Results indicate the enlarged translabyrinthine approach with transapical extension as an elective approach for removal of giant VS. The method permits achievement of a high rate of total removal with low incidence of complications.
The importance of the tensor tympani muscle in middle-ear physiology remains unclear. It has been related to the attenuation of sounds produced during the mastication process. Voluntary control over the tensor tympani muscle is an extremely rare event. However, an understanding of the potential audiometric effects of its contraction could aid the diagnosis of hearing disorders.
Objective: The aim of this work was to describe the dimensions of the crista fenestra and determine its presence by means of high-resolution computed tomography (CT) for the purpose of cochlear implantation via the round window approach. Methods: A series of 10 adult human temporal bones underwent high-resolution CT scanning and were further dissected for microscopic study of the round window niche. Results: In all of the specimens, the round window membrane was fully visualized after the complete removal of bony overhangs. The crista fenestra was identified as a sharp bony crest located in the anterior and inferior borders of the niche; its area ranged from 0.28 to 0.80 mm2 (mean 0.51 ± 0.18). The proportion of the area occupied by the crista fenestra in the whole circumference of the round window ranged from 23 to 50% (mean 36%). We found a moderate positive correlation between the area of the niche and the dimensions of the crista fenestra (Spearman rho: 0.491). In every case, high-resolution CT scanning was unable to determine the presence of the crista fenestra. Conclusion: The crista fenestra occupies a variable but expressive area within the bony round window niche. Narrower round window niches tended to house smaller crests. The presence of the crista fenestra is an important obstacle to adequate access to the scala tympani. Nevertheless, a high-resolution CT scan provides no additional preoperative information with regard to its presence for the purpose of surgical access to the scala tympani via the round window niche.
Data strongly suggest that acute induced hyperinsulinism suppresses cochlear function. Results may be attributed to loss of Na+K+ATPase activity in the stria vascularis, leading to loss of endocochlear potential and subsequent depolarization of cochlear hair cells as well as of neural cells in the auditory portion of cranial nerve VIII.
Hyperi nsulinism secondary to peripheral insulin resistance has been described as the most frequent etiologic factor in cochlear and vestibular syndromes. Aim: This experimental study recorded and analyzed evoked auditory potential changes using transtympanic electrocochleography (EcochG) during induced acute hyperinsulinism in an animal model. Materials and Methods: Six adult male sheep were randomly divided into 2 groups. The animals were submitted to EcochG under general anesthesia, and a peripheral blood sample was collected to measure glycemia and insulinemia. Animals in the intervention group (n=3) received regular human insulin IV (0.1 U/kg). The control group (n=3) received saline solution. Glycemia and insulinemia were measured simultaneously with the recording of evoked potentials at 10-minute intervals during 90 minutes. Results: The intervention group experienced a progressive suppression in action potential amplitude when compared to the control group (p=0.001). Conclusion: Data strongly suggest that acute induced hyperinsulinism suppresses cochlear function. Results may be attributed to loss of Na+K+ATPase activity in the stria vascularis, leading to loss of endocochlear potential and subsequent depolarization of cochlear hair cells as well as of neural cells in the auditory portion of cranial nerve VIII.
Objective
To investigate the prevalence of antibodies against SARS-CoV-2 in otorhinolaryngologists in southern Brazil, its relationship to demographic data, professional practice and reported symptoms of COVID-19, and compare it with official data on other health-care workers of the state and the general population in the same period.
Methods
In this cross-sectional multicenter study, otolaryngologists actively practicing officially registered in Rio Grande do Sul were screened for IgM and IgG antibodies against SARS-CoV-2. A questionnaire was also applied.
Results
We screened 358 (80.1%) of 447 actively practicing otolaryngologists (195 [54.5%] male; mean [SD] age, 47.77 [13.57] years; range, 26–84 years). Twenty-three were positive for IgM and/or IgG (6.4%). This result was significantly associated with reports of infected household contacts (19/315 negatives and 8/23 positives;
pp
< 0.001). From 23 seropositive participants, 14 were asymptomatic (60.9%;
pp
< 0.001). There were no significant associations between seroconversion and age, sex, number of patient appointments and surgical procedures, workplace (hospital or private practice), patients with or without respiratory symptoms, or level of personal protective equipment used. The rate of COVID-19 in all health-care workers in the state was 7.69% at the end of the same period. Data from state government seroprevalence was 5.26 (risk ratio [RR]; 95% CI 3.27–8.45) and 4.66 (RR; 95% CI 2.93–7.43) times higher in otolaryngologists than in the general population in August and September, respectively.
Conclusion
sOtolaryngologists had a higher seroconversion rate than the general population. Using personal protective equipment, the level of occupational exposure did not result in higher rates of infection than other health-care workers, but the presence of infected household contacts was associated with higher rates of seroconversion.
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