Alicia M. Quesnel

Delayed loss of hearing after hearing preservation cochlear implantation: Human temporal bone pathology and implications for etiology☆

After initially successful preservation of residual hearing with cochlear implantation, some patients experience subsequent delayed hearing loss. The etiology of such delayed hearing loss is unknown. Human temporal bone pathology is critically important in investigating the etiology, and directing future efforts to maximize long term hearing preservation in cochlear implant patients. Here we present the temporal bone pathology from a patient implanted during life with an Iowa/Nucleus Hybrid S8 implant, with initially preserved residual hearing and subsequent hearing loss. Both temporal bones were removed for histologic processing and evaluated. Complete clinical and audiologic records were available. He had bilateral symmetric high frequency severe to profound hearing loss prior to implantation. Since he was implanted unilaterally, the unimplanted ear was presumed to be representative of the pre-implantation pathology related to his hearing loss. The implanted and contralateral unimplanted temporal bones both showed complete degeneration of inner hair cells and outer hair cells in the basal half of the cochleae, and only mild patchy loss of inner hair cells and outer hair cells in the apical half. The total spiral ganglion neuron counts were similar in both ears: 15,138 (56% of normal for age) in the unimplanted right ear and 13,722 (51% of normal for age) in the implanted left ear. In the basal turn of the implanted left cochlea, loose fibrous tissue and new bone formation filled the scala tympani, and part of the scala vestibuli. Delayed loss of initially preserved hearing after cochlear implantation was not explained by additional post-implantation degeneration of hair cells or spiral ganglion neurons in this patient. Decreased compliance at the round window and increased damping in the scala tympani due to intracochlear fibrosis and new bone formation might explain part of the post-implantation hearing loss. Reduction of the inflammatory and immune response to cochlear implantation may lead to better long term hearing preservation post-implantation.

Otologic outcomes after blast injury: the Boston Marathon experience

Objective Otologic trauma was the most common physical injury sustained after the April 15, 2013, Boston Marathon bombings. The goal of this study is to describe the resultant otologic morbidity and to report on early outcomes. Study Design Multi-institutional prospective cohort study. Methods Children and adults seen for otologic complaints related to the Boston Marathon bombings comprised the study population. Participants completed symptom assessments, quality-of-life questionnaires, and audiograms at initial and 6-month visits. Otologic evaluation and treatment, including tympanoplasty results, were reviewed. Results More than 100 patients from eight medical campuses have been evaluated for blast-related otologic injuries; 94 have enrolled. Only 7% had any otologic symptoms before the blasts. Ninety percent of hospitalized patients sustained tympanic membrane perforation. Proximity to blast (RR = 2.7, p < 0.01) and significant nonotologic injury (RR = 2.7, p < 0.01) were positive predictors of perforation. Spontaneous healing occurred in 38% of patients, and tympanoplasty success was 86%. After oral steroid therapy in eight patients, improvement in hearing at 2 and 4 kHz was seen, although changes did not reach statistical significance. Hearing loss, tinnitus, hyperacusis, and difficulty hearing in noise remain persistent and, in some cases, progressive complaints for patients. Otologic-specific quality of life was impaired in this population. Conclusion Blast-related otologic injuries constitute a major source of ongoing morbidity after the Boston Marathon bombings. Continued follow-up and care of this patient population are warranted.

Third generation bisphosphonates for treatment of sensorineural hearing loss in otosclerosis

Objective To evaluate hearing outcomes in patients treated with third generation bisphosphonates for otosclerosis-related sensorineural hearing loss (SNHL). Hypothesis Otosclerosis is a disease of abnormal bone remodeling in the otic capsule. In recent years, third generation bisphosphonates, with more powerful anti-resorptive properties and increased bone affinity, have demonstrated effectiveness in the treatment of osteoporosis and other metabolic bone diseases. We hypothesized that newer generation bisphosphonates, such as risedronate and zoledronate, would be effective in slowing the progression of SNHL in patients with otosclerosis. Study Design Retrospective review. Setting Tertiary referral center, ambulatory care. Interventions Risedronate or zoledronate administration. Main Outcome Measures Bone conduction pure tone threshold averages (PTAs) and word recognition (WR) scores were examined for each ear before and after bisphosphonate treatment. Criteria for significant change were defined as greater than 10 decibels in PTA or between 4% and 18% in WR based on binomial variance. Results All 10 patients had audiometric progression of SNHL in the pretreatment monitoring interval and 12 ears met criteria for significant progression. All 10 patients (19 ears) showed at least no significant progression of SNHL (i.e., stabilization) at an average follow-up of 13 months. Two patients (3 ears) showed improvement by defined audiometric criteria. There were no major complications. Conclusion Treatment with zoledronate or risedronate stabilized progressive SNHL related to otosclerosis in this small group of patients. Further evaluation of third-generation bisphosphonate treatments is warranted.

Minimally invasive endoscopic management of subglottic stenosis in children: success and failure.

OBJECTIVE To assess the efficacy and safety of endoscopic management of subglottic stenosis both as a primary and as an adjunctive treatment in the pediatric population. METHODS Retrospective review of pediatric patients with subglottic stenosis undergoing endoscopic airway procedures at a tertiary care pediatric medical center. Outcomes were assessed by systematic review to determine the success and failure of the endoscopic approach. RESULTS Forty patients (22 male, 18 female) underwent endoscopic interventions for a diagnosis of subglottic airway stenosis between 2003 and 2006. Age ranged from 22 days old to 20 years old. Recorded degree of subglottic stenosis ranged from 10% to 99%. Fifty-three percent (21/40) had a history of prematurity, and 40% (16/40) had secondary airway diagnoses. Twenty-four patients underwent an endoscopic intervention initially (including laser or dilation, with or without topical mitomycin treatment), including four patients who underwent tracheostomy prior to the first endoscopic intervention. Sixteen underwent laryngotracheoplasty initially, including ten patients who underwent tracheostomy prior to the laryngotracheoplasty. Endoscopic treatment resulted in resolution of symptoms, and/or decannulation, and no further need for an open procedure in 58% of patients. Of the 24 patients undergoing endoscopic interventions initially, 14 patients underwent two or more endoscopic interventions, and 10 patients subsequently required tracheostomy or laryngotracheoplasty. When endoscopic procedures were used as an adjunct to laryngotracheoplasty, 60% (12/20) had resolution of symptoms, underwent decannulation, and did not require tracheostomy or revision laryngotracheoplasty. CONCLUSIONS The endoscopic approach can be successful in the management of properly selected patients with subglottic stenosis, either as the initial treatment modality or as an adjunctive treatment in cases of re-stenosis after open airway surgery. The likelihood of success with a minimally invasive procedure as the primary treatment decreases with worsening initial grade of subglottic stenosis.

Current strategies in management of intracanalicular vestibular schwannoma.

Purpose of reviewThe current practitioner is more often managing intracanalicular vestibular schwannomas than in the past, as improved imaging and heightened awareness leads to earlier diagnosis of these tumors. The role of observation, microsurgery, and radiation treatment in the management of intracanalicular tumors continues to evolve. The goal of this article is to evaluate and summarize recent literature pertaining to the management of intracanalicular vestibular schwannomas. Recent findingsWatchful waiting is an important management option for patients with minimal symptoms. The literature on the natural history of small vestibular schwannomas continues to expand, with particular emphasis on the expected hearing outcomes. Microsurgical techniques also focus on hearing preservation. Presence of fundal fluid and good or normal hearing preoperatively are positive predictors of hearing preservation after surgery. Long-term follow-up after radiation therapy for vestibular schwannomas continues to demonstrate excellent tumor control rates, although hearing preservation rates are modest. SummaryMultiple factors, including status of hearing, presence of vestibular symptoms, patient age, medical comorbidities, institutional outcomes, and patient preferences, help determine the management strategy for patients with an intracanalicular vestibular schwannoma.

When the bell tolls on Bell's palsy: finding occult malignancy in acute-onset facial paralysis.

PURPOSE This study reports 4 cases of occult parotid malignancy presenting with sudden-onset facial paralysis to demonstrate that failure to regain tone 6 months after onset distinguishes these patients from Bells palsy patients with delayed recovery and to propose a diagnostic algorithm for this subset of patients. MATERIALS AND METHODS A case series of 4 patients with occult parotid malignancies presenting with acute-onset unilateral facial paralysis is reported. RESULTS Initial imaging on all 4 patients did not demonstrate a parotid mass. Diagnostic delays ranged from 7 to 36 months from time of onset of facial paralysis to time of diagnosis of parotid malignancy. Additional physical examination findings, especially failure to regain tone, as well as properly protocolled radiologic studies reviewed with dedicated head and neck radiologists, were helpful in arriving at the diagnosis. CONCLUSION An algorithm to minimize diagnostic delays in this subset of acute facial paralysis patients is presented. Careful attention to facial tone, in addition to movement, is important in the diagnostic evaluation of acute-onset facial paralysis.

Multiple synchronous sites of origin of vestibular schwannomas in neurofibromatosis Type 2.

Background Neurofibromatosis Type 2 (NF2) is a dominantly inherited tumour syndrome with a phenotype which includes bilateral vestibular (eighth cranial nerve) schwannomas. Conventional thinking suggests that these tumours originate at a single point along the superior division of the eighth nerve. Methods High resolution MRI was performed in children genetically proven to have NF2. The superior vestibular nerve (SVN) and inferior vestibular nerve (IVN) were visualised along their course with points of tumour origin calculated as a percentage relative to the length of the nerve. Results Out of 41 patients assessed, 7 patients had no identifiable eighth cranial nerve disease. In 16 patients there was complete filling of the internal auditory meatus by a tumour mass such that its specific neural origin could not be determined. In the remaining 18 cases, 86 discrete separate foci of tumour origin on the SVN or IVN could be identified including 23 tumours on the right SVN, 26 tumours on the right IVN, 18 tumours on the left SVN and 19 tumours on the left IVN. Discussion This study, examining the origins of vestibular schwannomas in NF2, refutes their origin as being from a single site on the transition zone of the superior division of the vestibular nerve. We hypothesise a relationship between the number of tumour foci, tumour biology and aggressiveness of disease. The development of targeted drug therapies in addition to bevacizumab are therefore essential to improve prognosis and quality of life in patients with NF2 given the shortcomings of surgery and radiation treatments when dealing with the multifocality of the disease.

Hypertrophic Anterior Cervical Osteophytes Causing Dysphagia and Airway Obstruction

Hyperostosis of anterior cervical vertebral osteophytes can produce otolaryngological symptoms ranging from mild dysphagia, dysphonia, and foreign body sensation to severe food impaction and stridulous dyspnea. Airway compromise necessitating a tracheostomy is very rare. We discuss the case of an elderly man who presented with progressive dysphagia and a large hypopharyngeal mass as his initial manifestations of hypertrophic anterior cervical osteophytes. After a biopsy of the mass, the patient went into airway distress due to bilateral vocal fold fixation by the enlarging mass and consequently required a surgical airway. A combined team approach to the removal of the osteophytes successfully resolved his symptoms. The clinical, diagnostic, radiologic, and therapeutic principles involved in this case are presented and discussed. The recognition of hypertrophic osteophytes as a potential cause of common otolaryngological symptoms in the elderly population is paramount, as these symptoms can rapidly progress and lead to life-threatening airway obstruction. Medical and surgical interventions can be employed for the treatment of hypertrophic anterior cervical osteophytes, and they often result in favorable outcomes.

Correlation of computed tomography with histopathology in otosclerosis.

Objective Until now, the use of computed tomography (CT) in the diagnosis and evaluation of otosclerosis has been based on correlation of radiologic findings to patient histories, intraoperative examinations, and audiologic data. The purpose of this study was to compare CT findings in otosclerosis to histopathology. Study Design Prospective blinded. Setting Radiology department in a tertiary referral hospital and otopathology laboratory. Patients Temporal bones from patients with otosclerosis and other otologic diseases (used as controls). Intervention(s) Blinded review of specimen CT scans by radiologists and comparison of CT findings to histopathology of the same bones. Main Outcome Measure(s) Ability of CT to diagnose otosclerosis, identify otosclerotic foci in defined zones of the otic capsule, determine endosteal layer involvement, oval window (OW) obliteration, and round window (RW) obliteration. Results In a randomized blinded evaluation, radiologists identified 8 of 10 bones with otosclerosis and made 3 false-positive diagnoses from the 36 control bones. Radiologic examination correctly identified otosclerosis anterior to the oval window, in the pericochlear area, and in the round window niche in 17 of 17, 9 of 11, and 3 of 6 bones, respectively. CT correctly determined involvement of the endosteal layer, OW obliteration, and RW obliteration in 5 of 8, 2 of 2, and 2 of 2 temporal bones. Conclusion High-resolution CT is highly sensitive and specific for the diagnosis of otosclerosis when compared with histopathology. Very small and subtle otosclerotic foci seen on pathology may be missed on CT. Although CT was able to positively identify cochlear endosteal margin involvement, the false-negative rate on CT was significant.

Non-ototoxic local delivery of bisphosphonate to the mammalian cochlea

Hypothesis Local delivery of bisphosphonates results in superior localization of these compounds for the treatment of cochlear otosclerosis, without ototoxicity. Background Otosclerosis is a common disorder of abnormal bone remodeling within the human otic capsule. It is a frequent cause of conductive hearing loss from stapes fixation. Large lesions that penetrate the cochlear endosteum and injure the spiral ligament result in sensorineural hearing loss. Nitrogen-containing bisphosphonates (e.g., zoledronate) are potent inhibitors of bone remodeling with proven efficacy in the treatment of metabolic bone diseases, including otosclerosis. Local delivery to the cochlea may allow for improved drug targeting, higher local concentrations, and the avoidance of systemic complications. In this study, we use a fluorescently labeled bisphosphonate compound (6-FAM-ZOL) to determine drug localization and concentration within the otic capsule. Various methods for delivery are compared. Ototoxicity is evaluated by auditory brainstem responses and distortion product otoacoustic emissions. Methods 6-FAM-ZOL was administered to guinea pigs via intraperitoneal injection, placement of alginate beads onto the round window membrane, or microfluidic pump infusion via a cochleostomy. Hearing was evaluated. Specimens were embedded into resin blocks, ground to a mid-modiolar section, and quantitatively imaged using fluorescence microscopy. Results There was a dose-dependent increase in fluorescent signal after systemic 6-FAM-ZOL treatment. Local delivery via the round window membrane or a cochleostomy increased delivery efficiency. No significant ototoxicity was observed after either systemic or local 6-FAM-ZOL delivery. Conclusion These findings establish important preclinical parameters for the treatment of cochlear otosclerosis in humans.