Elizabeth H. Toh

Facial Nerve Grading System 2.0

Objective: To present an updated version of the original Facial Nerve Grading Scale (FNGS), commonly referred to as the House-Brackmann scale. Study Design: Controlled trial of grading systems using a series of 21 videos of individuals with varying degrees of facial paralysis. Results: The intraobserver and interobserver agreement was high among the original and revised scales. Nominal improvement is seen in percentage of exact agreement of grade and reduction of instances of examiners differing by more then one grade when using FNGS 2.0. FNGS 2.0 also offers improved agreement in differentiating between grades 3 and 4. Conclusion: FNGS 2.0 incorporates regional scoring of facial movement, providing additional information while maintaining agreement comparable to the original scale. Ambiguities regarding use of the grading scale are addressed.

Surgical treatment of Bell's palsy: Current attitudes†‡

To learn the current management of Bells palsy among practicing otologists and neurotologists and to better define the role of surgical decompression of the facial nerve in the treatment of Bells palsy.

Totally implantable hearing system: Five-year hearing results

1) To provide long‐term hearing outcome measures of a totally implantable hearing system (implant) and compare to the baseline unaided (BLU) and baseline aided (BLA) conditions, and 2) discuss relevant safety measures.

09:30: Expression Patterns in the Injured Cochlea Microenvironment

ynx and the contribution of individual structures (palate/tonsils, tongue, epiglottis, and lateral pharyngeal walls) to upper airway obstruction. Test-retest reliability was determined separately for the blinded and unblinded surgeons based on the agreement between the surgeon’s ratings for the two DISE procedures. RESULTS: Twenty-eight patients (6 female; 22 male) were studied with DISE. Preoperative polysomnography findings included a mean apnea-hypopnea index of 33.3 16.4 and a lowest oxygen saturation was 78.4 8.4%. For the DISE ratings, there was moderate-good agreement (weighted kappa 0.41-0.63) for the degree of obstruction at the level of the palate and hypopharynx. Agreement regarding the contribution of individual structures was moderate-good (Cohen’s kappa 0.44-0.71). Greater agreement was demonstrated for the unblinded surgeon ratings. CONCLUSIONS: The inter-rater reliability of DISE is moderate-good.

09:50: Prevention of Synaptic Edema by Noise Exposure in Chinchilla

through transplantation of stem cells are ongoing, though optimization of these techniques has not been achieved. In particular, there is a lack of understanding of what makes a particular cochlear microenvironment more suitable for successful transplantation. The present study was designed to examine changes in expression patterns of various trophic factors following chemical-induced cochlear injury in an effort to optimize cell transplantation techniques. METHODS: Stem cell survival has been noted in both “acuteinjury” (1-3 days after ouabain exposure) and “chronic-injury” (7 days or longer) cochleas, though a greater number of surviving cells are seen in the acute-injury group. In the present study, ouabain was applied to the round window niche of mice. The animals recovered for 24 hours to several days and the cochleas were harvested. The tissue was subjected to real time RT-PCR using primers for various trophic factors. Comparisons between control and treatment cochleas were performed while protein assays of ouabain-treated cochleas were also performed. RESULTS: Examination of ouabain-treated cochleas revealed differential expression patterns of both mRNA and protein for various trophic factors (VEGF, GFAP, MMP) as compared with control cochleas. In particular, real time RT-PCR analysis revealed a several-fold increase in MMP mRNA levels in acute-injury cochleas. Moreover, differences in expression patterns were also noted depending upon the duration of recovery after ouabain exposure. CONCLUSION: In the present study, several differences in expression patterns of various trophic factors were identified following injury with ouabain. In particular, MMP, a protein important in vasculogenesis, was found to be increased several-fold (mRNA levels) in the acute-injury cochleas. SIGNIFICANCE: An understanding of the cochlear microenvironment will be necessary for further growth in the area of cell transplantation. It is hoped that new treatments will be developed to help those with sensorineural hearing loss. SUPPORT: NIHDC7506 Resident Research Committee Grant, Medical University of South Carolina.

10:30: Intracochlear Injection of Adenovirus Vector to GJB2 KO Mice

recovery). Unpaired t-test was used for statistical analysis. RESULTS: The researchers successfully established a working electrical stimulation model of the injured rat facial nerve. The semi-eyeblink returned significantly earlier (3.71 0.97 vs. 9.57 1.86 days) in stimulated rats (p 0.008). Stimulated rats recovered all functions earlier, and also showed less variability in time to recovery. CONCLUSION: The present study establishes the first model of electrical stimulation of the injured facial nerve in rats. Electrical stimulation significantly reduces recovery time for the semi-eyeblink reflex, a marker of early facial nerve recovery. Electrically stimulated rats have shorter recovery times for all functions. Decreased variability in the recovery period of stimulated animals implies a consistent effect. Electrical stimulation initiates and accelerates facial nerve recovery in the rat model. SIGNIFICANCE: Translational research in accelerating facial nerve recovery in patients with facial nerve paralysis with anatomically contiguous nerve (Bell’s palsy, traumatic paralysis, iatrogenic paralysis). SUPPORT: Department of Otolaryngology Gregory Matz Research Fund, Loyola University Medical Center, Maywood, Illinois 60153, USA.

10:20: Effect of Vasopressin on Auditory Thresholds in Guinea Pigs

recovery). Unpaired t-test was used for statistical analysis. RESULTS: The researchers successfully established a working electrical stimulation model of the injured rat facial nerve. The semi-eyeblink returned significantly earlier (3.71 0.97 vs. 9.57 1.86 days) in stimulated rats (p 0.008). Stimulated rats recovered all functions earlier, and also showed less variability in time to recovery. CONCLUSION: The present study establishes the first model of electrical stimulation of the injured facial nerve in rats. Electrical stimulation significantly reduces recovery time for the semi-eyeblink reflex, a marker of early facial nerve recovery. Electrically stimulated rats have shorter recovery times for all functions. Decreased variability in the recovery period of stimulated animals implies a consistent effect. Electrical stimulation initiates and accelerates facial nerve recovery in the rat model. SIGNIFICANCE: Translational research in accelerating facial nerve recovery in patients with facial nerve paralysis with anatomically contiguous nerve (Bell’s palsy, traumatic paralysis, iatrogenic paralysis). SUPPORT: Department of Otolaryngology Gregory Matz Research Fund, Loyola University Medical Center, Maywood, Illinois 60153, USA.

10:10: Electrical Stimulation Facilitates Rat Facial Nerve Recovery

into three groups: Two groups received six hours of noise exposure (NE octave band, 105 dB SPL, centered at 4 kHz) and treated with either saline or CARBA (5.2mg/kg). One group received no noise and no treatment (controls). Treatments were given IP, one hour before and after noise and BID for two days prior to NE. Animals were humanely euthanized at two hours post-NE. Cochleae were processed for microscopy. Four IHCs from the basal turn of each ear, 16 IHCs from each group, were examined for synaptic edema using imaging software. RESULTS: Synaptic edema was found in 16 of 16 IHCs (100%) in the noise-saline, 4 of 16 (25%) in the noise-CARBA (p 0.01), and 2 of 16 in the controls (12.5%) (p 0.01). The number of dendrite edematous spaces per IHC ranged from 3-10 (average 4.13) in the noise-saline, from 1-6 (average 3) in the noise-CARBA, and from 1-4 (average 2.5) in the controls. Edema area was 34.52 21.27 (mean SD) in the noise-saline, 5.43 3.69 in the noise-CARBA (p 0.001), and 6.61 6.51 in the controls (p 0.003). CONCLUSION: The findings suggested that afferent dendrite edema from acoustic overexposure was prevented by a glutamate NMDA receptor antagonist carbamathione in a chinchilla model. SIGNIFICANCE: Using glutamate NMDA receptor antagonists for prevention of synaptic edema in acoustic overexposure will allow development of therapies to treat NIHL. SUPPORT: The Office of Naval Research and the Naval Medical Center San Diego supported this research. The views expressed are those of the authors and do not reflect the official policy or position of the Departments of the Navy, Departments of the Defense nor the United States Government.

10:00: Accelerated Rat Facial N. Recovery: Testosterone+Electrostim

into three groups: Two groups received six hours of noise exposure (NE octave band, 105 dB SPL, centered at 4 kHz) and treated with either saline or CARBA (5.2mg/kg). One group received no noise and no treatment (controls). Treatments were given IP, one hour before and after noise and BID for two days prior to NE. Animals were humanely euthanized at two hours post-NE. Cochleae were processed for microscopy. Four IHCs from the basal turn of each ear, 16 IHCs from each group, were examined for synaptic edema using imaging software. RESULTS: Synaptic edema was found in 16 of 16 IHCs (100%) in the noise-saline, 4 of 16 (25%) in the noise-CARBA (p 0.01), and 2 of 16 in the controls (12.5%) (p 0.01). The number of dendrite edematous spaces per IHC ranged from 3-10 (average 4.13) in the noise-saline, from 1-6 (average 3) in the noise-CARBA, and from 1-4 (average 2.5) in the controls. Edema area was 34.52 21.27 (mean SD) in the noise-saline, 5.43 3.69 in the noise-CARBA (p 0.001), and 6.61 6.51 in the controls (p 0.003). CONCLUSION: The findings suggested that afferent dendrite edema from acoustic overexposure was prevented by a glutamate NMDA receptor antagonist carbamathione in a chinchilla model. SIGNIFICANCE: Using glutamate NMDA receptor antagonists for prevention of synaptic edema in acoustic overexposure will allow development of therapies to treat NIHL. SUPPORT: The Office of Naval Research and the Naval Medical Center San Diego supported this research. The views expressed are those of the authors and do not reflect the official policy or position of the Departments of the Navy, Departments of the Defense nor the United States Government.

10:40: Molecular Diagnostic Strategies of EVAS in China and U.S.

PROBLEM: Mutations in the Pendrin gene (SLC26A4) are associated with congenital autosomal recessive hearing loss (DFNB4), often with accompanying temporal bone and/or thyroid abnormalities (Pendred Syndrome, PS). Evidence to date indicates that different populations exhibit different patterns of mutations, suggesting that local clinical testing strategies should reflect these differences. METHODS: The authors used DHPLC–based mutation analysis and bidirectional DNA sequencing to detect all possible mutations in the open reading frame and flanking sequences of SLC26A4 in a population of patients referred for genetic testing in China, and a comparable group of patients in the United States. RESULTS: The relatively higher proportion of Chinese patients with temporal bone abnormalities and deafness who had SLC26A4 mutations (47 of 50 families) and the different spectrum of SLC26A4 mutations in these two populations were found, and 11 previously unreported SLC26A4 mutations were discovered: 5 in the Chinese population (E303Q, G316X, X329, X467, X573), and 6 in the U.S. population (V250A, D266N, F354S, D697A, K715N, E737D), in addition to 14 reported mutations. CONCLUSION: Since this approach worked well in both clinical laboratory settings, the authors propose a practical diagnostic strategy: In China, to screen the two prevalent mutations IVS7-2A G and H723R first as an effective and affordable alternative to CT examination; in the U.S., information on temporal bone and thyroid abnormalities to be included in the clinical information submitted with clinical samples from deaf patients who are undergoing genetic testing and use two-tier analyses for detection of SLC26A4 mutations. SIGNIFICANCE: This study provides appropriate, efficient, and cost effective molecular diagnostic strategies for EVAS in deaf populations from both China and the U.S. SUPPORT: This work was supported by the Chinese National Nature Science Foundation Research Grant 30572015, Beijing Nature Science Foundation Research Grant 7062062 to Pu Dai and Chinese Capital Medical Development Scientific Funding 2005-1032 to Dongyi Han. 10:50 Axon Guidance Cues in the Developing Inner Ear Alyssa M Hackett, MD (presenter); Wei Gao; Ashish R Shah; Sabrina Kadri; Audra M Webber, MD; Yael Raz, MD