Faculty Bibliography

OBJECTIVES: To examine the conclusions and possible misinterpretations that may or may not be drawn from the 'outcome-matching method,' a study design recently used in the cochlear implant literature. In this method, subject groups are matched not only on potentially confounding variables but also on an outcome measure that is closely related to the outcome measure under analysis. For example, subjects may be matched according to their speech perception scores in quiet, and their speech perception in noise is compared. DESIGN: The present study includes two components, a simulation study and a questionnaire. In the simulation study, the outcome-matching method was applied to pseudo-randomly generated data. Simulated speech perception scores in quiet and in noise were generated for two comparison groups, in two imaginary worlds. In both worlds, comparison group A performed only slightly worse in noise than in quiet, whereas comparison group B performed significantly worse in noise than in quiet. In Imaginary World 1, comparison group A had better speech perception scores than comparison group B. In Imaginary World 2, comparison group B had better speech perception scores than comparison group A. The outcome-matching method was applied to these data twice in each imaginary world: 1) matching scores in quiet and comparing in noise, and 2) matching scores in noise and comparing in quiet. This procedure was repeated 10,000 times. The second part of the study was conducted to address the level of misinterpretation that could arise from the outcome-matching method. A questionnaire was administered to 54 students in a senior level course on speech and hearing to assess their opinions about speech perception with two different models of cochlear implant devices. The students were instructed to fill out the questionnaire before and after reading a paper that used the outcome-matching method to examine speech perception in noise and in quiet with those two cochlear implant devices. RESULTS: When pseudorandom scores were matched in quiet, comparison group A's scores in noise were significantly better than comparison group B's scores. Results were different when scores were matched in noise: in this case, comparison group B's scores in quiet were significantly better than comparison group A's scores. Thus, the choice of outcome measure used for matching determined the result of the comparison. Additionally, results of the comparisons were identical regardless of whether they were conducted using data from Imaginary World 1 (where comparison group A is better) or from Imaginary World 2 (where comparison group B is better). After reading the paper that used the outcome-matching method, students' opinions about the two cochlear implants underwent a significant change even though, according to the simulation study, this opinion change was not warranted by the data. CONCLUSIONS: The outcome-matching method can provide important information about differences within a comparison group, but it cannot be used to determine whether a given device or clinical intervention is better than another one. Care must be used when interpreting the results of a study using the outcome-matching method

The cortex is thought to be the primary site of sensory plasticity, particularly during development. Here, we report that large-scale reorganization of the mouse auditory midbrain tonotopic map is induced by a specific sound-rearing environment consisting of paired low- (16 kHz) and high-frequency (40 kHz) tones. To determine the potential for plasticity in the mouse auditory midbrain, we used manganese-enhanced MRI to analyze the midbrain tonotopic maps of control mice during normal development and mice reared in the two-tone (16 + 40 kHz) environment. We found that the tonotopic map emerged during the third postnatal week in normal mice. Before 3 weeks, a larger percentage of auditory midbrain responded to each of the suprathreshold test frequencies, despite the fact that the primary afferent projections are in place even before hearing onset. By 3 weeks, the midbrain tonotopic map of control mice was established, and manganese-enhanced MRI showed a clear separation between the 16- and 40-kHz responses. Two-tone rearing dramatically altered the appearance of these discrete frequency-specific responses. A significant volume of the auditory midbrain became responsive to both rearing frequencies, resulting in a large-scale reorganization of the tonotopic map. These results indicate that developmental plasticity occurs on a much greater scale than previously appreciated in the mammalian auditory midbrain

BACKGROUND: Oral tongue strength and swallowing ability are reduced in patients treated with chemoradiotherapy for oral and oropharyngeal cancer. METHODS: Patients with oral or oropharyngeal cancer treated with high-dose chemoradiotherapy underwent tongue strength, swallowing, and dietary assessments at pretreatment and 1, 3, 6, and 12 months posttreatment. Tongue strength was assessed using the Iowa Oral Performance Instrument (IOPI). Oral and pharyngeal residue was evaluated utilizing videofluoroscopy. RESULTS: Mean maximum tongue strength dropped a nonsignificant amount immediately after treatment, and then increased significantly at 6- and 12-months posttreatment completion. Analyses were adjusted for patient dropout. Tongue strength was not significantly correlated with swallow observations of percentage oral and pharyngeal residue. Ability to eat various diet consistencies was reduced after treatment but improved over time at a rate similar to changes in oral intake and type of diet. CONCLUSIONS: Parallel but not significant changes in oral intake, diet, and tongue strength in the first year post chemoradiation therapy need further study in a larger population.

OBJECTIVE: Surgical techniques for parotid gland neoplasm removal have been shaped over the years by the importance of the gland's relationship with the facial nerve, histologic behavior of parotid tumors, and recurrence rates from specific techniques. Parotidectomy with facial nerve dissection has become the procedure of choice in removal of parotid gland neoplasms because of the resulting low recurrence rate. However, these more comprehensive dissections can cause significant postoperative complications, some cosmetically devastating. We propose that a more limited dissection yields a similar low recurrence rate but with less risk of complications. STUDY DESIGN: Retrospective case series. METHODS: A retrospective review of the clinical outcomes and pathology of 27 patients who underwent extracapsular dissection for parotid gland neoplasms. RESULTS: All tumors were located in the superficial lobe of the parotid gland and size of the masses ranged from 4.0 to 1.0 cm (mean 2.4 cm) in diameter. Pathology of the parotid tumors consisted of 11 pleomorphic adenomas, six Warthin's tumors, six benign epithelial cysts, one sarcoid lesion, two lymphoid hyperplasia, and one Kaposi's sarcoma. There were no cases of capsular rupture. There was no temporary or permanent facial paralysis and no incidence of Frey's syndrome. One patient developed a sialocele, which was aspirated and resolved after 3 months. There were no recurrences with follow-up times between 5 months and 6 years (mean 41 mo). CONCLUSION: We advocate extracapsular dissection for benign parotid neoplasms because of the acceptable recurrence rates with limited complications as compared to superficial parotidectomy

BACKGROUND: The tall cell variant (TCV) is a histologic subtype of papillary thyroid carcinoma (PTC) that is more aggressive than 'classical' PTC. Most authors believe that TCV's worse prognosis is related to older age at presentation, larger tumor size, and high frequency of extrathyroid tumor extension (ETE). To assess the biologic and clinical behavior of TCV without ETE, we performed a detailed comparative clinicopathologic analysis of classical PTC and TCV without ETE. METHODS: TCV was defined as a PTC harboring >50% tall cells, while classical PTC was restricted to those tumors containing >1% papillae and <30% tall cells. Microscopic analysis and chart review identified 62 cases of TCV and 83 classical PTC without ETE. These patients were analyzed for various pathologic, imaging, and clinical parameters including outcome. RESULTS: There was no statistical difference between TCV and classical PTC in relation to age, gender, tumor size, risk stratification, type of therapy, and length of follow-up. TCV displayed more invasion of the tumor capsule and more often infiltrated into the thyroid capsule (p = 0.047 and 0.0004, respectively). Among patients with microscopically assessable regional lymph node (LN), 33 of 49 (67.3%) patients with TCV had LN metastasis at presentation, while only 24 of 60 (40%) classical PTC had positive nodes (p = 0.004). In multivariate analysis, histologic subtype (TCV vs. classical PTC) was the only independent factor associated with LN metastases (p = 0.007). In patients with adequate follow-up, 4 of 62 (6.5%) classical PTC and 7 of the 47 (14.9%) TCV had thyroid cancer recurrence (p = 0.202). TCV recurred at a distant site (3 of 47, 6.4%) while none of the 62 classical PTC developed distant metastases (p = 0.077). CONCLUSION: TCV without ETE is biologically a more aggressive tumor than classical PTC without ETE independent of age, gender, and tumor size

Solitary fibrous tumors (SFTs) are unusual mesenchymal tumors that were first described as primary spindle-cell neoplasms of the pleura. These tumors have been described in many other locations, including the urogenital system, orbit, mediastinum, and upper respiratory tract. Twenty-two cases of an SFT of the paranasal sinuses and nasal cavity have been reported, but none described a malignant SFT extending through the anterior skull base. A 70-year-old man had a 6-month history of unilateral left-sided epiphora and nasal obstruction. Computed tomography and magnetic resonance imaging showed a large left-sided nasal cavity mass with extension into the left extraconal orbit and intracranial extension through the left cribriform plate and ethmoid roof. The patient underwent preoperative embolization of the internal maxillary artery and a subsequent anterior craniofacial resection via a midfacial degloving approach and a left anterior craniotomy. Histopathological analysis of the specimen was consistent with a malignant SFT

OBJECTIVES: Ear anomalies and deafness are associated with CHARGE syndrome, which also presents with a cluster of features including coloboma of the eye, heart defects, atresia of the choanae, developmental retardation, and genitourinary abnormalities. The aim of this study is to explore the viability of cochlear implantation in children with CHARGE syndrome and to assess the outcome. STUDY DESIGN: Retrospective chart review. METHODS: Eleven children presenting with severe to profound sensorineural hearing loss associated with CHARGE syndrome were the subjects of this study. Routine audiometric measurements and the Infant Toddler Meaningful Auditory Integration Scale (IT-MAIS) were performed pre- and postoperatively. In addition, the degree of the subjects' cochlear deformity were measured and correlated to outcome. RESULTS: All patients had varying degrees of ear anomalies, seven patients suffered from coloboma of the eyes, two had heart defects, five exhibited choanal atresia, eleven showed developmental retardation, and six had genitourinary abnormalities. Ten of the children underwent cochlear implantation with complete insertion of the electrode array without complication and were followed over a 3-month to a 7-year period. The eleventh child was not implanted because of severe retardation. All of the implanted children showed varying, but limited degrees, of auditory benefit as measured by routine audiometry and the IT-MAIS. CONCLUSIONS: Careful treatment planning for children with sensorineural hearing loss and CHARGE syndrome can lead to varying, but limited degrees, of auditory benefit with no increase in surgical complications. Although the implant enhanced the children's 'connectivity' to the environment, it did not promote the development of oral language skills in this population

The neural representation of meaningful stimulus features is thought to rely on precise discharge characteristics of the auditory cortex. Precisely timed onset spikes putatively carry the majority of stimulus-related information in auditory cortical neurons but make a small contribution to stimulus representation in the auditory midbrain. Because these conclusions derive primarily from anesthetized preparations, we reexamined temporal coding properties of single neurons in the awake gerbil inferior colliculus (IC) and compared them with primary auditory cortex (AI). Surprisingly, AI neurons displayed a reduction of temporal precision compared with those in the IC. Furthermore, this hierarchical transition from high to low temporal fidelity was observed for both static and dynamic stimuli. Because most of the data that support temporal precision were obtained under anesthesia, we also reexamined response properties of IC and AI neurons under these conditions. Our results show that anesthesia has profound effects on the trial-to-trial variability and reliability of discharge and significantly improves the temporal precision of AI neurons to both tones and amplitude-modulated stimuli. In contrast, IC temporal properties are only mildly affected by anesthesia. These results underscore the pitfalls of using anesthetized preparations to study temporal coding. Our findings in awake animals reveal that AI neurons combine faster adaptation kinetics and a longer temporal window than evident in IC to represent ongoing acoustic stimuli