Optimizing vestibular implant electrode positioning using fluoroscopy and intraoperative CT imaging.

PURPOSE:  Vestibular implant electrode positioning close to the afferent nerve fibers is considered to be key for effective and selective electrical stimulation. However, accurate positioning of vestibular implant electrodes inside the semicircular canal ampullae is challenging due to the inability to visualize the target during the surgical procedure. This study investigates the accuracy of a new surgical protocol with real-time fluoroscopy and intraoperative CT imaging, which facilitates electrode positioning during vestibular implant surgery. METHODS:  Single-center case-controlled cohort study with a historic control group at a tertiary referral center. Patients were implanted with a vestibulocochlear implant, using a combination of intraoperative fluoroscopy and cone beam CT imaging. The control group consisted of five patients who were previously implanted with the former implant prototype, without the use of intraoperative imaging. Electrode positioning was analyzed postoperatively with a high-resolution CT scan using 3D slicer software. The result was defined as accurate if the electrode position was within 1.5 mm of the center of the ampulla. RESULTS: With the new imaging protocol, all electrodes could be positioned within a 1.5 mm range of the center of the ampulla. The accuracy was significantly higher in the study group with intraoperative imaging (21/21 electrodes) compared to the control group without intraoperative imaging (10/15 electrodes), (p = 0.008). CONCLUSION:  The combined use of intraoperative fluoroscopy and CT imaging during vestibular implantation can improve the accuracy of electrode positioning. This might lead to better vestibular implant performance.

[Management of patients with complex ear deformities]. / Prise en charge des patients présentant des déformations complexes du pavillon de l'oreille.

Complex ear reconstruction requires specialized multidisciplinary care. Most patients present with microtia, often associated with hearing disorders. The management of these disorders is a priority, and reconstruction of the external ear remains optional. Nowadays, auricular reconstruction is based on the subcutaneous implantation of either autologous cartilage or an allogeneic implant. Autologous reconstruction requires highly specialized surgical expertise and involves harvesting rib cartilage but carries a lower risk of exposure compared to allogeneic implants. Both techniques yield good results with a high success rate and have a positive impact on the social functioning and daily life of patients.

La reconstruction complexe du pavillon auriculaire nécessite une prise en charge multidisciplinaire spécialisée. La majorité des patients nécessitant ce geste présentent une microtie, souvent associée à des troubles de l'audition. La prise en charge de ceux-ci est prioritaire et la reconstruction du pavillon reste facultative. Aujourd'hui, la reconstruction du pavillon se base sur l'implantation sous-cutanée d'une maquette de cartilage autologue ou d'un implant allogène. La reconstruction autologue demande une expertise chirurgicale hautement spécialisée et nécessite un prélèvement de cartilage costal mais présente un risque d'exposition inférieur par rapport à l'implant allogène. Les deux techniques permettent d'atteindre de bons résultats avec un taux de réussite élevé et un effet positif sur le fonctionnement social et le quotidien des patients.

[Bullous myringitis demystified]. / La myringite bulleuse démystifiée.

Bullous myringitis - also called hemorrhagic myringitis or influenza otitis - is a vague entity, whose etiology and treatment are sources of controversy. In this review article, we demystify bullous myringitis in an illustrated way to recognize and treat it appropriately. Bullous myringitis seems to be a rare and peculiar manifestation of acute otitis media, which can be excessively painful and induce sensorineural hearing loss. Its management may be a medical emergency requiring the opening of hemorrhagic bullae and systemic corticotherapy. The responsible germs are the same as those found in acute otitis media (S. pneumoniæ, H. influenzæ, M. catarrhalis), and its treatment is identical, adapted to each clinical situation.

La myringite bulleuse ­ aussi appelée myringite hémorragique ou otite grippale ­ est une entité floue, dont l'étiologie et le traitement sont sources de controverse. Dans cet article de synthèse, nous démystifions la myringite bulleuse de façon illustrée, afin qu'elle puisse être reconnue et traitée adéquatement. La myringite bulleuse est une manifestation peu fréquente et particulière d'une otite moyenne aiguë, qui peut être excessivement douloureuse et entraîne volontiers une surdité neurosensorielle. Elle peut être une urgence médicale nécessitant l'ouverture des bulles et une corticothérapie systémique. Les germes responsables sont les mêmes que dans l'otite moyenne aiguë (S. pneumoniæ, H. influenzæ, M. catarrhalis) et son traitement identique, adapté à chaque situation clinique.

[Malignant external auditory canal tumors : management of a rare tumor]. / Tumeurs malignes du conduit auditif externe : prise en charge d'une tumeur rare.

Malignant tumors of the external auditory canal are rare tumors and very often diagnosed at an advanced stage due to non-specific symptoms. The best treatment is the radical surgery, eventually followed by radiotherapy. A multidisciplinary team is essential to realize an optimal management. Prognosis remains unfavorable for advanced tumors.

Les tumeurs malignes du conduit auditif externe (CAE) sont rares et leur diagnostic est souvent retardé en raison de symptômes peu spécifiques. Le traitement de choix consiste en une chirurgie radicale, éventuellement suivie d'une radiothérapie. Une équipe multidisciplinaire est indispensable pour une prise en charge optimale. Le pronostic reste défavorable dans les tumeurs avancées.

Optimized Signal Analysis to Quantify the Non-Linear Behaviour of the Electrically Evoked Vestibulo-Ocular Reflex in Patients with a Vestibular Implant.

INTRODUCTION: Different eye movement analysis algorithms are used in vestibular implant research to quantify the electrically evoked vestibulo-ocular reflex (eVOR). Often, standard techniques are used as applied for quantification of the natural VOR in healthy subjects and patients with vestibular loss. However, in previous research, it was observed that the morphology of the VOR and eVOR may differ substantially. In this study, it was investigated if the analysis techniques for eVOR need to be adapted to optimize a truthful quantification of the eVOR (VOR gain, orientation of the VOR axis, asymmetry, and phase shift). METHODS: "Natural" VOR responses were obtained in six age-matched healthy subjects, and eVOR responses were obtained in eight bilateral-vestibulopathy patients fitted with a vestibular implant. Three conditions were tested: "nVOR" 1-Hz sinusoidal whole-body rotations of healthy subjects in a rotatory chair, "eVOR" 1-Hz sinusoidal electrical vestibular implant stimulation without whole-body rotations in bilateral-vestibulopathy patients, and "dVOR" 1-Hz sinusoidal whole-body rotations in bilateral-vestibulopathy patients using the chair-mounted gyroscope output to drive the electrical vestibular implant stimulation (therefore also in sync 1 Hz sinusoidal). VOR outcomes were determined from the obtained VOR responses, using three different eye movement analysis paradigms: (1) peak eye velocity detection using the raw eye traces; (2) peak eye velocity detection using full-cycle sine fitting of eye traces; (3) peak eye velocity detection using half-cycle sine fitting of eye traces. RESULTS: The type of eye movement analysis algorithm significantly influenced VOR outcomes, especially regarding the VOR gain and asymmetry of the eVOR in bilateral-vestibulopathy patients fitted with a vestibular implant. Full-cycle fitting lowered VOR gain in the eVOR condition (mean difference: 0.14 ± 0.06 95% CI, p = 0.018). Half-cycle fitting lowered VOR gain in the dVOR condition (mean difference: 0.08 ± 0.04 95% CI, p = 0.009). In the eVOR condition, half-cycle fitting was able to demonstrate the asymmetry between the excitatory and inhibitory phases of stimulation in comparison with the full-cycle fitting (mean difference: 0.19 ± 0.12 95% CI, p = 0.024). The VOR axis and phase shift did not differ significantly between eye movement analysis algorithms. In healthy subjects, no clinically significant effect of eye movement analysis algorithms on VOR outcomes was observed. CONCLUSION: For the analysis of the eVOR, the excitatory and inhibitory phases of stimulation should be analysed separately due to the inherent asymmetry of the eVOR. A half-cycle fitting method can be used as a more accurate alternative for the analysis of the full-cycle traces.

Sound localization in patients with bilateral vestibulopathy.

PURPOSE: The goal of this study was to evaluate if bilaterally (partially) absent vestibular function during static sound localization testing, would have a negative impact on sound localization skills. Therefore, this study compared horizontal static sound localization skills of normal-hearing patients with bilateral vestibulopathy (BV) and healthy controls. METHODS: Thirteen normal-hearing patients with BV and thirteen age-matched healthy controls were included. Sound localization skills were tested using seven loudspeakers in a frontal semicircle, ranging from - 90° to + 90°. Sound location accuracy was analyzed using the root-mean-square error (RMSE) and the mean absolute error (MAE). To evaluate the severity of the BV symptoms, the following questionnaires were used: Dizziness Handicap Inventory (DHI), Oscillopsia severity questionnaire (OSQ), 12-item Spatial, Speech, and Qualities Questionnaire (SSQ12), and Health Utilities Index Mark 3 (HUI3). RESULTS: The RMSE and MAE were significantly larger (worse) in the BV group than in the healthy control group, with respective median RMSE of 4.6° and 0°, and a median MAE of 0.7° and 0°. The subjective reporting of speech perception, spatial hearing, and quality of life only demonstrated a moderate correlation between DHI (positive correlation) and HUI total score (negative correlation), and localization scores. CONCLUSION: Static sound localization skills of patients with BV were only mildly worse compared to healthy controls. However, this difference was very small and therefore most likely due to impaired cognitive function. The vestibular system does not seem to have a modulating role in sound localization during static conditions, and its impact is negligible in contrast to the impact of hearing impairment. Furthermore, the subjective reporting of speech perception, spatial hearing, and quality of life was not strongly correlated with localization scores.

[Benign paroxysmal positional vertigo: diagnostic and therapeutic maneuvers]. / Vertige positionnel paroxystique bénin: manœuvres diagnostiques et thérapeutiques.

Benign paroxysmal positional vertigo (BPPV) is a very frequent cause of vertigo. BPPV occurs when there is a pathological presence of otolith debris in the semicircular canals. The history of BPPV is often typical, with recurrent episodes of vertigo lasting less than one minute, triggered by head movements, without other neurological signs. The characteristics of the nystagmus observed during the diagnostic maneuvers of Hallpike and Supine Head Roll test allow the identification of the affected semicircular canal and the choice of the appropriate therapeutic maneuver, which in most cases will lead to recovery. This article presents the diagnostic and therapeutic maneuvers.

Le vertige positionnel paroxystique bénin (VPPB) est une cause très fréquente de vertige. Le VPPB se produit en cas de présence pathologique de débris d'otolithes dans les canaux semi-circulaires (CSC). L'anamnèse du VPPB est souvent typique, à savoir des épisodes de vertige récidivants d'une durée de moins d'une minute, déclenchés par les mouvements de la tête, sans autre signe neurologique. Les caractéristiques du nystagmus observé lors des manœuvres diagnostiques de Dix-Hallpike et du Supine Head Roll Test permettent d'identifier le CSC atteint et d'opter pour la manœuvre thérapeutique adéquate, qui permettra dans la majeure partie des cas la guérison. Cet article présente les manœuvres diagnostiques et thérapeutiques.

[Smarter medicine in Otorhinolaryngology - Top 5 List]. / Smarter Medicine in der ORL.

Smarter medicine in Otorhinolaryngology - Top 5 List Abstract. Many diseases or symptoms with a high prevalence in the population, such as vertigo / dizziness, tinnitus, or sinusitis, but also nasal bone fractures and otitis externa, lead to a high number of visits to the physicians due to their frequency alone. Often, conventional X-rays (sinusitis, nasal bone fractures) or - in cases of vertigo and tinnitus - magnetic resonance imaging are ordered for further diagnostic clarification even though the benefit of theses is not generally given according to the current state of knowledge. The indication for imaging can be set much more restrictive after critical review of these clinical conditions without reducing the quality of treatment. The same applies to the usage of systemic antibiotics in uncomplicated otitis externa, which can be reduced without any problems. The extensive discussion of these issues within the Society of Otorhinolarnygology (SGORL) formed the basis for the creation of the Top 5 -list with its recommendations which are presented in detail below.

[Superior canal dehiscence syndrome]. / Syndrome de déhiscence du canal semi-circulaire supérieur.

Superior canal dehiscence syndrome is due to a defect in the bone coverage of this canal. The presence of this « third window ¼ alters the biomechanics of the inner ear and can induce cochleo-vestibular symptoms, most commonly bone conduction hyperacusis, autophony, pulsatile tinnitus, and pressure- or sound-induced vertigo. Although the etiology remains unknown, it could be congenital. Head trauma or a Valsalva maneuver may also trigger the symptoms. The diagnosis is based on the association of specific symptoms, a characteristic auditory and vestibular workup and the presence of a dehiscence on a high-resolution CT-scan. Management can be medical or surgical in selected cases.

Le syndrome de déhiscence du canal semi-circulaire supérieur est dû à un défaut de couverture osseuse de ce canal. La présence de cette « troisième fenêtre ¼ modifie la biomécanique de l'oreille interne et peut induire des symptômes cochléovestibulaires, le plus souvent une hyperacousie en conduction osseuse, une autophonie, un acouphène pulsatile et des vertiges induits par un changement de pression ou par des sons. Même si l'étiologie reste inconnue, elle pourrait être congénitale. Un traumatisme crânien ou une manœuvre de Valsalva peuvent aussi être à l'origine des symptômes. Le diagnostic est basé sur l'association de symptômes spécifiques, d'un bilan auditif et vestibulaire caractéristique et de la présence d'une déhiscence sur un CT-scan de haute résolution. La prise en charge peut, dans certains cas, être médicale ou chirurgicale.

[Treatment of single-sided deafness by cochlear implantation]. / Traitement de la surdité unilatérale par l'implant cochléaire.

Single sided deafness diminishes speech understanding in noise and sound localization and thereby globally auditory performance. Most patients also suffer from tinnitus and indicate reduced quality of life. Patients have the choice to adapt to the new situation without treatment, to restore pseudostereophonic hearing by contralateral routing of signal (CROS) hearing aids or to restore binaural hearing using a cochlear implant in the deaf ear. This article summarizes the physiological base of binaural hearing and treatment options for single sided deafness with a special emphasis on the cochlear implant.

La surdité unilatérale diminue la compréhension dans le bruit et la capacité de localiser les sources sonores affectant ainsi globalement la performance auditive. De plus, la qualité de vie est souvent impactée par la présence d'un acouphène dérangeant. Les patients ont le choix de s'adapter à la situation sans traitement ou de reconstituer une pseudo-stéréophonie à l'aide d'un appareillage qui transmet l'information auditive arrivant sur l'oreille sourde à l'oreille saine (Contralateral Routing of Signals (CROS)). L'implant cochléaire est une alternative récente qui permet de « réactiver ¼ l'oreille atteinte et de redonner ainsi une audition binaurale. Les différentes options de réhabilitation auditive en cas de surdité unilatérale en mettant l'accent sur l'implant cochléaire sont discutées à l'aide d'un cas clinique.

LARS2-Perrault syndrome: a new case report and literature review.

BACKGROUND: Perrault syndrome is a rare recessive and genetically heterogeneous disorder characterized by sensorineural hearing loss in males and females and gonadal dysgenesis in females. Mutations in seven different genes have been identified: HARS2, HSD17B4, CLLP, C10orf, ERAL1, TWNK and LARS2. To date, 19 variants have been reported in 18 individuals with LARS2-Perrault syndrome. CASE PRESENTATION: Here we describe the case of an 8-year-old girl with compound heterozygous missense mutations in the LARS2 gene. We identified two missense mutations [c.457A > C, p.(Asn153His) and c.1565C > A, p.(Thr522Asn)] and subsequent familial segregation showed that each parent had transmitted a mutation. CONCLUSIONS: These results have implications for genetic counseling and provide insight into the functional role of LARS2. This case highlights the importance of an early diagnosis. Systematic genetic screening of children with hearing loss allows the early identification of a Perrault syndrome in order to ensure specific endocrinological surveillance and management to prevent secondary complications. Clinical data are compared with the other cases reported in the literature.

Restoring the High-Frequency Dynamic Visual Acuity with a Vestibular Implant Prototype in Humans.

INTRODUCTION: The vestibular implant could become a clinically useful device in the near future. This study investigated the feasibility of restoring the high-frequency dynamic visual acuity (DVA) with a vestibular implant, using the functional Head Impulse Test (fHIT). METHODS: A 72-year-old female, with bilateral vestibulopathy and fitted with a modified cochlear implant incorporating three vestibular electrodes (MED-EL, Innsbruck, Austria), was available for this study. Electrical stimulation was delivered with the electrode close to the lateral ampullary nerve in the left ear. The high-frequency DVA in the horizontal plane was tested with the fHIT. After training, the patient underwent six trials of fHIT, each with a different setting of the vestibular implant: (1) System OFF before stimulation; (2) System ON, baseline stimulation; (3) System ON, reversed stimulation; (4) System ON, positive stimulation; (5) System OFF, without delay after stimulation offset; and (6) System OFF, 25 min delay after stimulation offset. The percentage of correct fHIT scores for right and left head impulses were compared between trials. RESULTS: Vestibular implant stimulation improved the high-frequency DVA compared to no stimulation. This improvement was significant for "System ON, baseline stimulation" (p = 0.02) and "System ON, positive stimulation" (p < 0.001). fHIT scores changed from 19 to 44% (no stimulation) to maximum 75-94% (System ON, positive stimulation). CONCLUSION: The vestibular implant seems capable of improving the high-frequency DVA. This functional benefit of the vestibular implant illustrates again the feasibility of this device for clinical use in the near future.

[ENT and head and neck manifestations of the IgG4-related disease]. / Atteintes de la sphère ORL et cervicofaciale dans la maladie à IgG4.

IgG4-related disease is a rare multi-organic inflammatory disease that frequently involves the ENT and head and neck areas. In these cases, salivary gland and lacrimal gland involvement is very common and includes enlargement, infiltration, and formation of pseudotumours. Diagnosis of IgG4 related disease remains a challenge and relies on several clinical, serological, radiological and histopathological criteria to differentiate from other diseases with similar clinical presentation. Histology reveals IgG4 positive lymphoplasmocytic infiltrates, storiform fibrosis and obliterative phlebitis. Glucocorticoids are the first line of treatment and can be combined with other immunosuppressants. The prognosis is favorable if treatment is initiated early. Recurrences are common. Delay in diagnosis can have severe multi-organic consequences.

Rare et encore peu connue, la maladie à immunoglobuline G4 (IgG4) est multiorganique et se manifeste fréquemment dans la sphère oto-rhino-laryngologique et cervico-faciale. Dans ces cas, les glandes lacrymales et salivaires sont les plus fréquemment touchées, présentant des tuméfactions, infiltrations et pseudotumeurs. Le diagnostic reste un défi ; il repose sur des critères cliniques, sérologiques, radiologiques et histopathologies qui visent à la distinguer des nombreuses maladies de présentations cliniques similaires. À l'histologie, on retrouve un infiltrat lymphoplasmocytaire riche en plasmocytes IgG4+, une fibrose storiforme et des phlébites oblitérantes. Les glucocorticoïdes sont la première ligne de traitement et peuvent être associés à d'autres immunosuppresseurs. Le pronostic est favorable si le traitement est initié rapidement. Les récidives sont courantes. Un retard diagnostique peut avoir des conséquences multiorganiques sévères.

[The Mal de Débarquement Syndrome]. / Syndrome du mal de débarquement.

The Mal de Débarquement Syndrome (MdDS) is characterized by a persistent (> 1 month) sensation of self-motion, most of the time initially motion-triggered (i.e. boat, car, airplane travel). The symptoms are markedly diminished during a new exposure to passive motion. Female are more often affected. The vestibular functional assessment and cerebral imaging are normal. Chronic fatigue, headache, hypersensitivity to visual stimuli are other classical features of MdDS. The impact of MdDS on quality of life is significant. Maladaptation of the vestibulo-ocular reflex, abnormal functional connectivity as well as gonadal hormones imbalance are possible causes of the MdDS. Exposure to optokinetic stimulations, and transcranial magnetic stimulations open therapeutic perspectives.

Le syndrome du mal de débarquement (MdDS) est caractérisé par la persistance d'une sensation de mouvement (> 1 mois), souvent suite à un déplacement en moyen de transport. Les symptômes sont nettement diminués lors d'une nouvelle exposition à un mouvement passif. Les femmes sont plus fréquemment atteintes. Le bilan fonctionnel vestibulaire et l'imagerie cérébrale sont normaux. La fatigue chronique, les céphalées, l'hypersensibilité aux stimuli visuels sont également caractéristiques du MdDS. L'impact sur la qualité de vie est significatif. Une mauvaise adaptation du réflexe vestibulo-oculaire, un trouble de la connectivité fonctionnelle ainsi qu'un dérèglement des hormones gonadiques pourraient être à l'origine du MdDS. L'exposition à des stimulations optocinétiques et la stimulation magnétique transcrânienne ouvrent des perspectives thérapeutiques.

[Menière's disease, endolymphatic hydrops and MRI]. / Maladie de Menière, hydrops endolymphatique et IRM.

Menière's disease is characterized by episodic vertigo associated with fluctuating hearing loss, tinnitus and fullness of the ear on the affected side. Endolymphatic space enlargement - or endolymphatic hydrops (EH) - is a histological hallmark of the disease that does not explain all its clinical manifestations. Magnetic resonance imaging improvements now allow in vivo visualization of inner ear liquid spaces and appreciation of potential EH. This article discusses these advances and their potential diagnostic implications in the context of Menière's disease and more generally in cochleovestibular disorders.

La maladie de Menière est caractérisée par des épisodes récidivants de vertige associés à des fluctuations de l'audition, des acouphènes et une sensation de plénitude dans l'oreille atteinte. Même s'il ne permet pas d'expliquer toutes les manifestations de la maladie, l'élargissement de l'espace endolymphatique ­ ou hydrops endolymphatique (HE) ­ en est une caractéristique histologique classique. Les progrès de l'imagerie par résonance magnétique permettent maintenant la visualisation in vivo des espaces liquidiens de l'oreille interne et l'appréciation d'un éventuel HE. Cet article traite de ces avancées et leurs potentielles implications diagnostiques dans le contexte d'une maladie de Menière et plus généralement dans les affections cochléovestibulaires.

Acute cortical deafness in a child with MELAS syndrome.

Auditory impairment in mitochondrial disorders are usually due to peripheral sensorineural dysfunction. Central deafness is only rarely reported. We report here an 11-year-old boy with MELAS syndrome who presented with subacute deafness after waking up from sleep. Peripheral hearing loss was rapidly excluded. A brain MRI documented bilateral stroke-like lesions predominantly affecting the superior temporal lobe, including the primary auditory cortex, confirming the central nature of deafness. Slow recovery was observed in the following weeks. This case serves to illustrate the numerous challenges caused by MELAS and the unusual occurrence of acute cortical deafness, that to our knowledge has not be described so far in a child in this setting.

[Vestibular and visual stimulation : simultaneous perception or not ?] / Stimulation vestibulaire et visuelle : perception simultanée ou pas ?

The human brain is able to consider that two sensory stimuli are synchronous while they activate the cortex with some delay because they follow different neurological pathways. This process is only possible if the time interval between the two stimuli does not exceed a certain limit, called "Temporal Binding Window" (TBW). Studies of this parameter, involving the vestibular perception, are difficult because subjects must be moved, which generates parasitic proprioceptive information. By cons, in patients equipped with a vestibular implant, it is possible to generate a vestibular perception selectively by electrical stimulation of the vestibular nerve. These patients are therefore an unique model to study the TBW between visual and vestibular perception.

Le cerveau humain est capable de considérer que deux stimuli sensoriels sont synchrones alors qu'ils activent le cortex avec un décalage temporel dû au fait qu'ils suivent des voies neurologiques différentes. Ce processus n'est possible que si l'intervalle de temps entre les deux stimuli ne dépasse pas un certain délai, qu'on appelle « Temporal Binding Window ¼ (TBW). Etudier ce paramètre en mettant en jeu la perception vestibulaire est difficile puisqu'il faut bouger le sujet et donc générer aussi des informations proprioceptives. Par contre, chez les patients porteurs d'un implant vestibulaire, il est possible de délivrer une perception vestibulaire de façon sélective par stimulation électrique du nerf vestibulaire. Ces patients représentent donc un modèle unique pour étudier le TBW entre les perceptions visuelle et vestibulaire.

Perception of Discomfort Caused by a Unilateral Hearing Loss in People Suffering from a Total Bilateral Vestibular Loss.

The quality of life of patients suffering from a bilateral vestibular loss is severely altered. Patients mainly complain of oscillopsia, imbalance, and spatial disorientation. Up to now, there is no efficient treatment. Some teams around the world are working on the development of a vestibular implant for the restoration of the vestibular function based on the concept similar to that of a cochlear implant, stimulating the neural vestibular pathways through electrical pulses. There are different potential stimulation sites of the vestibular system, all raising the major concern about a potential hearing loss in the implanted ear. As this implant does not exist yet, patients cannot be informed of the risk of hearing loss due to the surgical intervention versus the benefits brought by the vestibular prosthesis. In order to better inform future vestibular implant candidates, we need to evaluate the handicap of patients with an actual unilateral hearing loss, and to compare it to the way that patients suffering from a bilateral vestibular loss perceive a potential unilateral hearing loss. For this, we used the HHIA questionnaire (Hearing Handicap Inventory for Adults) on 3 groups of participants, i.e. patients with a unilateral hearing loss, patients suffering from a bilateral vestibular loss but having normal hearing, and healthy subjects. The scores reported by patients with a unilateral hearing loss were much lower than those of the other 2 groups, indicating that people whose hearing is normal overstate the disability related to a unilateral hearing loss. Patients to whom a vestibular implant is proposed in order to correct their balance disorders may use this information to decide whether or not to choose an operation.

Vestibular Implants: 8 Years of Experience with Electrical Stimulation of the Vestibular Nerve in 11 Patients with Bilateral Vestibular Loss.

BACKGROUND: The concept of the vestibular implant is primarily to artificially restore the vestibular function in patients with a bilateral vestibular loss (BVL) by providing the central nervous system with motion information using electrical stimulation of the vestibular nerve. Our group initiated human trials about 10 years ago. METHODS: Between 2007 and 2013, 11 patients with a BVL received a vestibular implant prototype providing electrodes to stimulate the ampullary branches of the vestibular nerve. Eye movements were recorded and analyzed to assess the effects of the electrical stimulation. Perception induced by electrical stimulation was documented. RESULTS: Smooth, controlled eye movements were obtained in all patients showing that electrical stimulation successfully activated the vestibulo-ocular pathway. However, both the electrical dynamic range and the amplitude of the eye movements were variable from patient to patient. The axis of the response was consistent with the stimulated nerve branch in 17 out of the 24 tested electrodes. Furthermore, in at least 1 case, the elicited eye movements showed characteristics similar to those of compensatory eye movements observed during natural activities such as walking. Finally, diverse percepts were reported upon electrical stimulation (i.e., rotatory sensations, sound, tickling or pressure) with intensity increasing as the stimulation current increased. CONCLUSIONS: These results demonstrate that electrical stimulation is a safe and effective means to activate the vestibular system, even in a heterogeneous patient population with very different etiologies and disease durations. Successful tuning of this information could turn this vestibular implant prototype into a successful artificial balance organ.

Gustatory Function in Patients With Cerebellopontine Angle Masses.

OBJECTIVE: To investigate the impact of cerebellopontine angle (CPA) masses on subjective and measured taste function. STUDY DESIGN: Retrospective cross-sectional study. SETTING: Tertiary referral center. PATIENTS: Consecutive adult patients with untreated CPA masses. INTERVENTIONS: Gustatory function was psychophysically measured with Taste Strips (range, 0-16) on both sides of the tongue. Subjective taste complaints were assessed using a questionnaire. MAIN OUTCOME MEASURES: Half-sided taste impairment (hemi-ageusia) was defined as side-to-side asymmetry ≥4 points with <9 points on the side of the CPA mass. We used the Koos classification for vestibular schwannomas (VS) and, in the case of facial nerve palsy, the House-Brackmann grading system. RESULTS: We included 135 patients (mean [standard deviation (SD)] age, 55.3 ± 14.1 yr; 62 males). The most common CPA mass was VS (77%). Overall, the measured taste function was lower on the affected compared with the healthy side of the tongue (mean score, 9.8 ± 3.3 versus 11 ± 2.9; p < 0.0001). Looking for clinically relevant one-sided taste impairment revealed 18 (13.3%) patients with hemi-ageusia, but only 4 (30.8%) of those subjectively complained of taste dysfunction. Regarding VS, Koos IV masses presented the lowest score on the affected side (mean score, 7.5 ± 3.7). Six patients presented with facial palsy. Having facial palsy did not result in a lower Taste Strips score (p = 0.23). CONCLUSION: Before any CPA mass treatment, a measurable ipsilateral decrease in gustatory function is present in many patients. Most patients do not notice this preexisting taste impairment. From a medicolegal standpoint, this warrants consideration. To avoid postoperative claims regarding taste function, a preoperative assessment may be considered.