Dye Tracking Following Posterior Semicircular Canal or Round Window Membrane Injections Suggests a Role for the Cochlea Aqueduct in Modulating Distribution.
Frontiers in cellular neuroscience
2019; 13: 471
The inner ear houses the sensory epithelium responsible for vestibular and auditory function. The sensory epithelia are driven by pressure and vibration of the fluid filled structures in which they are embedded so that understanding the homeostatic mechanisms regulating fluid dynamics within these structures is critical to understanding function at the systems level. Additionally, there is a growing need for drug delivery to the inner ear for preventive and restorative treatments to the pathologies associated with hearing and balance dysfunction. We compare drug delivery to neonatal and adult inner ear by injection into the posterior semicircular canal (PSCC) or through the round window membrane (RWM). PSCC injections produced higher levels of dye delivery within the cochlea than did RWM injections. Neonatal PSCC injections produced a gradient in dye distribution; however, adult distributions were relatively uniform. RWM injections resulted in an early base to apex gradient that became more uniform over time, post injection. RWM injections lead to higher levels of dye distributions in the brain, likely demonstrating that injections can traverse the cochlea aqueduct. We hypothesize the relative position of the cochlear aqueduct between injection site and cochlea is instrumental in dictating dye distribution within the cochlea. Dye distribution is further compounded by the ability of some chemicals to cross inner ear membranes accessing the blood supply as demonstrated by the rapid distribution of gentamicin-conjugated Texas red (GTTR) throughout the body. These data allow for a direct evaluation of injection mode and age to compare strengths and weaknesses of the two approaches.
View details for DOI 10.3389/fncel.2019.00471
View details for PubMedID 31736710
History of Cranial Nerve-Implanted Stimulators in Otolaryngology.
Otolaryngologic clinics of North America
This article aims to clearly understand the historical development of cranial nerve-implanted stimulators in otolaryngology. The authors also discuss cranial nerve history; initial theory of the functional concept of animal spirit; electrical nerve impulse theory; first electrical otolaryngology cranial nerve stimulation devices; and the development of implanted stimulators.
View details for DOI 10.1016/j.otc.2019.09.012
View details for PubMedID 31699407
Ergonomic hazards in otolaryngology.
OBJECTIVES/HYPOTHESIS: To evaluate the presence of postural-related strain and musculoskeletal discomfort, along with the level of ergonomics training and the availability of ergonomic equipment among otolaryngology surgeons.STUDY DESIGN: Intraoperative observations and survey study.METHODS: Using the Rapid Entire Body Assessment score system to identify ergonomic hazards, we conducted intraoperative observations assessing operating room personnel during different otolaryngological subspecialty procedures. Based on these findings, otolaryngology surgeons at a single academic institution in the United States were sent a survey that evaluated ergonomic practice, environmental infrastructure, and prior ergonomic training or education.RESULTS: A response rate of 69% was obtained from 70 surgeons, with 72.9% of responding surgeons suffering from some level of back pain, with cervical spine pain being the most common. Interestingly, residents were equally affected when compared to more senior surgeons both in subjective survey reports and from observational risk analysis. Furthermore, 43.8% of surgeons reported suffering from the highest level of pain when standing, whereas only 12.5% experienced pain when sitting. Importantly, 10% stated that pain impacted their work. Only 24% of surgeons had any prior ergonomic training or education.CONCLUSIONS: Our data suggest that pain and disability induced by poor ergonomics are widespread among the otolaryngology community and confirm that surgeons rarely receive ergonomic training in the surgical context. Additionally, intraoperative observational findings identified that the majority of observed surgeons display poor posture, particularly a poor cervical angle and use of ergonomic setups, both of which increase ergonomic risk hazard. These data provide guidance for future interventional studies.LEVEL OF EVIDENCE: NA Laryngoscope, 2018.
View details for PubMedID 30474217