The effect of caffeine on hearing in a guinea pig model of acoustic trauma.

OBJECTIVE: Caffeine is a widely consumed substance affecting the metabolism of adenosine and cellular metabolism of calcium. Noise also affects these metabolic pathways while inducing hearing loss. The aim of this study was to determine the effect of daily intake of caffeine on hearing loss after an episode of acoustic trauma in guinea pigs. MATERIALS AND METHODS: In this pilot study, forty guinea pigs were randomly divided into four groups: group I (control, n=10) received intraperitoneal saline, group II (n=10) received intraperitoneal caffeine (120 mg/kg/day) for 14 days, group III (n=10) was exposed to noise (tone of 6 kHz at 120 dB for one hour) and group IV (n=10) was exposed to noise as group III and received caffeine as group II. Auditory brainstem responses were measured at four different frequencies (8, 16, 20, and 25 kHz) prior to and at intervals of 1h, 3 days, 10 days, and 14 days after the initial treatment. On day 14, morphological analysis was performed to assess the effects of caffeine on acoustic trauma. RESULTS: Aggravated hearing loss was observed in group IV after 10 days of follow-up. After 14 days, one of the four frequencies (8 kHz) tested showed statistically significant greater impairment in hearing (8.2 ± 3.6 dB, p=0.026). Auditory hair cells showed no difference while spiral ganglion cell counts were diminished in group IV (p<0.05). CONCLUSION: These findings indicate that caffeine may have a detrimental effect on hearing recovery after a single event of acoustic trauma.

Teaching communication skills to OTL-HNS residents: multisource feedback and simulated scenarios.

BACKGROUND: Effective communication has been linked to a reduction in adverse events and improved patient compliance. Currently in Otolaryngology - Head and Neck Surgery (OTL-HNS) residency programs, there is limited explicit teaching of communication skills. Our objective was to implement an educational program on communication skills for residents using multisource assessment in several simulation-based contexts throughout residency. METHODS: For three consecutive years, OTL-HNS residents were recruited to participate in a total of nine simulation-based clinical scenarios in which communication skills could be honed. This educational program was designed to provide instruction and practice of challenging ethics scenarios, with communication efficacy as a secondary goal. To facilitate this goal, a multisource assessment was paired with a debriefing process that involved attending staff, observing and participating residents, standardized patients, and invited content experts. RESULTS: Seventeen residents completed the curriculum for at least two consecutive years from 2009 to 2011. The internal-consistency reliability of the scenarios ranged from 0.88 to 0.96. The intraclass correlation was 0.19, as expected in this context. There was no statistical difference in the mean ratings of performance across post-graduate year (PGY) level (p = 0.201). Results from the random-intercept regression indicated that, on average, a learner's mean rating at baseline was 3.6/5 and increased significantly by 0.25 points per year (p < 0.05) as assessed by OTL-HNS staff members and peers. No significant improvement across time was found for ratings by non-medical assessors. CONCLUSION: Implementing an educational program focused on communication skills using a multisource assessment in various contexts has shown to be potentially effective at our institution, and resulted for yearly improvement and consolidation of performance of OTL-HNS residents as judged by faculty and residents. The inclusion of a multisource assessment in the simulation curriculum is key to allow for the representation of different perspectives on communication skills, for both the assessment and the debriefing process. Future studies are needed to explore the possibility of fully integrating this educational program into residence training in order to support deliberate communication skills teaching.

A longitudinal simulation-based ethical-legal curriculum for otolaryngology residents.

OBJECTIVE: To develop, implement, and evaluate a longitudinal, simulation-based ethics and legal curriculum designed specifically for otolaryngology residents. METHODS: Otolaryngology residents were recruited to participate in a yearly half-day ethical-legal module, the curriculum of which spanned 4 years. Each module included: three simulated scenarios, small-group multisource feedback, and large-group debriefings. Scenarios involved encounters with standardized patients. Residents' ethical-legal knowledge was assessed pre- and postmodule with multiple-choice questions, and ethical reasoning was assessed by a variety of evaluators during the simulated scenario using a locally developed assessment tool. Participants completed an exit survey at the end of each module. RESULTS: Eighteen residents completed four modules from the academic years of 2008 to 2009 to 2011 to 2012. The first year was considered a pilot module, and data were collected for the following 3 years. Knowledge of legal issues improved significantly among residents (mean at pre = 3.40 and post = 4.60, P < 0.05). Residents' ethical reasoning skills also improved across years (mean 3.60/5 in 2009-2010, 3.76/5 in 2010-2011, and 4.33 in 2011-2012, P < 0.05). Survey results revealed a statistically significant self-perceived improvement in ethics reasoning skills (mean pre = 3.62, post = 4.86, P < 0.05). Participants reported that the curriculum was relevant to their practice (85%), that the debriefings were of high quality (83%), and that they would recommend this module to others (88%). CONCLUSION: To our knowledge, this is the first study exploring a longitudinal simulation-based ethical-legal curriculum tailored to otolaryngology-head and neck surgery residents. This educational program resulted in a both objective and subjective improvement in legal and ethics knowledge and skills. LEVEL OF EVIDENCE: NA. Laryngoscope, 127:2501-2509, 2017.

Accuracy of Mobile-Based Audiometry in the Evaluation of Hearing Loss in Quiet and Noisy Environments.

Objectives (1) To compare the accuracy of 2 previously validated mobile-based hearing tests in determining pure tone thresholds and screening for hearing loss. (2) To determine the accuracy of mobile audiometry in noisy environments through noise reduction strategies. Study Design Prospective clinical study. Setting Tertiary hospital. Subjects and Methods Thirty-three adults with or without hearing loss were tested (mean age, 49.7 years; women, 42.4%). Air conduction thresholds measured as pure tone average and at individual frequencies were assessed by conventional audiogram and by 2 audiometric applications (consumer and professional) on a tablet device. Mobile audiometry was performed in a quiet sound booth and in a noisy sound booth (50 dB of background noise) through active and passive noise reduction strategies. Results On average, 91.1% (95% confidence interval [95% CI], 89.1%-93.2%) and 95.8% (95% CI, 93.5%-97.1%) of the threshold values obtained in a quiet sound booth with the consumer and professional applications, respectively, were within 10 dB of the corresponding audiogram thresholds, as compared with 86.5% (95% CI, 82.6%-88.5%) and 91.3% (95% CI, 88.5%-92.8%) in a noisy sound booth through noise cancellation. When screening for at least moderate hearing loss (pure tone average >40 dB HL), the consumer application showed a sensitivity and specificity of 87.5% and 95.9%, respectively, and the professional application, 100% and 95.9%. Overall, patients preferred mobile audiometry over conventional audiograms. Conclusion Mobile audiometry can correctly estimate pure tone thresholds and screen for moderate hearing loss. Noise reduction strategies in mobile audiometry provide a portable effective solution for hearing assessments outside clinical settings.

Association of Caffeine and Hearing Recovery After Acoustic Overstimulation Events in a Guinea Pig Model.

IMPORTANCE: Noise-induced hearing loss is an increasingly worrisome problem. Although caffeine intake is common in people involved in noise-related environments, the effect of caffeine on the recovery of hearing after a temporary threshold shift requires further understanding. OBJECTIVES: To determine whether caffeine impairs hearing recovery in a guinea pig model exposed to acoustic overstimulation. DESIGN, SETTING, AND SUBJECTS: This experiment at the McGill University Auditory Sciences Laboratory used 24 female albino guinea pigs (age, 6 months; weight, 500-600 g) divided randomly into 3 groups of 8 animals each. Group 1 was exposed to caffeine; group 2, acoustic overstimulation events (AOSEs); and group 3, both. Data were collected from July 1, 2013, to March 30, 2014, and analyzed from April 1 to August 1, 2014. INTERVENTIONS: Daily caffeine dose for groups 1 and 3 consisted of 25 mg/kg administered intraperitoneally for 15 days. The AOSEs were administered on days 1 and 8 and consisted of 1 hour of 110-dB pure-tone sound. MAIN OUTCOMES AND MEASURES: Serial auditory brainstem response (ABR) tests to determine the audiological threshold shift and recovery were obtained at baseline and on days 1 (1 hour after the first AOSE), 4, 8 (before and 1 hour after the second AOSE), 11, and 15. Scanning electron and light microscopy of the cochleas were performed to determine morphologic changes. RESULTS: The day 1 post-AOSE measurement resulted in a similar threshold shift in all animals in groups 2 and 3 at all frequencies tested (8, 16, 20, and 25 kHz). The maximum threshold shift was at 16 kHz, with a mean of 66.12 dB. By day 8, the threshold shift in group 2 recovered completely at all frequencies except 20 kHz, where a mean threshold shift of 20.63 dB of sound pressure level (SPL) was present. Hearing impairment in group 3 persisted in 8-, 16-, and 25-kHz frequencies with thresholds of 21.88, 28.13, and 26.25 dB SPL, respectively (P = .001). After a second AOSE at day 8, similar threshold shift and outcome were recorded on day 15 compared with day 8, with a mean threshold shift at 20 kHz of 29.38 dB SPL in group 2 and mean threshold shifts at 8, 16, 20, and 25 kHz of 29.38, 35.63, 40.63, and 38.75 dB SPL, respectively, in group 3. The difference in ABR threshold recovery was in concordance with scanning electronic and light microscopy findings for each group. CONCLUSIONS AND RELEVANCE: A daily dose of caffeine was found to impair the recovery of hearing after an AOSE.

Preservation of hearing in patients undergoing microsurgery for vestibular schwannoma: degree of meatal filling.

OBJECT: Preservation of hearing has become a standard goal in selected patients undergoing surgery for a vestibular schwannoma (VS). This study was aimed at analyzing the role played by filling of the internal auditory canal (IAC) as well as those played by preoperative hearing quality, and tumor size in the postoperative preservation of serviceable hearing (SH). METHODS: Three hundred eighty-six patients with VS were treated. Hearing preservation was attempted in 128 cases (33.2%) by using intraoperative monitoring and following a retrosigmoid approach. The maximal extrameatal size of the tumor, its extension within the IAC, and pre- and postoperative hearing quality, according to the Gardner-Robertson classification, were evaluated. Preservation of SH was achieved in 24.2% of the 128 patients. With respect to tumor size, SH was preserved in 39% of 77 patients harboring a tumor 15 mm wide or smaller and in 2% of 51 patients with lesions 16 mm wide or larger (p < 0.001). With regard to filling of the IAC, among 63 patients harboring a tumor 15 mm or smaller, in whom magnetic resonance images were available, SH was preserved in 52.8% of 36 patients with partial filling and in 25.9% of 27 patients with complete filling (p = 0.032). Concerning preoperative hearing quality, in the patients with tumors 15 mm or smaller, SH was preserved in 46.5% of 43 patients with Gardner-Robertson Class I hearing and 29.4% of 34 patients with Class II hearing (p = 0.126). Both tumor size and the extent of IAC filling proved statistically significant in a multivariable analysis (p < 0.001 and p = 0.026, respectively). CONCLUSIONS: Incomplete filling of the IAC and a tumor size of 15 mm or smaller are independent favorable factors in SH preservation. Excellent preoperative hearing appears to have a positive impact but does not have statistical significance. Intraoperative monitoring is useful in guiding the dissection; however, the surgeon's knowledge of topographical landmarks and meticulous surgical technique remain the essential factors of success.

High-resolution X-ray computed tomographic scanning of the human stapes footplate.

OBJECTIVES: The mechanical behaviour of the footplate and its annular ligament depends critically on their shape and orientation in the oval window, but accurate measurements have been difficult to make owing to their small size. Our aims are to visualize the footplate at high resolution and understand its dynamics. METHODS: The human cadaver stapes footplate was dissected, and very high-resolution x-ray computed tomographic (CT) scans, with voxel sizes from 4 to 8 pm, were performed. Locally developed software was used to reconstruct the images. RESULTS: The data permit us to explore minor details of shape and orientation. The footplate looks like a footprint, and the annular ligament has variable thickness, with a cleft (groove) in its anterior attachment to the oval window. The CT data also permit us to create a three-dimensional finite-element model that can simulate footplate motion. CONCLUSIONS: The results obtained lead to further understanding of the mechanical behaviour of the footplate and the annular ligament.

2-year review of a novel vestibular rehabilitation program in Montreal and Laval, Quebec.

OBJECTIVE: To evaluate the benefits of a vestibular rehabilitation program (VRP) in the Montreal-Laval area. DESIGN: The VRP was conceptualized by a panel of experts including otolaryngologists, physiotherapists, and researchers from McGill University and its teaching hospitals. From February 1999 to December 2001, 117 patients were seen, and 88 of them completed the VRP. SETTING: The VRP has been established at the Jewish Rehabilitation Hospital in Laval, PQ, to provide specialized rehabilitation to clients suffering from vertigo, dizziness, and/or impaired balance owing to lesions or disorders of the vestibular system. MAIN OUTCOME MEASURES: Presence or absence of nystagmus or vertigo during the Dix-Hallpike test, Dizziness Handicap Inventory (DHI), and Dynamic Gait Index (DGI). RESULTS: Thirty-five patients with benign paroxysmal positional vertigo of the posterior canal were treated with canalith repositioning manoeuvres. All of the patients (100%) had absence of nystagmus or vertigo after one to four treatment sessions. Forty-six patients with vestibular deficits or dizziness-disequilibrium completed the VRP, which consisted mainly of individualized eye-head and balance home exercise programs. At the end of the VRP, there was a significant decrease in DHI score (31 vs 57; p < .01) and a significant increase in DGI score (18.4 vs 22.6; p < .01). CONCLUSIONS: A range of modest to major improvements was shown by comparing initial and discharge scores of patients who had completed vestibular rehabilitation. The VRP appears to be beneficial for patients with a variety of vestibular disorders. Further research is needed to continue optimizing vestibular rehabilitation.