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Accurate information on eye position in the orbit is available from visual feedback, efference copy of the oculomotor commands and proprioceptive signals from the extraocular muscles (EOM). Whereas visual feedback and oculomotor commands have been extensively studied, central processing of EOM proprioceptive signals remains to be elucidated. A challenge to the field is to develop an approach to induce passive eye movements without physically contacting the eyes. A novel method was developed to generate passive eye movements in rats. A small rare-earth magnet disk (0.7 mm diameter, 0.5 mm thickness) was attached to the surface of a rat's eyeball. A metal rod (5 mm diameter) wrapped with an electromagnetic (EM) coil was placed near the magnet (8-15 mm). By passing currents to the EM coil, electromagnetic force (EMF) was generated and acted upon the magnet and induced passive eye movements. The EMF induced well-defined passive eye movements, whose directions were dependent on current polarity and amplitudes and peak velocities were dependent on current intensity and duration. Peak velocities of the EMF-induced eye movements were linearly related to amplitudes, exhibiting main sequence relationships similar to that of saccades in awake rats and eye movements induced by electrical microstimulation of the abducens nucleus in anesthetized rats. Histological examination showed that repetitive EMF stimulations did not appear to result in damages in the EOM fibers. These results validated the EMF approach as a novel tool to investigate EOM proprioceptive signals and their roles in visual localization and gaze control.

To understand measures of frailty among preoperative patients and explain how these can predict perioperative outcomes among patients with head and neck cancer.Retrospective cross-sectional case series with chart review.Academic tertiary medical center.A retrospective review was performed of patients presenting to an academic hospital following a surgical procedure for a head and neck cancer diagnosis. Charts were queried for preoperative medical diagnoses to calculate 2 frailty scores: the American College of Surgeons National Surgical Quality Improvement Program modified frailty index and the Johns Hopkins Adjusted Clinical Groups frailty index. The American Society of Anesthesiologists classification system was also analyzed as a predictor. Primary outcomes were mortality, 30-day readmission, and length of stay. Perioperative complications and discharge disposition were also evaluated.A total of 410 charts were queried between January 2014 and December 2017. Mortality was 11%; mean ± SD length of stay was 7.4 ± 5.5 days; and the readmission rate was 17%. The modified frailty index score significantly increased the odds of mortality (odds ratio = 1.475, P = .012) and readmission (odds ratio = 1.472, P = .004), the length of stay (relative risk = 1.136, P = .001), and the number of perioperative complications. The American Society of Anesthesiologists classification was also significantly associated with poor outcomes, including readmission, length of stay, and perioperative complications. The Adjusted Clinical Groups index was not a significant predictor of outcomes in this study population.This study demonstrated a significant increase in poor perioperative outcomes and mortality among patients with head and neck cancer and increased frailty, as measured by the modified frailty index.

The COVID-19 pandemic has created a number of considerations for otolaryngology; anosmia and ageusia in particular have gained significant attention. Here we present considerations in regard to treatment with quinine-derived drugs and the influence of masks on communication.

Background Nasal congestion and obstruction are reported in the majority of continuous positive airway pressure (CPAP) users and are frequently cited as reasons for noncompliance. To our knowledge, no study has demonstrated a change in objective or subjective nasal patency in patients with obstructive sleep apnea (OSA) after a therapeutic trial of CPAP therapy. Methods This prospective nonrandomized trial tested the hypothesis that CPAP therapy would result in both objective and subjective improvements in nasal patency in patients with OSA. Prior to initiation of CPAP, acoustic rhinometry (AR) was used to determine nasal volume and minimum cross-sectional area in the upright and reclined positions. Subjective nasal patency was assessed with the Nasal Obstruction Symptom Evaluation (NOSE) questionnaire. Both assessments were repeated at follow-up visits. Results AR data demonstrated a statistically significant increase in total nasal volume (TV) in the reclined position (p = 0.002) and minimum cross-sectional area (MCA) in both the sitting and reclined positions (p = 0.006, p = 0.021) in OSA patients after >30 days of CPAP therapy and with >70% compliance. NOSE scores decreased significantly (p = 0.038) representing an improvement in nasal patency. Conclusion Objective and subjective measurements of TV and MCA increased after initiation of CPAP therapy in this prospective study.

Blast overpressure has become an increasing cause of brain injuries in both military and civilian populations. Though blast's direct effects on the cochlea and vestibular organs are active areas of study, little attention has been given to the ear's contribution to the overall spectrum of blast injury. Acute autonomic responses to blast exposure, including bradycardia and hypotension, can cause hypoxia and contribute to blast-induced neurotrauma. Existing literature suggests that these autonomic responses are elicited through blast impacting the thorax and lungs. We hypothesize that the unprotected ear also provides a vulnerable locus for blast to cause autonomic responses. We designed a blast generator that delivers controlled overpressure waves into the ear canal without impacting surrounding tissues in order to study the ear's specific contribution to blast injury. Anesthetized adult rats' left ears were exposed to a single blast wave ranging from 0 to 110 PSI (0–758 kPa). Blast exposed rats exhibited decreased heart rates and blood pressures with increased blast intensity, similar to results gathered using shock tubes and whole-body exposure in the literature. While rats exposed to blasts below 50 PSI (345 kPa) exhibited increased respiratory rate with increased blast intensity, some rats exposed to blasts higher than 50 PSI (345 kPa) stopped breathing immediately and ultimately died. These autonomic responses were significantly reduced in vagally denervated rats, again similar to whole-body exposure literature. These results support the hypothesis that the unprotected ear contributes to the autonomic responses to blast. Keywords: Blast waves, Autonomic responses, Ear, Neurotrauma

Hypoglossal nerve stimulation is a promising new treatment for patients with obstructive sleep apnea. In the initial Stimulation Therapy for Apnea Reduction Trial, the overall rate of serious adverse events was

A robust temporary threshold shift (TTS) can create significant primary damage to the auditory synapse, termed cochlear synaptopathy (CS). The common model applied to examination of this pathology is a single noise exposure or extended duration exposures at relatively high noise dosages. It is unclear if a single noise exposure that does not produce physiological changes consistent with CS (such as suppressed suprathreshold responses) can create evidence consistent with the pathology induced by repeated exposures. Here, we exposed 16-week (wk) old Sprague-Dawley rats to repeated noise exposures (4 consecutive days, 8–16 kHz octave-band of noise, 97 dB SPL for 2 h) and examined measures of cochlear function (distortion product otoacoustic emissions) and auditory neural integrity (auditory brainstem response, wave 1 amplitude). Our results demonstrated a mean maximal threshold shift of 16 dB at 24 h post the initial noise exposure. Subsequent daily repeated exposures (4 consecutive days) resulted in diminished threshold shift at 24 h post repeated TTS. In addition to recovered thresholds, no sustained reduction in suprathreshold responses was observed. The findings are consistent with conditioning literature suggesting diminished TTS with repeated exposures. Repeated TTS that was not individually synaptopathic did not produce physiological evidence consistent with acute CS.