Creation of an incus recess for a middle-ear microphone using a drill or laser ablation: a comparison of equivalent noise level and middle ear transfer function.

PURPOSE: Studies have assessed the trauma and change in hearing function from the use of otological drills on the ossicular chain, but not the effects of partial laser ablation of the incus. A study of the effectiveness of a novel middle-ear microphone for a cochlear implant, which required an incus recess for the microphone balltip, provided an opportunity to compare methods and inform a feasibility study of the microphone with patients. METHODS: We used laser Doppler vibrometry with an insert earphone and probe microphone in 23 ears from 14 fresh-frozen cadavers to measure the equivalent noise level at the tympanic membrane that would have led to the same stapes velocity as the creation of the incus recess. RESULTS: Drilling on the incus with a diamond burr created peak noise levels equivalent to 125.1-155.0 dB SPL at the tympanic membrane, whilst using the laser generated equivalent noise levels barely above the baseline level. The change in middle ear transfer function following drilling showed greater variability at high frequencies, but the change was not statistically significant in the three frequency bands tested. CONCLUSIONS: Whilst drilling resulted in substantially higher equivalent noise, we considered that the recess created by laser ablation was more likely to lead to movement of the microphone balltip, and therefore decrease performance or result in malfunction over time. For patients with greatly reduced residual hearing, the greater consistency from drilling the incus recess may outweigh the potential benefits of hearing preservation with laser ablation.

Comparison of an Implantable Middle Ear Microphone and Conventional External Microphone for Cochlear Implants: A Clinical Feasibility Study.

OBJECTIVES: All commercially available cochlear implant (CI) systems use an external microphone and sound processor; however, external equipment carries lifestyle limitations. Although totally implantable devices using subcutaneous microphones have been developed, these are compromised by problems with soft tissue sound attenuation, feedback, and intrusive body noise. This in vivo pilot study evaluates a middle ear microphone (MEM) that aims to overcome these issues and compares hearing performance with that of an external CI microphone. DESIGN: Six adult participants with an existing CI were implanted with a temporary MEM in the contralateral ear. Signals from the MEM were routed via a percutaneous plug and cable to the CI sound processor. Testing was performed in the CI microphone and MEM conditions using a range of audiometric assessments, which were repeated across four visits. RESULTS: Performance of the MEM did not differ significantly from that of the CI on the assessments of Auditory Speech Sounds Evaluation loudness scaling at either 250 or 1000 Hz, or in the accuracy of repeating keywords presented at 70 dB. However, the MEM had significantly poorer aided sound-field thresholds, particularly at higher frequencies (≥4000 Hz), and significantly poorer performance on Arthur Boothroyd words presented at 55 dB, compared with the CI. CONCLUSION: In this pilot study, the MEM showed comparable performance to that of an external CI microphone across some audiometric assessments. However, performance with the MEM was poorer than the CI in soft-level speech (55 dB) and at higher frequencies. As such, the benefits of MEM need to be considered against the compromises in hearing performance. However, with future development, MEM is a potentially promising technology.

Inappropriate Use of the "Rosowski Criteria" and "Modified Rosowski Criteria" for Assessing the Normal Function of Human Temporal Bones.

Important research by Rosowski et al. [Twenty-Seventh Meeting of the Association for Research in Otolaryngology, 2004, p. 275] has led to a standard practice by the American Society for Testing Materials [West Conshohocken: ASTM International; 2014] to assess normal function of temporal bones used in the development of novel middle ear actuators and sensors. Rosowki et al. [Audiol Neurotol. 2007; 12(4): 265-76] have since suggested that the original criteria are too restrictive and have proposed modified criteria. We show that both the original and modified criteria are inappropriate for assessing individual temporal bones. Moreover, we suggest that both the original and modified Rosowski criteria should be applied with caution when assessing whether mean data from a study are within physiological norms because the multiple comparisons resulting from verification at each frequency will lead to very liberal rejection. The standard practice, however, has led to the collection of more extensive and consistent data. We suggest that it is now opportune to use these data to further modify the Rosowski criteria.

Causes and management of facial nerve palsy.

Facial nerve palsy causes disfigurement with cosmetic, functional and psychological repercussions. The facial nerve can be affected anywhere along its course. A comprehensive assessment considering all differential diagnoses is critical to optimal management, as prompt, appropriate therapy leads to better outcomes.

Size as a Risk Factor for Growth in Conservatively Managed Vestibular Schwannomas: The Birmingham Experience.

This article discusses conservatively managed tumors, whether larger tumors at presentation are more likely to grow, and whether position at presentation corresponds with growth. A review is presented of more than 900 patients managed at Queen Elizabeth Hospital, Birmingham, between 1997 and 2012. Tumors were arbitrarily divided into 3 groups: intracanalicular (IC), and extracanalicular (EC) tumors measuring 1 to 10 mm or 11 to 20 mm at the cerebellopontine angle. This series shows that larger EC tumors grow faster than IC tumors and that EC tumors overall at presentation are more likely to grow than IC tumors.

Bilateral sensorineural hearing loss and labyrinthitis ossificans secondary to neurosarcoidosis.

OBJECTIVE: To report a case of cochlear ossification as a result of neurosarcoidosis in a patient with bilateral profound sensorineural hearing loss. STUDY DESIGN: Case report: Setting University teaching hospital, tertiary referral center. PATIENT: Forty-year-old man with neurosarcoidosis and bilateral profound sensorineural hearing loss. Intervention Unilateral cochlear implantation. OUTCOME MEASURE: Aided thresholds speech perception tests. RESULTS: Marked improvement in hearing following implant. CONCLUSION: Patients with neurosarcoidosis are at risk of labyrinthitis ossificans. Early imaging of these patients is recommended and if early cochlear ossification is identified they should be offered rapid access to rehabilitation with a cochlear implant.

Cochlear implants to treat deafness caused by vestibular schwannomas.

OBJECTIVE: Rehabilitation of hearing is complicated in patients with profound bilateral hearing loss in the presence of sporadic vestibular schwannoma (VS) or neurofibromatosis 2 (NF2), especially if the tumor does not need to be removed. We present the outcome of patients who have had a cochlear implant in the tumor affected ear without removal of the primary tumor. DESIGN: This is a retrospective multicentre study investigating outcomes of cochlear implantation in profoundly deaf patients with vestibular schwannoma in the implanted ear. MATERIALS AND METHODS: Out of 11 implanted patients, 5 required no treatment for their tumor, whereas 6 had previously undergone radiotherapy. Nine patients experienced NF2, and 2 had unilateral VS in the only hearing ear. Postoperative hearing was assessed with open and closed set speech discrimination, including City University of New York (CUNY) in noise and Bamford, Kowal and Bench (BKB) sentence scores. RESULTS: Patients with untreated lesions experienced marked improvement in their BKB and CUNY scores in the implanted ear and were daily cochlear implant users. The improvement was less consistent in the patients who had radiotherapy where only 1 patient attained open set speech discrimination. CONCLUSION: Patients with unilateral VS (sporadic or those affected with NF2) whose tumor status was stable, benefited from cochlear implantation in their tumor-affected ear. Patients who had radiotherapy also benefited from CI, but their outcomes were variable.

Cautery of the tympanic membrane: the lesser known history of myringoplasty.

OBJECTIVE: To present the fascinating, controversial, and tumultuous history of tympanic cautery as a form of myringoplasty and describe the relevance of work more than 150 years old to modern practice and research. DATA SOURCES: More than 70 English, French, and German articles and books published over the last 400 years, which refer to some aspect of tympanic membrane cautery. HISTORY: The first recorded use of silver nitrate to stimulate closure of tympanic membrane perforations is by William Wilde in 1848. Since then, numerous modifications of this technique have been used, and its significance has waxed and waned in response to events within the speciality of otology and the wider world. CONCLUSION: There are lessons to be learned from the rise and fall of this once widely practiced technique. There exists a school of thought that believes that the significance of cautery lies not only in the history of otology but also in its future.

An unusual complication following translabyrinthine resection of an acoustic neuroma.

We report the case of a 58-year old man who presented with a 4 cm right acoustic neuroma. He underwent a translabyrinthine resection. Two years later he presented with multiple strokes and progressive generalised deterioration. A cerebral angiogram demonstrated an extensive right side cerebellar dural arteriovenous fistula with retrograde flow causing corticovenous reflux. The fistula was treated successfully endovascularly. There is only one published report of a dural arteriovenous fistula occurring following acoustic neuromas surgery. The pathogenesis and management of this unusual complication is discussed.

Intracranial lipomas affecting the cerebellopontine angle and internal auditory canal: a case series.

OBJECTIVE: To assess the long-term outcome of lipomas affecting the cerebellopontine angle (CPA) and internal auditory canal (IAC). PATIENTS: This is a retrospective, single-center study of 10 CPA and IAC lipomas that have presented for the last 6 years. There were 8 male and 2 female patients whose age ranged from 22 to 71 years. These lesions were distributed equally between left and right sides. INTERVENTION: The natural progression, audiovestibular signs and symptoms, imaging characteristics, and management options have been evaluated. MAIN OUTCOME MEASURE: Long-term clinical outcome was correlated with serial imaging and audiograms. RESULTS: The most common presenting feature was hearing loss with an average lesion size of 8 mm. Two patients experienced imbalance, with one requiring operative intervention for incapacitating vertigo. The other 9 were managed conservatively. Follow-up imaging was available for 8 cases, and no growth was observed in any of these, with an average follow-up of 3.5 years. CONCLUSION: Because of the resolution of modern imaging, lipomas of the IAC and CPA are increasingly being recognized and accurately diagnosed. Our data suggest that these lesions are more common than previously thought, representing approximately 1% of all lesions in this location referred to our center. With the absence of growth in 8 cases with follow-up average of 3.5 years as our basis, we recommend that these lesions are managed conservatively by serial imaging. In rare cases, surgery may be required if the lesion is resulting in incapacitating symptoms, such as significant balance disturbance.

Transtemporal approach to otogenic brain abscesses.

The standard current treatment of an otogenic brain abscess is drainage via neurosurgical burr hole or complete excision, followed by an otological procedure to eradicate the primary pathology ­ often at a later date. We describe the drainage of otogenic brain abscess via a transtemporal approach. We present a retrospective study of six cases, five children and one adult. All the children had acute middle ear disease while the adult patient had a petrous apex cholesteatoma. All cases had an otogenic intracranial abscess either in the posterior cranial fossa or in both posterior and middle cranial fossae. Diagnosis was confirmed by computed axial tomography (CT) scan. All the patients were treated by mastoidectomy and needle aspiration to drain the abscesses. In all cases the brain abscess and the ear pathology were successfully treated by a single stage transmastoid approach. The five paediatric patients had an extended cortical mastoidectomy approach to both intracranial pathology and ear disease except one patient who required a burr hole to drain a posteriorly located subdural posterior fossa abscess. The adult patient underwent petrosectomy, followed by transtemporal abscess drainage. There was postoperative pus recollection in one patient who required further aspiration. We conclude that transtemporal drainage of an otogenic brain abscess can successfully treat otological and intracranial pathology in a single operation. It has a low complication rate and avoids the need for a craniotomy or subsequent operations.

A protocol for the conservative management of vestibular schwannomas.

OBJECTIVES: To devise a protocol for the safe surveillance of vestibular schwannomas. STUDY DESIGN: Retrospective review of case records. SETTING: Tertiary referral neurotology clinic. PATIENTS: Three hundred twenty patients have been managed conservatively with a mean follow-up of 43 months since 1997. Two hundred seventy-six patients with at least 1 follow-up scan have been included in the study. INTERVENTION: Review of case records and radiologic data to devise management protocol. MAIN OUTCOMES MEASURED: Tumor growth rates, timing of detection of growth in growing tumors, and timing of detection of growth in tumors growing at different rates. RESULTS: Of 276 patients, 62 (22%) demonstrated growth. The mean growth rate for growing tumors was 4 mm annually (range, 0.5-17 mm/yr). Of the growing tumors, 65% grew slowly (0.5-5 mm/yr) and 35% grew more rapidly (>5-17 mm/yr). Four tumors displayed genuine nonlinear growth. Of the rapidly growing tumors, 16 of 19 were detected at the first follow-up magnetic resonance imaging (6 mo). Of all growing tumors, 90% were detected within 3 years. The remaining 10% were detected within a further 3 years. CONCLUSION: Growth is usually manifest in the first 3 years after presentation. We recommend an initial magnetic resonance imaging scan at 6 months, with scans to take place at annual intervals for 2 years. A further scan 2 years later will identify any patient with indolent tumors. Thereafter, follow-up should be lifelong every 5 years. Cystic tumors represent a particular threat to patients and should only be treated conservatively with caution.

Prescription of binaural hearing aids in the United Kingdom: a knowledge, attitude and practice (KAP) study.

The purpose of this questionnaire study was to evaluate the existing knowledge of binaural hearing and the attitudes and practices of prescribing bilateral hearing aids amongst otolaryngologists in the United Kingdom. Of the 950 questionnaires sent to the current members of the British Association of Otolaryngologists and Head and Neck Surgeons (BAO-HNS), there were 591 respondents (62 per cent). The true response rate with completed questionnaires was 59 per cent. Eighty-one per cent of the respondents were aware of the importance of binaural hearing and had a positive attitude towards binaural fitting. The practice of bilateral hearing aid prescriptions was found to be poor amongst all grades on the NHS (less than 10 per cent of all hearing aid prescriptions). This practice in the private sector was variable, dependent largely on patient preference and affordability. The practice of binaural prescription was higher for patients in the paediatric age group than amongst adults. Two common indications for hearing aid prescriptions for unilateral deafness were otitis media with effusion in children (23 per cent of respondents) and for tinnitus masking in adults (12 per cent of respondents). Many otolaryngologists believed that there was not enough evidence to support bilateral bone-anchored hearing aid implantation and bilateral cochlear implantation. Ninety-four per cent of the respondents believed that binaural hearing was as important as binocular vision.

Dermoid cyst of the infratemporal fossa.

Dermoid cysts are rare benign tumours, they represent the simplest form of teratoma. Approximately seven per cent affect the head and neck region, within this region they are frequently encountered in the area of the lateral eyebrow, the orbit and the nose. A case of a 17-year-old girl who developed a rapidly growing facial swelling due to an infratemporal fossa dermoid cyst is presented. A review of the literature using Medline has not revealed any previous reports of similar cases. The lesion was completely excised using a lateral approach to the infratemporal fossa.

Radiologic differentiation of intracranial epidermoids from arachnoid cysts.

OBJECTIVE: Intracranial epidermoids (cholesteatomas) mimic arachnoid cysts in their radiologic characteristics, especially in the cerebellopontine angle. It is essential to differentiate the two conditions because they warrant different therapeutic interventions. The objective of this study is to elucidate the different radiologic characteristics of the conditions. STUDY DESIGN AND SETTING: This was a retrospective study of 4 patients referred for a differential diagnosis and management of intracranial cystic lesions to the Departments of Neurotology/Neurosurgery and Neuroradiology in a tertiary referral university hospital. PATIENTS: Four patients of different age groups with cystic intracranial lesions, diagnosed epidermoid or arachnoid cysts, were chosen. A retrospective analysis of their case charts, radiologic and surgical interventions, and follow-up records was undertaken. METHODS: The imaging techniques used included computerized tomographic scans, magnetic resonance imaging (MRI) with T1, T2, proton-density, and gadolinium-enhanced T1 images. In addition, special MRI sequences were used that included fluid-attenuated inversion recovery and echo planar diffusion scanning. All the patients underwent an audiovestibular evaluation. RESULTS: Both lesions are characteristically well demarcated and have a homogeneous low density, similar to cerebrospinal fluid on computerized tomographic scan, showing no contrast enhancement. On MRI, epidermoids and arachnoid cysts usually appear hypointense on T1-weighted images and hyperintense on T2-weighted images. On fluid-attenuated inversion recovery, an arachnoid cyst tends to follow cerebrospinal fluid intensity, whereas an epidermoid becomes hyperintense. There are occasions when an epidermoid may appear as a low-intensity lesion on fluid-attenuated inversion recovery. This dilemma is resolved with the use of echo planar diffusion scanning, on which an epidermoid remains bright. CONCLUSION: The authors recommend the use of fluid-attenuated inversion recovery and diffusion sequence MRI when definitive radiologic diagnosis of cystic intracranial lesions becomes difficult with routine computerized tomographic scanning and MRI.