Faculty Bibliography

Even though speech signals trigger coding in the cochlea to convey speech information to the central auditory structures, little is known about the neural mechanisms involved in such processes. The purpose of this study was to understand the encoding of formant cues and how it relates to vowel recognition in listeners. Neural representations of formants may differ across listeners; however, it was hypothesized that neural patterns could still predict vowel recognition. To test the hypothesis, the frequency-following response (FFR) and vowel recognition were obtained from 38 normal-hearing listeners using four different vowels, allowing direct comparisons between behavioral and neural data in the same individuals. FFR was employed because it provides an objective and physiological measure of neural activity that can reflect formant encoding. A mathematical model was used to describe vowel confusion patterns based on the neural responses to vowel formant cues. The major findings were (1) there were large variations in the accuracy of vowel formant encoding across listeners as indexed by the FFR, (2) these variations were systematically related to vowel recognition performance, and (3) the mathematical model of vowel identification was successful in predicting good vs poor vowel identification performers based exclusively on physiological data.

Hearing-impaired individuals experience difficulties in detecting or understanding speech, especially in background sounds within the same frequency range. However, normally hearing (NH) human listeners experience less difficulty detecting a target tone in background noise when the envelope of that noise is temporally gated (modulated) than when that envelope is flat across time (unmodulated). This perceptual benefit is called modulation masking release (MMR). When flanking masker energy is added well outside the frequency band of the target, and comodulated with the original modulated masker, detection thresholds improve further (MMR+). In contrast, if the flanking masker is antimodulated with the original masker, thresholds worsen (MMR-). These interactions across disparate frequency ranges are thought to require central nervous system (CNS) processing. Therefore, we explored the effect of developmental conductive hearing loss (CHL) in gerbils on MMR characteristics, as a test for putative CNS mechanisms. The detection thresholds of NH gerbils were lower in modulated noise, when compared with unmodulated noise. The addition of a comodulated flanker further improved performance, whereas an antimodulated flanker worsened performance. However, for CHL-reared gerbils, all three forms of masking release were reduced when compared with NH animals. These results suggest that developmental CHL impairs both within- and across-frequency processing and provide behavioral evidence that CNS mechanisms are affected by a peripheral hearing impairment.

IMPORTANCE: Limited information exists regarding clinical outcomes of children undergoing extracapsular tonsillectomy and adenoidectomy (ETA) or intracapsular tonsillectomy and adenoidectomy (ITA) for treatment of obstructive sleep apnea syndrome (OSAS). OBJECTIVES: To quantify polysomnography (PSG) and clinical outcomes of ETA and ITA in children with OSAS and to assess the contribution of comorbid conditions of asthma and obesity. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study using medical records at a tertiary pediatrics inner-city hospital. Medical records from 89 children who underwent ETA or ITA between October 1, 2008, and December 31, 2013, were analyzed. The dates of our analysis were January 6, 2014, to April 11, 2014. Inclusion criteria required no evidence of craniofacial or neurological disorders, confirmation of OSAS by PSG within the 2 years before surgery, and a second PSG within the 2 years after surgery. INTERVENTIONS: Each child underwent ETA or ITA after being evaluated by a pediatric otolaryngologist and obtaining written parental informed consent. MAIN OUTCOMES AND MEASURES: Main primary outcomes were derived from PSG. Secondary outcomes included treatment failure, defined as residual OSAS with an obstructive apnea-hypopnea index of at least 5 events per hour. Comparisons were made between and within groups. Logistic regression was used to identify factors associated with treatment failure. RESULTS: Fifty-two children underwent ETA, and 37 children underwent ITA. Children in the ETA group were older (7.5 vs 5.2 years, P = .001) and more obese (60% [31 of 52] vs 30% [11 of 37], P = .004). However, both groups had similar severity of OSAS, with median preoperative obstructive apnea-hypopnea indexes of 17.0 in the ETA group and 24.1 in the ITA group (P = .21), and similar prevalences of asthma (38% [20 of 52] vs 38% [14 of 37]). After surgery, significant improvement was noted on PSG in both groups, with no differences in any clinical outcomes. There was no association between procedure type, age, or body mass index z score and treatment failure. However, in a subset of patients with asthma and obesity, ITA was associated with residual OSAS (odds ratio, 16.5; 95% CI, 1.1-250.2; P = .04). CONCLUSIONS AND RELEVANCE: Both ETA and ITA are effective modalities to treat OSAS, with comparable surgical outcomes on short-term follow-up. However, when comorbid diagnoses of both asthma and obesity exist, OSAS is likely to be refractory to treatment with ITA compared with ETA.

Importance: Limited data exist on performing major oral cavity resections and reconstructions without elective tracheotomy. Objectives: To describe a group of patients who successfully underwent major microvascular mandibular reconstruction without an elective tracheotomy and to perform a literature review to identify commonalities between our group and the available literature to identify potential common factors that might contribute to the success of this approach. Design, Setting, and Participants: Case series with retrospective medical chart review of 15 patients who underwent fibula microvascular free flap reconstruction of mandibular defects without tracheotomy between 2000 and 2014 (the most common indication was osteoradionecrosis) conducted at a tertiary referral hospital center. Exposures: Mandibular reconstruction with fibula free flap without elective tracheotomy. Main Outcomes and Measures: Perioperative morbidity and mortality with a focus on airway management and perioperative complications. Results: The median age of 15 patients (11 males and 4 females) at the time of reconstruction was 42 years (range, 10-64 years). The indication for surgery was nonmalignant pathologic abnormalities in 8 patients (53%), osteosarcoma in 4 patients (27%), and oral cavity squamous cell carcinoma in 3 patients (20%). All patients were intubated endonasally and, excepting 1 pediatric case, were extubated the day following surgery. The fibula spanned the parasymphysis and/or symphysis in 2 patients, and was limited to the mandibular body in others (mean length, 7.6 cm [range, 4.0-15.0 cm]). The flap design was osteocutaneous in 3 patients and osseous in the rest. No patient required reintubation or tracheotomy. No complications due to endonasal intubation occurred. The average hospital length of stay was 11 days. Conclusions and Relevance: Major oral cavity resection and reconstruction with microvascular free flaps can be performed safely without elective tracheotomy in a select group of patients. Limited data exist on patient selection criteria. Further studies are needed to identify favorable factors and develop protocols for safe patient selection.

OBJECTIVES/HYPOTHESIS: To evaluate the safety and efficacy of acoustic and electric sound processing for individuals with significant residual low-frequency hearing and severe-to-profound high-frequency sensorineural hearing loss. STUDY DESIGN: Prospective, single-arm repeated measures, single-subject design. METHODS: Fifty individuals, >/= 18 years old, with low-frequency hearing and severe high-frequency loss were implanted with the Cochlear Nucleus Hybrid L24 implant at 10 investigational sites. Preoperatively, subjects demonstrated consonant-nucleus-consonant word scores of 10% through 60% in the ear to be implanted. Subjects were assessed prospectively, preoperatively, and postoperatively on coprimary endpoints of consonant-nucleus-consonant words, AzBio sentences in noise, and self-assessment measures. RESULTS: Significant mean improvements were observed for coprimary endpoints: consonant-nucleus-consonant words (35.8 percentage points) and AzBio sentences in noise (32.0 percentage points), both at P < 0.001. Ninety-six percent of subjects performed equal or better on speech in quiet and 90% in noise. Eighty-two percent of subjects showed improved performance on speech in quiet and 74% in noise. Self-assessments were positive, corroborating speech perception results. CONCLUSION: The Nucleus Hybrid System provides significant improvements in speech intelligibility in quiet and noise for individuals with severe high-frequency loss and some low-frequency hearing. This device expands indications to hearing-impaired individuals who perform poorly with amplification due to bilateral high-frequency hearing loss and who previously were not implant candidates. LEVEL OF EVIDENCE: 2b. Laryngoscope, 2015.

BACKGROUND:The sublingual mucosa has been used for many years to apply allergenic extracts for the purpose of specific immunotherapy (IT). Although sublingual IT (SLIT) is both safe and efficacious, the density of antigen-presenting cells is higher in other regions of the oral cavity and vestibule, which make them a potentially desirable target for IT. OBJECTIVE:To present the concept of oral mucosal IT (OMIT) and to provide pilot data for this extended application of SLIT. METHODS:An open-label, 12-month, prospective study was undertaken as a preliminary step before a full-scale clinical investigation. Twenty-four individuals with allergic rhinitis received IT by applying allergenic extracts daily to either the oral vestibule plus oral cavity mucosa by using a glycerin-based toothpaste or to the sublingual mucosa by using 50% glycerin liquid drops. Adverse events, adherence rates, total combined scores, rhinoconjunctivitis quality-of-life questionnaire scores, changes in skin reactivity, and changes in serum antibody levels were measured for each participant. RESULTS:No severe adverse events occurred in either group. The adherence rate was 80% for the OMIT group and 62% for the SLIT group (p = 0.61). Decreased total combined scores were demonstrated for both the OMIT group (15.6%) and the SLIT group (22.3%), although this decrease did not reach statistical significance in either group. Both groups achieved a meaningful clinical improvement of at least 0.5 points on rhinoconjunctivitis quality-of-life questionnaire. A statistically significant rise in specific immunoglobulin G4 (IgG4) was seen in both groups over the first 6 months of treatment. CONCLUSION/CONCLUSIONS:OMIT and SLIT demonstrated similar safety profiles and adherence rates. Measurements of clinical efficacy improved for both groups, but only changes in IgG4 achieved statistical significance. These pilot data provide enough evidence to proceed with a full-scale investigation to explore the role of OMIT in the long-term management of allergic rhinitis.

OBJECTIVE:This study describes the potential application of intraoperative ultrasound imaging during transoral robotic surgery (TORS). METHODS:Ultrasound imaging was performed during transoral robotic resection of oropharyngeal tumors in 10 patients at a tertiary academic center. Ultrasound imaging was utilized to identify large-caliber vessels adjacent to the surgical site. Measurements were also taken on the ultrasound of tumor thickness to determine the deep margin. Following resection, the tumor was sectioned, and a gross measurement of the tumor thickness was obtained. RESULTS:Intraoperative ultrasound use led to the identification of larger-caliber blood vessels within the operative field prior to encountering them visually. Ultrasound could also aid in defining deep tumor margins; the tumor thickness measured via ultrasound was found to be accurate within 1 to 2 mm of the grossly measured tumor thickness. This allowed for focused, careful dissection to protect and avoid blood vessels during dissection as well as improved tumor resection. CONCLUSIONS:The use of intraoperative ultrasound provides additional information to the head and neck surgeon during TORS. This may be used to identify blood vessels and assess tumor margins, thereby improving the safety and efficacy of TORS.

BACKGROUND:Status dystonicus (SD) is a rare and potentially life-threatening complication of primary or secondary dystonia, characterized by acute worsening of dystonic movements. There is no consensus regarding optimal treatment, which may be medical and/or surgical. METHODS:We present our experience with pallidal deep brain stimulation (DBS) in 5 DYT1-positive patients with SD and provide a review of the literature to examine optimal management. RESULTS:Of the 5 patients treated with pallidal DBS, all experienced postoperative resolution of their dystonic crisis within a range of 1-21 days. Long-term follow-up resulted in 1 patient returning to preoperative baseline, 3 patients improving from baseline, and 1 patient making a complete recovery. Of the 28 SD patients (including our 5 patients) reported in the literature who were treated with DBS or ablative surgery, 26 experienced cessation of their dystonic crisis with a return to baseline function and, in most cases, clinical improvement. CONCLUSION:DBS is an effective therapeutic modality for the treatment of SD. In addition to the long-term benefits of stimulation, early and aggressive treatment may improve the overall outcome.

Testicular varicocele, which is defined as the dilation of the veins draining the testicle, has long been associated with a detrimental effect on testicular function. Despite a lack of high-quality, prospective data, recent evidence has shed light on potential links between varicocele and male infertility and serum testosterone levels. Similarly, varicocele repair has increasingly been shown to have a beneficial impact on pregnancy rates, semen parameters, and on improving serum testosterone in adult men. Numerous studies have assessed the optimal technique for varicocele repair and the bulk of the evidence has shown the microsurgical inguinal/subinguinal approach to have the highest success rates, the lowest overall complication rates, and the lowest recurrence rates. The management of varicocele in adolescents remains a clinical conundrum, but contemporary evidence suggests early deleterious effects of varicocele on testicular function in some patients. Well-designed prospective trials are critical to delineate the true impact and role of varicocele repair on male infertility and hypogonadism in adult and adolescent men.