Faculty Bibliography

BACKGROUND: Deep brain stimulation of the subthalamic nucleus (STN) has demonstrated efficacy in improving motor disability in Parkinson's disease. The recently developed quantitative susceptibility mapping (QSM) technique, which can accurately map iron deposits in deep brain nuclei, promises precise targeting of the STN. OBJECTIVE: To demonstrate the use of QSM to target STN effectively by correlating with classical physiological-based targeting measures in a prospective study. METHODS: The precision and accuracy of direct targeting with QSM was examined in a total of 25 Parkinson's disease patients between 2013 and 2015 at our institution. QSM was utilized as the primary magnetic resonance imaging (MRI) method to perform direct STN targeting on a stereotactic planning station utilizing computed tomography/MR fusion. Intraoperative microelectrode recordings (MER) were obtained to confirm appropriate trajectory through the sensorimotor STN. RESULTS: Estimations of STN thickness between the MER and QSM methods appeared to be correlated. Mean STN thickness was 5.3 mm. Kinesthetic responsive cells were found in > 90% of electrode runs. The mean radial error (+/-SEM) was 0.54 +/- 0.1 mm. Satisfactory clinical response as determined by Unified Parkinson's Disease Rating Scale (UPDRS III) was seen at 12 mo after surgery. CONCLUSION: Direct targeting of the sensorimotor STN using QSM demonstrates MER correlation and can be safely used for deep brain stimulation lead placement with satisfactory clinical response. These results imply that targeting based on QSM signaling alone is sufficient to obtain reliable and reproducible outcomes in the absence of physiological recordings.

Oxytocin is a hypothalamic neuropeptide first recognized as a regulator of parturition and lactation which has recently gained attention for its ability to modulate social behaviors. In this chapter, we review several aspects of the oxytocinergic system, focusing on evidence for release of oxytocin and its receptor distribution in the cortex as the foundation for important networks that control social behavior. We examine the developmental timeline of the cortical oxytocin system as demonstrated by RNA, autoradiographic binding, and protein immunohistochemical studies, and describe how that might shape brain development and behavior. Many recent studies have implicated oxytocin in cognitive processes such as processing of sensory stimuli, social recognition, social memory, and fear. We review these studies and discuss the function of oxytocin in the young and adult cortex as a neuromodulator of central synaptic transmission and mediator of plasticity.

OBJECTIVES/HYPOTHESIS: To describe the distribution of recurrent respiratory papillomatosis (RRP) lesions across 21 laryngeal anatomic regions in previously untreated patients at initial presentation to provide insight regarding the natural history of RRP. STUDY DESIGN: Multi-institutional, retrospective case series. METHODS: Initial laryngoscopic examination videos of 83 previously untreated patients with adult-onset RRP were reviewed. Papilloma locations were recorded using a 21-region laryngeal schematic. Multivariate analyses by anatomic subsite were conducted for the entire population and for subgroups stratified by sex, age, and proton pump inhibitor (PPI) usage. Heat maps were generated, hierarchically color coding the anatomic distribution of disease. RESULTS: In this cohort, RRP was most likely to occur on the true vocal folds (TVFs) and anterior commissure (P < .0001, odds ratio [OR]: 7.02); within the TVFs, the membranous vocal folds (MVFs) were most likely to be affected (P < .0001, OR: 3.56). The cohort was predominantly male (80.7%); males had a higher average number of affected sites (P = .005) and were more likely to have lesions in any laryngeal subsite (P < .0001, OR: 2.88,) compared to females. PPI users were more likely than nonusers to have disease in any laryngeal subsite (P = .0037, OR: 1.62), particularly in the posterior and subglottic regions (P = .0061, OR: 2.53). Age was not correlated with lesion prevalence or distribution. CONCLUSIONS: In untreated patients presenting to three laryngology clinics, the MVFs were most likely to be affected by RRP. Males had more anatomic sites affected by papilloma than females. The influence of PPI use on RRP distribution warrants further investigation. LEVEL OF EVIDENCE: 4. Laryngoscope, 2017.

OBJECTIVES: A postlingually implanted adult typically develops hearing with an intact auditory system, followed by periods of deafness (or near deafness) and adaptation to the implant. For an early implanted child whose brain is highly plastic, the auditory system matures with consistent input from a cochlear implant. It is likely that the auditory system of early implanted cochlear implant users is fundamentally different than postlingually implanted adults. The purpose of this study is to compare the basic psychophysical capabilities and limitations of these two populations on a spectral resolution task to determine potential effects of early deprivation and plasticity. DESIGN: Performance on a spectral resolution task (Spectral-temporally Modulated Ripple Test [SMRT]) was measured for 20 bilaterally implanted, prelingually deafened children (between 5 and 13 years of age) and 20 hearing children within the same age range. Additionally, 15 bilaterally implanted, postlingually deafened adults, and 10 hearing adults were tested on the same task. Cochlear implant users (adults and children) were tested bilaterally, and with each ear alone. Hearing listeners (adults and children) were tested with the unprocessed SMRT and with a vocoded version that simulates an 8-channel cochlear implant. RESULTS: For children with normal hearing, a positive correlation was found between age and SMRT score for both the unprocessed and vocoded versions. Older hearing children performed similarly to hearing adults in both the unprocessed and vocoded test conditions. However, for children with cochlear implants, no significant relationship was found between SMRT score and chronological age, age at implantation, or years of implant experience. Performance by children with cochlear implants was poorer than performance by cochlear implanted adults. It was also found that children implanted sequentially tended to have better scores with the first implant compared with the second implant. This difference was not observed for adults. An additional finding was that SMRT score was negatively correlated with age for adults with implants. CONCLUSIONS: Results from this study suggest that basic psychophysical capabilities of early implanted children and postlingually implanted adults differ when assessed in the sound field using their personal implant processors. Because spectral resolution does not improve with age for early implanted children, it seems likely that the sparse representation of the signal provided by a cochlear implant limits spectral resolution development. These results are supported by the finding that postlingually implanted adults, whose auditory systems matured before the onset of hearing loss, perform significantly better than early implanted children on the spectral resolution test.

OBJECTIVE: To determine the longitudinal effectiveness of the malleus to oval window stapedotomy technique among patients undergoing revision surgery when the incus is unavailable. STUDY DESIGN: Retrospective, case series. METHODS: Charts of 15 patients who underwent 17 malleus attachment stapedotomies performed by a single surgeon from 2000 to 2015 were reviewed. Surgery was ambulatory, transcanal, with laser technique, and under local anesthesia. RESULTS: Of 17 stapedotomies performed, there were nine first revisions, six second revisions, one third revision, and one fourth revision. There were no surgical complications. Mean preoperative air-bone gap (ABG) was 32.3 dB. Mean postoperative ABG at 6 months was 10.7 dB, and at last follow-up was 16.3 dB. Average length of follow-up was 36.5 months. At last follow-up, 100% of first revisions achieved ABG