Radiological findings in spontaneous cerebrospinal fluid leaks of the temporal bone.

BACKGROUND AND OBJECTIVE: Spontaneous cerebrospinal fluid leak of the temporal bone is an emerging clinical entity for which prompt and accurate diagnosis is difficult given the subtle signs and symptoms that patients present with. This study sought to describe the key temporal bone abnormalities in patients with spontaneous cerebrospinal fluid leak. METHODS: A retrospective cohort study was conducted of adult patients with biochemically confirmed spontaneous cerebrospinal fluid leak. Demographics and radiological features identified on computed tomography imaging of the temporal bones and/or magnetic resonance imaging were analysed. RESULTS: Sixty-one patients with spontaneous cerebrospinal fluid leak were identified. Fifty-four patients (88.5 per cent) underwent both temporal bone computed tomography and magnetic resonance imaging. Despite imaging revealing bilateral defects in over 75 per cent of the cohort, only two patients presented with bilateral spontaneous cerebrospinal fluid leaks. Anterior tegmen mastoideum defects were most common, with an average size of 2.5 mm (range, 1-10 mm). CONCLUSION: Temporal bone computed tomography is sensitive for the identification of defects when suspicion exists. In the setting of an opacified middle ear and/or mastoid, close examination of the skull base is crucial given that this fluid is potentially cerebrospinal fluid.

Quantification of biomaterial dispersion during otologic procedures and role of barrier drapes in Covid 2019 era - a laboratory model.

BACKGROUND: Aerosol generation during temporal bone surgery caries the risk of viral transmission. Steps to mitigate this problem are of particular importance during the coronavirus disease 2019 pandemic. OBJECTIVE: To quantify the effect of barrier draping on particulate material dispersion during temporal bone surgery. METHODS: The study involved a cadaveric model in a simulated operating theatre environment. Particle density and particle count for particles sized 1-10 µ were measured in a simulated operating theatre environment while drilling on a cadaveric temporal bone. The effect of barrier draping to decrease dispersion was recorded and analysed. RESULTS: Barrier draping decreased counts of particles smaller than 5 µ by a factor of 80 in the operating theatre environment. Both particle density and particle count showed a statistically significant reduction with barrier draping (p = 0.027). CONCLUSION: Simple barrier drapes were effective in decreasing particle density and particle count in the operating theatre model and can prevent infection in operating theatre personnel.

Expression of ACE2, TMPRSS2, and Furin in Mouse Ear Tissue, and the Implications for SARS-CoV-2 Infection.

OBJECTIVES/HYPOTHESIS: Intracellular entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) depends on the interaction between its spike protein with the cellular receptor angiotensin-converting enzyme 2 (ACE2) and depends on Furin-mediated spike protein cleavage and spike protein priming by host cell proteases, including transmembrane protease serine 2 (TMPRSS2). As the expression of ACE2, TMPRSS2, and Furin in the middle and inner ear remain unclear, we analyzed the expression of these proteins in mouse ear tissues. STUDY DESIGN: Animal Research. METHODS: We performed immunohistochemical analysis to examine the distribution of ACE2, TMPRSS2, and Furin in the Eustachian tube, middle ear spaces, and cochlea of mice. RESULTS: ACE2 was present in the nucleus of the epithelium of the middle ear and Eustachian tube, as well as in some nuclei of the hair cells in the organ of Corti, in the stria vascularis, and the spiral ganglion cells. ACE2 was also expressed in the cytoplasm of the stria vascularis. TMPRSS2 was expressed in both the nucleus and cytoplasm in the middle spaces, with the expression being stronger in the nucleus in the mucosal epithelium of the middle ear spaces and Eustachian tube. TMPRSS2 was present in the cytoplasm in the organ of Corti and stria vascularis and in the nucleus and cytoplasm in the spiral ganglion. Furin was expressed in the cytoplasm in the middle ear spaces, Eustachian tube, and cochlea. CONCLUSIONS: ACE2, TMPRSS2, and Furin are diffusely present in the Eustachian tube, middle ear spaces, and cochlea, suggesting that these tissues are susceptible to SARS-CoV-2 infection. LEVEL OF EVIDENCE: NA Laryngoscope, 131:E2013-E2017, 2021.