Acute and Longer-Term Effects of COVID-19 on Auditory and Vestibular Symptoms

OBJECTIVE

To evaluate long-term effects of COVID-19 on auditory and vestibular symptoms in a diverse cohort impacted by the initial 2020 COVID-19 infection in the pandemic's epicenter, before vaccine availability.

STUDY DESIGN

Cohort study of individuals with confirmed COVID-19 infection, diagnosed in the March-May 2020 infection wave. A randomized, retrospective chart review of 1,352 individuals was performed to identify those with documented new or worsening auditory (aural fullness, tinnitus, hyperacusis, hearing loss) or vestibular (dizziness, vertigo) symptoms. Those with documented symptoms (613 of the 1,352 initial cohort) were contacted for a follow-up telephone survey in 2021-2022 to obtain self-report of aforementioned symptoms.

SETTING

Academic tertiary hospital system in Bronx, NY.

PATIENTS

Adults 18 to 99 years old with confirmed COVID-19 infection, alive at time of review. One hundred forty-eight charts were excluded for restricted access, incomplete data, no COVID-19 swab, or deceased at time of review.

INTERVENTION

Confirmed COVID-19 infection, March to May 2020.

MAIN OUTCOMES MEASURES

Auditory and vestibular symptoms documented in 2020 medical records and by self-report on 2021 to 2022 survey.

RESULTS

Among the 74 individuals with documented symptoms during the first 2020 COVID-19 wave who participated in the 2021 to 2022 follow-up survey, 58% had documented vestibular symptoms initially in 2020, whereas 43% reported vestibular symptoms on the 2021 to 2022 survey ( p = 0.10). In contrast, 9% had documented auditory symptoms initially in 2020 and 55% reported auditory symptoms on the 2021 to 2022 survey ( p < 0.01).

CONCLUSIONS

COVID-19 may impact vestibular symptoms early and persistently, whereas auditory effects may have more pronounced long-term impact, suggesting the importance of continually assessing COVID-19 patients.

Sound category habituation requires task-relevant attention

Introduction

Processing the wealth of sensory information from the surrounding environment is a vital human function with the potential to develop learning, advance social interactions, and promote safety and well-being.

Methods

To elucidate underlying processes governing these activities we measured neurophysiological responses to patterned stimulus sequences during a sound categorization task to evaluate attention effects on implicit learning, sound categorization, and speech perception. Using a unique experimental design, we uncoupled conceptual categorical effects from stimulus-specific effects by presenting categorical stimulus tokens that did not physically repeat.

Results

We found effects of implicit learning, categorical habituation, and a speech perception bias when the sounds were attended, and the listeners performed a categorization task (task-relevant). In contrast, there was no evidence of a speech perception bias, implicit learning of the structured sound sequence, or repetition suppression to repeated within-category sounds (no categorical habituation) when participants passively listened to the sounds and watched a silent closed-captioned video (task-irrelevant). No indication of category perception was demonstrated in the scalp-recorded brain components when participants were watching a movie and had no task with the sounds.

Discussion

These results demonstrate that attention is required to maintain category identification and expectations induced by a structured sequence when the conceptual information must be extracted from stimuli that are acoustically distinct. Taken together, these striking attention effects support the theoretical view that top-down control is required to initiate expectations for higher level cognitive processing.

High Grade Ectopic Pituitary Adenoma within the Cerebellopontine Angle: A Case Report

Ectopic pituitary tumors are neoplasms with no connection to the pituitary gland and are commonly deposited in other areas of the anterior skull base. A 32-year-old female presented with a three-month history of right sided facial weakness, sensorineural hearing loss, diplopia, and severe headaches. Physical examination revealed a mid-dilated sluggishly reactive right pupil with slight limitation in all gazes, as well as right-sided orbicularis weakness, lagophthalmos, and decreased facial sensation. An MRI of the head without contrast revealed a 3.7 x 1.8 x 2.6 cm mildly enhancing mass in the right internal acoustic meatus and along the petrous ridge. The case was brought before the institution’s tumor board, where concern for higher grade pathology, such as hemangiopericytoma, was discussed. Per patient preference, surgical biopsy of the tumor was performed. Immunohistochemical staining revealed a WHO grade II neuroendocrine tumor, with cells staining positive for synaptophysin, chromogranin, and CD56, with a Ki-67 index of 8%. In addition to the ectopic location, this pituitary tumor was noted to be aggressive in nature based on its high Ki-67 index. Surgical excision or radiologic therapy of tumors involving the CPA are appropriate treatments in most cases.

Antibiotic Use in Lateral Skull Base Surgery: A Survey of the North American Skull Base Society

Objectives Antibiotic use in lateral skull base surgery (LSBS) has not been thoroughly investigated in the literature. There is wide variability in antibiotic use and insufficient data to guide management. This study aims to describe the factors and patterns influencing antibiotic use in LSBS among the membership of the North American Skull Base Society (NASBS).

Design An online-based survey was designed and distributed to the membership of the NASBS. Data was analyzed using bivariate analysis and logistic regression modeling.

Setting Online-based questionnaire.

Participants NASBS membership.

Main Outcome Measures Use of intraoperative antibiotics and use of postoperative antibiotics.

Results The survey response rate was 26% (208 respondents). Of the 208 total respondents, 143 (69%) respondents performed LSBS. Most respondents are neurosurgeons (69%) with the remaining being otolaryngologists (31%). The majority of respondents (79%) are fellowship-trained in skull base surgery. Academic or government physicians make up 69% of respondents and 31% are in private practice with or without academic affiliations. Bivariate analysis showed that practice setting significantly influenced intraoperative antibiotic use (p = 0.01). Geographic location significantly affected postoperative antibiotic use (p = 0.01). Postoperative antibiotic duration was significantly affected by presence of chronic otitis media, cerebrospinal fluid leak, and surgeon training (p = 0.02, p = 0.01, and p = 0.006, respectively). Logistic regression modeling showed that the motivation to reduce infection significantly impacted postoperative antibiotic use (p = 0.03).

Conclusion This study demonstrates significant variations in intraoperative and postoperative antibiotic use in LSBS among the NASBS membership. Appropriate guidelines for optimal perioperative antibiotic use patterns should be determined with randomized studies in the future.

Can the negative pressures found in obstructive sleep apnea and Eustachian tube dysfunction be related?

OBJECTIVE

The association between obstructive sleep apnea (OSA) and Eustachian tube dysfunction (ETD) is well known. When both exist in a single pediatric patient, one of the expected culprits is adenoid enlargement. We hypothesize, in contrast, that the negative pharyngeal pressure found in OSA may be transmitted to the middle ear as negative middle ear pressure (MEP), which subsequently results in pathology. The objective of this study was to determine whether the degree of OSA and MEP are associated while using MEP as a quantifiable measurement of ETD.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary academic center (Jan 2000-Jan 2018).

SUBJECTS AND METHODS

The relationship between apnea-hypopnea index (AHI) and MEP was examined. A non-anatomic model was utilized to support causality.

RESULTS

Thirty-four pediatric patients and twenty-three adult patients were included in the analysis. REM AHI showed a moderate negative correlation with MEP in children (r = -0.265), and a weak positive correlation with MEP in adults (r = 0.171). Children with an AHI in the severe OSA category had a more negative mean MEP than those in the mild category (p = 0.36). Adults with an AHI in the severe OSA category had a more positive mean MEP than those in the mild category (p = 0.11).

CONCLUSION

In children, increasing severity of OSA is associated with a negative MEP, suggesting that negative pressure associated with OSA may be transmitted to the middle ear. In adults, increasing severity of OSA is associated with a more positive MEP.

Response Advantage for the Identification of Speech Sounds

The ability to distinguish among different types of sounds in the environment and to identify sound sources is a fundamental skill of the auditory system. This study tested responses to sounds by stimulus category (speech, music, and environmental) in adults with normal hearing to determine under what task conditions there was a processing advantage for speech. We hypothesized that speech sounds would be processed faster and more accurately than non-speech sounds under specific listening conditions and different behavioral goals. Thus, we used three different task conditions allowing us to compare detection and identification of sound categories in an auditory oddball paradigm and in a repetition-switch category paradigm. We found that response time and accuracy were modulated by the specific task demands. The sound category itself had no effect on sound detection outcomes but had a pronounced effect on sound identification. Faster and more accurate responses to speech were found only when identifying sounds. We demonstrate a speech processing "advantage" when identifying the sound category among non-categorical sounds and when detecting and identifying among categorical sounds. Thus, overall, our results are consistent with a theory of speech processing that relies on specialized systems distinct from music and other environmental sounds.

Surgical approaches to the petrous apex

The petrous apex is a difficult to reach surgical area due to its deep position in the skull base and many vital surrounding structures. Petrous apex pathology ranges from extradural cholesterol granulomas, cholesteatomas, asymmetric pneumatization, and osteomyelitis to intradural meningiomas and schwannomas. Certain lesions, such as cholesterol granulomas, can be managed with drainage while neoplastic lesions must be completely resected. Surgical options use open, endoscopic, and combined techniques and are categorized into anterior, lateral, and posterior approaches. The choice of approach is determined by the nature of the pathology and location relative to vital structures and extension into surrounding structures and requires thorough preoperative evaluation and discussion of surgical goals with the patient. The purpose of this state-of-the-art review is to discuss the most commonly used surgical approaches to the petrous apex, and the anatomy on which these approaches are based.

Novel use of video glasses during binocular microscopy in the otolaryngology clinic

INTRODUCTION

The development of portable, high resolution video displays such as video glasses allows clinicians the opportunity to offer patients an increased ability to visualize aspects of their physical examination in an ergonomic and cost-effective manner. The objective of this pilot study is to trial the use of video glasses for patients undergoing binocular microscopy as well as to better understand some of the potential benefits of the enhanced display option.

METHODS

This study was comprised of a single treatment group. Patients seen in the otolaryngology clinic who required binocular microscopy for diagnosis and treatment were recruited. All patients wore video glasses during their otoscopic examination. An additional cohort of patients who required binocular microscopy were also recruited, but did not use the video glasses during their examination. Patients subsequently completed a 10-point Likert scale survey that assessed their comfort, anxiety, and satisfaction with the examination as well as their general understanding of their otologic condition.

RESULTS

A total of 29 patients who used the video glasses were recruited, including those with normal examinations, cerumen impaction, or chronic ear disease. Based on the survey results, patients reported a high level of satisfaction and comfort during their exam with video glasses. Patients who used the video glasses did not exhibit any increased anxiety with their examination. Patients reported that video glasses improved their understanding and they expressed a desire to wear the glasses again during repeat exams.

CONCLUSION

This pilot study demonstrates that video glasses may represent a viable alternative display option in the otolaryngology clinic. The results show that the use of video glasses is associated with high patient comfort and satisfaction during binocular microscopy. Further investigation is warranted to determine the potential for this display option in other facets of patient care as well as in expanding patient understanding of disease and anatomy.

Synaptic calcium regulation in hair cells of the chicken basilar papilla

Cholinergic inhibition of hair cells occurs by activation of calcium-dependent potassium channels. A near-membrane postsynaptic cistern has been proposed to serve as a store from which calcium is released to supplement influx through the ionotropic ACh receptor. However, the time and voltage dependence of acetylcholine (ACh)-evoked potassium currents reveal a more complex relationship between calcium entry and release from stores. The present work uses voltage steps to regulate calcium influx during the application of ACh to hair cells in the chicken basilar papilla. When calcium influx was terminated at positive membrane potential, the ACh-evoked potassium current decayed exponentially over ∼100 ms. However, at negative membrane potentials, this current exhibited a secondary rise in amplitude that could be eliminated by dihydropyridine block of the voltage-gated calcium channels of the hair cell. Calcium entering through voltage-gated channels may transit through the postsynaptic cistern, since ryanodine and sarcoendoplasmic reticulum calcium-ATPase blockers altered the time course and magnitude of this secondary, voltage-dependent contribution to ACh-evoked potassium current. Serial section electron microscopy showed that efferent and afferent synaptic structures are juxtaposed, supporting the possibility that voltage-gated influx at afferent ribbon synapses influences calcium homeostasis during long-lasting cholinergic inhibition. In contrast, spontaneous postsynaptic currents ("minis") resulting from stochastic efferent release of ACh were made briefer by ryanodine, supporting the hypothesis that the synaptic cistern serves primarily as a calcium barrier and sink during low-level synaptic activity. Hypolemmal cisterns such as that at the efferent synapse of the hair cell can play a dynamic role in segregating near-membrane calcium for short-term and long-term signaling.

Epithelioid hemangioendothelioma of the middle ear in a child

The differential diagnosis of middle ear masses encompasses a wide variety of pathologic conditions. In this report, we describe the case of a 6-year-old girl who presented with facial nerve weakness and was found to have a middle ear mass. The mass was excised, and final pathology revealed hemangioendothelioma. This report describes the youngest patient with this diagnosis presenting as a middle ear mass in the Western literature. This article provides this patient's presentation, imaging and histopathologic findings, and clinical course and reviews the current literature on this unique pathologic diagnosis.

Identification of four novel exon 5 splice variants of the mouse mu-opioid receptor gene: functional consequences of C-terminal splicing

The rat mu-opioid receptor clone in which novel exon 5 was found in the place of exon 4 (MOR-1B) was one of the first MOR-1 variants described. We now have identified the mouse homolog of the rat MOR-1B as well as four additional variants derived from splicing from exon 3 into different sites within exon 5. The sequences of all of the variants were identical except for the intracellular tip of the C terminus encoded by exon 5, where each variant predicted a unique amino acid sequence ranging from 2 to 39 amino acids. All of the mMOR-1B variants were selective for mu-opioids in receptor-binding assays, as anticipated, because they all have identical binding pockets defined by the transmembrane domains. However, the relative potency and efficacy of mu-agonists to each other varied from variant to variant in guanosine 5'-O-(3-[35S]thio)triphosphate-binding studies, as shown by morphine-6beta-glucuronide, which was the most efficacious agent against mouse MOR-1B1 (mMOR-1B1) and the least efficacious agent against mMOR-1B2. mMOR-1B4 was quite unusual. Although mMOR-1B4 was mu-selective in receptor-binding studies and antagonists labeled mMOR-1B4 well, the binding affinities of most of the mu-agonists were far lower than those seen with mMOR-1, suggesting that the 39 amino acids at the C terminus of mMOR-1B4 influences the conformation of the receptor and its ligand recognition site itself either directly or through its interactions with other proteins. In conclusion, alterations in the amino acid sequence of the C terminus do not alter the mu-specificity of the receptor but they can influence the binding characteristics, efficacy, and potency of mu-opioids.

Highly cooperative control of endocytosis by clathrin

Clathrin assembles into a dynamic two-dimensional lattice on the plasma membrane where it plays a critical role in endocytosis. To probe the regulation of this process, we used siRNA against clathrin, in combination with single cell assays for transferrin uptake as well as total internal reflection microscopy, to examine how endocytic rates and membrane dynamics depend upon cellular clathrin concentration ([Clathrin]). We find that endocytosis is tightly controlled by [Clathrin] over a very narrow dynamic range such that small changes in [Clathrin] can lead to large changes in endocytic rates, indicative of a highly cooperative process (apparent Hill coefficient, n > 6). The number of clathrin assemblies at the cell surface was invariant over a wide range of [Clathrin]; however, both the amount of clathrin in each assembly and the subsequent membrane dynamics were steeply dependent on [Clathrin]. Thus clathrin controls the structural dynamics of membrane internalization via a strongly cooperative process. We used this analysis to show that one important regulator of endocytosis, the actin cytoskeleton, acts noncompetitively as a modulator of clathrin function.

Impaired PtdIns(4,5)P2 synthesis in nerve terminals produces defects in synaptic vesicle trafficking

Phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P2) has an important function in cell regulation both as a precursor of second messenger molecules and by means of its direct interactions with cytosolic and membrane proteins. Biochemical studies have suggested a role for PtdIns(4,5)P2 in clathrin coat dynamics, and defects in its dephosphorylation at the synapse produce an accumulation of coated endocytic intermediates. However, the involvement of PtdIns(4,5)P2 in synaptic vesicle exocytosis remains unclear. Here, we show that decreased levels of PtdIns(4,5)P2 in the brain and an impairment of its depolarization-dependent synthesis in nerve terminals lead to early postnatal lethality and synaptic defects in mice. These include decreased frequency of miniature currents, enhanced synaptic depression, a smaller readily releasable pool of vesicles, delayed endocytosis and slower recycling kinetics. Our results demonstrate a critical role for PtdIns(4,5)P2 synthesis in the regulation of multiple steps of the synaptic vesicle cycle.

Targeted chemical disruption of clathrin function in living cells

The accurate assignment of molecular roles in membrane traffic is frequently complicated by the lack of specific inhibitors that can work on rapid time scales. Such inhibition schemes would potentially avoid the complications arising from either compensatory gene expression or the complex downstream consequences of inhibition of an important protein over long periods (>12 h). Here, we developed a novel chemical tool to disrupt clathrin function in living cells. We engineered a cross-linkable form of clathrin by using an FK506-binding protein 12 (FKBP)-clathrin fusion protein that is specifically oligomerized upon addition of the cell-permeant cross-linker FK1012-A. This approach interrupts the normal assembly-disassembly cycle of clathrin lattices and results in a specific, rapid, and reversible approximately 70% inhibition of clathrin function. This approach should be applicable to a number of proteins that must go through an assembly-disassembly cycle for normal function.

Expression of Panulirus shaker potassium channel splice variants

In Drosophila shaker voltage-dependent potassium channels, alternative splicing at the amino and carboxy termini produces currents with different electrophysiological characteristics. We have cloned alternatively spliced forms of shaker from the spiny lobster Panulirus interruptus. Alternative exons were found at three sites of the gene; eight different 5' exons, two alternative exons encoding the pore-forming P region, and an alternative 3' exon. Two of the different amino terminal splice forms were expressed with two alternatively spliced pore forms to produce channels with markedly different characteristics. One of the amino termini produced a channel with transient characteristics while the other produced a delayed rectifier-type channel. The effects of alternative exons at the amino terminus and in the P region appear to be additive. Our results provide new information on the structural requirements for rapid N-type inactivation.

Alternative splicing in the pore-forming region of shaker potassium channels

We have cloned cDNAs for the shaker potassium channel gene from the spiny lobster Panulirus interruptus. As previously found in Drosophila, there is alternative splicing at the 5' and 3' ends of the coding region. However, in Panulirus shaker, alternative splicing also occurs within the pore-forming region of the protein. Three different splice variants were found within the P region, two of which bestow unique electrophysiological characteristics to channel function. Pore I and pore II variants differ in voltage dependence for activation, kinetics of inactivation, current rectification, and drug resistance. The pore 0 variant lacks a P region exon and does not produce a functional channel. This is the first example of alternative splicing within the pore-forming region of a voltage-dependent ion channel. We used a recently identified potassium channel blocker, kappa-conotoxin PVIIA, to study the physiological role of the two pore forms. The toxin selectively blocked one pore form, whereas the other form, heteromers between the two pore forms, and Panulirus shal were not blocked. When it was tested in the Panulirus stomatogastric ganglion, the toxin produced no effects on transient K+ currents or synaptic transmission between neurons.