Faculty Bibliography

OBJECTIVE:The effectiveness of upper airway stimulation via hypoglossal nerve stimulation for obstructive sleep apnea depends upon the pattern of tongue muscle activation produced. This study investigated the nature of contralateral tongue muscle activation by unilateral hypoglossal nerve stimulation using intraoperative nerve integrity monitoring in conjunction with electromyography and explored the relationship between contralateral tongue muscle activation and polysomnographic measures of obstructive sleep apnea severity. STUDY DESIGN/METHODS:Prospective case series. SETTING/METHODS:Tertiary care medical center. SUBJECTS AND METHODS/METHODS:Fifty-one patients underwent unilateral (right) hypoglossal nerve stimulator implantation for obstructive sleep apnea. Neurophysiological data included electromyographic responses in ipsilateral (right) and contralateral (left) genioglossus muscles in response to intraoperative bipolar probe stimulation (0.3 mA) of medial hypoglossal nerve branches. Clinical data included pre- and postoperative apnea-hypopnea indices and oxygen desaturation levels. RESULTS:A subset of patients (20/51, 39%) exhibited electromyographic responses in both the ipsilateral and contralateral genioglossus (bilateral), whereas the remaining patients (31/51, 61%) exhibited electromyographic responses only in the ipsilateral genioglossus (unilateral). The baseline characteristics of bilateral and unilateral responders were similar. Both groups exhibited significant and comparable improvements in apnea-hypopnea index and oxygen desaturations after hypoglossal nerve stimulation. Neither the amplitude nor the latency of contralateral genioglossus responses was predictive of clinical outcomes. CONCLUSION/CONCLUSIONS:A subset of patients undergoing unilateral hypoglossal nerve stimulation exhibits activation of contralateral genioglossus muscles. Patients with unilateral and bilateral genioglossus responses exhibit comparable, robust improvements in apnea-hypopnea index and oxygen desaturation levels.

OBJECTIVE:To determine the diagnostic efficacy and clinical value of preoperative computed tomography (CT) and magnetic resonance imaging (MRI) among patients with suspected temporal bone encephaloceles (TBE). STUDY DESIGN/METHODS:Retrospective chart review from 2006 to 2018. SETTING/METHODS:Tertiary referral center. SUBJECTS AND METHODS/METHODS:The subjects underwent surgery for a clinically suspected TBE or cerebrospinal fluid (CSF) leak. Preoperative imaging test characteristics of CT and MRI, including sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were calculated for TBE scans and compared with intraoperative findings. RESULTS:= .004). CONCLUSION/CONCLUSIONS:CT and MRI provide complementary information that may aid surgical planning. However, imaging cannot always rule out TBE. In cases with high clinical suspicion, surgical confirmation is often required for definitive diagnosis and treatment. The cost of an additional preoperative study should be considered before its use.

Background/UNASSIGNED:Upper Airway Stimulation (UAS) is a well-established therapy option for obstructive sleep apnea (OSA). Aims/UNASSIGNED:There are no data on whether respiratory sensing contributes to successful UAS therapy. Materials & Methods/UNASSIGNED:After initial measurements of 3 implanted patients (M1), the sensing signal was inverted (M2) without changing other parameters. Two weeks later, the signal was converted back again, and the sensitivity of breathing cycle detection was turned to a very low state (M3). Results/UNASSIGNED:At M2 and M3, the apnea-hypopnea index and oxygen desaturation index increased. Discussion/UNASSIGNED:Correct respiratory sensing is important for controlling OSA using UAS. Conclusions/UNASSIGNED:Therefore, implant centers should should optimize respiratory sensing placement and adjustment.

OBJECTIVE:Although a growing body of data support the functional connectivity between the precuneus and the medial temporal lobe during states of resting consciousness as well as during a diverse array of higher-order functions, direct structural evidence on this subcortical circuitry is scarce. Here, the authors investigate the very existence, anatomical consistency, morphology, and spatial relationships of the cingulum bundle V (CB-V), a fiber tract that has been reported to reside close to the inferior arm of the cingulum (CingI). METHODS:Fifteen normal, formalin-fixed cerebral hemispheres from adults were treated with Klingler's method and subsequently investigated through the fiber microdissection technique in a medial to lateral direction. RESULTS:A distinct group of fibers is invariably identified in the subcortical territory of the posteromedial cortex, connecting the precuneus and the medial temporal lobe. This tract follows the trajectory of the parietooccipital sulcus in a close spatial relationship with the CingI and the sledge runner fasciculus. It extends inferiorly to the parahippocampal place area and retrosplenial complex area, followed by a lateral curve to terminate toward the fusiform face area (Brodmann area [BA] 37) and lateral piriform area (BA35). Taking into account the aforementioned subcortical architecture, the CB-V allegedly participates as a major subcortical stream within the default mode network, possibly subserving the transfer of multimodal cues relevant to visuospatial, facial, and mnemonic information to the precuneal hub. Although robust clinical evidence on the functional role of this stream is lacking, the modern neurosurgeon should be aware of this tract when manipulating cerebral areas en route to lesions residing in or around the ventricular trigone. CONCLUSIONS:Through the fiber microdissection technique, the authors were able to provide original, direct structural evidence on the existence, morphology, axonal connectivity, and correlative anatomy of what proved to be a discrete white matter pathway, previously described as the CB-V, connecting the precuneus and medial temporal lobe.

Flexible laryngoscopy, the gold-standard evaluation of the larynx and the pharynx, is one of the most commonly performed procedures in otolaryngology. During the coronavirus disease 2019 (COVID-19) pandemic, flexible laryngoscopy represents a risk for patients and an occupational hazard for otolaryngologists and any clinic staff involved with the procedure or endoscope reprocessing. Here we present a set of recommendations on flexible laryngoscopy performance during the pandemic, including patient selection, personal protective equipment, and endoscope disinfection, based on a consensus reached during a virtual webinar on March 24, 2020, attended by approximately 300 participants from the American laryngology community.

BACKGROUND:Some petroclival meningiomas cause trigeminal nerve compression leading to disabling trigeminal neuralgia. Tumor resection and nerve decompression can offer pain relief but may not be feasible in all patients. Simultaneous stereotactic radiosurgery (SRS) to the tumor and nerve is another option. It is an effective means of treating meningiomas and trigeminal neuralgia separately, but there is limited data regarding the efficacy and outcomes of their concomitant treatment. CASE DESCRIPTION/METHODS:We present our series of four patients who presented with trigeminal neuralgia secondary to a petroclival mass causing compression of the trigeminal nerve. All patients underwent SRS to both the petroclival mass and trigeminal nerve in a single-session. The average margin tumor dose was 12.25Gy (range, 12 to 12.5Gy) and average maximum trigeminal nerve dose was 80Gy (range, 75 to 85Gy). Barrow Neurologic Institute (BNI) Pain Intensity Scores in all patients prior to intervention were a grade IV or V. At last follow-up (average = 29.8 months), all patients were pain free (BNI I or IIIA). Two patients experienced reduced facial sensation in either one or all three distributions. No brainstem edema was seen. CONCLUSION/CONCLUSIONS:This series highlights the benefit and safety of simultaneous treatment of petroclival tumors and the trigeminal nerve in a single session for patients affected by tumor related trigeminal neuralgia.

The rapid spread of SARS-CoV-2 in 2019 and 2020 has resulted in a worldwide pandemic characterized by severe pulmonary inflammation, effusions, and rapid respiratory compromise. The result of this pandemic is a large and increasing number of patients requiring endotracheal intubation and prolonged ventilator support. The rapid rise in endotracheal intubations coupled with prolonged ventilation requirements will certainly lead to an increase in tracheostomy procedures in the coming weeks and months. Performing tracheostomy in the setting of active COV-SARS-CoV-2, when necessary, poses a unique situation, with unique risks and benefits for both the patient and the health care providers. The New York Head and Neck Society has collaborated on this document to provide guidance on the performance of tracheostomies during the SARS-CoV-2 pandemic.

The novel Coronavirus (COVID-19) has created a deadly pandemic that is now significantly impacting the United States. Otolaryngologists are considered high risk for contracting disease, as the virus resides in the nasal cavity, nasopharynx, and oropharynx. While valuable work has been publicized regarding several topics in Rhinology, we discuss other aspects of our specialty in further detail. There are several issues regarding Rhinologic practice that need to be clarified both for the current epidemic as well as for future expected "waves." In addition, as the pandemic dies down, guidelines are needed to optimize safe practices as we start seeing more patients again. These include protocols pertinent to safety, in-office Rhinologic procedures, the substitution of imaging for endoscopy, and understanding the appropriate role of telemedicine. We discuss these aspects of Rhinology as well as practical concerns relating to telemedicine and billing, as these issues take on increasing importance for Rhinologists both in the present and the future.

Direct access through the sinuses and nasopharyngeal mucosa in the endoscopic endonasal approach (EEA) raises concern for a contaminated operative environment and subsequent infection. The reported rate of meningitis in endoscopic endonasal skull base surgery in the literature ranges from 0.7 to 3.0% [1, 2]. The only factor identified as being independently associated with meningitis in a statistically significant manner is cerebrospinal fluid (CSF) leak [1-5]. However, many centers performing high volume of EEAs use postoperative antibiotic coverage independent of the presence intraoperative or postoperative CSF leak. Furthermore, while meningitis remains a severe concern, most centers use postoperative gram-positive coverage to prevent toxic shock syndrome caused by Staphylococcus aureus infection in the setting of prolonged nasal packing. There are currently a multitude of approaches regarding perioperative antibiotic coverage in EEAs [1-4]. Given the lack of consensus in the literature and our experience regarding the benefit of discontinuation of prolonged prophylactic antibiotics throughout the breadth of neurosurgical procedures, we sought to analyze the need for postoperative antibiotics in EEAs further. As such, we performed a prospective analysis compared with a retrospective cohort to delineate whether discontinuation of postoperative antibiotics leads to a change in the rate of postoperative infections. The retrospective cohort consisted of patients who underwent an EEA from January 1, 2013 to May 31, 2019. These patients all received postoperative antibiotics while nasal packing was in place (median 7 days). Starting on April 1, 2019 until August 1, 2019, we discontinued postoperative antibiotic use. Patients from this group made up the prospective cohort. The retrospective cohort had 315 patients (66% pituitary macroadenomas vs. 7% microadenomas, 4% meningiomas, 4% craniopharyngiomas, 4% chordomas, and 15% others) while the prospective group had 23 patients (57% pituitary macroadenomas, 30% craniopharyngiomas, 8% meningiomas/chordomas, and 5% others). The primary endpoint was rate of postoperative infections and specifically, meningitis and multidrug resistant organism (MDRO) infections. There was no statistically significant difference in the use of nasal packing (p = 0.085), intraoperative CSF leak (p = 0.133), and postoperative CSF leak (p = 0.507) between the two groups. There was also no significant difference in the number of patients with positive preoperative MSSA and MRSA nasal swabs (p = 0.622). There was a significant decrease in the number of patients discharged with antibiotics (55.1% in the retrospective and 4.5% in the prospective group, p = 0.000). The number of patients with positive blood cultures (p = 0.701) and positive urine cultures (p = 0.691) did not differ significantly between the two groups. Finally, there was no statistically significant difference in postoperative CSF infections (p = 0.34) or MDRO infections (0.786) between the two groups. We describe promising preliminary results that demonstrate that discontinuation of postoperative antibiotics in EEAs do not lead to a statistically significant increase in the rate of postoperative CSF or MDRO infections. The previous algorithm for postoperative antibiotic coverage in our center, like many centers, called for gram-positive coverage, which may have contributed to the overall preponderance of gram-negative meningitis cases in this cohort