Otologic Research Articles

Imaging findings in otitis media and resulting secondary lesions in dogs and cats - an image essay.

Over the past 2 decades, the increasing availability of computed tomography (CT) and magnetic resonance imaging (MRI) as well as the growing professional expertise have significantly improved the diagnostics of middle and inner ear diseases in dogs and cats. In answering some of the diagnostic questions, CT and MRT demonstrate equivalent performance. For most questions, however, there are differences in the diagnostic performance due to the physical imaging properties of the 2 modalities.CT is more sensitive in demonstrating involvement of the bulla wall and is more effective for detecting abnormal content within the tympanic bulla. In addition, with CT it is often easier to guide tissue samplings. On the other hand, structural changes of the soft tissues of the skull, head, meninges, brain, and nerves are not or only insufficiently detectable on CT images. MRI is clearly superior here. Therefore, MRI is essential for the characterization of materials inside the bulla cavity and for demonstrating the extent of any central spread of otitis media (OM).In this image essay, CT and MRI features of OM and resulting secondary lesions described in the literature are analyzed and summarized. Own image examples are used for illustration. Information on the etiology, pathogenesis, pathomorphology, and clinical signs important for understanding these changes are presented in concise descriptions.

Pattern of Diseases Presenting in ENT Outpatient Department in a Postgraduate Teaching Hospital in S.I.T.E. Area Karachi

Ear, Nose and Throat (ENT) diseases are one of the public health problems and affect a huge number of the patient around the globe. Objective: To determine the pattern of ENT disorders or diseases in those patients who were attended outpatient department of ORL in a postgraduate teaching hospital of Karachi. Methods: Patients presenting at ENT OPD were selected randomly for the study. Data about ENT problems and information were collected through well structured questionnaire. After data collection, it was entered and analyzes by using software SPSS-23. Variables were age, sex, residence, socioeconomic status and different ENT diseases including wax, otitis media, allergic rhinitis, pharyngitis, tonsillitis, Deviated Nasal Septum (DNS) etc. Results: Male patients were 585 (46.8%) while female patients were 665 (53.2%) out of 1250 patients. Most of the patients were from industrial areas 775 (62%) and 475 (38%) were from city areas. 355 (28%) were suffering from wax followed by acute otitis media 300 (24%), acute tonsillitis and deviated nasal septum each in 225 (18%), otitis externa 150 (12%) and acute pharyngitis 145 (11%). In our study, a huge number of 72% of cases had ear disorders. 43.2% of patients had nasal issues, while 45.2% were related to laryngopharyngeal issues. Conclusions: Majority of the patients attending outpatient ENT department were related to ear wax followed by acute otitis media, acute tonsillitis, DNS, otitis externa, acute pharyngitis and many patients have multiple diseases.

Feasibility of Multimodal Artificial Intelligence Using GPT-4 Vision for the Classification of Middle Ear Disease: Qualitative Study and Validation.

The integration of artificial intelligence (AI), particularly deep learning models, has transformed the landscape of medical technology, especially in the field of diagnosis using imaging and physiological data. In otolaryngology, AI has shown promise in image classification for middle ear diseases. However, existing models often lack patient-specific data and clinical context, limiting their universal applicability. The emergence of GPT-4 Vision (GPT-4V) has enabled a multimodal diagnostic approach, integrating language processing with image analysis. In this study, we investigated the effectiveness of GPT-4V in diagnosing middle ear diseases by integrating patient-specific data with otoscopic images of the tympanic membrane. The design of this study was divided into two phases: (1) establishing a model with appropriate prompts and (2) validating the ability of the optimal prompt model to classify images. In total, 305 otoscopic images of 4 middle ear diseases (acute otitis media, middle ear cholesteatoma, chronic otitis media, and otitis media with effusion) were obtained from patients who visited Shinshu University or Jichi Medical University between April 2010 and December 2023. The optimized GPT-4V settings were established using prompts and patients' data, and the model created with the optimal prompt was used to verify the diagnostic accuracy of GPT-4V on 190 images. To compare the diagnostic accuracy of GPT-4V with that of physicians, 30 clinicians completed a web-based questionnaire consisting of 190 images. The multimodal AI approach achieved an accuracy of 82.1%, which is superior to that of certified pediatricians at 70.6%, but trailing behind that of otolaryngologists at more than 95%. The model's disease-specific accuracy rates were 89.2% for acute otitis media, 76.5% for chronic otitis media, 79.3% for middle ear cholesteatoma, and 85.7% for otitis media with effusion, which highlights the need for disease-specific optimization. Comparisons with physicians revealed promising results, suggesting the potential of GPT-4V to augment clinical decision-making. Despite its advantages, challenges such as data privacy and ethical considerations must be addressed. Overall, this study underscores the potential of multimodal AI for enhancing diagnostic accuracy and improving patient care in otolaryngology. Further research is warranted to optimize and validate this approach in diverse clinical settings.

Comprehensive diallel analysis of combining ability and heterosis to Fusarium verticillioides ear rot resistance in maize

AbstractMaize (Zea mays L.) Fusarium ear rot (FER), which is caused by the fungal pathogen Fusarium verticillioides, is a major ear disease affecting maize production in China. Developing resistant maize hybrids is a cost‐effective and environmentally friendly method of reducing yield losses due to FER. Using the nail punch inoculation method, 17 highly resistant and 16 highly susceptible inbred lines were identified in this study, and a large‐scale maize hybrid consisting of 528 F1’s was produced using a half‐diallel cross model. The hybrids were inoculated with F. verticillioides in 6 year–location environment combinations during 2020–2022. Our results showed that estimates of genotypic, environmental, and genotype × environment interaction variance components were very significant (p < 0.001). All the crosses generated from highly resistant inbred lines exhibited high kernel resistance, whereas those generated from highly susceptible inbred lines mostly exhibited high susceptibility to FER. Crosses between resistant and susceptible inbred lines showed intermediate resistance to FER. The general combining ability (GCA) effect was greater than the specific combining ability effect across multiple environments, indicating that the inheritance of FER resistance was mainly influenced by additive genetic effects. The correlation coefficient between the expected GCA value and hybrid resistance was 0.789, whereas that between the mid‐parent value and hybrid resistance was only 0.644. Inbred performance per se and their corresponding hybrids across multiple environments were significantly correlated (r = 0.823). However, no relationship was observed between the FER resistance of F1’s and that of their parental heterotic groups.

Assessing the usefulness of tubomanometry as a diagnostic tool in Eustachian tube dysfunction.

This study aims to evaluate the validity and reliability of tubomanometry (TMM) in diagnosing obstructive Eustachian tube dysfunction (OETD) before balloon Eustachian tuboplasty (BET). A prospective cohort study was conducted, involving 25 patients with sinonasal pathology, 75 patients with middle ear disease, and 25 healthy subjects, totaling 250 ears. All participants underwent comprehensive physical examinations, including TMM, nasal videoendoscopy, otoendoscopy, Valsalva maneuver (VM), tympanometry, and audiometry. Additionally, various scales such as ETDQ-7 and ETS-7 were employed. Tympanometry served as the gold standard for assessing OETD, and comparisons were made among the measures across the three groups. Among the 125 participants, 44.8% (n = 56) were female, and 55.2% (n = 69) were male, with ages ranging from 19 to 93years (M = 48.5; SD = 15.6). In our study, VM demonstrated high sensitivity (86.3%) when tympanometry was considered the gold standard. Conversely, TMM, ETDQ-7, and ETS-7 exhibited high specificity, with ETDQ-7 showing the highest specificity (87.4%). Regarding TMM, all R values in patients within the middle ear disease group were pathological (R > 1). TMM has exhibited notable specificity as a diagnostic tool compared to tympanogram and VM. Nonetheless, the combination of TMM and ETDQ-7 has enabled us to conduct a diagnostic assessment with high sensitivity and specificity for chronic OETD diagnosis.

Knowledge and Practice of Amran University Students toward Ear and Hearing Health

The World Health Organization (WHO) has detected an urgent need for action to prevent and manage ear diseases and hearing loss. However, the first step is to identify the areas of knowledge deficiency within the population. The aim of the study was to evaluate knowledge of university students' community in managing and preventing ear disease and hearing loss. This was a cross-sectional study conducted during February 2023 at Amran University using an online ontological questionnaire. Data was retrieved and processed in Excel spreadsheet and analyzed using SPSS version 29. A total of 330 participants responded to the online questionnaire, of whom 84.5% were male, with a mean age of 21.43 ± 1.77. Among them, 15.8% reported previous ear problems, while 41.2% had relatives with ear or hearing problems. Exposure to loud noise was reported by 37.6%, and 52.2% reported listening to headphones loudly. The overall correct response rate to the statements was 73.2%, indicating a lack of certain important knowledge. The study results showed a need for official campaigns to educate the Yemeni population. Moreover, they indicated the necessity of conducting a survey on a much wider scale to aid in the development of appropriate health communication strategies and the promotion of ear and hearing health.

Deep Learning Method for Rapid Simultaneous Multistructure Temporal Bone Segmentation.

To develop and validate a deep learning algorithm for the automated segmentation of key temporal bone structures from clinical computed tomography (CT) data sets. Cross-sectional study. A total of 325 CT scans from a clinical database. A state-of-the-art deep learning (DL) algorithm (SwinUNETR) was used to train a prediction model for rapid segmentation of 9 key temporal bone structures in a data set of 325 clinical CTs. The data set was manually annotated by a specialist to serve as the ground truth. The data set was randomly split into training (n = 260) and testing (n = 65) sets. The model's performance was objectively assessed through external validation on the test set using metrics including Dice, Balanced accuracy, Hausdorff distances, and processing time. The model achieved an average Dice coefficient of 0.87 for all structures, an average balanced accuracy of 0.94, an average Hausdorff distance of 0.79 mm, and an average processing time of 9.1 seconds per CT. The present DL model for the automated simultaneous segmentation of multiple structures within the temporal bone from CTs achieved high accuracy according to currently commonly employed objective analysis. The results demonstrate the potential of the method to improve preoperative evaluation and intraoperative guidance in otologic surgery.

Masked speech recognition by 6–13-year-olds with early-childhood otitis media: effects of acoustic condition and otologic history

Objective To investigate speech recognition in school-age children with early-childhood otitis media (OM) in conditions with noise or speech maskers with or without interaural differences. To also investigate the effects of three otologic history factors. Design Using headphone presentation, speech recognition thresholds (SRTs) were measured with simple sentences. As maskers, stationary speech-shaped noise (SSN) or two-talker running speech (TTS) were used. The stimuli were presented in a monaural and binaural condition (SSN) or a co-located and spatially separated condition (TTS). Based on the available medical records, overall OM duration, OM onset age, and time since the last OM episode were estimated. Study sample 6–13-year-olds with a history of recurrent OM (N = 42) or without any ear diseases (N = 20) with normal tympanograms and audiograms at the time of testing. Results Mixed-model regression analyses that controlled for age showed poorer SRTs for the OM group (Δ-value = 0.84 dB, p = 0.009). These appeared driven by the spatially separated, binaural, and monaural conditions. The OM group showed large inter-individual differences, which were unrelated to the otologic history factors. Conclusions Early-childhood OM can affect speech recognition in different acoustic conditions. The effects of the otologic history warrant further investigation.

Recreational music exposure and hearing health in young adults

ObjectiveThis study aimed to compare daily and total recreational music exposure levels and extended-spectrum audiogram results in young adults without pre-existing hearing problems.DesignThe study included healthy volunteers aged 18–25 with no known ear disease or hearing loss. Participants completed a questionnaire, underwent otoscopic and tympanometric examinations, and determined preferred music volumes in an audiometry booth using calibrated music samples of their preferred genres. Hearing thresholds up to 16 kiloHertz (kHz) were measured. Daily music exposure for each participant was normalized to 8 h to calculate a time-weighted average of 8 h (TWA8). Total exposure (TE) was calculated by multiplying TWA8 by the number of years of music listening.ResultsA total of 32.4% of participants had TWA8s above 65 dB. Their hearing thresholds at 125, 250, 500, and 16,000 Hz and the average of 125 Hz–8 kHz were significantly higher. Participants with TWA8s above 65 dB were also more prone to speaking loudly and experiencing communication difficulties on the phone. Those with a TE of more than 400 experienced significantly more speech discrimination difficulty in noisy environments and temporary hearing loss/tinnitus after exposure to loud music. Participants with a TE above 700 had worse thresholds at 4, 14, and 16 kHz frequencies, as well as 125–8000 Hz and 500–4000 Hz averages compared to those with a TE below 700.ConclusionsThis study provides evidence that recreational music with much lower exposure levels than the universally accepted TWA8 of 85 dB could negatively impact hearing in healthy young adults. Therefore, maintaining a maximum TWA8 of 65 dB is recommended.

Hearing loss prevalence and burden of disease in China: Findings from provincial-level analysis.

Without timely and effective rehabilitation, hearing loss may profoundly affect human life quality. China has a large population of hearing-impaired individuals, which imposes a heavy health burden on society. Moreover, this population is projected to increase rapidly owing to China's aging society. We used data from a population-representative epidemiological investigation of hearing loss and ear diseases in four Chinese provinces. We estimated the national prevalence using multiple linear regression of the age-group proportions and prevalence in 31 provinces with clustering analysis. We used years lived with disability (YLDs) to analyze the disease burden and forecasted the prevalence of hearing loss by 2060 in China. An estimated 115 million people had moderate-to-complete hearing loss in 2015 across the 31 provinces of China (8.4% of 1.37 billion people). Of these, 85.7% were older than age 50years (99 million people) and 2.4% were younger than 20years old (2.8 million people). Of all YLDs attributable to hearing loss, 68.9% were attributable to moderate-to-complete cases. By 2060, a projected 242 million people in China will have moderate-to-complete hearing loss, a 110.0% increase from 2015. The hearing loss prevalence in China is high. Population aging and socioeconomic factors substantially affect the prevalence and severity of hearing loss and the disease burden. The prevalence and severity of hearing loss are unevenly distributed across different provinces. Future public health policies should take these trends and regional variations into account.

Success and safety of endoscopic versus microscopic resection of temporal bone paraganglioma: a meta-analysis.

Temporal bone paraganglioma (TBP) are the most common tumors of the middle ear. They pose a challenge in otologic surgery due to their extensive vascularity and intricate location within the middle ear. This meta-analysis aimed to compare the safety and efficacy of two surgical approaches, microscopic middle ear surgery (MMES) and endoscopic middle ear surgery (EMES), in the resection of TBP. Eligible studies published after 1988 were identified through systematic searches of "PubMed", "Scopus" and "Google Scholar". Retrospective studies and randomized/non-randomized control trials reporting on surgical approaches for TBP with a minimum of five adult patients were included. A total of 595 records were initially identified. After removing 229 duplicates, 349 articles were excluded based upon article subject, title and abstract. Following the review of full texts, 13 articles were assessed for eligibility. The pooled analysis included a total of 529 ears, with a complication rate of 7.8% for EMES and 14.2% for MMES. Subgroup differences indicated no significant variation between the two methods (p = 0.2945). Both EMES and MMES demonstrated favorable surgical outcomes with low complication rates for TBP resection. These findings suggest that EMES is a safe and effective method for TBP resection and one that is comparable to MMES. Since the risk of bleeding is significant in these tumors, a third-hand technique, endoscopic bipolar cautery or laser-assisted hemostasis should be considered. Conversion to MMES is another option when visibility is critically affected by bleeding.

Frequency-Specific Analysis of Hearing Outcomes after Surgery for Chronic Ear Diseases

Frequency-Specific Analysis of Hearing Outcomes after Surgery for Chronic Ear Diseases

Effect of maternal vaccination on infant morbidity in Bangladesh

BackgroundRisk factors of infant mortality in Africa and south Asian countries have been broadly discussed. However, infant morbidity is largely underestimated. We analyzed the data from a randomized vaccine trial in Bangladesh to identify and assess the effect of risk factors on infant morbidity.MethodsPregnant women were randomly assigned to receive either inactivated influenza vaccine or pneumococcal polysaccharide vaccine and the infants were randomly assigned to receive 7-valent pneumococcal conjugate vaccine or Hib conjugate vaccine at week 6, 10 and 14. The data were collected from August 2004 through December 2005. Each pair of infant and mother were followed for 24 weeks after birth with weekly visits. Generalized estimating equations (GEE) for repeated measurements and Poisson regression models were used to identify the risk factors and evaluate their effect on the longitudinal incidence and total number of episodes of respiratory illness with fever (RIF), diarrhea disease, ear problem and pneumonia.ResultsA total of 340 pregnant women were randomized with mean age of 25 years. The baseline mother and infant characteristics were similar between two treatment groups. Exclusive breastfeeding and higher paternal education level were common factors associated with lower infant morbidity of RIF (adjusted OR = 0.40 and 0.94 with p < 0.01 and p = 0.02, respectively), diarrhea disease (adjusted OR = 0.39 and 0.95 with p < 0.01 and p = 0.04, respectively), and ear problem (adjusted OR = 0.20 and 0.76 with p < 0.01 and p < 0.01, respectively). Maternal influenza vaccine significantly reduced the incidence of RIF (adjusted OR = 0.54; p < 0.01) but not diarrhea disease or ear problem (p > 0.05). Female infants had lower incidence of diarrhea disease (adjusted OR = 0.67; p = 0.01) and ear problem (adjusted OR = 0.12; p = 0.01).ConclusionsMaternal influenza vaccination, exclusive breastfeeding, female children, and higher paternal education level significantly reduced the infant morbidity within the 24 weeks after birth in Bangladesh.

Prioritizing Disease Diagnosis in Neonatal Cohorts through Multivariate Survival Analysis: A Nonparametric Bayesian Approach.

Understanding the intricate relationships between diseases is critical for both prevention and recovery. However, there is a lack of suitable methodologies for exploring the precedence relationships within multiple censored time-to-event data, resulting in decreased analytical accuracy. This study introduces the Censored Event Precedence Analysis (CEPA), which is a nonparametric Bayesian approach suitable for understanding the precedence relationships in censored multivariate events. CEPA aims to analyze the precedence relationships between events to predict subsequent occurrences effectively. We applied CEPA to neonatal data from the National Health Insurance Service, identifying the precedence relationships among the seven most commonly diagnosed diseases categorized by the International Classification of Diseases. This analysis revealed a typical diagnostic sequence, starting with respiratory diseases, followed by skin, infectious, digestive, ear, eye, and injury-related diseases. Furthermore, simulation studies were conducted to demonstrate CEPA suitability for censored multivariate datasets compared to traditional models. The performance accuracy reached 76% for uniform distribution and 65% for exponential distribution, showing superior performance in all four tested environments. Therefore, the statistical approach based on CEPA enhances our understanding of disease interrelationships beyond competitive methodologies. By identifying disease precedence with CEPA, we can preempt subsequent disease occurrences and propose a healthcare system based on these relationships.

Endoscopic transcanal underlay myringoplasty using a platelet-rich fibrin (PRF) membrane

BackgroundTympanic membrane perforations are among the most common indications for otological surgery. Surgeons from all around the world have made accidental and intentional contributions to find the perfect graft material and the best approach to perform tympanoplasty. Platelet-rich fibrin (PRF) use in myringoplasty has been popular in the last decade among many surgeons. We aimed to evaluate the efficacy of using PRF only as a graft material in myringoplasty.MethodsWe conducted a prospective study including 20 patients with dry central tympanic membrane perforations. The patients underwent endoscopic transcanal myringoplasty using a platelet-rich fibrin membrane by underlay technique. Follow-up was done 3 months postoperatively regarding graft uptake and hearing outcome by audiological assessment using pure tone audiometry.ResultsSixty percent of patients were surgically successful with complete healing of the tympanic membrane, 10% were partially successful with partial healing of the tympanic membrane, and 30% failed with complete loss of graft. The mean air-bone gap closure was 3.5 dB. No major complications were reported.ConclusionEndoscopic myringoplasty using platelet-rich fibrin alone can be performed in cases with tympanic membrane perforations as an alternative to using other autologous grafts. It is a new reliable method for myringoplasty, as well as being an easy, time-saving procedure that avoids the need for any skin incision.

The population morbidity with diseases of ear and mastoid and accessibility of otorhinolaryngological care

The article analyses level and dynamics of morbidity of diseases of ear and mastoid in the Sakha Republic (Yakutia) in 2020-2021 and availability of otorhinolaryngological care. The methods of comparative statistics and mathematical analysis were applied to analyze official data provided by the Yakut Republic Medical Information and Analytical Center, the specialized Department of Otorhinolaryngology, the Republic Hospital № 2 - Center for Emergency Medical Care and the Federal State Statistics Service of Russia. The study established increasing trend of increasing morbidity of these diseases in both the adult and child population. In 2021, the growth rate of overall morbidity of adult population reached 17.7% and 8.8% in children, as compared to 2020. The primary morbidity of adults made up to 22.3%, in children - 15.7%. The comparative analysis demonstrated higher rates of general morbidity in the Republic: by 0.5% as compared with the Russian Federation and by 14.1% as compared with the Far Eastern Federal Okrug. The level of primary morbidity was lower than similar indicators of the compared territories by 17.1% and 3.0%, respectively. It is worth noting that analyzed morbidity of diseases of ear and mastoid reflects prevalence of ENT diseases in the region only indirectly, as the statistical data do not allow to estimate separately rate of upper respiratory tract lesions. Meanwhile, respiratory diseases rank first in the structure of population diseases in Yakutia. The growth of disability in children due to diseases of ear and mastoid requires attention. Among children of 0-17 years old, the indicator of primary disability increased from 0.38 to 0.8 per 10,000 of children population (increase of 110.5%); in children 0-3 years old - from 0.9 to 2.3 per 10,000 of the child population (an increase of 155.6%). The analysis of the number of beds in otorhinolaryngology wards established that that the bed capacity per 10,000 population was 0.6 that is significantly lower than the established standards. The article emphasizes need to adjust the Federal standards for hospital bed capacity, taking into account climatic and geographical conditions of the region, which contribute to spread and chronization of ENT diseases.

The MAP kinase FvHog1 regulates FB1 synthesis and Ca2+ homeostasis in Fusarium verticillioides

The high osmolarity glycerol 1 mitogen-activated protein kinase (Hog1-MAPK) cascade genes are important for diverse biological processes. The activated Hog1 upon multiple environmental stress stimuli enters into the nucleus where it directly phosphorylates transcription factors to regulate various physiological processes in phytopathogenic fungi. However, their roles have not been well-characterized in Fusarium verticillioides. In this study, FvHog1 is identified and functionally analyzed. The findings reveal that the phosphorylation level and nuclear localization of FvHog1 are increased in Fumonisin B1 (FB1)-inducing condition to regulate the expression of FB1 biosynthesis FUM genes. More importantly, the deletion mutants of Hog1-MAPK pathway show increased sensitivity to Ca2+ stress and elevated intracellular Ca2+ content. The phosphorylation level and nuclear localization of FvHog1 are increased with Ca2+ treatment. Furthermore, our results show that FvHog1 can directly phosphorylate Ca2+-responsive zinc finger transcription factor 1 (FvCrz1) to regulate Ca2+ homeostasis. In conclusion, our findings indicate that FvHog1 is required for FB1 biosynthesis, pathogenicity and Ca2+ homeostasis in F. verticillioides. It provides a theoretical basis for effective prevention and control maize ear and stalk rot disease.

AKT answer relating to management of ear problems

AKT answer relating to management of ear problems

AKT question relating to management of ear problems

AKT question relating to management of ear problems

Kontrollü Hipotansif Anestezi ile Yapılan Timpanoplastilerde Baş Pozisyonunun Serebral Oksijen Saturasyonu Üzerine Etkisi

Objective: Our goal was to examine the impact of head position, which had not been examined before, on cerebral oxygenation in tympanoplasties performed in the reverse Trendelenburg position during controlled hypotension. Methods: This prospective study was conducted in our clinic between July 2020 and November 2020. A total of 81 patients aged 18-59 years, who had an ASA physical condition classification score of 1-2 and were evaluated in two groups according to the type of surgery. In the tympanoplasty group, the head was turned to the contralateral ear and placed in minimal extension while in the septoplasty group, the head was kept in the neutral position. The regional cerebral oxygen saturation (c-rSO2) values of the right and left sides were recorded continuously with O3 regional oximetry probes on both sides throughout the operation. Results: When an overall examination was performed without separating the tympanoplasty group as right/left, the median oxygen saturation level was 69.50% (Q1:61.00-Q3:72.00) for the operated side and 74.00% (Q1:66.00-Q3:79.00) for the contralateral side. The oxygen saturation of the operated side was statistically significant lower (p&lt;0.001). The median oxygen saturation of the operated side in the tympanoplasty group [69.50% (Q1: 61.00- Q3:72.00)] was statistically significantly lower than that of the septoplasty group [72.00% (Q1:65.25-Q3:77.75)] (p=0.004). Conclusion: This study showed that the rotation of the head 45° or above in the revers Trendelenburg supine position causes cerebral desaturation on the opposite side of rotation. Keywords: Anesthesia, blood pressure, ear, intracranial hypotension, otologic surgical procedures