Occlusion of the Lateral Semicircular Canal, Endolymphatic Sac Surgery, and Cochlear Implantation: A Low Destructive Treatment for Unilateral Ménière's Disease and Deafness.

INTRODUCTION: Surgical treatment of Ménière's disease (MD) and deafness aims to treat vertigo and hearing disabilities. Current treatment options like labyrinthectomy and cochlear implantation (CI) have shown acceptable results but are destructive. Less destructive procedures, like the occlusion of the lateral semicircular canal and endolymphatic sac surgery, have been shown to be successful in vertigo control. The combination of both procedures with CI has not been investigated; therefore the objective of this study was to investigate the outcome of this combination in patients with single-sided MD and moderately severe to complete sensorineural hearing loss. METHODS: In this retrospective study, 10 patients with single-sided MD and moderately severe to complete sensorineural hearing loss were included. In all of them, a single-staged surgery, which consisted of CI, endolymphatic sac surgery, and occlusion of the lateral semicircular canal, was performed. The surgery was performed after a failed conservative therapy trial. The clinical outcome was evaluated by the Dizziness Handicap Inventory (DHI) and audiological tests. These were assessed preoperatively, 3 and 6 months after surgery. An MRI with a hydrops sequence was performed to support the clinical diagnosis. RESULTS: After the combined surgery, the mean DHI testing improved significantly from 71 to 30. Mean audiological monosyllabic speech testing outcome with the cochlea implant was 65% at 65 dB. The residual hearing of 2 patients could be preserved after the surgical procedure. CONCLUSION: The combination of occlusion of the lateral semicircular canal, endolymphatic sac surgery, and CI is an efficient low traumatic treatment for patients with a single-sided MD and moderately severe to complete sensorineural hearing loss.

Superior semicircular canal dehiscence postoperative outcomes: a case series of 350 repairs.

BACKGROUND: Superior Semicircular Canal Dehiscence (SSCD) is a dehiscence of the otic capsule which normally lies over the superior semicircular canal. This database constitutes the largest series of SSCD patients to date. OBJECTIVE: To determine what preoperative factors, if any, contribute to postoperative outcomes and evaluate symptom resolution in a large SSCD patient cohort. METHODS: A single-institution, retrospective chart review collected patient demographics, intraoperative findings, and pre-and postoperative symptoms. Fisher's exact t-test was performed for unpaired categorical variables, with a significance level of p < 0.05. RESULTS: 350 SSCD repairs were performed. The median age was 52 years (range: 17-86 years, ± 6.4 years), and the median follow-up duration was 4.6 months (range: 0.03-59.5 months, ± 6.8 months). Preoperative hearing loss was significantly associated with female sex (p = 0.0028). The most reported preoperative symptoms were tinnitus (77.4%), dizziness (74.0%), autophony (66.3%), amplification (63.7%), and disequilibrium (62.6%). Between patients who received unilateral versus bilateral SSCD repair, the greatest postoperative symptomatic resolution was seen in autophony (74.9%, p < 0.001), amplification (77.3%, p = 0.00027), hyperacusis (77.4%, p = 0.023), hearing (62.9%, p = 0.0063), and dizziness (54.6%, p < 0.001) for patients with unilateral SSCD repair. CONCLUSION: Surgical repair via the middle cranial fossa approach can significantly resolve auditory, vestibular, and neurological symptoms of patients with SSCD. Although this is one of the largest single-institution SSCD studies to date, future multi-institutional, prospective studies would be beneficial to validate these results.

Evaluation of clinical predictors of postoperative outcomes in tegmen defect patients with and without concurrent superior semicircular canal dehiscence and cerebrospinal fluid leak.

OBJECTIVES: Tegmen and superior semicircular canal defects have been well studied, yet the factors contributing to their onset and progression are widely debated. The clinical utility of intraoperative intracranial pressure measurements has yet to be tested. This report aims to use intraoperative opening pressure and concurrent superior semicircular canal dehiscence (SSCD) to analyze factors influencing disease course and clinical outcomes in patients with tegmen dehiscence. METHODS: A retrospective analysis of 61 patients who underwent tegmen defect repair was performed. Multiple variables of interest including body mass index (BMI), presence of SSCD, presence of dural venous sinus stenosis, opening pressure, and acetazolamide therapy use were recorded. The cohort was divided into those with or without concurrent SSCD and those presenting with or without cerebrospinal fluid (CSF) leak for analysis. RESULTS: A linear relationship between opening pressure and BMI (p = 0.009) was noted; however, intraoperative opening pressure was not associated with disease outcome. Concurrent SSCD was present in 25 % of patients, while 62 % presented with CSF leak. The concurrent SSCD group exhibited higher opening pressure, higher likelihood of having dural sinus stenosis, and higher likelihood of being discharged on acetazolamide. The CSF leak group had higher likelihood of obstructive sleep apnea and persistent symptoms. CONCLUSIONS: In patients undergoing tegmen defect repair, concurrent SSCD suggests increased disease severity. The presence of preoperative CSF leak predicts persistent symptoms following repair. BMI is linearly correlated with intracranial pressure in these patients.

Impact of superior semicircular canal dehiscence on cochlear implant audiologic outcomes.

PURPOSE: Determine whether adult cochlear implant users with radiographic superior semicircular canal dehiscence experience clinically significant differences in audiological outcomes when compared to cochlear implant users with normal temporal bone anatomy. MATERIALS AND METHODS: Retrospective, single institution review. Adult, post-lingual deaf patients implanted between 2010 and 2020. Inclusion criteria included age 18 years or older, available preoperative computed tomography imaging, and preoperative and postoperative AzBio audiological data for at least 6 months of cochlear implant use. Preoperative and postoperative AzBio Sentence Test scores were compared between patients with normal temporal bone anatomy and those with radiographic superior semicircular canal dehiscence or near dehiscence. RESULTS: 110 patients met inclusion criteria. Mean AzBio score for normal temporal bone anatomy group improved from 35.2 % (SD 28.2) preoperatively to 70.3 % (SD 25.7) postoperatively, an improvement of 35.1 % (SD 28.6). Mean AzBio score for near dehiscent temporal bone anatomy group improved from 26.6 % (SD 28.9) preoperatively to 64.5 % (SD 30.6) postoperatively, an improvement of 37.9 % (SD 27.9). Mean AzBio score for dehiscent temporal bone anatomy group improved from 26.3 % (SD 20.4) preoperatively to 65.1 % (SD 27.6) postoperatively, an improvement of 38.7 % (SD 26.9). Utilizing the one-way analysis of variance test, there was no significant difference in audiologic outcomes between the three groups. CONCLUSIONS: Patients with complete or near complete radiographic superior canal dehiscence at the time of cochlear implantation achieve similar improvements in speech perception scores compared to normal anatomy adult cochlear implant users.

Surgical decision-making in superior canal dehiscence syndrome with concomitant otosclerosis.

OBJECTIVE: The diagnosis and management of Superior Canal Dehiscence Syndrome (SCDS) with concomitant otosclerosis can be a challenge. Otosclerosis can mask SCDS symptoms and stapes surgery may reveal or exacerbate vestibular symptoms. Our aim is to present four cases of SCDS with concomitant otosclerosis and thereby informing the reader about the possibility of this dual occurrence and its implications for treatment. CASES: Four patients with SCDS and concomitant otosclerosis are presented. Two patients underwent surgical treatment for both SCDS and otosclerosis and two patients opted for conservative management. OUTCOMES: The main differences between surgically and non-surgically treated cases are the presence of autophony and pressure-induced vertigo and a more severe experience of symptoms in surgically treated cases. Surgically treated cases achieved a sizeable reduction in postoperative air-bone gap and resolution of vestibular symptoms. CONCLUSION: The subjective severity of symptoms in combination with shared decision-making is key in determining the appropriate treatment plan for SCDS and concomitant otosclerosis.

Trans-mastoid plugging of superior semicircular canal dehiscence: long-term follow-up.

OBJECTIVE: To evaluate the long-term outcomes of trans-mastoid plugging of superior semicircular canal dehiscence (SSCD), focusing on complicated cases. METHODS: In this cohort study, we included all patients who underwent trans-mastoid plugging of SSCD between 2009 and 2019. We evaluated the symptoms (autophony, sound-/pressure-induced vertigo, disequilibrium, aural fullness and pulsatile tinnitus) before and 1 year after surgery in the medical records. We systematically assessed the current symptoms 6.2 ± 3 years postoperative (range 2.2-12.3 years) using questionnaires sent by post and validated by telephone interviews. We also documented any complications and the need for further procedures. We compared pure tone and speech audiometry before and 1 year after surgery. Finally, the degree of mastoid pneumatisation and mastoid tegmen anatomy were reviewed on preoperative CT scans. RESULTS: We included 24 ears in 23 patients. No complications were recorded, and none required a second procedure for SSCD. Following surgery, oscillopsia and Tullio phenomena resolved in all patients. Hyperacusis, autophony, and aural fullness were also settled in all patients except one. Balance impairment persisted to some degree in 35% of patients. No deterioration over the years was reported regarding the above symptoms. On average, bone conduction pure tone average pre- and 1 year postoperative were 13.7 ± 17 and 20.5 ± 18 dB, respectively (P = 0.002). Air bone gaps were reduced from 12.7 ± 8 to 5.9 ± 6 (P = 0.001). Two patients had a significant sclerotic mastoid, three had a prominent low-lying mastoid tegmen, and two had both. Anatomy had no effect on outcome. CONCLUSION: Trans-mastoid plugging of SSCD is a reliable and effective technique which achieves long-lasting symptom control, even in cases with sclerotic mastoid or low-lying mastoid tegmen.

Treatment of Meniere's disease with simultaneous triple semicircular canal occlusion and cochlear implantation.

OBJECTIVE: Report three cases of simultaneous triple semicircular canal occlusion (TSCO) and cochlear implantation (CI) as the treatment of intractable Meniere's disease (MD). CASE REPORTS: Patients with MD can present occasionally with intractable vertigo and profound sensorineural hearing loss (SNHL). TSCO and CI have been proposed to control vertigo and restore profound deafness in patients with MD separately. However, a few studies have reported simultaneous TSCO and CI in the same surgical procedure for the treatment of MD. In the present study, we described three patients with MD showing incapacitating vertigo and severe SNHL who underwent simultaneous TSCO and CI after examinations of auditory system, vestibular system, and imaging. Their symptoms were significantly alleviated during the follow-up period. CONCLUSION: The combined TSCO and CI remains a viable treatment option which is effective for the control of vertigo as well as the restoring of hearing in patients with MD.

Ankle Audiometry: A Clinical Test for the Enhanced Hearing Sensitivity for Body Sounds in Superior Canal Dehiscence Syndrome.

INTRODUCTION: The aim of this study was to develop a clinical test for body sounds' hypersensitivity in superior canal dehiscence syndrome (SCDS). METHOD: Case-control study, 20 patients affected by SCDS and body sounds' hypersensitivity and 20 control matched subjects tested with a new test called ankle audiometry (AA). The AA consisted of a psychoacoustic hearing test in which the stimulus was substituted by a controlled bone vibration at 125, 250, 500, and 750 Hz, delivered at the medial malleolus by a steel spring-attached bone transducer prototype B250. For each subject, it was defined an index side (the other being non-index), the one with major symptoms in cases or best threshold for each tested frequency in controls. In 3 patients, the AA was measured before and after SCDS surgery. RESULTS: The AA thresholds for index side were significantly lower in SCDS patients (115.6 ± 10.5 dB force level [FL]) than in control subjects (126.4 ± 8.56 dB FL). In particular, the largest difference was observed at 250 Hz (-16.5 dB). AA thresholds in patients were significantly lower at index side in comparison with non-index side (124.2 ± 11.4 dB FL). The response obtained with 250 Hz stimuli outperformed the other frequencies, in terms of diagnostic accuracy for SCDS. At specific thresholds' levels (120 dB FL), AA showed relevant sensitivity (90%) and specificity (80%) for SCDS. AA did not significantly correlate to other clinical markers of SCDS such as the bone and air conducted hearing thresholds and the vestibular evoked myogenic potentials. The AA thresholds were significantly modified by surgical intervention, passing from 119.2 ± 9.7 to 130.4 ± 9.4 dB FL in 3 patients, following their relief in body sounds' hypersensitivity. CONCLUSION: AA showed interesting diagnostic features in SCDS with significantly lower hearing thresholds in SCDS patients when compared to healthy matched subjects. Moreover, AA could identify the affected or more affected side in SCDS patients, with a significant threshold elevation after SCDS surgery, corresponding in body sounds' hypersensitivity relief. Clinically, AA may represent a first objective measure of body sounds' hypersensitivity in SCDS and, accordingly, be an accessible screening test for SCDS in not tertiary audiological centers.

What is the most important factor to preserve hearing in lateral semicircular canal fistula surgeries, fistula size or bony structure?

PURPOSE: Cholesteatoma on lateral semicircular canal (LSCC) fistula > 2 mm in size is likely to be unmanipulated due to the risk of sensorineural hearing loss. However, the matrix can be successfully removed without hearing loss when it is > 2 mm. The purpose of the study was to evaluate surgical experience over the past 10 years and to suggest the important factor for the hearing preservation in LSCC fistula surgeries. METHODS: According to the fistula size and symptoms, 63 patients with LSCC fistula were grouped as follows: Type I (fistula < 2 mm), Type II (≥ 2 mm and < 4 mm without vertigo), Type III (≥ 2 mm and < 4 mm with vertigo), Type IV (≥ 4 mm), and Type V (any size fistula but with deafness at the initial visit). The cholesteatoma matrix was meticulously manipulated and removed by experienced surgeons. RESULTS: Only two patients completely lost their hearing after surgery (4.5%). However, the loss was inevitable because their cholesteatomas were highly invasive and there was also facial nerve canal involvement; thus, the bony structure of the LSCC was already destroyed by the cholesteatoma. Unlike these two Type IV patients, Type I-III patients, and those with a fistula size < 4 mm, did not lose their sensorineural hearing. If the structure of the LSCC was maintained, hearing loss did not occur even if the fistula size ≥ 4 mm. CONCLUSIONS: The preservation of the labyrinthine structure is more important than the defect size of the LSCC fistula. If the structure is intact, cholesteatoma matrices lying on the defect can be safely removed, even though the size of bony defect is large.

[Superior semicircular dehiscence syndrome]. / Dehiszenzsyndrom des oberen Bogengangs.

Disorders of the equilibrium have a variety of etiologies and are common reasons for medical consultations. A thorough diagnostic workup is mandatory. A dehiscent superior semicircular canal may be a rare, but characteristic situation which is responsible for specific symptoms and clinical findings. Typical are sound and/or pressure induced vertigo, autophonia, pulsatile tinnitus, hyperacusis and aural fullness. High resolution CT-scan of the temporal bone reveals a missing bony cover over the superior semicircular canal such causing a third "mobile window". Besides patients' counselling plugging and/or resurfacing via a transmastoid or transtemporal approach may be therapeutic options.

"Sandwich technique" enables preservation of hearing and antivertiginous effect in cholesteatomatous labyrinthine fistula.

PURPOSE: The aim of the study was to assess hearing, surgical and clinical results of the treatment in patients with cholesteatomatous labyrinthine fistula (LF) focusing on the different techniques and materials used in the management. METHODS: Study group included 465 patients. Cases with LFs discovered or confirmed during surgical procedure were thoroughly analyzed. RESULTS: LFs were noted in 11.4% of all cases. Thirty-eight patients, with all follow-up data available, were included into the further analysis. Most LFs were located in the lateral semicircular canal (87%). LFs were assessed as small in 2 cases, as medium in 24 patients while 12 were described as large. Based on Dornhoffer and Milewski classification, 50% of LFs were classified as IIa, 24% as IIb, 6 LFs were very deep (type III), while 4-superficial (type I). The size and type of LF did not influence postsurgical complaints (p = 0.1070, p = 0.3187, respectively). Vertigo was less frequent in LFs treated by "sandwich technique", especially those with opened endosteum. In 30 (79%) patients, hearing improved or did not change after surgery. Hearing outcomes were significantly better in the ears operated by means of CWU technique (p = 0.0339), in LFs with intact membranous labyrinth (p = 0.0139) and when "sandwich technique" was performed (p = 0.0159). Postsurgical bone conduction thresholds levels were significantly better in LFs covered by "sandwich method" (p = 0.0440). CONCLUSION: "Sandwich technique" (temporal fascia-bone pate-temporal fascia) enables preservation of hearing as well as antivertiginous effect in patients with cholesteatomatous labyrinthine fistula.

Evaluation of the transmastoid plugging approach for superior semicircular canal dehiscences: a retrospective series of 30 ears.

PURPOSE: The classical surgical approach for superior semicircular canal dehiscences (SSCD) is via the extradural middle cranial fossa. This pathway is used to resurface or to plug the SSC. In this paper, we present long-term data on an alternative route: the transmastoid pathway. The predictive factors for a successful surgery are equally presented in this paper. METHODS: Thirty reports of patients operated between September 2007 to January 2020 were analysed. SSCD was confirmed by the association of concordant complaints, audiometric data, cervical vestibular evoked myogenic potentials (cVEMP) responses and computerized tomography findings. Before and after surgery, the following factors were analysed: auditory and vestibular subjective symptoms, Tullio phenomenon, pure-tone audiometry thresholds for air and bone conduction, air-bone gap, cVEMP threshold, and computerized tomography data, for instance the size of the dehiscence. RESULTS: The follow-up is 21 months on average. The transmastoid approach significantly improves all symptoms (although there were less probing results for the vestibular symptoms). Objectively, we can observe, a closure of the audiometric air-bone gap on the low frequencies and an improvement in the cVEMP. The only correlation that was identified was between the preoperative cVEMP results and the postoperative air conduction. CONCLUSIONS: The originality of this study is the long postoperative follow-up. It allowed us to evaluate the symptoms in the long term and to determine a predictive factor of postoperative complication, which has not yet been described until today.The transmastoid plugging technique is safe and effective. Additional long-term data with a larger cohort are needed to confirm our results and correlation studies.

Decompression of the geniculate ganglion and labyrinthine segments of the facial nerve through a middle cranial fossa approach using an ultrasonic surgical system: an anatomic study.

PURPOSE: The aim of this study is to evaluate the feasibility and the safety of a novel, alternative method for bone tissue management in facial nerve decompression by a middle cranial fossa approach. Several applications of Piezosurgery technology have been described, and the technique has recently been extended to otologic surgery. The piezoelectric device is a bone dissector which, using micro-vibration, preserves the anatomic integrity of soft tissue thanks to a selective action on mineralized tissue. METHODS: An anatomic dissection study was conducted on fresh-frozen adult cadaveric heads. Facial nerve decompression was performed by a middle cranial fossa approach in all specimens using the piezoelectric device under a surgical 3D exoscope visualization. After the procedures, the temporal bones were examined for evidence of any injury to the facial nerve or the cochleovestibular organs. RESULTS: In all cases, it was possible to perform a safe dissection of the greater petrosal superficial nerve, the geniculate ganglion, and the labyrinthine tract of the facial nerve. No cases of semicircular canal, cochlea, or nerve damage were observed. All of the dissections were carried out with the ultrasonic device without the necessity to replace it with an otological drill. CONCLUSION: From this preliminary study, surgical decompression of the facial nerve via the middle cranial fossa approach using Piezosurgery seems to be a safe and feasible procedure. Further cadaveric training is recommended before intraoperative use, and a wider case series is required to make a comparison with conventional devices.

Three-dimensional imaging for the localization of related anatomical structures during surgery on the internal auditory canal.

BACKGROUND: The Fisch infra-temporal fossa approach (Fisch's method), first proposed in 1970, is commonly used during internal auditory canal (IAC) surgery with an approach that advances through the middle cranial fossa. This study was designed to address the technical difficulties encountered in recognizing and localizing the arcuate eminence with respect to the superior semicircular canal (SSC). METHODS: Forty men and 40 women (18-57 years of age) without space-occupying lesions in the petrous part of the temporal bone were selected for the study. In total, 160 samples were obtained from both sides of the temporal bone. The temporal bone in these 160 samples was scanned using computed tomography, and a three-dimensional coordinate system was established to measure the three-dimensional coordinate values of structures adjacent to the arcuate eminence, the SSC, and the IAC. RESULTS: The results showed that the shape of the arcuate eminence is highly variable. Approximately 23.12% of samples had no obvious arcuate eminence, which prevented the use of Fisch's method to localize the SSC. The arcuate eminence was difficult to identify in 37 samples. CONCLUSIONS: Analysis samples showed that the SSC was located in a fan ring centered at the midpoint of the upper edge of the petrous portion of the temporal bone. The arcuate eminence did not correspond directly with the SSC, as the former was located posterolateral to the latter in 85.83% of samples. The angle between the SSC and the IAC ranged from 0° to 60° degrees, as reported previously by Fisch. However, the angle typically ranged from 10-30° in our study.

Outcomes after mini-craniotomy middle fossa approach combined with mastoidectomy for lateral skull base defects.

PURPOSE: Controversy exists regarding the ideal approach for repair of lateral skull base defects. Our goal is to report the outcomes following middle cranial fossa (MCF) mini-craniotomy combined with mastoidectomy for patients with superior semicircular canal dehiscence (SSCD), spontaneous cerebrospinal fluid (CSF) leak, and cholesteatoma. MATERIALS AND METHODS: A retrospective database from chart review was formed consisting of 97 patients who met surgical criteria: SSCD, spontaneous CSF leak, and cholesteatoma. Mini-craniotomy MCF approach (<4 × 2 cm in size) combined with mastoidectomy was performed. All patients were admitted directly to the ICU postoperatively. Multiple factors were assessed, including need for revision surgery, duration of surgery, length of post-operative stay, and hospital readmission. RESULTS: Average surgery time was 110 min with no intraoperative complications. The average length of hospitalization was 2 days with an average ICU stay of 1 day. There were no neurologic complications; however, there were 3 inpatient complications (3%) which included 1 patient (1%) that had wound breakdown and 2 patients (2%) that had severe post-operative vertigo. A total of 8 patients (8%) required revision surgery and these were primarily for SSCD. The 30-day readmission rate was 3%. CONCLUSION: In the current series, all patients that underwent mini-craniotomy MCF surgery combined with mastoidectomy had minimal complications, short surgical time, limited hospital stay, low revision surgery rate and few hospital readmissions. This combined approach offers superior visualization of lateral skull base defects without the morbidity and risk typically associated with traditional, extensive MCF surgery.

A case of perilymphatic fistula caused by surgical drilling with preserved normal hearing.

We introduce our horrible experience of lateral semicircular canal exposure due to unintended drilling during left facial nerve decompression. Nearly half of the canal was drilled-out, however, the membranous labyrinth was preserved and the defect was covered with temporal fascia. Immediately after surgery, the patient complained of vertigo with right beating nystagmus. However, the patient could hear an audible tuning fork sound and the Weber-test showed left-sided deviation. The vertigo gradually subsided and the facial palsy was completely recovered 3 months after the surgery. One and half years later, the patient spent a normal life with normal hearing nevertheless after this terrifying episode.

Transcanal endoscopic management of lateral semicircular canal fistula: preliminary experience.

INTRODUCTION: Labyrinthine fistula is one of the most frequent complications of cholesteatoma (CHO), occurring in about 8% of cases in the literature. In about 90% of cases, it is located at the level of the lateral semicircular canal, and its clinical manifestation includes vertigo, nystagmus and positive Hennebert and Tullio signs. The management of lateral semicircular canal fistula (LSCF) secondary to CHO classically requires a retroauricular access by performing a canal wall-up (CWU) or canal wall-down (CWD) mastoidectomy. However, in case of a CHO confined to the tympanic cavity causing a LSCF on the ampullar arm, a transcanal exclusive endoscopic approach could be considered. AIMS: The aim of this study is to describe the feasibility of a transcanal exclusive endoscopic approach in the management of a CHO confined to the tympanic cavity causing a LSCF on the ampullar arm. METHODS: From January 2019 to December 2020, three patients with LSCF secondary to mesotympanic CHO underwent transcanal exclusive endoscopic ear surgery repair at the Department of Otolaryngology-Head and Neck Surgery, University Hospital of Modena, Italy. RESULTS: This technique was successfully employed to treat LSCF in all three cases and was planned as a two-stage surgery, performing ossiculoplasty after 12-18 months. Functional outcomes were also satisfactory: complete eradication of CHO, hearing preservation and complete resolution of symptoms. CONCLUSIONS: In case of a CHO confined to the tympanic cavity causing an LSCF on the ampullar arm, a transcanal exclusive endoscopic approach could be considered as a feasible and safe technique.

Interactions between Auditory and Vestibular Modalities during Stimulation with a Combined Vestibular and Cochlear Prosthesis.

BACKGROUND: A combined vestibular and cochlear prosthesis may restore hearing and balance to patients who have lost both. To do so, the device should activate each sensory system independently. OBJECTIVES: In this study, we quantify auditory and vestibular interactions during interleaved stimulation with a combined 16-channel cochlear and 6-channel vestibular prosthesis in human subjects with both hearing and vestibular loss. METHODS: Three human subjects were implanted with a combined vestibular and cochlear implant. All subjects had severe-to-profound deafness in the implanted ear. We provided combined stimulation of the cochlear and vestibular arrays and looked for interactions between these separate inputs. Our main outcome measures were electrically evoked slow-phase eye velocities during nystagmus elicited by brief trains of biphasic pulse stimulation of the vestibular end organs with and without concurrent stimulation of the cochlea, and Likert scale assessments of perceived loudness and pitch during stimulation of the cochlea, with and without concurrent stimulation of the vestibular ampullae. RESULTS: All subjects had no auditory sensation resulting from semicircular canal stimulation alone, and no sensation of motion or slow-phase eye movement resulting from cochlear stimulation alone. However, interleaved cochlear stimulation did produce changes in the slow-phase eye velocities elicited by electrical stimulation. Similarly, interleaved semicircular canal stimulation did elicit changes in the perceived pitch and loudness resulting from stimulation at multiple sites in the cochlea. CONCLUSIONS: There are significant interactions between different sensory modalities during stimulation with a combined vestibular and cochlear prosthesis. Such interactions present potential challenges for stimulation strategies to simultaneously restore auditory and vestibular function with such an implant.

Quality of life outcomes after transmastoid plugging of superior semicircular canal dehiscence.

PURPOSE: This study was performed to evaluate the effectiveness and impact on quality of life in patients undergoing plugging of superior semicircular canal dehiscence using the transmastoid approach. MATERIALS AND METHODS: Retrospective chart review with prospective outcomes assessment, using validated quantitative scoring systems, was performed on 10 patients (23-76 years) who underwent transmastoid plugging of superior semicircular canal dehiscence between February 2014 and February 2018 at a tertiary referral center. Pre-operative and post-operative autophony and vertigo were measured by The Autophony Index and the Dizziness Handicap Index. Overall quality of life following intervention was measured by the Glasgow Benefit Inventory. Subjective improvement, audiological changes, and subjective quality of life changes were also recorded. RESULTS: A significant reduction in the total Dizziness Handicap Index was seen following transmastoid repair of superior semicircular canal dehiscence (p = 0.0078). This was also evident when subgroup analysis of the Dizziness Handicap Index was performed, as physical (p = 0.0273), emotional (p = 0.0078), and functional subgroups were all significantly reduced (p = 0.0117). Autophony was also significantly reduced following intervention (p = 0.0312). Overall quality of life was seen to be improved following surgery as measured by the Glasgow Benefit Inventory (p = 0.0345). CONCLUSION: Our data suggest that transmastoid plugging of a dehiscence in the superior semicircular canal is a safe and effective means of improving autophony, dizziness and overall quality of life in these patients. We believe that these results should be taken into consideration in discussions regarding surgical approach for patients who are contemplating this procedure.

Middle-ear cholesteatoma co-existing with labyrinthine fistula and vestibular schwannoma.

BACKGROUND: Many conditions, among them vestibular schwannoma and middle ear cholesteatoma with lateral semicircular canal destruction, may be associated with asymmetrical sensorineural hearing loss (SNHL) and vertigo. However, the probability that these two distinct disease entities causing the same symptoms occur in a single patient is very low, approximately 1 per 28 billion per 1 year. METHODS: We present the case of a 40-year-old male admitted to our clinic because of chronic middle ear inflammation with concomitant tinnitus vertigo, and deafness in the right ear. The patient was diagnosed with lateral semicircular canal fistula caused by middle-ear cholesteatoma and concomitant vestibular schwannoma. Canal wall-down surgery was carried out to remove the cholesteatoma, followed by gamma knife radiosurgery for the vestibular schwannoma. RESULTS: Vertigo and tinnitus resolved within 3 days after the ear surgery, and gamma knife treatment resulted in the complete involution of the vestibular schwannoma. The patient presented with completely dry middle-ear cavity and no recurrence of the cholesteatoma was observed during a 3-year follow-up. CONCLUSION: As the hereby reported condition is very rare, the results cannot be compared with any similar report published previously. Nevertheless, based on the outcome, the treatment strategy seems to be both reasonable and effective.