The Effects of Hypoxia on Middle Ear Pressure Regulation.

Background: Middle ear (ME) pressure regulation has been suggested as a physiological mechanism that maintains pressure equilibrium between the ME and the ambient environment. This mechanism would be based on a complex sensorineural reflex loop composed of mechanoreceptors, an integrative center, and efferent neural pathways. Our aim was to demonstrate that hypoxic conditions, which would inhibit mechanoreceptors in general, similarly participate in the inhibition of the opening of the Eustachian tube (ET), and thus, to suggest that such receptors are involved in the overall regulation of ME pressure. Materials and Methods: Among 14 healthy volunteers, tubomanometry was performed in normoxia followed by hypoxia, and 3 parameters were evaluated for each ear under each condition, allowing the evaluation of the reactivity of the system: ET opening latency index (R), the Index of Velum Contraction (IVC), and the latency of pressure instauration (C2-C1). Results: Hypoxia induced a significant increase in the opening latency index of ET opening, without deleterious effects on the quality (IVC) and latency (C2-C1) of soft palate contraction. Conclusions: Our study supports the theory of a sensorineural reflex loop and provides evidence for the existence of mechanoreceptors, whose function is modified by changes in oxygen partial pressure, able to collect information on pressure variations between the ME and the external environment.

Incidental Effect of Long-Term Tacrolimus Treatment on Sporadic Vestibular Schwannoma Volume Shrinkage and Clinical Improvement.

OBJECTIVE: We describe the effect of long-term tacrolimus delivery on sporadic vestibular schwannoma (VS). PATIENT: A 48-year-old woman who was diagnosed a right VS. INTERVENTION: Long-term tacrolimus delivery following liver transplant. MAIN OUTCOME MEASURES: Clinical examination, audiometric test, and gadolinium-contrasted magnetic resonance imaging. RESULTS: During the reported follow-up period, the patient felt hearing improvement especially in noisy environment. This was consistent with a clear audiometric improvement. Over a 26 months follow-up period, we noticed a 50% volume regression and a 40% decrease in the intensity of enhancement of the tumor after gadolinium injection. CONCLUSION: Tacrolimus, an immunosuppressant used to prevent rejection in organ transplant, could lead to VS volume shrinkage and hearing improvement. Tacrolimus could be an interesting new therapeutic weapon, especially for VS in Neurofibromatosis type 2.

Validation of French versions of the Facial Disability Index and the Facial Clinimetric Evaluation Scale, specific quality of life scales for peripheral facial palsy patients.

OBJECTIVES: To translate and validate French versions of two health-related quality of life questionnaires for patients with peripheral facial palsy: Facial Disability Index (FDI) and Facial Clinimetric Evaluation (FaCE) scale. DESIGN: Prospective cohort study. SETTING: University tertiary referral centre. PARTICIPANTS: A pilot test was performed on 10 subjects (5 patients with facial palsy of more than 1-month duration and 5 normal subjects), and then 67 adult patients with facial palsy were enrolled in the validation study. MAIN OUTCOME MEASURES: Translation of the original questionnaires has followed international guidelines using a forward-backward translation method. A pilot test and a validation study based on the translated questionnaires were performed. Internal consistency, test-retest reliability, validity and responsiveness were assessed. Validity was assessed by comparing to SF-36 and Sunnybrook/House-Brackmann grading systems. Subjects answered scales twice within a one-week interval. RESULTS: Sixty-seven patients were enrolled, among which 63 completed scales one week later (retest). For physical and social functions of FDI and FaCE scores, Cronbach's α representing internal consistency was 0.88, 0.70 and 0.89, and test-retest reliability by intra-class correlation coefficients was 0.81, 0.86 and 0.89, respectively. The correlation of facial movement score of FaCE scale was good with Sunnybrook/House-Brackmann grading systems (0.73 and -0.75, P < 0.01). The correlation of social function of FaCE scale was excellent with social function of SF-36 (0.8, P < 0.01). CONCLUSIONS: French versions of FDI and FaCE scale are psychometrically valid. Both questionnaires can be used for clinical studies to assess the quality of life of patients with peripheral facial palsy.

Intracanalicular Vestibular Schwannomas: Initial Clinical Manifestation, Imaging Classification, and Risk Stratification for Management Proposal.

INTRODUCTION: There is no consensus about the use of observation as a therapeutic modality for intracanalicular vestibular schwannoma (ICVS). The objective of this study was to describe tumor evolution, its correlation with initial size, stage of vestibular schwannoma, clinical presentation and to propose a risk classification for tumor growth with a therapeutic decision algorithm. METHODS: Fifty-three patients with ICVS were followed prospectively from 2010 to 2015. The mean follow-up was 32 months. Patients underwent clinical examination, audiogram, magnetic resonance imaging at 6, 12, and then 12 months intervals within the first 5 years of initial diagnosis. We analyzed the patient's clinical course, audiologic changes, initial tumor location, and correlation of different parameters with ICVS growth. RESULTS: Fourteen patients (26%) deteriorated their hearing level and 17 patients (27%) showed tumor growth during the follow-up period. Growth was noted during the first year of observation in 13 patients (76.5%). Considering initial presentation: tumor size, intracanalicular staging, and hearing level, patients with larger vestibular schwannoma, extension to the fundus regardless of tumor size, higher initial pure-tone average, and speech recognition test showed a significantly higher rate of tumor growth. ICVS evolution was not correlated with hearing deterioration with time. DISCUSSION: We should consider observation a therapeutic modality. We valid the intrameatal staging as prognostic factor and propose a stratification of patients into low, moderate, or high risk for potential tumor growth to guide the initial management of ICVS.

Histological identification of nasopharyngeal mechanoreceptors.

The auditory tube plays a fundamental role in regulating middle ear pressure. A "system" sensitive to a pressure gradient between the middle ear and the ambient environment is necessary. The presence of mechanoreceptors in the middle ear and the tympanic membrane has been studied, but the presence of these receptors in the nasopharyngeal region remains unclear. The aim of this study is to confirm the presence of pressure sensitive corpuscles in the nasopharynx. An experimental study was conducted on five fresh and unembalded human cadavers. The pharyngeal ostium of the auditory tube and its periphery was removed in one piece by video-assisted endonasal endoscopy. Samples were fixed in formaldehyde solution, embedded in paraffin, and cut. Slides were analyzed by HES (Hematoxyline Eosine Safran) coloration, by S100 protein and neurofilament protein immunostaining. Encapsulated nerve endings were researched and identified by slides analysis. Eight samples were included in our study. On seven samples, Ruffini corpuscles were identified in the mucosa of the posterior area of the pharyngeal ostium, with a higher concentration in the pharyngeal recess and in the posterior nasopharyngeal wall. Our study identified nasopharyngeal mechanoreceptors that could detect the nasopharyngeal pressure and, by extension, the atmospheric pressure. These findings support the theory of the neuronal reflex arc of isobaric system of the middle ear, based on the existence of a "system" sensitive to a pressure gradient between the middle ear and the ambient environment. Understanding of this system has been helpful in the diagnosis and management of middle ear diseases.