Inner Ear Disorders Research Articles

Insidious Cases of Enlarged Vestibular Aqueduct (EVA) Syndrome Resembling Otosclerosis: Clinical Features for Differential Diagnosis and the Role of High-Resolution Computed Tomography in the Pre-Operative Setting.

Enlarged vestibular aqueduct (EVA) syndrome can mimic otosclerosis in adults, presenting with an air-bone gap (ABG) and even absent stapedial reflexes. The ABG in inner-ear disorders is currently the object of several authors' studies and seems to be related to a third mobile window (TMW) phenomenon. This can lead to misdiagnosis and inappropriate treatment. Given that it would be inappropriate and harmful to perform CT scans in all patients with a clinical diagnosis of otosclerosis, this study aims to highlight some clinical features useful for the differential diagnosis between otosclerosis and these rare cases of EVA presenting with an ABG, thus enabling the identification of suspected cases to be tested with CT scans. Between April and May 2024, a narrative review was conducted focusing on the differential diagnosis between some rare cases of EVA and otosclerosis. Clinical, audiological, and radiologic features of both conditions were investigated. This review demonstrates the diagnostic challenge in differentiating atypical cases of EVA from otosclerosis in a subset of patients. Clinical and audiological features are important for differential diagnosis, but may not always be sufficient. Therefore, high-resolution computed tomography (HRCT) of the temporal bone plays a pivotal role in definitive diagnosis. In some specific cases, pre-operative imaging assessment using HRCT emerges as an essential tool for differentiating these two conditions and avoiding unnecessary stapes surgery.

Autosomal Recessive Non-Syndromic Deafness: Is AAV Gene Therapy a Real Chance?

The etiology of sensorineural hearing loss is heavily influenced by genetic mutations, with approximately 80% of cases attributed to genetic causes and only 20% to environmental factors. Over 100 non-syndromic deafness genes have been identified in humans thus far. In non-syndromic sensorineural hearing impairment, around 75-85% of cases follow an autosomal recessive inheritance pattern. In recent years, groundbreaking advancements in molecular gene therapy for inner-ear disorders have shown promising results. Experimental studies have demonstrated improvements in hearing following a single local injection of adeno-associated virus-derived vectors carrying an additional normal gene or using ribozymes to modify the genome. These pioneering approaches have opened new possibilities for potential therapeutic interventions. Following the PRISMA criteria, we summarized the AAV gene therapy experiments showing hearing improvement in the preclinical phases of development in different animal models of DFNB deafness and the AAV gene therapy programs currently in clinical phases targeting autosomal recessive non syndromic hearing loss. A total of 17 preclinical studies and 3 clinical studies were found and listed. Despite the hurdles, there have been significant breakthroughs in the path of HL gene therapy, holding great potential for providing patients with novel and effective treatment.

Treating Sensorineural Hearing Loss: Recent Advances in Inner Ear Drug Delivery

Abstract: This review aims to provide historical, present, and future drug deliveries for treating in-ner ear disorders. Systemic delivery, such as antibiotics and steroids for the inner ear, was the basis on which current drug delivery systems and devices have been researched and developed. Re-searchers and clinicians had to develop and deliver drugs locally due to adverse effects caused by drugs systemically. Intratympanic method of antibiotics and steroid delivery has been common; however, newer techniques such as microcatheter implantation, hydrogels, nanoparticles, and intra-cochlear implants are being investigated successfully. Recently advances in microfluidic and mi-crosystems technology have applied medications directly into the inner ear. This technology will also be adopted to deliver gene therapy, RNA interference technology, and stem cell therapy by cli-nicians in the future.

Characterizing a Joint Reflection-Distortion OAE Profile in Humans With Endolymphatic Hydrops.

Endolymphatic hydrops (EH), a hallmark of Meniere disease, is an inner-ear disorder where the membranes bounding the scala media are distended outward due to an abnormally increased volume of endolymph. In this study, we characterize the joint-otoacoustic emission (OAE) profile, a results profile including both distortion- and reflection-class emissions from the same ear, in individuals with EH and speculate on its potential utility in clinical assessment and monitoring. Subjects were 16 adults with diagnosed EH and 18 adults with normal hearing (N) matched for age. Both the cubic distortion product (DP) OAE, a distortion-type emission, and the stimulus-frequency (SF) OAE, a reflection-type emission, were measured and analyzed as a joint OAE profile. OAE level, level growth (input/output functions), and phase-gradient delays were measured at frequencies corresponding to the apical half of the human cochlea and compared between groups. Normal hearers and individuals with EH shared some common OAE patterns, such as the reflection emissions being generally higher in level than distortion emissions and showing more linear growth than the more strongly compressed distortion emissions. However, significant differences were noted between the EH and N groups as well. OAE source strength (a metric based on OAE amplitude re: stimulus level) was significantly reduced, as was OAE level, at low frequencies in the EH group. These reductions were more marked for distortion than reflection emissions. Furthermore, two significant changes in the configuration of OAE input/output functions were observed in ears with EH: a steepened growth slope for reflection emissions and an elevated compression knee for distortion emissions. SFOAE phase-gradient delays at 40 dB forward-pressure level were slightly shorter in the group with EH compared with the normal group. The underlying pathology associated with EH impacts the generation of both emission types, reflection and distortion, as shown by significant group differences in OAE level, growth, and delay. However, hydrops impacts reflection and distortion emissions differently. Most notably, DPOAEs were more reduced by EH than were SFOAEs, suggesting that pathologies associated with the hydropic state do not act identically on the generation of nonlinear distortion at the hair bundle and intracochlear reflection emissions near the peak of the traveling wave. This differential effect underscores the value of applying a joint OAE approach to access both intracochlear generation processes concurrently.

Epidemiology of benign paroxysomal positional vertigo (BPPV) and risk factors for secondary BPPV: a population-based study

BackgroundBPPV (benign paroxysmal positional vertigo) is a disorder that causes sudden, spinning sensation for few seconds with specific head movements. Of all disorders of inner ear that causes dizziness, BPPP is the most common one. To understand this disorder, we conducted a retrospective study at a tertiary care ENT hospital in Eastern India.Aims and objectives1. To know the incidence of BPPV among all vertigo patients.2. To know the age-sex distribution of BPPV.3. To identify secondary causes of BPPV and their prevalence.4. To know the incidence of different canal BPPVs.5. To ascertain the treatment outcome of different particle repositioning maneuvers in BPPV.MethodsTotal 575 patients presented to the vertigo clinic from 15 September 2018 to 21 March 2022. Out of them 151 patients (26.6%) were diagnosed with BPPV by proper history taking, clinical examination including provocative tests. They were treated with appropriate particle repositioning maneuvers (PRM). Patients were followed for mean 6 months and results were analyzed.Results and analysisOf all vertigo patients, BPPV constitutes 26.6% of cases, making it most common cause of peripheral vertigo. It commonly affects 40–60 years of age group with equal sex predilection. Eighty-three percent of cases were idiopathic, secondary causes include vestibular migraine, Meniere’s disease, labyrinthitis, and orthostatic hypotension. Posterior canal was most commonly affected (74%), followed by lateral and anterior canal. Particle repositioning maneuver (PRM) cures 96% of all BPPV patients (75% needs only one PRM, 15% requires the second one) with overall success rate of 96% after 6 months of follow-up.ConclusionBPPV is the most common cause of peripheral vertigo. One has to understand the anatomy, physiology and pathophysiology of vestibular system to provide better patient care in these patients. Particle repositioning maneuver (PRM) is the treatment for BPPV.

Hearing rehabilitation and microbial shift after middle ear surgery with Vibrant Soundbridge in patients with chronic otitis media

IntroductionPatients with otitis media (OM) encounter significant functional hearing impairment with conductive, or a combined hearing loss and long-term sequelae involving impaired speech/language development in children, reduced academic achievement and irreversible disorders of middle and inner ear requiring a long time therapy and/or multiple surgeries. In its persistent chronic form, Otitis media (COM) can often only be treated by undergoing ear surgery for hearing restoration. The persistent inflammatory reaction plays a major role, often caused by multi-resistant pathogens in the ear. Herein, we present outcomes of patients implanted with currently the only FDA approved active Middle Ear Implant Vibrant Soundbridge (VSB), suffering from persistent COM.MethodsThe study enrolled 42 patients, treated by performing middle ear (ME) surgery to different extents and implanted with the VSB to various structures in the ME. Included were 17 children and 25 adults that had recurrent and/or persisting OM and significant hearing loss. Preoperative and postoperative patients' audiometric data were evaluated and the benefit with VSB assessed using the Glasgow Benefit Inventory for adults and pediatric cohorts. The microbial spectrum of pathogens was assessed before and after surgery, exploring the colonization of the otopathogens, as well as the intestinal microbiome from individually burdened patients.ResultsThe mean functional gain is 29.7 dB HL (range from 10 to 56.2 dB HL) with a significant improvement in speech intelligibility in quiet. Following VSB implantation, no significant differences in coupling were observed at low complication rates. Postoperatively patients showed significantly increased benefit with VSB compared to the untreated situation, including less otorrhea, pain, medical visits, and medication intake, with no recurrent OM and significant bacterial shift in otopathogens. The analysis of the intestinal microbiome displayed a high abundance of bacterial strains that might be linked to chronic and persistent inflammation.ConclusionsFunctional ear surgery including rehabilitation with a VSB in patients suffering from COM present to be safe and effective. The successful acceptance accompanied by the improved audiological performance resulted in significant benefit with VSB, with a shift in the ear pathogens and altered microbiome and thus is a great opportunity to be treated.

EFFECTIVENESS OF SEMONT MANEUVER ALONG WITH VESTIBULAR REHABILITATION IN ADULT WITH BENIGN PAROXYSMAL POSITIONAL VERTIGO: RCT

Background: BPPV is dened as an inner-ear disorder characterized by repeated episodes of positional vertigo. Vertigo and balance disorders are the most relevant factors among older adults and associated with immobility, decreased participation and ADL. In BPPV, SM is preferred, in which vestibular debris is shifted from the semilunar-canal by rapidly putting the patient in various positions. VR is an exercise-based therapy, which consists of various eye, head and body movements to stimulate the vestibular-system. Objective:The purpose of the study was to nd the effectiveness of SM in adult people to reduce symptoms, improve balance and QoL with BPPV. Study design:RCT Methods: In 4-weeks interventional study, 30 participants with features of BPPV were studied. They were divided into 2 groups by simple random sampling; Group A: experimental group and Group B: control group. Pre and post-treatment data were collected and analyzed using SPSS 22.0. McNemar and Paired t-test were used to nd out the signicance of the treatment. Results: A signicant improvement was found in balance through the BBS and reduced symptoms through Dix-Hallpike test (p<0.05) after treatment. A greater statistically signicant difference was seen in Group A. Conclusion: The study concluded that the combined effect of SM along with VR shows signicant improvement in reducing symptoms of BPPV and improve the balance and QoL.

Molecular Mechanisms and Biological Functions of Autophagy for Genetics of Hearing Impairment.

The etiology of hearing impairment following cochlear damage can be caused by many factors, including congenital or acquired onset, ototoxic drugs, noise exposure, and aging. Regardless of the many different etiologies, a common pathologic change is auditory cell death. It may be difficult to explain hearing impairment only from the aspect of cell death including apoptosis, necrosis, or necroptosis because the level of hearing loss varies widely. Therefore, we focused on autophagy as an intracellular phenomenon functionally competing with cell death. Autophagy is a dynamic lysosomal degradation and recycling system in the eukaryotic cell, mandatory for controlling the balance between cell survival and cell death induced by cellular stress, and maintaining homeostasis of postmitotic cells, including hair cells (HCs) and spiral ganglion neurons (SGNs) in the inner ear. Autophagy is considered a candidate for the auditory cell fate decision factor, whereas autophagy deficiency could be one of major causes of hearing impairment. In this paper, we review the molecular mechanisms and biologic functions of autophagy in the auditory system and discuss the latest research concerning autophagy-related genes and sensorineural hearing loss to gain insight into the role of autophagic mechanisms in inner-ear disorders.

Incidence of Inner Ear Disorders in Various Forms of Acute Otitis Media in ENT Practices in Germany.

The aim of this study was to determine the incidence of inner ear involvement in various forms of acute otitis media (AOM) in ear, nose, and throat (ENT) practices in Germany. Patients who had been diagnosed with various forms of AOM in the years 2010 to 2017 were enrolled in the study from a nationwide, representative practice database (Disease Analyzer, IQVIA). In these patients, the incidence of simultaneous or subsequent inner ear disorders (IED) was determined within 7 days and within 12 months from the date of an AOM diagnosis. A total of 286 186 patients with AOM were enrolled. The most frequent diagnoses were "nonsuppurative otitis media, unspecified" (47.6%) and "otitis media, unspecified" (39.0%). The diagnoses of hemorrhagic bullous myringitis (BM) or influenza-induced AOM were very rarely found in the database. The highest incidence of IED after 7 days and 12 months was found in "nonsuppurative otitis media, unspecified" (7.7% and 15.9%, respectively), followed by "otitis media, unspecified" (5.6% and 13.5%, respectively). The incidences of the most frequent IED "hearing loss, unspecified" and "sensorineural hearing loss, unspecified" increased proportionally with increasing patient age, while the rare diagnoses of "labyrinthitis" and "ototoxic hearing loss" were evenly distributed among the age groups. In ENT practices in Germany, both various forms of AOM, as well as simultaneous or subsequent IED, are mostly being coded in an unspecific way, while specific forms such as hemorrhagic BM, influenza-induced AOM, and labyrinthitis are coded very rarely. Older patients have a higher risk of IED in AOM. A visit due to AOM seems to be a regular occasion for the initial diagnosis of hearing impairment in the elderly individuals. The highest risk of IED was found in nonsuppurative AOM.

Dietary Restriction for The Treatment of Meniere's Disease.

Meniere's disease (MD) is an idiopathic inner ear disorder characterized by spontaneous recurrent vertigo, fluctuating sensorineural hearing loss (SNHL), aural fullness and tinnitus. Endolymphatic hydrops (EH) of the inner ear is currently considered the pathophysiological mechanisms that underlies typical symptoms of MD. MD diagnosis is based on the criteria of the Baràny Society. There are many therapeutic options for MD, but none is considered effective by the scientific community. The first-line treatment commonly includes dietary modification, as low salt diet and reduction of alcohol and caffeine daily intake. Although some studies showed a positive effect of these dietary restrictions, even in the prevention of recurrences, currently there is no uniform consensus on their usefulness. New dietary approach, such SPC-flakes, are being evaluated: further assessments will be needed to validate their use in clinical practice.

Inner-Ear Disorders Presenting with Air-Bone Gaps: A Review.

Air-bone gaps (ABGs) are commonly found in patients with conductive or mixed hearing loss generally due to outer- and/or middle-ear diseases such as otitis externa, tympanic membrane perforation, interruption or fixation of the ossicular chain, and chronic suppurative otitis media. ABGs can also be found in correlation with inner-ear disorders, such as endolymphatic hydrops, enlarged vestibular aqueduct syndrome, semicircular canal dehiscence, gusher syndrome, cochlear dehiscence, and Paget disease's as well cerebral vascular anomalies including dural arteriovenous fistula. The typical clinical presentation of inner-ear conditions or cerebral vascular anomalies causing ABGs includes audiological and vestibular symptoms like vertigo, oscillopsia, dizziness, imbalance, spinning sensation, pulsatile or continuous tinnitus, hyperacusis, autophony, auricular fullness, Tullio's phenomenon, and Hennebert's sign. Establishing a definitive diagnosis of the underlying condition in patients presenting with an ABG is often challenging to do and, in many patients, the condition may remain undefined. Results from an accurate clinical, audiological, and vestibular evaluation can be suggestive for the underlying condition; however, radiological assessment by computed tomography and/or magnetic resonance imaging is mandatory to confirm any diagnostic suspicion. In this review, we describe and discuss the most recent updates available regarding the clinical presentation and diagnostic workup of inner-ear conditions that may present together with ABGs.

RAAV-Mediated Cochlear Gene Therapy: Prospects and Challenges for Clinical Application.

Over the last decade, pioneering molecular gene therapy for inner-ear disorders have achieved experimental hearing improvements after a single local or systemic injection of adeno-associated, virus-derived vectors (rAAV for recombinant AAV) encoding an extra copy of a normal gene, or ribozymes used to modify a genome. These results hold promise for treating congenital or later-onset hearing loss resulting from monogenic disorders with gene therapy approaches in patients. In this review, we summarize the current state of rAAV-mediated inner-ear gene therapies including the choice of vectors and delivery routes, and discuss the prospects and obstacles for the future development of efficient clinical rAAV-mediated cochlear gene medicine therapy.

Are viral-infections associated with Ménière's Disease? A systematic review and meta-analysis of molecular-markers of viral-infection in case-controlled observational studies of MD.

Despite considerable research, it remains controversial as to whether viral-infections are associated with Meniere’s Disease (MD), a clinically heterogeneous set of chronic inner-ear disorders strongly associated with endolymphatic hydrops. Here, we investigated whether viral-infections are associated with MD through a systematic review and meta-analysis of observational clinical studies using molecular-diagnostics. Eligible for inclusion were case-controlled studies which ascertained molecular-determinants of past or present viral-infection through either viral nucleic acids or host serological marker in MD cases and non-MD controls. Across online databases and grey literature, we identified 210 potentially relevant articles in the English language, from which a total of 14 articles fully satisfied our eligibility criteria such that meta-groups of 611 MD-cases and 373 controls resulted. The aggregate quality of the modest-sized (14 studies) body of evidence was limited and varied considerably with regards to participant selection, matching, and ascertainment(s) and determinant(s) of viral-infection. Most data identified concerned the human cytomegalovirus (CMV), and meta-analysis of eligible studies revealed that evidence of CMV-infection was associated approximately three-fold with MD compared to controls, however the timing of the infections was indeterminate as the pooled analyses combined antiviral serological markers with viral nucleic acid markers. No association was found for any of HSV-1, -2, VZV, or EBV. Associative analyses of any viral species not aforementioned were precluded by limited data, and thus potential associations between other viral species and MD, especially other than Herpesviridae, are yet to be characterised. Overall, we have found a small association between CMV-infection and MD, however it is to be determined for what sub-groups of MD this finding may be relevant, and ideally the reported association remains would be reproduced by a greater volume of higher quality evidence.

Abnormal visuo-vestibular interactions in vestibular migraine: a cross sectional study.

Vestibular migraine is among the commonest causes of episodic vertigo. Chronically, patients with vestibular migraine develop abnormal responsiveness to both vestibular and visual stimuli characterized by heightened self-motion sensitivity and visually-induced dizziness. Yet, the neural mechanisms mediating such symptoms remain unknown. We postulate that such symptoms are attributable to impaired visuo-vestibular cortical interactions, which in turn disrupts normal vestibular function. To assess this, we investigated whether prolonged, full-field visual motion exposure, which has been previously shown to modulate visual cortical excitability in both healthy individuals and avestibular patients, could disrupt vestibular ocular reflex and vestibular-perceptual thresholds of self-motion during rotations. Our findings reveal that vestibular migraine patients exhibited abnormally elevated reflexive and perceptual vestibular thresholds at baseline. Following visual motion exposure, both reflex and perceptual thresholds were significantly further increased in vestibular migraine patients relative to healthy controls, migraineurs without vestibular symptoms and patients with episodic vertigo due to a peripheral inner-ear disorder. Our results provide support for the notion of altered visuo-vestibular cortical interactions in vestibular migraine, as evidenced by vestibular threshold elevation following visual motion exposure.

High Resolution M-mode Evaluation of Jugular Vein Valves in Patients with Neurological and Neurosensory Disorders.

High prevalence of valve absence was found in the internal jugular vein (IJV) of healthy volunteers by means of M-mode high-resolution Echo Colour Doppler (ECD). However, the prevalence of valve in neurovascular disorders linked to Chronic Cerebrospinal Venous Insufficiency (CCSVI) is still unknown. A cohort of 83 Healthy Controls (HC), 71 Multiple Sclerosis (MS), 99 Inner Ear Disorders (IED) underwent ECD investigation of the IJV valve, including M-mode evaluation and related hemodynamics. The primary outcome measure was characterization of valve presence, morphology and motility, whereas the secondary outcome was the rate of flow alteration. Bilateral valve presence was found in 38% of HC, 58% of MS and 25% of IED, whereas, bilateral valve absence was recorded in 16% of HC, 10% of MS and 31% of IED (p<0.003). Bicuspid morphology was more prevalent in HC 56%, while monocusp was more prevalent in patients: 75% MS and 57% IED (p<0.0001). The main finding was the presence of mobile valve leaflets in 98% of HC, contrarily fixed valve leaflets were recorded in 82% of MS and in 41% of IED, p< 0.0001. Finally, by stratifying the entire cohort according to the presence of mobile and not mobile valve leaflets, normal monodirectional and phasic flow were commonly found in the mobile leaflets subgroup, p<0.0001. In patients with miscellaneous neurological disorders, a significant higher rate of defective valves was found with respect to HC. The latter condition is strongly associated to brain outflow abnormalities described in CCSVI condition.

Dario Alpini, a pioneer of venous and lymphatics disorders of the inner ear

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Exploring Methods to Measure the Prevalence of Ménière's Disease in the US Clinformatics™ Database, 2010-2012

Recent studies on the epidemiology of the inner-ear disorder Ménière's disease (MD) use disparate methods for sample selection, case identification and length of observation. Prevalence estimates vary geographically from 17 to 513 cases per 100,000 people. We explored the impact of case detection strategies and observation periods in estimating the prevalence of MD in the USA, using data from a large insurance claims database. Using case detection strategies of ≥1, ≥2 and ≥3 ICD-9 claim codes for MD within a 1-year period, the 2012 prevalence estimates were 66, 27 and 14 cases per 100,000 people, respectively. For ≥1, ≥2 and ≥3 insurance claims within a 3-year observation period, the prevalence estimates were 200, 104 and 66 cases per 100,000 people, respectively. Estimates based on a single claim are likely to overestimate prevalence; this conclusion is aligned with the American Academy of Otolaryngology-Head and Neck Foundation criteria requiring ≥2 definitive episodes for a definite diagnosis, and it has implications for future epidemiologic research. We believe estimates for ≥2 claims may be a more conservative estimate of the prevalence of MD, and multiyear estimates may be needed to allow for adequate follow-up time.

Disease-specific sparing of the anterior semicircular canals in bilateral vestibulopathy.

Bilateral vestibular loss (BVL) is often diagnosed with great delay and an underlying cause is only identified in 50-80%. We measured horizontal and vertical semicircular canal function using the video-head-impulse test (vHIT) and hypothesized that specific vHIT-patterns may be linked to certain etiologies. We retrospectively analyzed 109 BVL-patients linked to aminoglycoside vestibulotoxicity (n=16), Menière's disease (n=10), infectious inner-ear disorders (n=11), sensorineural hearing-loss (n=11), cerebellar-ataxia-neuropathy-vestibular-areflexia-syndrome (CANVAS, n=5), other causes (n=19) as well as those with unknown origin (n=47). Vestibulo-ocular reflex gains and cumulative saccade amplitudes were measured with vHIT, and the functional integrity of all semicircular canals was rated. Overall, anterior canal hypofunction (n=86/218) was identified significantly (p<0.001) less often than horizontal (n=186/218) and posterior (n=194/218) hypofunction. Preserved anterior canal function was associated with aminoglycoside vestibulotoxicity, Menière's disease and BVL of unknown origin, while no such sparing was found for inner-ear infections, CANVAS and sensorineural hearing loss. Semicircular canal function in BVL shows disease-specific dissociations, potentially related to reduced vulnerability or superior recovery of the anterior canals. In patients with suspected BVL we recommend quantifying vHIT gains and saccade amplitudes for all semicircular canals as the pattern of canal hypofunction may help identifying the underlying disorder.

1F41 内リンパ水腫の基底板振動シミュレーション : 外有毛細胞のactivityを考慮した蝸牛有限要素モデルによる解析

Endolymphatic hydrops is a disorder of inner ear and is associated with abnormal fluctuations in the endolymph fluid. These fluctuations cause an increase of pressure in scala media of the cochlea. The symptoms of endolymphatic hydrops include hearing loss especially at low frequencies and balance problems. To investigate the reason of hearing loss at low frequencies, we aim to analyze endolymphatic hydrops with the finite element cochlear model which is considered activity of outer hair cells. At first, we developed models of endolymphatic hydrops by loading static pressure in scala media. Each pressure of model is 10, 100, 500 Pa. Next, we analyzed the normal cochlear model and the endolymphatic models with loading sound pressure at frequency of 125 Hz to 2 kHz. As the results, the displacement of the basilar membrane of the endolymphatic hydrops model was smaller than the numerical result obtained from the normal cochlear model at low frequencies under 500 Hz. Also, characteristic frequency of the endolymphatic model was not matched with characteristic frequency of the normal cochlear model at low frequencies. These results show that increase of pressure in scala media might cause hearing loss at low frequencies.

A Prospective Study on Electronystagmography (ENG) to Detect Vestibular Disorders Using Simplified GUI

Electronystagmography (ENG) refers to the clinical test that monitors the involuntary movements of the eye due to an effect called Nystagmus. The procedure is also used to detect disorders of inner ear that are responsible for vertigo and imbalance. In clinical practice, various tests such as caloric test, calibration test, gaze test, pendulum tracking test, opto-kinetics test, positional test and Rhomberg's test were generally performed to diagnose the vestibular dysfunction. Such procedure were found to be very time consuming and cumbersome for the patients. This prospective study investigates the screening of the vestibular dysfunction by integrating the readymade hardware unit with a compact software tool to reduce the clinical test duration. Electrooculography (EOG) based physiological signal is used to record the eye movements during ENG. The proposed research study aims in developing a simplified procedure towards the analysis of ENG signals. The proposed methodology not only helps in reducing the time for performing such procedures but also helps in reducing the discomforts to the subject. The procedure showed the effectiveness in terms of recognizing the required biomarkers for various activities. For the pilot study, 25 healthy male and 25 female test subjects in the age group of 19-21 years were considered. Experimental set up was arranged to record EOG signals with all activities with time duration of 10 minutes. Two features namely spike rhythmicity and auto regressive feature using Burg's method were extracted from the recorded raw signal. A typical Elman feedback neural network was introduced to perform the binary classification to identify the pattern, (Nystagmus left ear-Nystagmus right ear, Vertical-Horizontal and Gaze-Pendulum) respectively. An overall classification accuracy (CA) of 93.8% was achieved that confirms the effectiveness of the test required to detect nystagmus. The system needs to be validated with large experimental data to confirm the accuracy for clinical screening and validation.