Faculty Bibliography

Carcinoma of unknown primary (CUP) comprises approximately 1%-5% of all head and neck malignancies. Primary site detection rates for metastatic cervical squamous cell carcinoma (SCC) remain variable, with current diagnostic imaging unable to identify all tumours. Prevailing evidence suggests that most head and neck CUP are located in the oropharynx. Diagnostic surgical efforts have been directed at sampling the entire oropharynx. Present techniques that make this possible include transoral robotic surgery (TORS). TORS Lingual tonsillectomy or tongue base mucosectomy performed in the setting of head and neck CUP increases the detection rate of occult tumour. The indication, surgical technique, evidence base, and controversies of performing TORS in the context of the unknown primary are presented.

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.

OBJECTIVE:To assess bimodal auditory performance in children with a cochlear implant (CI) and contralateral auditory brainstem implant (ABI). METHODS:This is a retrospective case review performed at a tertiary referral center. Four patients with cochlear nerve deficiency initially underwent cochlear implantation but were not benefiting from their devices and underwent ABI in the contralateral ear. The main outcome measures included age-appropriate speech perception and production assessments. RESULTS:Three subjects performed better on their auditory perception assessments using both of their devices than with either device alone. One subject had only preliminary outcomes, but subjectively performed best with both devices. CONCLUSIONS:We observed continued improvement in CI performance over time, even if no benefit was evident before the decision for ABI. This could suggest that ABI and CI have a synergistic effect, or it could simply be the adaptive ability of the developing brain to utilize the signals coming from these devices. There is preliminary evidence to support choosing the ear contralateral to the CI for an ABI in a pediatric patient with bilateral cochlear nerve deficiency.

Purpose: Prior studies have shown correlation between relative cerebral blood volume (rCBV) and patient survival and tumor genomics. The purpose of this study was to determine whether rCBV values correlate with isocitrate dehydrogenase (IDH) mutation status, genome-wide CNV (copy number variation) and patient overall survival in diffuse gliomas. Materials & Methods: 107 treatment naive gliomas (62 patients from TCGA/TCIA dataset and 45 patients from our institute) (44 glioblastoma and 63 lower grade gliomas) with DSC T2* perfusion data were included. IDH mutation and survival data were assayed by the TCGA, and pre-surgical imaging collected by The Cancer Imaging Archive. CNVabundance plots obtained with Illumina 850k EPIC DNA methylation arrays were reviewed in 19 patients. The association of rCBV with tumor genomics, CNV and overall survival were analyzed. Results: IDH-wildtype gliomas (44.8%) demonstrated higher rCBV values (rCBV = 6.87 +/- 3.09) than IDH-mutated gliomas (55.2%, rCBV =2.21 +/- 1.71 for 1p/19q codeleted gliomas and 2.09 +/- 2.00 for non-codeleted gliomas, ANOVA, p<0.0001). rCBV is a significant predictor of overall survival (HR 1.23, p<0.0001). Gliomas with rCBV < 3.80 showed better survival (n = 54, median survival time unobserved) than gliomas with rCBV > 3.8 (n = 53, median 18 months; log-rank p<0.0001). IDHwt gliomas with high rCBV had the worst survival (10.6% surviving at 3 years, 95% CI (4%, 30%)). CNV-S IDHmut 1p19q noncodeleted gliomas demonstrated significantly lower mean rCBV (1.4 +/- 0.4) than CNV-U gliomas (4.0 +/- 1.1, p = 0.009). Conclusion: IDHwt gliomas show higher rCBV than IDHmut gliomas irrespective of the glioma grade. Higher rCBV measurements are associated with poorer survival in the entire cohort and also within IDHmut and IDHwt gliomas. IDHmut 1p19q noncodeleted gliomas with higher CNV abundance (CNV-U) also show higher CBV when compared with those with lesser degree of CNVabundance (CNV-S)

Background/UNASSIGNED:While effective for the repair of large skull base defects, the Hadad-Bassagasteguy nasoseptal flap increases operative time and can result in a several-week period of postoperative crusting during re-mucosalization of the denuded nasal septum. Endoscopic transsphenoidal surgery for pituitary adenoma resection is generally not associated with large dural defects and high-flow cerebrospinal fluid (CSF) leaks requiring extensive reconstruction. Here, we present the posterior nasoseptal flap as a novel technique for closure of skull defects following endoscopic resection of pituitary adenomas. This flap is raised in all surgeries during the transnasal exposure using septal mucoperiosteum that would otherwise be discarded during the posterior septectomy performed in binostril approaches. Methods/UNASSIGNED:We present a retrospective, consecutive case series of 43 patients undergoing endoscopic transsphenoidal resection of a pituitary adenoma followed by posterior nasoseptal flap placement and closure. Main outcome measures were extent of resection and postoperative CSF leak. Results/UNASSIGNED:The mean extent of resection was 97.16 ± 1.03%. Radiographic measurement showed flap length to be adequate. While a defect in the diaphragma sellae and CSF leak were identified in 21 patients during surgery, postoperative CSF leak occurred in only one patient. Conclusions/UNASSIGNED:The posterior nasoseptal flap provides adequate coverage of the surgical defect and is nearly always successful in preventing postoperative CSF leak following endoscopic transsphenoidal resection of pituitary adenomas. The flap is raised from mucoperiosteum lining the posterior nasal septum, which is otherwise resected during posterior septectomy. Because the anterior septal cartilage is not denuded, raising such flaps avoids the postoperative morbidity associated with the larger Hadad-Bassagasteguy nasoseptal flap.