRI is challenging as the strong magnetic field and loud noise during MRI may both stimulate the vestibular organ. This study aimed to characterize the cortical activity during natural stimulation of the human vestibular organ. Two fluorodeoxyglucose (FDG)-PET scans were obtained after natural vestibular stimulation in a self-propelled chair. Two types of stimuli were applied: (a) rotation (horizontal semicircular canal) and (b) linear sideways movement (utriculus). A comparable baseline FDG-PET scan was obtained after sitting motion-less in the chair. In both stimulation paradigms, significantly increased FDG uptake was measured bilaterally in the medial part of Heschl's gyrus, with some overlap into the posterior insula. This is the first neuroimaging study to visualize cortical processing of natural vestibular stimuli. FDG uptake was demonstrated in the medial-most part of Heschl's gyrus, normally associated with the primary auditory cortex. This anatomical localization seems plausible, considering that the labyrinth contains both the vestibular organ and the cochlea.

Targeted Allele Suppression Prevents Progressive Hearing Loss in the Mature Murine Model of Human TMC1 Deafness

Hearing loss is the most common human sensory deficit. Its correction has been the goal of several gene-therapy based studies exploring a variety of interventions. Although these studies report varying degrees of success, all treatments have targeted developing inner ears in neonatal mice, a time point in the structural maturation of the cochlea prior to 26 weeks gestational age in humans. It is unclear whether cochlear gene therapy can salvage hearing in the mature organ of Corti. Herein, we report the first study to test gene therapy in an adult murine model of human deafness. Using a single intracochlear injection of an artificial microRNA carried in an AAV vector, we show that RNAi-mediated gene silencing can slow progression of hearing loss, improve inner hair cell survival, and prevent stereocilia bundle degeneration in the mature Beethoven mouse, a model of human TMC1 deafness. The ability to study gene therapy in mature murine ears constitutes a significant step toward its translation to human subjects.

Quantitative assessment of vestibular otopathology in granulomatosis with polyangitis: A temporal bone study

Objective

To investigate the temporal bone histopathology of vasculitis, especially in the vestibular organs, in granulomatosis with polyangitis (GPA).

Methods

Using light and differential interference contrast microscopy, we examined 12 human temporal bones from six deceased GPA patients and 12 histopathologically normal human temporal bones from six deceased age‐matched patients.

Results

In the GPA group, three patients had undergone tympanostomy tube placement. Two of them had suffered mixed hearing loss; one, sensorineural hearing loss; and one, conductive hearing loss. Of the 12 specimens in the GPA group, the granulation tissue invaded the round window niche in seven; cochlear hair cells were not preserved in five. Hemosiderin was deposited in the stria vascularis in eight specimens, in the ampulla or semicircular duct in 10, and in the vestibule in three. The spiral ligament showed severe loss of cellularity in two specimens. In the GPA group, type I vestibular hair cell density was significantly decreased; however, type II vestibular hair cell density did not significantly differ between the GPA group and the control group.

Conclusion

Our histopathologic findings in human temporal bone specimens of GPA patients delineated changes in the tympanic membrane, middle ear cavity, round window membrane, organ of Corti, stria vascularis, spiral ligament, ampulla, semicircular duct, and vestibule. Type I vestibular hair cell density significantly decreased in the GPA group, as compared with the control group.

Level of Evidence

N/A

Absence of Atoh1 induced partially different cell fates of cochlear and vestibular sensory epithelial cells in mice

Background： Atoh1, also named Math1, is essential for the development of inner ear hair cells. Many studies have confirmed that the absence of Atoh1 resulted in a total loss of inner ear hair cells, which indicates that Atoh1 plays very similar roles in the development of hair cells in the cochlea and vestibule. Objective： The aim of this study was to evaluate whether Atoh1 plays different roles in the cochlea and vestibule.

MATERIAL AND METHODS

We generated Atoh1-null mice by inbreeding Atoh1^cre/+ heterozygous mice and compared with the epithelial cell status of the cochlea and vestibule.

RESULTS

We found that no inner ear hair cells were detected in Atoh1-null mice. However, a different cell status was found in the mutant cochlea and vestibule on the last embryonic day (E18.5). In the Atoh1-null cochlea, the epithelial cells that should develop into hair cells were totally absent, while in the Atoh1-null vestibule, most of the epithelial cells that should develop into hair cells still survived.

CONCLUSIONS

Our data indicate that Atoh1 may have similar but partially different functions in the development of hair cells in the cochlea and vestibule.

Neuroanatomy and inner ear labyrinths of the narwhal, Monodon monoceros, and beluga, Delphinapterus leucas (Cetacea: Monodontidae)

Narwhals (Monodon monoceros) and belugas (Delphinapterus leucas) are the only extant members of the Monodontidae, and are charismatic Arctic-endemic cetaceans that are at risk from global change. Investigating the anatomy and sensory apparatuses of these animals is essential to understanding their ecology and evolution, and informs efforts for their conservation. Here, we use X-ray CT scans to compare aspects of the endocranial and inner ear labyrinth anatomy of extant monodontids and use the overall morphology to draw larger inferences about the relationship between morphology and ecology. We show that differences in the shape of the brain, vasculature, and neural canals of both species may relate to differences in diving and other behaviors. The cochleae are similar in morphology in the two species, signifying similar hearing ranges and a close evolutionary relationship. Lastly, we compare two different methods for calculating 90var - a calculation independent of body size that is increasingly being used as a proxy for habitat preference. We show that a 'direct' angular measurement method shows significant differences between Arctic and other habitat preferences, but angle measurements based on planes through the semicircular canals do not, emphasizing the need for more detailed study and standardization of this measurement. This work represents the first comparative internal anatomical study of the endocranium and inner ear labyrinths of this small clade of toothed whales.

Regional deposition of nasal sprays in adults: A wide ranging computational study

The present work examines regional deposition within the nose for nasal sprays over a large and wide ranging parameter space by using numerical simulation. A set of 7 realistic adult nasal airway geometries was defined based on computed tomography images. Deposition in 6 regions of each nasal airway geometry (the vestibule, valve, anterior turbinate, posterior turbinate, olfactory, and nasopharynx) was determined for varying particle diameter, spray cone angle, spray release direction, particle injection speed, and particle injection location. Penetration of nasal spray particles through the airway geometries represented unintended lung exposure. Penetration was found to be relatively insensitive to injection velocity, but highly sensitive to particle size. Penetration remained at or above 30% for particles exceeding 10 μm in diameter for several airway geometries studied. Deposition in the turbinates, viewed as desirable for both local and systemic nasal drug delivery, was on average maximized for particles ranging from ~20 to 30 μm in diameter, and for low to zero injection velocity. Similar values of particle diameter and injection velocity were found to maximize deposition in the olfactory region, a potential target for nose-to-brain drug delivery. However, olfactory deposition was highly variable between airway geometries, with maximum olfactory deposition ranging over 2 orders of magnitude between geometries. This variability is an obstacle to overcome if consistent dosing between subjects is to be achieved for nose-to-brain drug delivery.

[Photochemical induced vestibular ischemiawith icy water test in guinea pigs]

Objective:To ascertain the effects of a new method of photochemical reaction in vestibular function in guinea pigs.Method:Local photochemical reaction was initiated by systemic injection of rose bengal(20mg), photoillumination of the vestibule through medial wall of epitympanum for 30 minutes was started immediately after the injection of rose bengal, with a optic fiber connected to a xenon light (wavelength, 540nm; photointense, 500-600 mW/cm ²). There were 20 guinea pigs divided random equally into 2 groups. Group 1 was injected with rose bengal. Group 2 was control, injected with physiological saline solution. The ice caloric tests were performed on the second day.Result:The test group (7 ears) and the control group (6 ears) with test nystagmus showed mean frequencies were（2.0±0.33）times/s and（3.7±0.33）times/s,the mean amplitude were (3.1±0.39)mm and (3.5±0.54)mm,and the mean duration were (44.7±17.22)s and (62.0±7.22)s respectively.The nystagmus frequency difference was statistically significant, but the amplitude and the duration of the nystagmus were not significantly different. There was no obvious spontaneous nystagmus in the two groups, and there were negative results of ice water test (3 ears in the test group and 4 ears in the control group).Conclusion:Photochemical reaction can induce the ischemic state of the vestibule system in guinea pig, and produce an acute vestibular dysfunction, and ice water test shows that the frequency of nystagmus is reduced.

[The analysis of the value of spontaneous nystagmus in peripheral vestibular hypofunction]

Objective:To study the characteristics and clinical value of spontaneous nystagmus in patients with peripheral vestibular dysfunction.Method:Sixty cases with acute unilateral peripheral vestibular dysfunction were studied.All were diagnozed as vestibular neuritis(VN) . The relationship between SN and disease duration,DP and UW were analyzed.Result:SN was present in49 patients(81.7%)and absent in the remaining 11(18.3%).The intensity of SN ranged from 0.5°/s-20.4°/s and had negative correlation with the disease duration(r=-0.478，P<0.01). The patients were divided into 3 groups (mild,medium and severe) according to SN intensity,with median duration of disease being 6.5 d，5 d and 3 d respectively. The difference between groups was statistically significant(χ²=9.071，P<0.01).The result of the caloric test were as following：caloric test revealed DP in 44 cases（89.8%） of SN ;DP values were normal in 8 cases（10.2%）;SN intensity was positively correlated with DP value（r=0.513,P<0.01） ;unilateral weakness was found in 35 cases（71.4%）,with the direction of SN towards the weakness side in 4 cases and towards the opposite direction in the remaining 31 cases; 7 cases（14.3%）had bilateral weakness and 7 cases（14.3%）normal. There were no relationship between the intensity of SN and UW value（r=-0.321,P>0.05）.The UW value of patients with SN (40.9±26.3）% was compared to the group without SN（29.9±18.2）% . The difference was statistically significant (F=4.497,P<0.05).Conclusion:The intensity of SN in patients with acute unilateral peripheral vestibular dysfunction was often moderate and severe. The intensity of SN waned as the disease progressed or the direction reversed,The vestibular injury in patient with SN was more severe than those without. SN is useful in clinical assessment of vestibular injury and compensatory status.

Risk Assessment of Neonatal Exposure to Low Frequency Noise Based on Balance in Mice

General electric devices and ventilation systems are known to generate low frequency noise (LFN) with frequencies of <100 Hz. Previous studies showed that exposure to LFN caused impairments of balance in humans and mice during adulthood. On the other hand, a previous study showed that noise levels in the neonatal intensive care unit (NICU) were greater than those in general home or office environments. Therefore, it is possible that neonates have a potential risk to be exposed to LFN in the NICU. However, the risk of neonatal exposure to LFN remains unclear in humans and mice. In this study, male ICR mice were exposed to LFN at 100 Hz for 4 weeks after birth and then subjected to rotarod and beam crossing tests in order to assess LFN-mediated risk of imbalance during the neonatal period. Exposure to LFN at 70 dB, but not exposure to LFN up to 60 dB, during the neonatal period significantly decreased performance scores for rotarod and beam crossing tests compared to the scores of the control group. The number of calbindin-positive hair cells in the saccule and utricle was decreased in mice exposed to LFN at 70 dB for 4 weeks in the neonatal phase. Cessation of exposure for 10 weeks did not result in recovery of the decreased performance in rotarod and beam crossing tests. Thus, our results suggest that 70 dB is a possible threshold for exposure to LFN for 4 weeks during the neonatal period causing unrecoverable imbalance in mice.

Single cell analysis of the inner ear sensory organs

The inner ear is composed of a complex mixture of cells, which together allow organisms to hear and maintain balance. The cells in the inner ear, which undergo an extraordinary process of development, have only recently begun to be studied on an individual level. As it has recently become clear that individual cells, previously considered to be of uniform character, may differ dramatically from each other, the need to study cell-to-cell variation, along with distinct transcriptional and regulatory signatures, has taken hold in the scientific community. In conjunction with high-throughput technologies, attempts are underway to dissect the inter- and intra-cellular variability of different cell types and developmental states of the inner ear from a novel perspective. Single cell analysis of the inner ear sensory organs holds the promise of providing a significant boost in building an omics network that translates into a comprehensive understanding of the mechanisms of hearing and balance. These networks may uncover critical elements for trans-differentiation, regeneration and/or reprogramming, providing entry points for therapeutics of deafness and vestibular pathologies.

Deterioration of Vestibular Cells in Labyrinthitis

OBJECTIVE

To quantitatively assess the effect of serous labyrinthitis, suppurative labyrinthitis, and labyrinthitis ossificans on vestibular hair cells, dark cells, and transitional cells.

METHODS

We examined human temporal bone specimens with serous labyrinthitis, suppurative labyrinthitis, and labyrinthitis ossificans, then compared them with age-matched control groups without labyrinthitis. We evaluated the density of type I and II vestibular hair cells, dark cells, and transitional cells in the peripheral sensorial organs.

RESULTS

The mean density of type I vestibular hair cells in the maculae of the saccule significantly differed between the serous labyrinthitis group and its control group. The loss of type I and II vestibular hair cells in all of the peripheral sensorial organs was significantly higher in the suppurative labyrinthitis group than in its control group. The mean density of dark cells in the lateral and posterior semicircular canals was significantly lower in the suppurative labyrinthitis group than in its control group. The mean density of type I and II vestibular hair cells, dark cells, and transitional cells was significantly lower in the labyrinthitis ossificans group than in its control group.

CONCLUSION

The loss of vestibular hair cells and degenerative changes in dark cells and transitional cells could affect vestibular function in patients with labyrinthitis.

Volumetric measurements of the inner ear in patients with Meniere's disease using three-dimensional magnetic resonance imaging

CONCLUSION

This study described the lateralities of axial length of inner ear (ALIE), of the volume of inner ear (VIE) and age-related differences of the volume of inner ear components in patients with chronic rhinosinusitis (CRS). Age-related differences were found in ALIE and the positive correlation in ALIE and the volume of the cochlea (VC) of the affected ear in patients with Meniere's disease (MD).

OBJECTIVE

To identify side or sex-related differences in the ALIE, the length of the spiral canal of cochlea (LSCC), and the volume of components of the inner ear in MD and CRS.

METHODS

Thirty-two with unilateral MD and 14 with CRS were included. Images were acquired with a 3.0-tesla unit using SPACE sequences. The ALIE was measured and the VIE, VC, the volume of the vestibule (VV), and of the semi-circular canals (VSC) were also measured.

RESULTS

In CRS, ALIE of the right ear in males was significantly longer than in females. Patients younger than 60 years old with CRS had a significantly larger VIE, VC, and VSC than older than 60. In MD, the ALIE in older than 60 was longer than below 60.

[Significance of five symptoms scoring sheet in the clinical diagnosis of BPPV]

Objective:To identify the validity of five symptoms scoring sheet that based on the patients who are suffering from benign paroxysmal positional vertigo(BPPV), and explore its effects and significance in the clinical diagnosis of BPPV.Method:A total of 484 patients with vertigo were included. All the patients were firstly assessed with five symptoms scoring sheet(repeated transient vertigo or aggravating vertigo during looking up, bending, getting out of bed, rolling over in bed and quick head movements) before being confirmed by Dix-Hallpike test and rolling test. Evaluating the predictive ability of this scoring sheet in the diagnosis of BPPV with ROC analysis.Result:According to the ROC analysis , the sensitivity and specificity were 95.4% and 80.3% respectively when the score >7, and an area under receiver operating characteristic curve(AUC) was 0.923.Conclusion:Five symptoms scoring sheet is useful and convenient in diagnosing BPPV, which can be used in BPPV screening and guide the vertigo patients to receive further test and treatment.

Pathologic Changes of the Peripheral Vestibular System Secondary to Chronic Otitis Media

OBJECTIVE

To evaluate the histopathologic changes of dark, transitional, and hair cells of the vestibular system in human temporal bones from patients with chronic otitis media.

STUDY DESIGN

Comparative human temporal bone study.

SETTING

Otopathology laboratory.

SUBJECTS AND METHODS

To compare the density of vestibular dark, transitional, and hair cells in temporal bones with and without chronic otitis media, we used differential interference contrast microscopy.

RESULTS

In the chronic otitis media group (as compared with the age-matched control group), the density of type I and type II hair cells was significantly decreased in the lateral semicircular canal, saccule, and utricle (P < .05). The density of type I cells was also significantly decreased in the chronic otitis media group in the posterior semicircular canal (P = .005), but that of type II cells was not (P = .168). The mean number of dark cells was significantly decreased in the chronic otitis media group in the lateral semicircular canal (P = .014) and in the posterior semicircular canal (P = .002). We observed no statistically significant difference in the density of transitional cells between the 2 groups (P > .1).

CONCLUSION

The findings of our study suggest that the decrease in the number of vestibular sensory cells and dark cells could be the cause of the clinical symptoms of imbalance of some patients with chronic otitis media.

Form and function of the mammalian inner ear

The inner ear of mammals consists of the cochlea, which is involved with the sense of hearing, and the vestibule and three semicircular canals, which are involved with the sense of balance. Although different regions of the inner ear contribute to different functions, the bony chambers and membranous ducts are morphologically continuous. The gross anatomy of the cochlea that has been related to auditory physiologies includes overall size of the structure, including volume and total spiral length, development of internal cochlear structures, including the primary and secondary bony laminae, morphology of the spiral nerve ganglion, and the nature of cochlear coiling, including total number of turns completed by the cochlear canal and the relative diameters of the basal and apical turns. The overall sizes, shapes, and orientations of the semicircular canals are related to sensitivity to head rotations and possibly locomotor behaviors. Intraspecific variation, primarily in the shape and orientation of the semicircular canals, may provide additional clues to help us better understand form and function of the inner ear.

Partial Hearing Preservation after Translabyrinthine Vestibular Schwannoma Resection: Case Report and Review of the Literature

Objectives To describe a unique case report of a patient who had partial hearing preservation after translabyrinthine (TL) removal of a vestibular schwannoma (VS). Study Design Case report. Methods The patient's chart was reviewed for hearing levels before and after surgery. Preoperative magnetic resonance imaging (MRI) was compared with postoperative MRI for determination of completeness of tumor removal. The literature on hearing preservation after TL resection is reviewed. Results A 42-year-old woman underwent a TL removal of a VS. The patient's preoperative pure tone average (PTA) was 70 dB and word recognition score (WRS) was 40%. Postoperatively, the patient was able to hear ambient noise in the surgical ear. Her bone conduction PTA was 70 dB, but the WRS score dropped to 2%. One year later, she continues to hear ambient noise and sound in the operative ear. Discussion This is the fifth reported case of partial hearing preservation after TL VS resection. It suggests that by preserving the vestibule and the fluids within the vestibule when possible, there maybe enough residual auditory neural structures for a traditional cochlear implant to benefit such a patient. In addition, preserving the incus when possible may help maintain air conduction to help patients with sound localization.

Characteristics of vertigo and the affected vestibular nerve systems in idiopathic bilateral vestibulopathy

CONCLUSION

Vertigo attacks in IBV patients involving both the superior and inferior vestibular nerve systems were significantly more severe than vertigo attacks in patients with selective involvement of the inferior vestibular nerve system alone.

OBJECTIVE

To investigate the relationship between the frequency and duration of vertigo and the affected vestibular nerve system in idiopathic bilateral vestibulopathy (IBV).

METHODS

This study categorized 44 IBV patients into the following three sub-groups according to the affected vestibular nerve system: superior, inferior, and mixed type. These patients were also categorized into the following three sub-groups according to their clinical time course: progressive type showing no episodes of vertigo, sequential type showing recurrent vertigo attacks and single-attack type showing a single episode of vertigo.

RESULTS

Ten, 11 and 23 patients were classified as the superior, the inferior, and the mixed type, respectively. Seventeen, 23, and four patients were classified as the progressive, the sequential, and the single-attack type, respectively. For the patients having one or more vertigo attacks, the duration of the vertigo attack was longer than 24 h in 69% of the mixed type, and the duration of vertigo in the mixed type was significantly longer than that in the inferior type (p < 0.05).

Quantitative assessment of vestibular otopathology in otosclerosis: A temporal bone study

OBJECTIVES/HYPOTHESIS

To determine if peripheral vestibular otopathology is present in human temporal bones with otosclerosis.

STUDY DESIGN

Comparative human temporal bone study.

METHODS

Seventy-four human temporal bones from 46 subjects with otosclerosis (mean age of 61 ± 18 years) and 20 within histologically normal limits from 17 subjects (mean age of 59 ± 14 years) were included in this study. Temporal bones with otosclerosis were divided into those with and without endosteal involvement. Using differential interference contrast microscopy at 1008× magnification, type I and type II vestibular hair cell counts were performed on each vestibular sense organ in which the neuroepithelia was oriented perpendicular to the plane of section. The organ-specific cell densities (cells/0.01 mm(2) surface area) were compared between the groups with and without endosteal involvement, and also compared to counts in the nonotosclerosis control group using Student's t-test.

RESULTS

Mean type I and type II hair cell densities of all vestibular structures in the group with endosteal involvement were significantly lower compared to the group without endosteal involvement. Mean type I and type II hair cell densities of all vestibular structures in the group with endosteal involvement were also significantly lower compared to the control group, but they were not in the group without endosteal involvement compared to the control group.

CONCLUSION

Endosteal involvement of otosclerotic foci is associated with vestibular hair cell loss that may contribute to the vestibular symptoms in otosclerosis.

LEVEL OF EVIDENCE

N/A. Laryngoscope, 126:E118-E122, 2016.

Gene Expression by Mouse Inner Ear Hair Cells during Development

Hair cells of the inner ear are essential for hearing and balance. As a consequence, pathogenic variants in genes specifically expressed in hair cells often cause hereditary deafness. Hair cells are few in number and not easily isolated from the adjacent supporting cells, so the biochemistry and molecular biology of hair cells can be difficult to study. To study gene expression in hair cells, we developed a protocol for hair cell isolation by FACS. With nearly pure hair cells and surrounding cells, from cochlea and utricle and from E16 to P7, we performed a comprehensive cell type-specific RNA-Seq study of gene expression during mouse inner ear development. Expression profiling revealed new hair cell genes with distinct expression patterns: some are specific for vestibular hair cells, others for cochlear hair cells, and some are expressed just before or after maturation of mechanosensitivity. We found that many of the known hereditary deafness genes are much more highly expressed in hair cells than surrounding cells, suggesting that genes preferentially expressed in hair cells are good candidates for unknown deafness genes.

Rapid adaptation of multisensory integration in vestibular pathways

Sensing gravity is vital for our perception of spatial orientation, the control of upright posture, and generation of our everyday activities. When an astronaut transitions to microgravity or returns to earth, the vestibular input arising from self-motion will not match the brain's expectation. Our recent neurophysiological studies have provided insight into how the nervous system rapidly reorganizes when vestibular input becomes unreliable by both (1) updating its internal model of the sensory consequences of motion and (2) up-weighting more reliable extra-vestibular information. These neural strategies, in turn, are linked to improvements in sensorimotor performance (e.g., gaze and postural stability, locomotion, orienting) and perception characterized by similar time courses. We suggest that furthering our understanding of the neural mechanisms that underlie sensorimotor adaptation will have important implications for optimizing training programs for astronauts before and after space exploration missions and for the design of goal-oriented rehabilitation for patients.

Convergence vs. Specialization in the ear region of moles (Mammalia)

We investigated if and how the inner ear region undergoes similar adaptations in small, fossorial, insectivoran-grade mammals, and found a variety of inner ear phenotypes. In our sample, afrotherian moles (Chrysochloridae) and the marsupial Notoryctes differ from most other burrowing mammals in their relatively short radii of semicircular canal curvature; chrysochlorids and fossorial talpids share a relatively long interampullar width. Chrysochlorids are unique in showing a highly coiled cochlea with nearly four turns. Extensive cochlear coiling may reflect their greater ecological dependence on low frequency auditory cues compared to talpids, tenrecids, and the marsupial Notoryctes. Correspondingly, the lack of such extensive coiling in the inner ear of other fossorial species may indicate a greater reliance on other senses to enable their fossorial lifestyle, such as tactile sensation from vibrissae and Eimer's organs. The reliance of chrysochlorids on sound is evident in the high degree of coiling and in the diversity of its mallear types, and may help explain the lack of any semiaquatic members of that group. The simplest mallear types among chrysochlorids are not present in the basal-most members of that clade, but all extant chrysochlorids investigated to date exhibit extensive cochlear coiling. The chrysochlorid ear region thus exhibits mosaic evolution; our data suggest that extensive coiling evolved in chrysochlorids prior to and independently of diversification in middle ear ossicle size and shape.

Virtual reality training improves balance function

Virtual reality is a new technology that simulates a three-dimensional virtual world on a computer and enables the generation of visual, audio, and haptic feedback for the full immersion of users. Users can interact with and observe objects in three-dimensional visual space without limitation. At present, virtual reality training has been widely used in rehabilitation therapy for balance dysfunction. This paper summarizes related articles and other articles suggesting that virtual reality training can improve balance dysfunction in patients after neurological diseases. When patients perform virtual reality training, the prefrontal, parietal cortical areas and other motor cortical networks are activated. These activations may be involved in the reconstruction of neurons in the cerebral cortex. Growing evidence from clinical studies reveals that virtual reality training improves the neurological function of patients with spinal cord injury, cerebral palsy and other neurological impairments. These findings suggest that virtual reality training can activate the cerebral cortex and improve the spatial orientation capacity of patients, thus facilitating the cortex to control balance and increase motion function.

Amplitude modulated vestibular evoked myogenic responses: a study of carrier and modulating frequencies

CONCLUSION

Responses with greater amplitude were recorded when carrier frequencies were modulated at 37, 40, and 43 Hz. These responses can be recorded even in patients with significant sensorineural hearing loss, from the sternocleidomastoid (SCM) muscle for a 500 Hz tone, 100% modulated at 40 Hz.

OBJECTIVE

To determine the best carrier and modulating frequencies to evoke steady-state myogenic responses.

METHODS

The present study investigated 156 ears of 78 normal-hearing young adults, with carrier frequencies of 250, 500, and 1000 Hz, modulated at 20, 37, 40, 43, 70, 77, and 80 Hz, with an intensity of 95 dBA. Furthermore, we observed responses evoked by stimulus carrier frequency of 500 Hz, modulated at 40 Hz, with an intensity of 95 dBA in a group of five subjects with severe sensorineural loss.

RESULTS

Responses were found for all stimuli studied (p < 0.01). Modulated stimuli at frequencies of 37, 40, and 43 Hz evoked better steady-state vestibular evoked myogenic potential (S-VEMP) (p < 0.05). No statistically significant differences were found between the group of normal hearers and the group of subjects with hearing loss (p = 0.431), for the stimulus used.