Faculty Bibliography

OBJECTIVE: High channel count electrode arrays allow for the monitoring of large-scale neural activity at high spatial resolution. Implantable arrays featuring many recording sites require compact, high bandwidth front-end electronics. In the present study, we investigated the use of a small, light weight, and low cost digital current-sensing integrated circuit for acquiring cortical surface signals from a 61-channel micro-electrocorticographic (ECoG) array. APPROACH: We recorded both acute and chronic ECoG signal from rat auditory cortex using our novel digital current-sensing headstage. For direct comparison, separate recordings were made in the same anesthetized preparations using an analog voltage headstage. A model of electrode impedance explained the transformation between current- and voltage-sensed signals, and was used to reconstruct cortical potential. We evaluated the digital headstage using several metrics of the baseline and response signals. MAIN RESULTS: The digital current headstage recorded neural signal with similar spatiotemporal stastics and auditory frequency tuning compared to the voltage signal. The signal-to-noise ratio of auditory evoked responses (AERs) was significantly stronger in the current signal. Stimulus decoding based on true and reconstructed voltage signals were not significantly different. Recordings from an implanted system showed AERs that were detectable and decodable for 52 days. The reconstruction filter mitigated the thermal current noise of the electrode impedance and enhanced overall SNR. SIGNIFICANCE: We developed and validated a novel approach to headstage acquisition that used current-input circuits to independently digitize 61 channels of ECoG measurements of the cortical field. These low-cost circuits, intended to measure photo-currents in digital imaging, not only provided a signal representing the local cortical field with virtually the same sensitivity and specificity as a traditional voltage headstage but also resulted in a small, light headstage that can easily be scaled to record from hundreds of channels.

The consequences of developmental hearing loss have been reported to include both sensory and cognitive deficits. To investigate these issues in a non-human model, auditory learning and asymptotic psychometric performance were compared between normal hearing (NH) adult gerbils and those reared with conductive hearing loss (CHL). At postnatal day 10, before ear canal opening, gerbil pups underwent bilateral malleus removal to induce a permanent CHL. Both CHL and control animals were trained to approach a water spout upon presentation of a target (Go stimuli), and withhold for foils (Nogo stimuli). To assess the rate of task acquisition and asymptotic performance, animals were tested on an amplitude modulation (AM) rate discrimination task. Behavioral performance was calculated using a signal detection theory framework. Animals reared with developmental CHL displayed a slower rate of task acquisition for AM discrimination task. Slower acquisition was explained by an impaired ability to generalize to newly introduced stimuli, as compared to controls. Measurement of discrimination thresholds across consecutive testing blocks revealed that CHL animals required a greater number of testing sessions to reach asymptotic threshold values, as compared to controls. However, with sufficient training, CHL animals approached control performance. These results indicate that a sensory impediment can delay auditory learning, and increase the risk of poor performance on a temporal task.

Due to its central location, the nose plays a prominent role in facial aesthetics. As tastes have shifted and techniques have advanced, the accepted "ideal" appearance and proportions of the nose have evolved over time. By assessing the aesthetics of the nasal dorsum through the use of lines and angles, one can more precisely elucidate a goal for the patient's postoperative nasal shape, which should, in turn, guide the surgeon to execute specific operative maneuvers needed to achieve that contour. In assessing the aesthetics of the nasal dorsum, practitioners calculate and observe aspects such as the paired dorsal aesthetic lines, the nasofrontal angle, and the nasofacial angle. There is also additional consideration given to nasal tip position as this must fit harmoniously with the shape of the dorsum. In contrast to the established aesthetic lines and angles, using nasal geometric polygons for the aesthetic evaluation and development of operative goals in rhinoplasty has recently been described in the literature. Constructed ideals, in the form of proportions, lines, and angles, should be used with caution, as there are many factors to consider in the aesthetic analysis of the nasal dorsum, including ethnic differences, and subjective and changing views of beauty.

OBJECTIVES/HYPOTHESIS:As our population ages, injuries attributable to falls continue to increase, impacting healthcare delivery. Evaluation of craniofacial trauma with focus on elderly patients remains an underappreciated concern. Our objectives were to evaluate injury trends associated with elderly bathroom falls, as this information may be useful for counseling and preventive purposes. STUDY DESIGN:Database review. METHODS:The National Electronic Injury Surveillance System was evaluated for craniofacial trauma among patients 60 years and older presenting to the emergency department (ED) (2010-2014). Injury descriptions were reviewed for mechanism of injury, patient demographics, and other injury characteristics. RESULTS:In total, 7.2% of the estimated 3.4 million ED visits for elderly craniofacial trauma were bathroom related. Females comprised the majority (60.9%) of patients, and a plurality of patients were in their 80s. A greater proportion of facial injuries resulted from syncope (16.6% vs. 10.9% compared to head injuries). Toilets facilitated a greater proportion of facial insults and were more likely to require admission; the most common mechanism was "falling off." Showers contributed a majority of head injuries and had a lower median age than toilet injuries. Fractures comprised 12.6% of facial injuries; of craniofacial fractures, common sites included the nose (54%), mandible (6%), and orbit (6%). Admitted patients were significantly older than those who were released. CONCLUSIONS:Bathroom falls result in a significant proportion of elderly traumatic injury. The trends we present offer the opportunity for targeted preventative measures to decrease the occurrence of these events. Additionally, this information may adjunct a detailed history and physical to ensure appropriate patient management. LEVEL OF EVIDENCE:4 Laryngoscope, 127:820-827, 2017.

Cavernous sinus thrombosis is a rare but well-documented complication of sinus disease, propagated by intracranial spread of infection via valveless veins of the midface, with facial cellulitis as an uncommon source of infection. We present a case of significant intracranial thromboses secondary to nasal dorsal abscess after trauma that was successfully treated with bedside drainage of the abscess in addition to broad-spectrum antibiotics, anticoagulation, and steroids, and remains asymptomatic with seven months follow-up.

Significant technological advances have fostered a movement toward minimally invasive surgical interventions for the management of ventral skull base malignancies. The care of patients with these lesions ideally involves an interdisciplinary skull base team that includes otolaryngologists, neurologic surgeons, radiation oncologists, and medical oncologists. This overview describes considerations essential for diagnosis, prognosis, and preoperative evaluation. Furthermore, surgical nuances, strategies for skull base reconstruction, and nonsurgical options are briefly discussed. Our hope is that this overview may be useful as an up-to-date description of the challenging clinical scenarios associated with these lesions.

The production and perception of music is preferentially mediated by cortical areas within the right hemisphere, but little is known about how these brain regions individually contribute to this process. In an experienced singer undergoing awake craniotomy, we demonstrated that direct electrical stimulation to a portion of the right posterior superior temporal gyrus (pSTG) selectively interrupted singing but not speaking. We then focally cooled this region to modulate its activity during vocalization. In contrast to similar manipulations in left hemisphere speech production regions, pSTG cooling did not elicit any changes in vocal timing or quality. However, this manipulation led to an increase in the pitch of speaking with no such change in singing. Further analysis revealed that all vocalizations exhibited a cooling-induced increase in the frequency of the first formant, raising the possibility that potential pitch offsets may have been actively avoided during singing. Our results suggest that the right pSTG plays a key role in vocal sensorimotor processing whose impact is dependent on the type of vocalization produced.

An evolving paradigm in global outreach in radiation oncology has been the implementation of a more region-specific, needs-based approach to help close the gap in radiation services to low- and middle-income countries through the use of innovative tools in information and communication technology. This report highlights 4 information and communication technology tools in action today: (1) the NCCN Framework for Resource Stratification of NCCN guidelines, (2) ASTRO e-Contouring, (3) i.treatsafely.org, and (4) ChartRounds.com. We also render special consideration to matters related to global outreach that we believe require distinct attention to help us meet the goals established by the 2011 United Nations Declaration on noncommunicable diseases: (1) trainee advancement toward careers in global health, (2) ethical challenges of international outreach, (3) critical importance of political advocacy, and (4) collaboration with Industry.