Otic Capsule Dehiscences Simulating Other Inner Ear Diseases: Characterization, Clinical Profile, and Follow-Up-Is Ménière's Disease the Sole Cause of Vertigo and Fluctuating Hearing Loss?

INTRODUCTION

We present a series of six cases whose clinical presentations exhibited audiovestibular manifestations of a third mobile window mechanism, bearing a reasonable resemblance to Ménière's disease and otosclerosis. The occurrence of these cases in such a short period has prompted a review of the underlying causes of its development. Understanding the pathophysiology of third mobile window syndrome and considering these entities in the differential diagnosis of conditions presenting with vertigo and hearing loss with slight air-bone gaps is essential for comprehending this group of pathologies.

MATERIALS AND METHODS

A descriptive retrospective cohort study of six cases diagnosed at a tertiary center. All of them went through auditive and vestibular examinations before and after a therapeutic strategy was performed.

RESULTS

Out of 84 cases of dehiscences described in our center during the period from 2014 to 2024, 78 belonged to superior semicircular canal dehiscence, while 6 were other otic capsule dehiscences. Among these six patients with a mean age of 47.17 years (range: 18-73), all had some form of otic capsule dehiscence with auditory and/or vestibular repercussions, measured through hearing and vestibular tests, with abnormalities in the results in five out of six patients. Two of them were diagnosed with Ménière's disease (MD). Another two had cochleo-vestibular hydrops without meeting the diagnostic criteria for MD. In two cases, the otic capsule dehiscence diagnosis resulted from an intraoperative complication due to a gusher phenomenon, while in one case, it was an accidental radiological finding. All responded well to the proposed treatment, whether medical or surgical, if needed.

CONCLUSIONS

Otic capsule dehiscences are relatively new and unfamiliar entities that should be considered when faced with cases clinically suggestive of Ménière's disease, with discrepancies in complementary tests or a poor response to treatment. While high-sensitivity and specificity audiovestibular tests exist, completing the study with imaging, especially petrous bone CT scans, is necessary to locate and characterize the otic capsule defect responsible for the clinical presentation.

Early Detection of Hearing Loss among the Elderly

BACKGROUND

Age-related hearing loss (ARHL) is a complex communication disorder that affects the cochlea and central auditory pathway. The goal of this study is to characterize this type of hearing loss and to identify non-invasive, inexpensive, and quick tests to detect ARHL among elderly adults, seeking to preserve quality of life and reduce the burden on healthcare systems.

METHODS

An observational, prospective study is conducted with >55-year-old subjects divided into the following groups: normal range (Group A), detected but not treated (Group B), and detected and treated (Group C). During follow-up, Speech Spatial Qualities (SSQ12), and Hearing Handicap Inventory in the Elderly Screening test (HHIE-S) questionnaires were assessed, along with hearing levels (hearing thresholds at 4 kHz were studied in more depth), and a series of tests and questionnaires to assess balance, cognitive level, level of dependence, and depression.

RESULTS

A total of 710 patients were included in this study. The duration of hearing loss (11.8 yr. in Group B and 21.0 yr. in Group C) and average time-to-treatment for Group C (14.1 yr.) are both protracted. Both of the used questionnaires show statistically significant differences among the groups, revealing greater handicaps for Group C. Audiometry performed at 4 kHz shows how hearing loss progresses with age, finding differences between men and women. There is a correlation between time-to-treatment in Group C and the cognitive test DSST (-0.26; p = 0.003).

CONCLUSIONS

HHIE-S, SSQ12, and 4 kHz audiometry are sensitive and feasible tests to implement in screening programs.

Hearing and Balance in Healthy Aging Project: Characterization of Hearing, Balance, and Other Associated Disorders in Three Population Groups Aged 55 and Over

INTRODUCTION

Active aging emphasizes optimizing health and participation for a better quality of life as people age. This paper explores the significant impact of hearing loss and balance disorders on the elderly. Age-related hearing loss is thought to contribute to communication breakdown and cognitive dysfunctions. The "hearing and balance in healthy aging" project focuses on early detection, mitigation, and advocacy. Objectives include exploring epidemiological traits, evaluating overall well-being impact, proving positive intervention effects, and advocating societal care for the elderly with hearing loss and balance disorders, aiming to reduce their broader impact on cognition, independence, and sociability.

METHODS

This study is observational, prospective study. Subjects over 55 years old with a follow-up every year or every 2 years were divided into three groups, according to their hearing and balance: within the normal range (group A), detected and not treated (group B), and detected and treated (group C). At each visit, they underwent a series of tests or questionnaires, evaluating different areas: hearing, balance, cognition, depression, dependence, tinnitus, loneliness, health.

RESULTS

A total of 710 patients were included in the study. The distribution of patients was as follows: group A - 210 patients, group B - 302 patients, and group C - 198 patients. Significant differences were found between the three groups related to age, sex, educational level, bilingualism, and work activity. In group C, there was a higher percentage of males, older than in groups A and B, and the percentage of individuals with a university education was lower (28%), as was the rate of bilingualism (23%). In terms of hearing, significant differences were found in the three groups in the mean PTA, speech discrimination in quiet, and the HINT test, with worse results for group C. Only patients in group C presented a perception of hearing impairment, and the handicap caused by hearing impairment worsened from group A to C. Concerning balance, both tests performed (TuGT and DHI) revealed increased difficulty in maintaining autonomous walking from group A to C, which, again, exhibited the worst results, with statistically significant differences across the group. Analysis about cognition revealed significant differences in DSST questionnaires and in TMT scores, where group C had the worst scores. In HUI3 questionnaire scores, the differences between each and every group were statistically significant, with group C showing moderate disability.

CONCLUSION

This extensive analysis, encompassing a considerable number of subjects, reveals significant findings that have important implications for the early prevention of hearing loss and its consequent consequences. At the same time, these data represent an initial exploration, which raises the need for in-depth examinations of additional factors and longer follow-up to continue contributing insights and knowledge for a healthy aging.

Acute histological reactions in the otolith organs to inner ear drug delivery through a cochlear implant

Introduction

Cochlear implantation is currently regarded as a safe and minimally invasive procedure. However, cochlear implantation can have an impact on vestibular function, despite the lack of correlation between patient symptomatology and damage in vestibular tests. Thus, the present study aims to analyze the presence of hydrops and histological reactions at the level of the vestibule after cochlear implantation with dexamethasone pump delivery in Macaca fascicularis (Mf).

Materials and methods

A detailed histological study was conducted on a total of 11 Mf. All 11 Mf were divided into three groups: 5 Mf were implanted with an electrode array HL-14 connected to a pump delivering FITC-dextran for 24 h (Group A); 4 Mf were implanted with a CI electrode array attached to a pump for FITC-dextran delivery for 7 days (Group B); and 2 Mf were considered the control group, without any kind of cochlear device implantation (Group C). After drug deliver, the selected macaques were euthanized to collect tissue samples for histological analysis. An experienced observer, focusing on the utricle and saccule areas, conducted a blinded inner ear histology analysis.

Results

Surgical procedures were successfully performed in all cases. No signs of cochlear reaction to the device were observed, including neither collapse nor fibrosis. Endolymphatic sinus dilatation was observed in Mf4A and Mf3B, while cochlear hydrops was observed in Mf3A. The mean areas of the utricle and saccule exhibited some statistically significant differences, specifically, in the saccule between groups C and both groups A (p = 0.028) and B (p = 0.029); however, no significant differences were observed between groups A and B or among comparisons of the utricle.

Discussion

A significant concern relates to the safety of cochlear implantation with regard to vestibular preservation and hearing. New advancements in electrode arrays, such as CI devices coupled with delivery pumps, pose a challenge in maintaining minimally traumatic surgical concept-based procedures without affecting the inner ear homeostasis. The implantation of this device may cause vestibular hydrops in the saccule, indicating that the longer the time of substance release, the greater the grade of hydrops evidenced at the saccular level. Apart from this finding, the risk of histological damage to the vestibule is low.

Bone Conduction Implants: Comparative of Audiometric Results and Quality of Life Bonebridge® vs Osia®

INTRODUCTION

Bone conduction implants have been indicated for patients with conductive hearing loss, mixed hearing loss, and even profound unilateral sensorineural hearing loss. With the introduction of Bonebridge®, new transcutaneous implant options emerged. The latest is Osia®, a direct-drive variant or active systems where the implant directly generates and applies vibration to the bone.

MATERIALS AND METHODS

Retrospective study of two cohorts of patients treated with active bone conduction implants at a single center, one with the Bonebridge® device and the other with Osia®.

OUTCOMES

Fourteen patients were included, seven in each group (n=14). The Bonebridge® group showed an average hearing gain in tonal intelligibility thresholds of 32.43±21.39 dB and a gain in the average intelligibility threshold (with 50% discrimination) of 26.29±19.10 dB. In the Osia® group, there was a gain in average tonal thresholds of 41.49±14.16 dB and 23.72±6.98 dB in average intelligibility thresholds. Both devices contributed to improvements in patients' quality of life, as assessed with APHAB in all the variables studied in the test. Both devices offer rehabilitation for hearing loss as an alternative to hearing aids. The Osia® system shows statistically significant(p<0.05) improvements in mid and high frequencies, but Bonebridge® slightly outperforms in speech understanding at 50%. Differences in average tonal thresholds and quality of life are not statistically significant.

CONCLUSIONS

While auditory improvement is observed post-implantation, other aspects, such as intelligibility thresholds and quality of life, lack statistical significance. Given the limited experience with Osia® and the small sample size, the choice of the device should be personalized. Although the literature is inconsistent due to small sample sizes and variable approaches, some studies suggest potential advantages of the Osia® system, especially in speech comprehension in different environments and greater hearing gain compared to Bonebridge®.

Congruence and incongruence on the radiological and functional examination of inner ear hemorrhage

BACKGROUND

Inner ear hemorrhage (IEH) is an increasingly recognized cochlear lesion that can cause sensorineural hearing loss (SNHL). Magnetic resonance imaging (MRI) is known to be the best imaging modality for clarifying the causes of SNHL and providing images that point to those causes.

AIMS

Evaluate the lesional patterns in patients with presumed Inner ear hemorrhage (IEH) from radiological and functional aspects.

MATERIAL AND METHODS

We retrospectively reviewed 10 patients performed in our institution from 2014 to 2020, with suspected labyrinthine hemorrhage based on radiological and functional examination.

RESULTS

We included 8 patients with IEH and sensorineural hearing loss (SNHL). The median age was 55 years (range: 3 months - 78 years). The results from the MRI and functional tests were compared for each end-organ. Only three cases (37.5%) showed a correlation between signal abnormalities and dysfunction in the labyrinthine apparatus.

CONCLUSIONS

In patients with SNHL inner ear hemorrhage needs to be ruled out in the differential diagnosis, so specific MRI sequences should be requested. It represents a way to a better understanding of the disorder and the variety of findings claim for a complete auditory and vestibular testing.

Next-generation sequencing improves precision medicine in hearing loss

Background: An early etiological diagnosis of hearing loss positively impacts children's quality of life including language and cognitive development. Even though hearing loss associates with extremely high genetic and allelic heterogeneity, several studies have proven that Next-Generation Sequencing (NGS)-based gene panel testing significantly reduces the time between onset and diagnosis. Methods: In order to assess the clinical utility of our custom NGS GHELP panel, the prevalence of pathogenic single nucleotide variants, indels or copy number variants was assessed by sequencing 171 nuclear and 8 mitochondrial genes in 155 Spanish individuals with hearing loss. Results: A genetic diagnosis of hearing loss was achieved in 34% (52/155) of the individuals (5 out of 52 were syndromic). Among the diagnosed cases, 87% (45/52) and 12% (6/52) associated with autosomal recessive and dominant inheritance patterns respectively; remarkably, 2% (1/52) associated with mitochondrial inheritance pattern. Although the most frequently mutated genes in this cohort were consistent with those described in the literature (GJB2, OTOF or MYO7A), causative variants in less frequent genes such as TMC1, FGF3 or mitCOX1 were also identified. Moreover, 5% of the diagnosed cases (3/52) were associated with pathogenic copy number variants. Conclusion: The clinical utility of NGS panels that allows identification of different types of pathogenic variants-not only single nucleotide variants/indels in both nuclear and mitochondrial genes but also copy number variants-has been demonstrated to reduce the clinical diagnostic odyssey in hearing loss. Thus, clinical implementation of genomic strategies within the regular clinical practice, and, more significantly, within the newborn screening protocols, is warranted.

Magnetic Resonance Volumetric Quantification of Vestibular Endolymphatic Hydrops in Patients with Unilateral Definite Meniere's Disease Using 3D Inversion Recovery with Real Reconstruction (3D-REAL-IR) Sequence

BACKGROUND

The 3D-REAL-IR MRI sequence allows for an in vivo visualization of endolymphatic hydrops. Qualitative assessment methods of the severity of vestibular and cochlear hydrops are the most commonly used.

METHODS

A quantitative volumetric measurement of vestibular EH in patients with definite unilateral Ménière's disease using the 3D-REAL-IR sequence and the calculation of the endolymphatic ratio (ELR) was intended.

RESULTS

Volumetric calculations of the vestibules, vestibular endolymph and vestibular ELR are performed in 96 patients with unilateral Ménière's disease and correlated with classic qualitative grading scales.

CONCLUSIONS

Quantitative volumetric measurement of vestibular hydrops using the 3D-REAL-IR sequence is feasible and reproducible in daily clinical practice. Vestibular ELR values exceeding 60% defined radiologically significant vestibular hydrops, while values below 30% defined radiologically non-significant vestibular hydrops.

Histopathological reaction in the vestibule after cochlear implantation in Macaca fascicularis

Cochlear implantation surgery (CI) is considered a safe procedure and is the standard treatment for the auditory rehabilitation in patients with severe-to-profound sensorineural hearing loss. Although the development of minimally traumatic surgical concepts (MTSC) have enabled the preservation of residual hearing after the implantation, there is scarce literature regarding the vestibular affection following MTCS. The aim of the study is to analyze histopathologic changes in the vestibule after CI in an animal model (Macaca fascicularis). Cochlear implantation was performed successfully in 14 ears following MTCS. They were classified in two groups upon type of electrode array used. Group A (n = 6) with a FLEX 28 electrode array and Group B (n = 8) with HL14 array. A 6-month follow-up was carried out with periodic objective auditory testing. After their sacrifice, histological processing and subsequent analysis was carried out. Intracochlear findings, vestibular presence of fibrosis, obliteration or collapse is analyzed. Saccule and utricle dimensions and neuroepithelium width is measured. Cochlear implantation was performed successfully in all 14 ears through a round window approach. Mean angle of insertion was >270° for group A and 180-270° for group B. In group A auditory deterioration was observed in Mf 1A, Mf2A and Mf5A with histopathological signs of scala tympani ossification, saccule collapse (Mf1A and Mf2A) and cochlear aqueduct obliteration (Mf5A). Besides, signs of endolymphatic sinus dilatation was seen for Mf2B and Mf5A. Regarding group B, no auditory deterioration was observed. Histopathological signs of endolymphatic sinus dilatation were seen in Mf 2B and Mf 8B. In conclusion, the risk of histological damage of the vestibular organs following minimally traumatic surgical concepts and the soft surgery principles is very low. CI surgery is a safe procedure and it can be done preserving the vestibular structures.

A Paradoxical Clinical Coincidence: Benign Paroxysmal Positional Vertigo and Bilateral Vestibulopathy

Benign paroxysmal positional vertigo (BPPV) and bilateral vestibulopathy (BVL) are two completely different forms of vestibular disorder that occasionally occur in the same patient. We conducted a retrospective review searching for that coincidence in our database of the patients seen over a 15-year period and found this disorder in 23 patients, that is 0.4%. More frequently they occurred sequentially (10/23) and BPPV was diagnosed first. Simultaneous presentation occurred in 9/23 patients. It was subsequently studied, but in a prospective manner, in patients with BPPV on all of whom a video head impulse test was performed to search for bilateral vestibular loss; we found it was slightly more frequent (6/405). Both disorders were treated accordingly, and it was found that the results follow the general trend in patients with only one of those disorders.

Apogeotropic Horizontal Canal Benign Paroxysmal Positional Vertigo: Zuma e Maia Maneuver versus Appiani Variant of Gufoni

Benign paroxysmal positional vertigo (BPPV) is one of the most common disorders that causes dizziness. The incidence of horizontal semicircular canal (HSC) BPPV ranges from 5% to 40.5% of the total number of BPPV cases diagnosed. Several studies have focused on establishing methods to treat BPPV caused by the apogeotropic variant of the HSC, namely, the Appiani maneuver (App). In 2016, a new maneuver was proposed: the Zuma e Maia maneuver (ZeM), based on inertia and gravity. The aim of this study is to analyze the efficacy of App versus ZeM in the resolution of episodes of BPPV produced by an affectation of the horizontal semicircular canal with apogeotropic nystagmus (Apo-HSC). A retrospective, quasi-experimental study was conducted. Patients attended in office (November 2014–February 2019) at a third-level hospital and underwent a vestibular otoneurology assessment. Those who were diagnosed with Apo-HSC, treated with App or ZeM, were included. To consider the efficacy of the maneuvers, the presence of symptoms and/or nystagmus at the first follow up was studied. Patients classified as “A” were those with no symptoms, no nystagmus; “A/N+”: no symptoms, nystagmus present during supine roll test; “S”: symptoms present. Previous history of BPPV and/or otic pathology and calcium levels were also compiled. From the 54 patients included, 74% were women. The average age was 69. Mean follow-up: 52.51 days. In those patients without previous history of BPPV (n = 35), the probability of being group “A” was 63% and 56% (p = 0.687) when treated with App and ZeM, respectively, while being “A/N+” was 79% and 87% for App and ZeM (p = 0.508). Of the 19 patients who had previous history of BPPV, 13% and 64% were group “A” when treated with App and ZeM (p = 0.043), and 25% and 82% were “A/N+” after App and ZeM, respectively (p = 0.021). In conclusion, for HSC cupulolithiasis, ZeM is more effective than App in those cases in which there is a history of previous episodes of BPPV (“A”: 64% (p = 0.043); “A/N+”: 82% (p = 0.021)).

Low-Dose Intratympanic Gentamicin for Unilateral Ménière‘s Disease: Accuracy of Early Vestibulo-Ocular Reflex Gain Reduction in Predicting Long-Term Clinical Outcome

Background

The number of intratympanic gentamicin (ITG) injections needed to achieve vertigo control in patients with intractable Ménière's disease (MD) may vary from a single dose to several instillations. Changes in different vestibular test results have been used to define an endpoint of treatment, including the decrease of the vestibulo-ocular reflex (VOR) gain elicited by the head-impulse test.

Objective

To assess the accuracy of the VOR gain reduction after horizontal canal stimulation, as measured with the video head-impulse test (vHIT) 1 month after the first intratympanic injection, in predicting the need for one or more instillations to control vertigo spells in the long term.

Methods

The VOR gain reduction was calculated in 47 patients submitted to (ITG) therapy 1 month after the first instillation.

Results

Single intratympanic treatment with gentamicin has a 59.6% efficacy in vertigo control in the long term. Hearing change in the immediate period after treatment (1 month) is not significant to pre-treatment result and is similar for patients who needed multiple doses due to recurrence. Chronic disequilibrium and the need for vestibular rehabilitation were less frequent in patients with a good control of vertigo with just one single injection of gentamicin. A fair accuracy was obtained for the VOR gain reduction of the horizontal canal (area under the curve = 0.729 in the Receiver Operating Characteristic analysis) in predicting the need for one or more ITG.

Conclusions

Single intratympanic treatment with gentamicin is an effective treatment for patients with MD. That modality of treatment has very limited damaging effect in hearing. The degree of vestibular deficit induced by the treatment is significant as measured by the reduction in the gain of the VOR but not useful for prognostic purposes.

Speech Recognition During Follow-Up of Patients with Ménière’s Disease: What Are We Missing?

Background: Hearing loss causes a significant reduction in the quality of life of patients with Ménière’s disease. Although speech recognition is also affected, it has not been extensively studied. The objective of the study was to describe speech recognition behavior during a prolonged period in patients with unilateral Ménière’s disease.

Methods: A prospective case–control study was performed. The case group included patients with defined unilateral Ménière’s disease and the control group included patients with progressive non-fluctuating hearing loss. Patients underwent an auditory evaluation periodically. Pure-tone audiometry and speech recognition tests—speech recognition threshold and speech discrimination score—were administered. The dissociation between pure-tone audiometry and speech recognition was assessed through a linear regression analysis. During follow-up, Ménière’s disease patients were subdivided into a stable and fluctuating subgroup (a change of >20% in the speech discrimination score with a change no greater than 15 dB in pure-tone audiometry).

Results: The average follow-up time was 79.9 months. Fifty-seven patients were included (30 cases, 27 controls). Dissociation between pure-tone audiometry and speech recognition threshold began to appear in the case group after 21 months, and it was statistically significant at 108 months. Duration of the disease was the only variable studied that influenced the dissociation. The fluctuation subgroup in cluded 56.6% of the cases.

CONCLUSION: We described 2 audiological peculiarities in Ménière’s disease patients: dissociation between pure-tone audiometry and speech recognition during the evolution of the disease and the fluctuation of speech recognition regardless of the change in pure-tone audiometry. Our results highlight the importance of performing speech recognition tests during follow-up in patients with Ménière’s disease.

Endolymphatic hydrops in the unaffected ear of patients with unilateral Ménière's disease

PURPOSE

Current studies show that frequency tuning modification is a good marker for the detection of endolymphatic hydrops (EH) employing magnetic resonance imaging (MRI) in patients with Ménière's disease (MD). The purpose of the present study is to analyze the auditory and vestibular function with audiometric and vestibular-evoked myogenic potentials (VEMP) responses, respectively, in both the affected and unaffected ears of patients with unilateral MD using MRI as diagnostic support for the degree of EH.

METHODS

We retrospectively reviewed the medical records of 76 consecutive patients with unilateral definite MD (age 55 (28-75); 39 women, 37 men). MRI was used through intravenous gadolinium administration, audiometry, and VEMPs. Functional tests were performed up to a week after the MRI. All were followed up one year after imaging utilizing clinical, auditory, and vestibular testing to rule out bilateral involvement.

RESULTS

In the unaffected ear, the mean pure-tone average is normal even in cases with hydrops and, for a similar severity of hydrops is significantly lower than in the affected ear. Significant differences for the amplitude of the response at 0.5 kHz, at 1 kHz between the affected and unaffected ears were found to be lower in the affected ears. The relative amplitude ratio (1 Kz-0.5 kHz) was significantly lower in the affected ear and in the case of the oVEMP response depends on the degree of EH. The response in the unaffected ear was not modified by the presence or the degree of hydrops.

CONCLUSION

In the unaffected ear, hydrops is not associated with hearing deterioration. For a similar degree of hydrops, hearing loss is significantly greater in the affected ear. The endolymphatic hydrops in the vestibule induces a frequency bias in the VEMP response only in the affected ear and not in the unaffected ear. Because of these findings we consider that hydrops does not represent an active disorder in the unaffected ear.

Endolymphatic Hydrops in Fluctuating Hearing Loss and Recurrent Vertigo

Background: Endolymphatic hydrops (EH) is the histopathological hallmark of Ménière's disease (MD) and has been found by in vivo magnetic resonance imaging (MRI) in patients with several inner ear syndromes without definite MD criteria. The incidence and relevance of this finding is under debate.

Purpose: The purpose of the study is to evaluate the prevalence and characteristics of EH and audiovestibular test results in groups of patients with fluctuating audiovestibular symptoms not fulfilling the actual criteria for definite MD and compare them with a similar group of patients with definite MD and a group of patients with recent idiopathic sudden neurosensory hearing loss (ISSNHL).

Material and Methods: 170 patients were included, 83 with definite MD, 38 with fluctuating sensorineural hearing loss, 34 with recurrent vertigo, and 15 with ISSNHL. The clinical variables, audiovestibular tests, and EH were evaluated and compared. Logistic proportional hazard models were used to obtain the odds ratio for hydrops development, including a multivariable adjusted model for potential confounders.

Results: No statistical differences between groups were found regarding disease duration, episodes, Tumarkin spells, migraine, vascular risk factors, or vestibular tests; only hearing loss showed differences. Regarding EH, we found significant differences between groups, with odds ratio (OR) for EH presence in definite MD group vs. all other patients of 11.43 (4.5–29.02; p < 0.001). If the ISSNHL group was used as reference, OR was 55.2 (11.9–253.9; p < 0.001) for the definite MD group, 9.9 (2.1–38.9; p = 0.003) for the recurrent vertigo group, and 5.1 (1.2–21.7; p = 0.03) for the group with fluctuating sensorineural hearing loss.

Conclusion: The percentage of patients with EH varies between groups. It is minimal in the ISSNHL group and increases in groups with increasing fluctuating audiovestibular symptoms, with a rate of severe EH similar to the known rate of progression to definite MD in those groups, suggesting that presence of EH by MRI could be related to the risk of progression to definite MD. Thus, EH imaging in these patients is recommended.

Inner ear drug delivery through a cochlear implant: Pharmacokinetics in a Macaque experimental model

OBJECTIVES

The method of drug delivery directly into the cochlea with an implantable pump connected to a CI electrode array ensures long-term delivery and effective dose control, and also provides the possibility to use different drugs. The objective is to develop a model of inner ear pharmacokinetics of an implanted cochlea, with the delivery of FITC-Dextran, in the non-human primate model.

DESIGN

A preclinical cochlear electrode array (CI Electrode Array HL14DD, manufactured by Cochlear Ltd.) attached to an implantable peristaltic pump filled with FITC-Dextran was implanted unilaterally in a total of 15 Macaca fascicularis (Mf). Three groups were created (5 Mf in each group), according to three different drug delivery times: 2 hours, 24 hours and 7 days. Perilymph (10 samples, 1μL each) was sampled from the apex of the cochlea and measured immediately after extraction with a spectrofluorometer. After scarifying the specimens, x-Rays and histological analysis were performed.

RESULTS

Surgery, sampling and histological analysis were performed successfully in all specimens. FITC-Dextran quantification showed different patterns, depending on the delivery group. In the 2 hours injection experiment, an increase in FITC-Dextran concentrations over the sample collection time was seen, reaching maximum concentration peaks (420-964µM) between samples 5 and 7, decreasing in successive samples, without returning to baseline. The 24-hours and 7-days injection experiments showed even behaviour throughout the 10 samples obtained, reaching a plateau with mean concentrations ranging from 2144 to 2564 µM and from 1409 to 2502µM, respectively. Statistically significant differences between the 2 hours and 24 hours groups (p = 0.001) and between the 2 hours and 7 days groups (p = 0.037) were observed, while between the 24 hours and 7 days groups no statistical differences were found.

CONCLUSIONS

This experimental study shows that a model of drug delivery and pharmacokinetics using an active pump connected to an electrode array is feasible in Mf. An infusion time ranging from 2 to 24 hours is required to reach a maximum concentration peak at the apex. It establishes then an even concentration profile from base to apex that is maintained throughout the infusion time in Mf. Flow mechanisms during injection and during sampling that may explain such findings may involve cochlear aqueduct flow as well as the possible existence of substance exchange from scala tympani to extracellular spaces, such as the modiolar space or the endolymphatic sinus, acting as a substance reservoir to maintain a relatively flat concentration profile from base to apex during sampling. Leveraging the learnings achieved by experimentation in rodent models, we can move to experiment in non-human primate with the aim of achieving a useful model that provides transferrable data to human pharmacokinetics. Thus, it may broaden clinical and therapeutic approaches to inner ear diseases.

A novel maneuver for diagnosis and treatment of torsional-vertical down beating positioning nystagmus: anterior canal and apogeotropic posterior canal BPPV

Introduction

In patients with benign paroxysmal positional vertigo, BPPV; a torsional-vertical down beating positioning nystagmus can be elicited in the supine straight head-hanging position test or in the Dix-Hallpike test to either side. This type of nystagmus can be explained by either an anterior canal BPPV or by an apogeotropic variant of the contralateral posterior canal BPPV Until now all the therapeutic maneuvers that have been proposed address only one possibility, and without first performing a clear differential diagnosis between them.

Objective

To propose a new maneuver for torsional-vertical down beating positioning nystagmus with a clear lateralization that takes into account both possible diagnoses (anterior canal-BPPV and posterior canal-BPPV).

Methods

A prospective cohort study was conducted on 157 consecutive patients with BPPV. The new maneuver was performed only in those with torsional-vertical down beating positioning nystagmus with clear lateralization.

Results

Twenty patients (12.7%) were diagnosed with a torsional-vertical down beating positioning nystagmus. The maneuver was performed in 10 (6.35%) patients, in whom the affected side was clearly determined. Seven (4.45%) patients were diagnosed with an anterior canal-BPPV and successfully treated. Two (1.25%) patients were diagnosed with a posterior canal-BPPV and successfully treated with an Epley maneuver after its conversion into a geotropic posterior BPPV.

Conclusion

This new maneuver was found to be effective in resolving all the cases of torsional-vertical down beating positioning nystagmus-BPPV caused by an anterior canal-BPPV, and in shifting in a controlled way the posterior canal-BPPV cases of the contralateral side into a geotropic-posterior-BPPV successfully treated during the followup visit. Moreover, this new maneuver helped in the differential diagnosis between anterior canal-BPPV and a contralateral posterior canal-BPPV.

Sculpting the temporal bone: an easy reversible cochlear implant electro-array stabilization technique

PURPOSE

Since the beginning of cochlear implant (CI) surgery, several techniques to fixate the electrode array at the cochleostomy and stabilize it have been described; however, most techniques use autologous tissues such as fascia, muscle, fat or fibrin glue. We describe a new surgical technique aimed to stabilize the electrode array of a CI without using autologous tissues or artificial materials.

MATERIALS AND METHODS

The surgical technique described consists in creating three stabilizing channels in the temporal bone for the electrode array. The first one in a partially opened aditus, the second one in a partially preserved Koerner's septum (KS) and the last one in the sinodural angle. The procedure was performed in five human temporal bones using a straight array; a radiography was made to confirm the correct placement of the electrode array and afterwards all temporal bones were shaken using a Titramax 1000 platform. The correct placement of the array post-shaking was then confirmed using the microscope and another radiography.

RESULTS

No migration of the electrodes outside the cochlea was observed. The CI cable remained in the same position at the aditus and the KS in all the temporal bones. In three cases (60%), the electrode array moved away from the groove carved in the sinodural angle.

CONCLUSIONS

The new surgical technique described stabilizes the electrode array using the temporal bone's normal anatomy, preserving the middle ear spaces, facilitating the ulterior explantation and reimplantation if necessary, and may reduce cost and surgery time.

Correlation between High-Resolution Computed Tomography Scan Findings and Histological Findings in Human Vestibular End Organs and Surgical Implications

BACKGROUND

Histological study of vestibular end organs has been challenging due to the difficulty in preserving their structures for histological analysis and due to their complex geometry. Recently, radiology advances have allowed to deepen the study of the membranous labyrinth.

SUMMARY

A review and analysis of surgical implications related to the anatomy of the vestibular end organ is performed. Radiological advances are key in the advancement of the knowledge of the anatomy and pathology of the vestibule. Thus, application of such knowledge in the development or improvement of surgical procedures may facilitate the development of novel techniques. Key Messages: During the last few decades, the knowledge of the anatomy of the auditory system through histology and radiology had improved. Technological advances in this field may lead to a better diagnosis and therapeutic approach of most common and important diseases affecting the inner ear.

Hearing Impairment and Quality of Life in Adults with Asymmetric Hearing Loss: Benefits of Bimodal Stimulation

OBJECTIVES

Bimodal stimulation for asymmetric hearing loss is an emerging treatment with proven audiometric outcomes. Our objectives are to assess the changes of the hearing impairment and the quality of life of patients treated with this type of stimulation, when compared to a unilateral Cochlear Implant (CI) stimulated condition.

MATERIALS AND METHODS

31 patients with asymmetric hearing loss (Group 1) were recruited for the study. They were divided into three groups, based on their hearing loss in the ear treated with the hearing aid: Group 1A (Pure Tone Audiometry (PTA) between 41 and 70 decibels (dB)); Group 1B, (PTA between 71 and 80 dB) and Group 1C (PTA between 81 and 90 dB). 30 patients had profound, bilateral hearing loss. Then, users of a unilateral cochlear implant were recruited for the control group. Their hearing impairment and quality of life were analyzed with questionnaires Abbreviated Profile of Hearing Aid Benefit (APHAB), Speech, Spatial and Qualities of Hearing Scale (SSQ) and the Health Utilities Index (HUI). They were followed up for at least 2 years.

RESULTS

The group with the asymmetric hearing loss obtains a statistically significant clinical improvement in the APHAB under category "with hearing aid" compared to "without hearing aid". The group with the asymmetric hearing loss benefits more across basically all variables compared with the control group in the SSQ. Group 1A obtains the best outcome of the sample in the HUI.

CONCLUSION

Bimodal stimulation and better hearing in the ear treated with the hearing aid reduce hearing impairment and improve the quality of life.

Bilateral Vestibular Hypofunction in the Time of the Video Head Impulse Test

OBJECTIVES

Bilateral vestibulopathy is a clinical syndrome in which laboratory testing plays a crucial diagnostic role. We aimed to establish the frequency of detection of that finding in a tertiary level hospital considering the new methods of laboratory vestibular examination nowadays in use, with respect to the conventional caloric and rotatory chair test approaches.

DESIGN

Two similar time periods (5 years) were retrospectively evaluated, and the demographic, clinical data and test results from 4,576 patients were reviewed. In the first period, the diagnosis was based on caloric and rotatory chair tests and, in the second, on the video head impulse test.

RESULTS

Of the patients included, 3.77% in the first period and 4.58% in the second met the criteria for bilateral vestibular hypofunction; there was no significant difference between both periods.

CONCLUSIONS

The functional vestibular evaluation to detect bilateral deficiency makes no significant difference to the number of patients diagnosed with a bilateral vestibulopathy. New diagnostic categories probably depend not only on the availability and accessibility of complete vestibular and visual-vestibular evaluation, but also on recent advances in defining vestibular disorders. Bilateral vestibular hypofunction manifests with very different patterns. Progress in more detailed definition (clinical and laboratory) is needed, in particular when all 6 semicircular canals and both maculae are available for testing.

Comparative study of two different perimodiolar and a straight cochlear implant electrode array: surgical and audiological outcomes

PURPOSE

To compare the surgical and audiological outcomes with two perimodiolar electrode arrays (Nucleus 512-Contour Advance® y Nucleus 532-Slim Perimodiolar®) and a straight electrode array (Nucleus 422/522).

METHODS

Patients were retrospectively selected from our cochlear implant program database. Only patients with a history of bilateral, sensorineural postlingually profound hearing loss who underwent cochlear implant surgery with either a N512, a N532 or a N422 were included. Throughout a year of follow-up, pure tone audiometry (PTA), speech perception, Impedances and T-C Thresholds levels were analyzed. Surgical data were also analyzed.

RESULTS

66 patients were included (19-CI532, 20-CI512 and 27-CI422). The most common type of cochlea access with the N532, N512 and N422 was through an extended round window, a promontorial cochleostomy and a pure round window, respectively. No significant differences were observed after 12 months in Mean PTA and Speech recognition. No significant differences were seen in the levels of hearing preservation at frequencies of 250 and 500. The average values of the impedances were significantly higher in the CI group N532 and N422 than in the N512. The mean values of the T and C levels were significantly lower in the CI groups N532 and N422 compared with the N512.

CONCLUSIONS

No significant differences were observed after 12 months in Mean PTA and Speech recognition; however, a faster acquisition of auditory results were observed in the group of patients treated with the CI N532. The type of electrode array influences in the type of cochleostomy.

Cochlear-Internal Canal and Cochlear-Facial Dehiscence: A Novel Entity

Different types of otic capsule dehiscence restricted to the cochlea have been described. Here we describe the case of a patient with a cochlear-internal auditory canal dehiscence associated with a cochlear-facial dehiscence not reported before. A 53-year-old patient with severe to profound sensorineural hearing loss due to bilateral Meniere's disease underwent a cochlear implant surgery on the right ear. Preoperative brain magnetic resonance imaging findings were reported to be normal; during surgery, a cerebrospinal fluid gusher occurred at the time of round window opening. Postoperative computed tomography imaging showed a bony dehiscence at two levels of the otic capsule.

Vestibulo-Cochlear Function After Cochlear Implantation in Patients With Meniere's Disease

OBJECTIVES

To measure the auditory (pure tone audiometry and word recognition scores) and vestibular (video head impulse test and vestibular myogenic potentials) outcomes in patients diagnosed with Meniere's disease (MD) who underwent cochlear implantation.

MATERIAL AND METHODS

This prospective study included 23 cochlear implant users with MD and 29 patients diagnosed with far-advanced otosclerosis (the control group).

RESULTS

The preoperative mean pure tone average thresholds were 99 and 122.5 dB for the Meniere's and control groups, respectively. Word recognition scores after cochlear implant yielded a median of 80% and 72% for the Meniere's and control groups, respectively. Semicircular canal gain was not observed to vary post implantation (mean variation for lateral, posterior, and anterior plane was 0, 0.03, and 0, respectively). The mean ocular and cervical myogenic potentials asymmetry varied as 9.65% and 18.39%, respectively.

CONCLUSIONS

The auditory performance improved in patients with MD similar to the general cochlear implant population. No major dysfunction of otolithic or semicircular canal function was demonstrated after the implantation surgery.

Cochlear Implant Electrode Array From Partial to Full Insertion in Non-Human Primate Model

OBJECTIVES

To determine the feasibility of progressive insertion (two sequential surgeries: partial to full insertion) of an electrode array and to compare functional outcomes.

MATERIAL AND METHODS

8 normal-hearing animals (Macaca fascicularis (MF)) were included. A 14 contact electrode array, which is suitably sized for the MF cochlea was partially inserted (PI) in 16 ears. After 3 months of follow-up revision surgery the electrode was advanced to a full insertion (FI) in 8 ears. Radiological examination and auditory testing was performed monthly for 6 months. In order to compare the values a two way repeated measures ANOVA was used. A p-value below 0.05 was considered as statistically significant. IBM SPSS Statistics V20 was used.

RESULTS

Surgical procedure was completed in all cases with no complications. Mean auditory threshold shift (ABR click tones) after 6 months follow-up is 19 dB and 27 dB for PI and FI group. For frequencies 4, 6, 8, 12, and 16 kHz in the FI group, tone burst auditory thresholds increased after the revision surgery showing no recovery thereafter. Mean threshold shift at 6 months of follow- up is 19.8 dB ranging from 2 to 36dB for PI group and 33.14dB ranging from 8 to 48dB for FI group. Statistical analysis yields no significant differences between groups.

CONCLUSION

It is feasible to perform a partial insertion of an electrode array and progress on a second surgical time to a full insertion (up to 270º). Hearing preservation is feasible for both procedures. Note that a minimal threshold deterioration is depicted among full insertion group, especially among high frequencies, with no statistical differences.

Endolymphatic hydrops severity in magnetic resonance imaging evidences disparate vestibular test results

OBJECTIVES

It has been suggested that in Ménière's disease (MD) a dissociated result in the caloric test (abnormal result) and video head-impulse test (normal result) probably indicates that hydrops affects the membranous labyrinth in the horizontal semicircular canal (HSC). The hypothesis in this study is that based on endolymphatic hydrops' cochleocentric progression, hydrops should also be more severe in the vestibule of these patients than in those for whom both tests are normal.

METHODS

22 consecutive patients with unilateral definite MD were included and classified as NN if both tests were normal or AN if the caloric test was abnormal. MRI evaluation of endolymphatic hydrops was carried out with a T2-FLAIR sequence performed 4h after intravenous gadolinium administration. The laterality and degree of vestibular endolymphatic hydrops and the presence or absence of cochlear endolymphatic hydrops were recorded. Demographic data, audiometric and vestibular evoked myogenic potentials were collected, and video head-impulse and caloric tests were performed.

RESULTS

Patients in both groups (NN and AN) were similar in terms of demographic data and hearing loss. The interaural asymmetry ratio was significantly higher for ocular and cervical VEMP in patients in the AN group. There was a significantly higher degree of hydrops in the vestibule of the affected ear of AN patients (χ²; p=0.028).

CONCLUSION

Significant canal paresis in the caloric test is associated with more severe endolymphatic hydrops in the vestibule as detected with gadolinium-enhanced MRI and with a more severe vestibular deficit.

LEVEL OF EVIDENCE

2a.

Treatment for Hearing Loss among the Elderly: Auditory Outcomes and Impact on Quality of Life

The study aim was to determine the benefit of cochlear implantation and hearing aids in older adults diagnosed with hearing loss and to evaluate the index of depression, anxiety and quality of life after such treatments. A retrospective cohort comprised 117 patients older than 65 years and diagnosed with moderate to profound hearing loss who were included and classified into 2 groups (treated vs. non-treated). A battery of tests including auditory (pure-tone average, disyllabic words in quiet at 65 dB SPL) and findings from a series of questions relevant to quality of life were compared between both groups. Auditory outcomes for disyllabic words were 58.21% for the cochlear implant-treated group and 82.8% for the hearing aid-treated group. There was a positive effect on anxiety, depression, health status and quality of life in the cochlear implant group versus the profound hearing loss control group. We conclude that older adults with moderate to profound hearing loss gain benefit from hearing aids or cochlear implants not only in terms of improved hearing function, but also in terms of positive effects on anxiety, depression, health status and quality of life.

[Guidelines for cochlear implant indication in Navarre]

Cochlear implants are indicated in severe to profound hearing loss with no benefit with hearing aids. Since the beginning of cochlear implants 30 years ago, auditory outcomes have been improving due to changes introduced in differ-ent areas: electrode design, strategy, surgical technique... Given good results within this period of time, cochlear implant indication has varied too. The aim of this paper is to show an update on indication criteria for cochlear implantation in Navarre, for application in daily practice. The indications are established by consensus amongst the hospitals of the region.

The effect of intra-tympanic dexamethasone on the vestibular function in patients with recurrent vertigo

CONCLUSION

The low clinical efficacy of the treatment for patients included in this work correlates with no noticeable effect on the vestibular function.

OBJECTIVE

To assess follow-up in patients with idiopathic and secondary Ménière's disease after treatment with intra-tympanic dexamethasone and correlate clinical findings with changes in the vestibular-ocular reflex elicited after stimulation of each of the six semicircular canals.

METHODS

This is a single center retrospective review of patients presenting the clinical symptomatology of Meniérè's disease treated with intra-tympanic dexamethasone. An audiometric evaluation was performed in each patient before and after treatment. The study cohort was divided into two groups: those evaluated after a short period of time and after a long period of time.

RESULTS

The study included 30 patients, mean age = 61 years. Differences in mean pure-tone average before and after treatment were non-significant for both treated (0.61 dB, p = 0.723) and untreated (0.59 dB, p = 0.609) ears. Vestibular-ocular reflex gain averages in the treated ear after treatment were 0.73 (superior semicircular canal), 0.86 (horizontal semicircular canal), and 0.69 (posterior semicircular canal). The gain did not vary significantly in the Superior (p = 0.194), the Horizontal (p = 0.646), or the Posterior Semicircular Canal (p = 0.820). Similar were obtained for the untreated ear.

Long-term follow-up of late onset vestibular complaints in patients with cochlear implant

CONCLUSION

Patients with cochlear implants should be treated no differently than non-implanted patients with similar symptomatology.

OBJECTIVES

To describe the spectrum of symptomatology, treatment, and long-term follow-up of patients with cochlear implant and vestibular complaints.

METHODS

This retrospective study included 25 patients with late onset vestibular complaints (more than 1 month post-implantation). Each patient underwent an extensive interrogatory and physical exam with ancillary test to complete a diagnosis. Treatment was given according to this and all patients followed a vestibular rehabilitation program.

RESULTS

The total population was 72% male and 28% female, median age was 58 years; minimal follow-up was 9 months (mean = 51, median = 34). Cochleostomy was performed in eight cases and round window insertion was performed in 19 (two patients were removed from each group in the analysis due to their bilateral implantation under a different approach). The mean time from implant to vestibular symptoms was 53 months, median = 32; a Kaplan Meier graphic showed the round window approach has faster onset of symptoms with statistical significance (p = 0.020). The most common complaint was instability in all patients and after both surgical approaches. No difference in symptoms was found with a Kruskall Wallis test except for vertigo spells (more common in the round window approach). In 12 patients the symptomatology was attributed to the implanted side. In the long-term follow-up a relatively high number of patients (20/25) recovered with standard treatment, suggesting the presence of the implant is not associated with poor recovery prognosis.

Functional Neuroimaging Studies in Asymmetric Hearing Loss

This article presents an analysis of the impact of functional neuroimaging studies (positron emission tomography, PET) in asymmetric hearing loss based on the clinical expertise obtained from a group of 21 patients. In these patients, PET studies are performed at rest and after auditory stimulation in order to measure the increase in brain activity in the ipsi- and contralateral cortex, providing supporting evidence to recommend a specific treatment and the side to implant. In conclusion, PET is a useful tool for selected cases in which information on the metabolic status of the auditory pathway can drive the decision regarding the treatment of the most appropriate ear. However, in view of our small sample, further research is needed to confirm our results in this topic.

Surgical findings and auditory performance after cochlear implant revision surgery

The objective of this study was to review cochlear reimplantation outcomes in the tertiary hospital and analyze whether facts such as type of failure, surgical findings, or etiology of deafness have an influence. A retrospective study including 38 patients who underwent cochlear implant revision surgery in a tertiary center is performed. Auditory outcomes (pure tone audiometry, % disyllabic words) along with etiology of deafness, type of complication, issues with insertion, and cochlear findings are included. Complication rate is 2.7 %. Technical failure rate is 57.9 % (50 % hard failure and 50 % soft failure), and medical failure (device infection or extrusion, migration, wound, or flap complication) is seen in 42.1 % of the cases. Management of cochlear implant complications and revision surgery is increasing due to a growing number of implantees. Cases that require explantation and reimplantation of the cochlear implant are safe procedures, where the depth of insertion and speech perception results are equal or higher in most cases. Nevertheless, there must be an increasing effort on using minimally traumatic electrode arrays and surgical techniques to improve currently obtained results.

Single intratympanic gentamicin injection in Ménière's disease: VOR change and prognostic usefulness

OBJECTIVE

Assess angular vestibular-ocular reflex (VOR) changes after treatment with intratympanic gentamicin (ITG) for Ménière's disease (MD) and impact on short-term follow-up.

DESIGN

Prospective study.

METHODS

Patients submitted to ITG for unilateral MD. The gain VOR and the presence of compensatory saccades elicited by rapid head impulses were measured using the video head impulse test (vHIT).

RESULTS

The study included 31 subjects (mean age: 59 years). Functional Level Scale (FLS) distributions were 35,5% (FLS3); 32,2% (FLS4); and 32,2% (FLS5). Mean follow-up was 21 ± 7 months. Multiple injections were needed in nine patients. VOR gain in the treated ear was significantly reduced in all subjects and for all the semicircular canals (paired samples t test; P < 0,05). Gain averages after treatment were 0,61 (superior); 0,69 (horizontal); and 0,47 (posterior). A horizontal canal VOR gain superior to 0,80 after treatment was associated with the need for a second gentamicin injection (Chi-square; P = 0,003). Gain asymmetry between the symptomatic and asymptomatic ear (GASM) was increased after treatment. The rate of vestibular function reduction was 47,9%; 26,0%; and 35,8% for the superior, horizontal, and posterior canals, respectively. According to the receiving operator characteristic curve, the amount of change in GASM must be greater than 7 in order to predict the avoidance of a second procedure (area under the curve [AUC] horizontal canal = 0,861) and the amount of vestibular function reduction in the pathologic ear in patients with a controlled disease must be greater than 17,8% (AUC horizontal canal = 0,843).

CONCLUSIONS

When evaluated with the vHIT, intratympanic gentamicin changes in VOR seem to foresee short-term control of vertigo attacks.

LEVEL OF EVIDENCE

4.

The vestibulo-ocular reflex assessment in patients with Ménière's disease: examining all semicircular canals

Abstract Conclusion: The distribution of abnormal results is not uniform between different canals in each patient; the most frequent gain reduction is obtained for the posterior canal. Gain reduction reflects the disease duration and amount of hearing loss.

OBJECTIVE

To test the hypothesis that the vestibulo-ocular reflex (VOR) evoked after stimulation of each semicircular canal behaves in a different manner in patients with unilateral definite Ménière's disease.

METHODS

We studied the VOR evoked by rapid head-impulses in the plane of the 6 semicircular canals in 36 patients. It was evaluated with a video system that analyzes the head and eye velocity and the gain was the objective measure.

RESULTS

In 12 (33.3%) patients the examination of both ears was normal for all the semicircular canals, in 12 patients the results from the affected ear were abnormal in at least 1 of the semicircular canals, in 11 (30.5%) patients the results were abnormal in at least 1 of the semicircular canals in both the affected and unaffected ears, and in 1 (2.9%) patient the results were abnormal only in the unaffected ear. The most frequent abnormal result was obtained from the posterior canal of the affected ear and from the coupled superior canal of the unaffected ear. The distribution of abnormal findings was dependent on the disease duration and hearing loss.

Vestibulo-ocular reflex in patients with superior semicircular canal benign paroxysmal positional vertigo (BPPV)

CONCLUSION

The function of all the semicircular canals in patients with idiopathic benign paroxysmal positional vertigo (BPPV) in whom otoconial debris is located in the superior semicircular canal (SSC) is normal.

OBJECTIVE

BPPV of SSC is an infrequent entity in which otoconial debris evokes vertigo and nystagmus in the head-hanging position and during anterior flexion of the patient.

METHODS

We studied the vestibulo-ocular reflex (VOR) in 12 patients with this particular type of BPPV. The reflex was evoked by rapid head impulses in the plane of the three semicircular canals in the affected and the normal ear. The reflex was evaluated with a video system that analyzes the head and eye velocity: the gain (the relation between both magnitudes) was the objective measure.

RESULTS

The mean gain of VOR was within normal limits for the six semicircular canals and there were no significant differences between the same canals on each side of patients with BPPV in whom canalolithiasis was located in the SSC. However, gain asymmetry was different for each pair of canals.

Clinical and video-assisted examination of the vestibulo-ocular reflex: a comparative study

INTRODUCTION

The assessment of the vestibulo-ocular reflex (VOR) is one of the main steps in clinically evaluating patients with dizziness. It can be performed at the bedside with common head-impulse test in which eye position is analysed at the end of the head-thrust. It is an important test due to its high specificity but low sensitivity.

MATERIAL AND METHODS

We studied 179 patients with different types of balance- affecting disorders. The results were analysed in contingency tables. The clinical test was classified as normal or abnormal according to the absence or existence, respectively, of fixation saccades once the head-thrust was ended. The video head-impulse test (vHIT) was classified according to vestibulo-ocular reflex (VOR) gain and presence of fixation saccades. The speed of the slow phase of spontaneous nystagmus was also quantified, as well as the caloric test results.

RESULTS

There were significant differences (Chi-square test, P=0.00) for the findings in the clinical evaluation and with the vHIT: 32.1% of the tests performed yielded different findings in both tests. In the vHIT, the differences were due to the finding of normal gain with saccades; in these patients, the mean canal paresis was significantly abnormal: 39% ± 10%.

CONCLUSIONS

The distribution of findings for the VOR bedside examination and for that with the help of a video system are significantly different; as such, the video head-impulse examination is not simply an added VOR detection and registration system. The difference relies mainly on a vHIT response characterised as of normal gain but with fixation saccades. These have been considered as the cause for the low sensitivity of the bedside VOR examination and sometimes regarded as normal responses; we have demonstrated that these findings are abnormal according to the findings of higher canal paresis in the caloric test.

[Orthostatic tremor inducing instability]

Orthostatic tremor (OT) is a neurological disease of unknown aetiology. It is defined by the presence of a 10-20 Hz tremor in the legs while standing still. Symptoms described are dizziness and instability that diminish if the patient sits down or leans on something; drinking small amounts of alcohol significantly reduces OT. Due to the dizziness and/or unsteadiness, these patients are usually referred to the neuro-otology department. We report 4 cases diagnosed with OT. The diagnosis of OT should be considered for patients with instability. The clinical history is a key factor to suspect this entity, and the diagnosis is given by the register of 10-20 Hz contractions on limb electromyography. Treatment for this disease consists of medical treatment; the first option is clonazepam.