Faculty Bibliography

OBJECTIVE: A real-time MRI "movie" during natural sleep ("Sleep MRI") allows observation of dynamic airway obstructions in obstructive sleep apnea syndrome (OSAS) patients. The purpose of this article was to determine the reliability of assessing these obstructions. STUDY DESIGN: Cross-sectional diagnostic test evaluation. SETTING: Academic referral center. SUBJECTS AND METHODS: A total of 23 Sleep MRI sequences randomly selected from 20 consecutive OSAS patients were analyzed by two experienced sleep surgeons on two separate occasions separated by at least two weeks. Five dimensions were assessed: presence or absence of any obstruction, presence or absence of a retropalatal obstruction, presence or absence of a retroglossal obstruction, presence or absence of a swallow, and duration of an obstructive event. RESULTS: For all dimensions measured, intra-rater reliability coefficients ranged from a low of 0.95 to a high of 1.0 for each rater. Inter-rater reliability coefficients ranged from a low of 0.85 to a high of 1.0. On two separate evaluations separated by at least two weeks, rater 1 identified a retropalatal obstruction in 100 percent of sequences, whereas rater 2 did so in 91 percent and 96 percent of the sequences, respectively. Retroglossal obstruction was identified in 57 percent (rater 1) and 65 percent (rater 2) of sequences. CONCLUSION: Intra-rater and inter-rater reliability coefficients are very high for determination of presence or absence of any obstruction, presence or absence of a retropalatal obstruction, presence or absence of a retroglossal obstruction, presence or absence of a swallow, and duration of obstruction from Sleep MRI sequences in OSAS patients.

The basic principle of anterior skull base surgery is to provide adequate exposure to enable three dimensional resection of skull base tumors. Negative surgical margins, which is within the control of surgeon, is the principle prognostic factor in anterior skull base tumors. Open skull base approaches is the standard of care for malignant anterior skull base tumors. Benign lesions may be resected by alternate minimally invasive approaches. Advances in anterior skull base surgery, in particular the facial translocation approaches allows wide exposure of the tumors with minimal retraction of the brain. The outcome of anterior skull base tumors have steadily increased over the years with disease free survival comparable to other malignant neoplasm of the head and neck region. This review described various surgical approaches and pertaining anatomy and pathology of anterior skull base tumors.

HYPOTHESIS: A new intraoral bone-conduction device has advantages over existing bone-conduction devices for reducing the auditory deficits associated with single-sided deafness (SSD). BACKGROUND: Existing bone-conduction devices effectively mitigate auditory deficits from single-sided deafness but have suboptimal microphone locations, limited frequency range, and/or require invasive surgery. A new device has been designed to improve microphone placement (in the ear canal of the deaf ear), provide a wider frequency range, and eliminate surgery by delivering bone-conduction signals to the teeth via a removable oral appliance. METHODS: Forces applied by the oral appliance were compared with forces typically experienced by the teeth from normal functions such as mastication or from other appliances. Tooth surface changes were measured on extracted teeth, and transducer temperature was measured under typical use conditions. Dynamic operating range, including gain, bandwidth, and maximum output limits, were determined from uncomfortable loudness levels and vibrotactile thresholds, and speech recognition scores were measured using normal-hearing subjects. Auditory performance in noise (Hearing in Noise Test) was measured in a limited sample of SSD subjects. Overall comfort, ease of insertion, and removal and visibility of the oral appliance in comparison with traditional hearing aids were measured using a rating scale. RESULTS: The oral appliance produces forces that are far below those experienced by the teeth from normal functions or conventional dental appliances. The bone-conduction signal level can be adjusted to prevent tactile perception yet provide sufficient gain and output at frequencies from 250 to 12,000 Hz. The device does not damage tooth surfaces nor produce heat, can be inserted and removed easily, and is as comfortable to wear as traditional hearing aids. The new microphone location has advantages for reducing the auditory deficits caused by SSD, including the potential to provide spatial cues introduced by reflections from the pinna, compared with microphone locations for existing devices. CONCLUSION: A new approach for SSD has been proposed that optimizes microphone location and delivers sound by bone conduction through a removable oral appliance. Measures in the laboratory using normal-hearing subjects indicate that the device provides useful gain and output for SSD patients, is comfortable, does not seem to have detrimental effects on oral function or oral health, and has several advantages over existing devices. Specifically, microphone placement is optimized for reducing the auditory deficit caused by SSD, frequency bandwidth is much greater, and the system does not require surgical placement. Auditory performance in a small sample of SSD subjects indicated a substantial advantage compared with not wearing the device. Future studies will involve performance measures on SSD patients wearing the device for longer periods.

Rodent pain models play an important role in understanding the mechanisms of nociception and have accelerated the search for new treatment approaches for pain. Creating an objective metric for orofacial nociception in these models presents significant technical obstacles. No animal assay accurately measures pain-induced orofacial dysfunction that is directly comparable to human orofacial dysfunction. We developed and validated a high throughput, objective, operant, nociceptive animal assay, and an instrument to perform the assay termed the dolognawmeter, for evaluation of conditions known to elicit orofacial pain in humans. Using the device our assay quantifies gnawing function in the mouse. We quantified a behavioral index of nociception and demonstrated blockade of nociception in three models of orofacial pain: (1) TMJ inflammation, (2) masticatory myositis, and (3) head and neck cancer. This assay will be useful in the study of nociceptive mediators involved in the development and progression of orofacial pain conditions and it will also provide a unique tool for development and assessment of new therapeutic approaches

OBJECTIVE:To characterize the endoscopic anatomy of the sphenoid sinus and the adjacent clivus and cavernous sinus, and to review patient outcomes for neoplasms in this region. STUDY DESIGN/METHODS:Cadaver dissection and chart review. SETTING/METHODS:Cadaver laboratory and tertiary care center. SUBJECTS AND METHODS/METHODS:Fresh-frozen cadaver heads were dissected to study the endoscopic anatomy of the sphenoclival region. Retrospective chart review of patients undergoing endoscopic resection of sphenoclival neoplasms between 2000 and 2008 was performed. RESULTS:Transnasal endoscopic access to the sphenoid sinus was obtained in 10 cadaver heads. A clival window with mean dimensions of 1.4 cm x 1.7 cm was created. Through the clival window, identification and dissection of the basilar and vertebral arteries, mamillary bodies, third ventricle, cranial nerves III through VI, and cervical rootlets were possible. Nineteen patients with mean age of 56.2 years were treated. The most common pathologies were inverted papilloma (5), chordoma (4), squamous cell carcinoma (2), and adenoid cystic carcinoma (2). None of the patients required adjunct craniotomies. Nine patients received adjuvant therapies. Thirteen (68.4%) patients had no evidence of disease, five (26.3%) patients were alive with disease, and one (5.3%) patient died of disease at mean follow-up of 32.6 months. CONCLUSION/CONCLUSIONS:The sphenoclival region poses a significant surgical challenge given its central location at the skull base and proximity to critical structures. This study demonstrates that transnasal endoscopic access to the sphenoclival region is technically feasible and allows successful surgical extirpation of tumors with a low complication rate and acceptable patient outcomes.

To review existing patient reported outcomes measures (PROMs) used in dysphonic populations to assess the procedures used in their development and the extent to which these meet current development standards for content generation and psychometric evaluation. The study is a systematic review. A systematic review of Medline, Cumulative Index to Nursing & Allied Health, and Health and Psychosocial Instruments databases was completed using voice, quality of life, and PROMs as keywords. We identified all patient or parent-reported questionnaires measuring quality of life associated with voice disorders from the review findings. Questionnaires were appraised for adherence to international guidelines for the development and evaluation of PROMs as outlined by the Scientific Advisory Committee of the Medical Outcome Trust. Nine PROMs fulfilled the inclusion criteria. The quality of these questionnaires was variable with regard to instrument development and none met all of the current, recommended criteria. Of the nine questionnaires, the Voice Symptom Scale underwent the most rigorous development process. Furthermore, many instruments have been augmented to allow for proxy administration, failing to address quality of life-related issues specific to the target population. Instrument development is often overlooked when attempting to quantify patient reported outcomes in dysphonic patients. Careful instrument development procedures are required to ensure that PROMs are valid, reliable, and responsive. Our review suggests that the deficits in psychometric properties of the current voice-related PROMs may be, at least in part, due to deficits in the development process. Furthermore, these data suggest the potential utility of a novel PROM adhering to rigorous international standards to better ensure that clinicians appreciate the variables most relevant to patients with voice disorders and address some of the psychometric shortcomings of the currently used questionnaires

Gait dysfunction and falling are major sources of disability for patients with advanced Parkinson's disease (PD). It is presently thought that the fundamental defect is an inability to generate normal stride length. Our data suggest, however, that the basic problem in PD gait is an impaired ability to match step frequency to walking velocity. In this study, foot movements of PD and normal subjects were monitored with an OPTOTRAK motion-detection system while they walked on a treadmill at different velocities. PD subjects were also paced with auditory stimuli at different frequencies. PD gait was characterized by step frequencies that were faster and stride lengths that were shorter than those of normal controls. At low walking velocities, PD stepping had a reduced or absent terminal toe lift, which truncated swing phases, producing shortened steps. Auditory pacing was not able to normalize step frequency at these lower velocities. Peak forward toe velocities increased with walking velocity and PD subjects could initiate appropriate foot dynamics during initial phases of the swing. They could not control the foot appropriately in terminal phases, however. Increased treadmill velocity, which matched the natural PD step frequency, generated a second toe lift, normalizing step size. Levodopa increased the bandwidth of step frequencies, but was not as effective as increases in walking velocity in normalizing gait. We postulate that the inability to control step frequency and adjust swing phase dynamics to slower walking velocities are major causes for the gait impairment in PD.

In the present study, a computational model of phoneme identification was applied to data from a previous study, wherein cochlear implant (CI) users' adaption to a severely shifted frequency allocation map was assessed regularly over 3 months of continual use. This map provided more input filters below 1 kHz, but at the expense of introducing a downwards frequency shift of up to one octave in relation to the CI subjects' clinical maps. At the end of the 3-month study period, it was unclear whether subjects' asymptotic speech recognition performance represented a complete or partial adaptation. To clarify the matter, the computational model was applied to the CI subjects' vowel identification data in order to estimate the degree of adaptation, and to predict performance levels with complete adaptation to the frequency shift. Two model parameters were used to quantify this adaptation; one representing the listener's ability to shift their internal representation of how vowels should sound, and the other representing the listener's uncertainty in consistently recalling these representations. Two of the three CI users could shift their internal representations towards the new stimulation pattern within 1 week, whereas one could not do so completely even after 3 months. Subjects' uncertainty for recalling these representations increased substantially with the frequency-shifted map. Although this uncertainty decreased after 3 months, it remained much larger than subjects' uncertainty with their clinically assigned maps. This result suggests that subjects could not completely remap their phoneme labels, stored in long-term memory, towards the frequency-shifted vowels. The model also predicted that even with complete adaptation, the frequency-shifted map would not have resulted in improved speech understanding. Hence, the model presented here can be used to assess adaptation, and the anticipated gains in speech perception expected from changing a given CI device parameter

OBJECTIVE: To determine the difference in nasal bone narrowing between 2 techniques: the low lateral intranasal perforating osteotomy technique and the low lateral continuous osteotomy technique. METHODS: A retrospective analysis of preoperative and postoperative photographs to determine the changes of the dorsal width of the nose (width of plateau of the nose, or dorsal nasal highlight) and the ventral width (junction of the flattened surface of the maxilla and the ascending nasal process of the maxilla). RESULTS: Twenty patients underwent continuous osteotomies, and 40 underwent intranasal perforating osteotomies. The continuous osteotomy technique had a preoperative to postoperative decrease in the ventral width of 7.0% (P < .01). The perforating osteotomy technique had a decrease in the ventral width of 3.6% (P < .001). Neither technique resulted in a statistically significant change in dorsal width (P < .25). There was no significant difference in ventral and dorsal narrowing when comparing continuous osteotomies to perforating. CONCLUSIONS: Both the continuous and perforating osteotomy technique resulted in a decrease in the ventral nasal bone width. No statistical difference was found between continuous and perforating osteotomy techniques in the amount of nasal bone narrowing (P < .25)

Since the advent of cochlear implantation, candidacy criteria have slowly broadened to include increasingly younger patients. Spurred by evidence demonstrating both perioperative safety and significantly increased speech and language benefit with early auditory intervention, children younger than 12 months of age are now being successfully implanted at many centers. This review highlights the unique challenges involved in cochlear implantation in the very young child, specifically diagnosis and certainty of testing, anesthetic risk, surgical technique, intraoperative testing and postoperative programming, long-term safety, development of receptive and expressive language, and outcomes of speech perception. Overall, the current body of literature indicates that cochlear implantation prior to 1 year of age is both safe and efficacious