BackgroundA petrous apex mucocele is a rare benign cystic lesion that can present with symptoms due to pressure on surrounding structures, including the internal carotid artery, Meckel's cave and the fifth and sixth cranial nerves, as well as the cavernous sinus region and inner ear.MethodsA 36-year-old male presented with 8 months of diplopia when looking to the right, a right-sided temporoparietal headache, and paresthesia in the right half of his face. An MRI revealed a 26 × 32 × 37 mm lesion in the right petrous apex. The lesion's signal characteristics were most consistent with a mucocele. We performed an endoscopic endonasal transclival marsupialization and created a wide drainage opening, which we supported by inserting a stent containing mometasone furoate.ResultsThe postoperative course was marked by transient arterial hypertension, which required antihypertensive treatment. Postoperative imaging studies revealed no intracranial complications and confirmed that the drainage pathway remained patent.ConclusionIn the differential diagnosis of lesions in the medial portion of the petrous apex, a mucocele should be considered. In appropriately selected cases, endoscopic endonasal marsupialization can be an effective option. To maintain postoperative patency of the drainage pathway, an implant containing mometasone furoate may also be used.

Autoimmune inner ear disease (AIED) is a spectrum of diseases that may present solely as fluctuating sensorineural hearing loss triggered by unknown stimuli, or it may occur in association with other systemic rheumatic diseases. This article will review primary AIED as well as the etiologies of secondary AIED. It will also describe the epidemiology, pathophysiology, diagnosis, and management, including corticosteroids and steroid-sparing treatments.

Sensorineural hearing loss in mammals is essentially irreversible. Mature cochlear hair cells, once lost, do not regenerate. Non-mammalian vertebrates retain this ability, but in the mammalian organ of Corti, supporting cells lose their proliferative and transdifferentiation competence after birth. Reactivation of classical developmental pathways has also shown limited success in the adult cochlea. In this review, we first synthesize published evidence on Hippo-Yes-associated protein(YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) signaling in the inner ear, including studies of inner-ear progenitors, organ of Corti growth, vestibular sensory epithelia, cochlear hair-cell injury, neonatal cochlear regeneration models, and emerging adult cochlear data. On this basis, we then evaluate the biomechanical brake hypothesis, which proposes that injury-associated mechanical remodeling may interact with Hippo-YAP/TAZ signaling to restrict supporting-cell plasticity in the mature mammalian cochlea. Rather than presenting this hypothesis as an established mechanism, we treat it as an evidence-graded framework that must be tested against alternative explanations, including protective epithelial repair, cell-cycle inhibition, epigenetic restriction, and loss of developmental competence. The available literature suggests that Hippo-YAP/TAZ signaling participates in several inner-ear processes, including progenitor expansion, sensory epithelial growth, species-dependent vestibular repair, otoprotective responses, and supporting-cell proliferation under defined experimental conditions. However, direct evidence that injury-induced mechanical remodeling causally suppresses YAP/TAZ-dependent regeneration in the adult cochlea remains limited. We therefore distinguish among developmental, neonatal, vestibular, ex vivo, and adult in vivo evidence, and identify where current findings support, weaken, or remain insufficient to establish the biomechanical brake model. Finally, we outline specific gaps that should guide future work: comprehensive tabulation of Hippo-related inner-ear studies, adult supporting-cell lineage tracing, spatial mapping of cochlear mechanical properties and Hippo activity, cell-subtype-specific perturbation of YAP/TAZ signaling, functional assessment by auditory brainstem response and distortion product otoacoustic emission, and long-term evaluation of epithelial stability. This organization is intended to clarify what Hippo-YAP/TAZ signaling has already been shown to do in the inner ear, what remains speculative, and which experiments are required before mechanobiological modulation can be considered a plausible regenerative strategy.

Oral endotracheal intubation in rats is useful for cranial, thoracic, and survival experiments but remains technically demanding. We evaluated a simple method using a modified 5-Fr vascular sheath and a smartphone-connected ear-pick endoscope in 30 male Sprague-Dawley rats (8-12 weeks, 300-400 g). Under 3% isoflurane anesthesia and vecuronium bromide-induced neuromuscular blockade, the sheath was shortened to approximately 8 cm, and its modified inner dilator was advanced into the trachea under endoscopic visualization; the sheath was then advanced over the dilator and connected to mechanical ventilation. Intubation was successful in all rats, with first-attempt success in 28/30 (93.3%). No major complications occurred, although minor oral bleeding was observed in several rats. This method may provide a practical option for rat airway management.

Dimethyl sulfoxide (DMSO) is widely used as a solvent in auditory and vestibular pharmacology, yet its direct effects on cochlear function are not well defined. We tested whether DMSO in artificial perilymph, delivered through the posterior semicircular canal in mice, alters distortion product otoacoustic emissions (DPOAEs) and medial olivocochlear (MOC)-mediated cochlear responses in the absence of active drug. Artificial perilymph alone produced no measurable change in either MOC-mediated responses or baseline DPOAEs. In contrast, 5% DMSO progressively increased MOC-mediated suppression, 10% DMSO produced a more marked enhancement of MOC-mediated suppression, and 15% DMSO initially enhanced MOC-mediated suppression but subsequently caused progressive loss of both baseline DPOAEs and MOC-mediated suppression. Averaged response profiles showed a concentration dependent increase in MOC-mediated suppression, and Hill-type analysis yielded an EC50 of 5.29% DMSO. At higher concentrations, 15% DMSO elevated DPOAE threshold by approximately 30 dB. Because DMSO containing solutions were markedly hyperosmotic relative to artificial perilymph, osmotic stress likely contributed to the observed effects. To test direct cochlear action, we also examined outer hair cell (OHC) electromotility ex vivo using optical coherence tomography in gerbils. In this preparation, 5% DMSO reversibly reduced OHC electromotility without obvious structural damage. These findings indicate that DMSO effects depend on centration and experimental context. Although 1% DMSO produced no measurable effect, direct perilymphatic exposure to concentrations of 5% or greater altered MOC-mediated responses and OHC electromotility. These results support the continued use of matched vehicle controls, particularly when higher DMSO concentrations are required for local inner ear delivery.

Southwest and Central Asia were pivotal regions for the domestication and dispersal of domestic herbivores. Here we investigate long-term variation in bony labyrinth morphology of domestic bovids (sheep, goats and cattle) across the last 10 000 years. We focused on the osseous cavity of the inner ear, located within the petrous bone. We analysed semicircular canal (SC) size and shape using micro-computed tomography and geometric morphometrics (GMM) on 78 modern reference specimens and 234 archaeological petrous bones from 51 sites spanning the Iranian Plateau, Central Asia, the Caucasus and the Indus Valley. Bony labyrinth morphometrics yielded a strong taxonomic signal, enabling species-level identification of 228 out of 234 specimens and revealing greater diversity than anticipated. Comparative analyses further documented contrasting, nonlinear diachronic trajectories in SC size and shape among sheep, goats and cattle, reflecting species-specific responses to domestication and long-term herd management. Together, these results demonstrate that bony labyrinth GMM provides a robust, non-destructive framework for taxonomic identification and evolutionary inference and underscore how long-term, interdisciplinary approaches can capture the complex, nonlinear dynamics of animal domestication across the longue durée.