Faculty Bibliography

Background: Oxytocin is essential for social interactions and maternal behavior. However, little is known about how oxytocin modulates neural circuits to improve social and maternal outcomes. We describe a synaptic mechanism by which oxytocin enhances signal-to-noise ratio in left primary auditory cortex to improve mouse maternal behavior. Methods: We performed electrophysiological recordings, and used anatomical, optogenetic and behavioral techniques to examine the role of oxytocin in maternal behavior in wild-type C57BL/6 and Oxytocin-IRES-Cre mice. Results: Virgins females, who do not initially retrieve distressed pups, rapidly expressed retrieval behavior after receiving oxytocin under dam and pups co-housing conditions. Retrieval onset was accelerated in 20/36 mice receiving systemic oxytocin and in 5/7 mice receiving optogenetic stimulation (P=0.03, 0.05, respectively; Fisher's two-tailed exact test). To confirm regional sites of action subserving improved maternal behavior, we generated novel antibodies that bind to the mouse oxytocin receptor. Oxytocin receptors were preferentially expressed in the left auditory cortex (19% left cells, 14% right cells, n=21, P=0.001). Finally, we utilitzed in vivo whole-cell recordings to measure spiking/synaptic responses to pup calls. Pup call responses were lateralized, with co-tuned/temporally-precise responses in left auditory cortex of maternally-experienced but not maternal-naive adults. Pairing calls with oxytocin enhanced call-evoked responses in virgin dams by balancing the magnitude/ timing of inhibition with excitation, transitioning the auditory cortex from a virgin-like state to a maternal state. Conclusions: Our study provides a biological basis for the lateralization of vocal processing and emergence of experience-based social learning. These studies inform behavioral therapies involving oxytocin administration

OBJECTIVE AND IMPORTANCE: Preoperative chronic otitis media (COM) is a risk factor for postoperative infection after cochlear implantation (CI), but its management varies by surgeon. Our case highlights a strategy for implant preservation in a patient with a history of recurrent cochlear implant infection. CLINICAL PRESENTATION: A 70-year-old woman with a history of chronic lymphocytic leukemia presented in 2005 with bilateral COM and sensorineural hearing loss meeting CI candidacy. Four months after left mastoid obliteration with abdominal fat graft and external auditory canal closure, a left CI was placed. Subsequent postauricular cellulitis resolved with oral antibiotics. A similar two-stage CI was performed on the right without complication. During the following year, numerous left-sided infections and fluid collections developed but were treated unsuccessfully with intravenous (IV) antibiotics and operative debridement. With concern for biofilm colonization, the implant was explanted and the electrode left in the cochlea. After reimplantation in 2010, infections resumed despite long-term IV antibiotics and incision and drainage. Intervention and technique In 2012, the left mastoid cavity was exteriorized and converted to standard canal wall-down anatomy. Bone pate was placed over the electrode, followed by cadaveric acellular dermis and a split-thickness skin graft. After more than 2 years, her better-performing CI remains infection-free. CONCLUSION: After 6 years of postoperative infections unresponsive to aggressive medical management, surgical interventions, and period of device removal, our patient's infections resolved after mastoid exteriorization and multilayered protection of the electrode. This strategy may enable implant preservation in patients with recurrent post-CI infection in an obliterated cavity.

INTRODUCTION: Although rare, complications in cochlear implantation may result from surgical or technical mishaps, reaction to the foreign body, infection, or mechanical device failure. Delayed cerebrospinal fluid (CSF) leak is a rarely reported condition that may present with asymptomatic swelling over the receiver-stimulator (RS). In our practice, meticulous drilling of a bony well is important in preventing device migration and maintaining a low device profile but there is the potential for immediate or delayed complication from this technique. OBJECTIVE: We report two cases of the diagnosis and management of delayed extradural CSF collection of the RS bony well and describe its successful management. PATIENTS: Two pediatric cochlear implant patients, 10 and 17 months of age with devices from different manufacturers. INTERVENTION(S): Operative exploration and repair without device removal. MAIN OUTCOME AND RESULTS: Although the initial postoperative course was uncomplicated with both patients receiving benefit from their device, both presented at varying intervals month(s) later with swelling over the RS. There were no signs of infection but the swelling prevented use of the device. Extradural CSF collection was suspected, confirmed operatively, and repaired with complete resolution without the need for reimplantation. CONCLUSION: Delayed CSF leak may present as an asymptomatic swelling over the RS after cochlear implantation. Sterile fluid aspiration may confirm the diagnosis and management can proceed conservatively or with operative exploration and repair. Future device designs with lower profiles may facilitate device fixation while allowing for a more shallow well, further reducing the risk of this rare complication.

OBJECTIVES: To develop consensus recommendations for peri-operative tracheotomy care in pediatric patients. METHODS: Expert opinion by the members of the International Pediatric Otolaryngology Group (IPOG). The mission of the IPOG is to develop expertise-based consensus recommendations for the management of pediatric otolaryngologic disorders with the goal of improving patient care. The consensus recommendations herein represent the first publication by the group. RESULTS: Consensus recommendations including pre-operative, intra-operative, and post-operative considerations, as well as sedation and nutrition management are described. These recommendations are based on the collective opinion of the IPOG members and are targeted to (i) otolaryngologists who perform tracheotomies on pediatric patients, (ii) intensivists who are involved in the shared-care of these patients, and (iii) allied health professionals. CONCLUSION: Pediatric peri-operative tracheotomy care consensus recommendations are aimed at improving patient-centered care in this patient population.

Objective: Cerebral venous sinus thrombosis (CVST) is a rare but potentially dangerous complication following craniotomies involving the posterior fossa, the skull base, and craniotomies involving the superior sagittal sinus. Surgical manipulation of the sinuses has been shown to cause sinus thromboses of varying degrees. This phenomenon is often clinically silent, with only a small number of patients becoming symptomatic. Recent advances in neuroimaging provide higher resolution evaluation of cerebral sinuses pre and postoperatively, often revealing clinically silent filling defects. Although sinus thrombosis can be a major cause of morbidity and mortality, its incidence and factors that contribute to its formation in the postoperative population remain unclear. In addition, current guidelines advise to anticoagulate with Heparin upon diagnosis, which can be contraindicated for immediate post craniotomy patients. The goal of this study is to evaluate retrospective data of patient outcomes and factors that might contribute to sinus thrombus formation. Methods: A retrospective chart review was conducted at NYU Langone Medical Center. Ninety-seven patients were included who underwent either a retrosigmoid/translabrynthine/suboccipital resection of a posterior fossa tumor or a supratentorial craniotomy for resection of parasagittal/falcine tumor between July 1, 2014 and July 1, 2015. Pre operative Magnetic Resonance Venography (MRV) was obtained per the attending surgeon's discretion. Based on intraoperative findings, clinical symptoms, and surgeon's preference, a postoperative MRV was obtained. Decision to treat a thrombosis was made based on the results of the MRV and clinical symptoms. Treatments included observation, intravenous fluids (IVF) alone, anti-platelet therapy with Aspirin alone, or a combination of the two. Results: A total of 7 of 97 patients (7.22%) had postoperative sinus thrombosis. Of those patients, 5 had occlusion of the venous sinuses. In the occlusion group, 4 had preoperative imaging documenting patency of the sinuses. An additional 2 patients had postoperative MRVs revealing partial thrombosis of the sinus, 1 that was new and 1 that did not have a preoperative MRV for comparison. Compared with the cohort of patients without postoperative thromboses, there was no significant difference in age, BMI, length of surgery, or surgical approach. Of the 5 patients with postoperative thrombotic occlusion, 4 underwent intervention (1 with IVF alone, 2 with IVF and aspirin, and 1 with aspirin alone). Two patients with thromboses also developed CSF leaks requiring lumbar drainage and operative repair. One patient had a persistent CSF leak requiring a shunt. Of the 2 patients with partial thrombosis, 1 was placed on IVF and aspirin. At 3 months follow up, 1 out of 5 patients in the occlusion group had recanalization of the previously thrombosed sinus. Conclusions: MRV is a non-invasive method to evaluate the caliber and patency of dural venous sinuses in post craniotomy patients. Symptomatic thrombosis is rare and can be managed either conservatively or with IVF and/or anti platelet therapy, both which are safer than anticoagulation with heparin in post craniotomy patients. A larger prospective trial is necessary to further characterize the incidence of postoperative venous sinus thrombosis, identify risk factors, and to devise recommendations for therapy

Background: Salvage surgery for progressive symptoms or recurrent growth of vestibular schwannoma (VS) after stereotactic radiosurgery (SRS) is uncommon. It has been reported to be more difficult, the same or easier than expected compared with microsurgical resection (MS) of treatment-naive VS, with variable facial nerve outcomes. We conducted a matched cohort analysis to evaluate facial nerve outcomes for patients undergoing MS for progressive symptoms or recurrent growth of VS after SRS compared with MS for treatment-naive VS. Methods: We evaluated the records of 365 non-NF2 VS patients treated with MS from 2001 to 2014. All patients who had postoperative notes were considered to have "adequate follow-up" and included in the study. Nine patients underwent resection for VS after prior SRS (MS-POST SRS) with no prior intervention, 7 of which had adequate follow-up, and 331 patients that underwent MS for treatment naive VS (MS-NO SRS), 317 of which had adequate follow-up. From this dataset, we created propensity score matched cohorts to retrospectively compare facial nerve preservation and clinical outcomes. The propensity score model incorporated age at surgery, tumor size, and pre-operative HB grade, and cases were matched at a ratio of 4:1 MS-NO SRS to MS-POST SRS cases. Results: The MS-POST SRS (n = 7) and MS-NO SRS (n = 28) groups differed only in preoperative hearing status (p < 0.01). Preoperative HB grades were similar between MS-POST SRS and MS-NO SRS groups (p>0.3). The average time-to-intervention after SRS in the MS-POST SRS group was 44.4 months. The indication for MS after SRS was symptom progression with tumor growth in 4 cases, and only tumor growth in the remaining 3. Postoperatively, 3 cases in the MS-POST SRS group demonstrated improvement in HB grade and none became worse whereas 3 of 28 cases in the MS-NO SRS group demonstrated improvement and 12 cases had decrement in HB grade relative to baseline (p < 0.05). There was no significant difference in the extent of resection with both cohorts (MS-POST SRS and MS-NO SRS) attaining gross total resection in 85.7% of cases. Subsequent intervention was not required for any case in the MS-POST SRS group and 2 cases in the MS-NO SRS group, although this difference was not significant. Both cases requiring subsequent intervention in the MS-POST SRS group were gross total resections via the translabyrinthine approach, with subsequent intervention required at 62 and 48 months. There were no significant differences in the complication rate for individual complications or the overall complication rate between cohorts. Conclusions: At a center with high clinical volume, microsurgical resection of VS after prior SRS was associated with good postoperative facial nerve preservation and low morbidity, comparable to those observed in resection of treatment-naive VS. In addition there were similar outcomes in terms of extent of resection between the two groups. The good outcomes reported here may reflect a confluence of factors which include patient selection, the experience of the attending surgeons, the use of more contemporary SRS dosing protocols during initial treatment for these patients, and divergent goals of therapy between cohorts

Background: The transcochlear approach extends the anterior exposure afforded by the translabyrinthine technique. Although this wider exposure allows improved access to cranial nerves and the brainstem with less retraction on the cerebellum, the classical description involving facial nerve transposition often results in permanent facial paresis. This study discusses the role of the transcochlear approach in resection of cerebellopontine angle tumors including patient selection, surgical technique, and outcomes. Study Design: Retrospective review. Methods: This is a retrospective review conducted at a single academic institution. Cases performed by our skull base team (neurotologist and neurosurgeon) between 2000 and 2015 were reviewed. All cases utilizing the transcochlear approach were included. Factors including tumor size, completeness of resection, facial nerve function, post-operative complications, and length of stay were analyzed. Results: Fourteen cases were included. All of these patients had pre-operative severe hearing loss except for two in which surgery was performed urgently in the setting of hydrocephalus and brainstem compression. Eight out of 14 patients had pre-operative facial paresis. Tumor size ranged from 2.2-7 cm in greatest dimension (mean = 4.56 cm). All patients underwent a transcochlear approach to and removal of tumor with blind sac of the external auditory canal. In addition, 3 patients underwent an immediate facial nerve to hypoglossal anastomosis. Post-operatively, patients remained in the hospital for 3-5 days (mean = 4). Of the patients who started out with normal facial nerve function (n = 6), 3 recovered to House-Brackmann scores II or greater. There were no reported CSF leaks requiring hospitalization and 1 abdominal hematoma from fat graft harvest. There was a single mortality reported in the peri-operative period; however, on autopsy the cause of death was unrelated to the surgery itself or any subsequent intracranial event. Conclusions: As in other surgical approaches destructive to the labyrinth, patients were selected with consideration of their pre-operative hearing status and/or their candidacy for hearing preservation surgery. Patients with pre-operative facial nerve paralysis and hearing loss were deemed particularly appropriate candidates for the transcochlear technique given the additional exposure and the lack of added morbidity. In these cases the surgeon also has the option to perform dynamic facial nerve reanimation at the time of tumor resection

Oxytocin promotes social interactions and recognition of conspecifics that rely on olfaction in most species. The circuit mechanisms through which oxytocin modifies olfactory processing are incompletely understood. Here, we observed that optogenetically induced oxytocin release enhanced olfactory exploration and same-sex recognition of adult rats. Consistent with oxytocin's function in the anterior olfactory cortex, particularly in social cue processing, region-selective receptor deletion impaired social recognition but left odor discrimination and recognition intact outside a social context. Oxytocin transiently increased the drive of the anterior olfactory cortex projecting to olfactory bulb interneurons. Cortical top-down recruitment of interneurons dynamically enhanced the inhibitory input to olfactory bulb projection neurons and increased the signal-to-noise of their output. In summary, oxytocin generates states for optimized information extraction in an early cortical top-down network that is required for social interactions with potential implications for sensory processing deficits in autism spectrum disorders.

The human vocal folds are complex structures made up of distinct layers that vary in cellular and extracellular composition. The mechanical properties of vocal fold tissue are fundamental to the study of both the acoustics and biomechanics of voice production. To date, quantitative methods have been applied to characterize the vocal fold tissue in both normal and pathologic conditions. This review describes, summarizes, and discusses the most commonly employed methods for vocal fold biomechanical testing. Force-elongation, torsional parallel plate rheometry, simple-shear parallel plate rheometry, linear skin rheometry, and indentation are the most frequently employed biomechanical tests for vocal fold tissues and each provide material properties data that can be used to compare native tissue to diseased or treated tissue. Force-elongation testing is clinically useful, as it allows for functional unit testing, while rheometry provides physiologically relevant shear data, and nanoindentation permits micrometer scale testing across different areas of the vocal fold as well as whole organ testing. Thoughtful selection of the testing technique during experimental design to evaluate a hypothesis is critical to optimize biomechanical testing of vocal fold tissues.

BACKGROUND: Cadaveric face transplant models are routinely used for technical allograft design, perfusion assessment, and transplant simulation but are associated with substantial limitations. The purpose of this study was to describe the experience of implementing a translational donor research facial procurement and solid organ allograft recovery model. METHODS: Institutional review board approval was obtained, and a 49-year-old, brain-dead donor was identified for facial vascularized composite allograft research procurement. The family generously consented to donation of solid organs and the total face, eyelids, ears, scalp, and skeletal subunit allograft. RESULTS: The successful sequence of computed tomographic scanning, fabrication and postprocessing of patient-specific cutting guides, tracheostomy placement, preoperative fluorescent angiography, silicone mask facial impression, donor facial allograft recovery, postprocurement fluorescent angiography, and successful recovery of kidneys and liver occurred without any donor instability. Preservation of the bilateral external carotid arteries, facial arteries, occipital arteries, and bilateral thyrolinguofacial and internal jugular veins provided reliable and robust perfusion to the entirety of the allograft. Total time of facial procurement was 10 hours 57 minutes. CONCLUSIONS: Essential to clinical face transplant outcomes is the preparedness of the institution, multidisciplinary face transplant team, organ procurement organization, and solid organ transplant colleagues. A translational facial research procurement and solid organ recovery model serves as an educational experience to modify processes and address procedural, anatomical, and logistical concerns for institutions developing a clinical face transplantation program. This methodical approach best simulates the stressors and challenges that can be expected during clinical face transplantation. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.