Development and Optimization of Universal Bone Conduction Hearing Spectacles

Background: Non-implantable bone anchored hearing devices (BCHDs) are utilized for patients with conductive or mixed hearing loss who are unsuitable for conventional hearing aids or have unresolved middle ear issues. These devices can be surgically implanted or attached using adhesive plates, dental sticks, elastic headbands, or bone conduction spectacles. Optimal fitting of bone conduction spectacles requires appropriate frame selection and contact pressure in the temporal and mastoid areas. The ANSI S3.6 and DIN EN ISO 389-3 standards recommend a contact area of approximately 1.75 cm2 and a maximum force of 5.4 N for effective sound transmission and comfort. Methods: This study aimed to evaluate the technical fit and mechanical stability of universal bone conduction hearing spectacles compared to established systems. A Sen-Pressure 02 thin-film sensor connected to an Arduino Uno R3 board measured contact force in the temporal and mastoid areas. Several BCHDs were tested, including the Bruckhoff la belle BC D50/70, Radioear B71 headset, Radioear B71 elastic headband, Cochlear Baha SoundArc M, and Cochlear Baha elastic headband, on a PVC artificial head, with data analyzed using ANOVA and LSD post hoc tests. Results: The la belle BC D50/70 spectacles showed comparable contact force to established BCHDs, ensuring adequate sound transmission and comfort. Significant differences were observed between the systems, with the Radioear B71 headset exhibiting the highest forces. The la belle BC D50/70 had similar forces to the Radioear B71 elastic headband. Conclusion: The la belle BC D50/70 universal bone conduction hearing spectacles are a technically equivalent alternative to established BCHDs, maintaining pressure below 5.4 N. Future research should explore the impact of different contact forces on performance and comfort, and the integration of force control in modified spectacles. This study indicates that the la belle BC D50/70 is a viable alternative that meets audiological practice requirements.

Endoscopic push through tragal cartilage tympanoplasty: A 10-year retrospective review of our technique and outcomes

BACKGROUND Endoscopic ear surgery(EES)provides a magnified,high-definition view of the otological surgical field.EES allows otologists to avoid surgical incisions and associated postoperative complications.It is an ideal technique for the perfor-mance and teaching of tympanoplasty.AIM To examine the efficacy of total Endoscopic Push Through Tragal Cartilage Tympanoplasty(EPTTCT),at our institution over a 10-year period.METHODS A retrospective analysis of 168 cases of EPTTCT for closure of small to medium tympanic membrane perforations from 2013-2023 was conducted.Patient sex,age range(pediatric vs adult),etiology of injury,success rate,complications,and postoperative hearing status were collected.RESULTS Graft uptake results indicated success in 94%of patients,with less than a 2%complication rate.Postoperative pure tone audiometry demonstrated hearing status improvement in 69%of patients.CONCLUSION EPTTCT has been shown to be effective in tympanic membrane perforation closures with minimal complications.This study further demonstrates the efficacy and safety of these procedures in a single-center review.

Lessons learned in delayed identification of a misplaced electrode array in the vestibule

To report a case of cochlear implantation with a misplaced electrode array in the vestibule and the causes for the delay in identification.A 23-year-old male with left single-sided deafness underwent cochlear implantation.The intraoperative assessment did not reveal any major red flags of electrode array misplacement.He did not display any vestibular symptoms postoperatively but showed poor speech performance,even though the aided tone audiometry revealed good sound detection thresholds.High-resolution computed tomography(HRCT)showed that the entire perimodiolar electrode array was situated within the vestibule,and a revision surgery was conducted.Retrospective analysis of the neural response telemetry(NRT)revealed subtle differences in responses between the misplaced and correctly placed electrode arrays.Unlike previously reported cases,the patient did not display vestibular symptoms despite the misplacement of the electrode in the vestibule due to existing weakness in otolithic function.Further investigation is warranted when a motivated patient with normal inner ear anatomy does not show benefit with the cochlear implant post-operatively.

Post Thyroidectomy Assessment of Intact Parathyroid Hormone for Early Prediction of Hypocalcaemia

Background: As the half-life of intact parathyroid hormone (iPTH) is very low, it reflects parathyroid insufficiency within minutes to hours after total thyroidectomy. Therefore, iPTH level assessment in the postoperative period can be used to predict the development of hypocalcaemia. The optimal time point to measure serum iPTH is important for the accurate prediction of hypocalcaemia. Aim: This paper aims to evaluate the ability of iPTH as an early predictive marker of hypocalcaemia and determine which time iPTH is more able to predict postoperative hypocalcaemia. Method: This prospective observational study was conducted in the Department of Otolaryngology-Head & Neck Surgery, BSMMU, Dhaka, from July 2020 to December 2021, with 67 patients who underwent total thyroidectomy. iPTH levels were measured on the day before the operation and at 1 hour, 4 hours, and 24 hours after the operation. S.calcium levels were measured on the day before the operation and 1st postoperative day. All the data were compiled and sorted properly and were analyzed statistically. Results: Postoperative hypocalcaemia developed in 18 cases, with an incidence of 26.9%. Pearson correlation showed a significant correlation between postoperative iPTH at 1 hr, 4 h, and 24 hr with 1st postoperative calcium value. The Receiver operating characteristic (ROC) curve was processed for the postoperative iPTH at 1 hr, 4 h, and 24 hr. The sensitivity, specificity, cut-off value, and mean AUC found 93.9%, 94.4%, ≤14.0, 0.988;95.9%, 94.4%, ≤09.5, 0.993 and 91.8%, 94.4%, ≤11.0, 0.993 respectively. Conclusion: iPTH can be used as an early predictor of post-thy-roidectomy hypocalcaemia. 4 hr iPTH showed more sensitivity and specificity for a cut-off value near the laboratory reference range.

Malignant glaucoma treated by low-dose laser cycloplasty: a 1-year multicenter prospective noncomparative study

AIM:To report a one-year clinical outcomes of low-dose laser cycloplasty(LCP)among malignant glaucoma patients.METHODS:In this prospective,multicenter,noncomparative clinical study,participants with malignant glaucoma were recruited and underwent LCP at eight ophthalmic centers in China.Patients were followed up at 1wk,1,3,6,and 12mo.Intraocular pressure(IOP),number of glaucoma medications,anterior chamber depth(ACD),and complications were recorded.Anatomical success was defined as the reformation of the anterior chamber based on slit-lamp biomicroscopy.Recurrence was defined by the presence of a shallow orflat anterior chamber after initial recovery from treatment.RESULTS:A total of 34 eyes received LCP.Mean IOP and medications decreased from 36.1±11.5 mm Hg with 3.3±1.5 glaucoma medications pre-treatment to 20.9±9.8 mm Hg(P<0.001)with 2.9±1.6 medications(P=0.046)at 1d,and 17.4±6.7 mm Hg(P<0.001)with 1.3±1.7 medications(P<0.001)at 12mo.The ACD increased from 1.1±0.8 mm at baseline to 1.7±1.0 mm and to 2.0±0.5 mm at 1d and 12mo,respectively.A total of 32(94.1%)eyes achieved initial anatomical success.During follow-up,2(5.9%)eyes failed and 8(23.5%)eyes relapsed,yielding a 12-month anatomical success rate of 64.3%.Complications including anterior synechia(8.82%),choroidal/ciliary detachment(5.88%)and hypopyon(2.94%)were observed within 1wk.CONCLUSION:LCP is simple,safe,and effective in reforming the anterior chamber in malignant glaucoma.

A morphometric study of the structures bordering the infra-cochlear corridor-Relevant for endoscopic/microscopic ear surgery

Application of surgical endoscope, used alone or in combination with the surgical microscope, for the operative management of ear and temporal bone conditions may allow improved access and clearance of disease. Preservation of normal structures may also be improved.As the use of this tool is increasing, the need for better understanding of the anatomy of the ear is becoming evident. This is particularly so for endoscopic surgery aiming at removal of lesions involving the infra-cochlear corridor and/or petrous apex.Human temporal bone-derived labyrinth casts(molds), originally made for endolymphatic duct and sac analysis which genuinely represent the membranous labyrinth and its adjacent soft tissues, were morphometrically analyzed in terms of the anatomic relations between structures in and around the infra-cochlear corridor. The distance between the petrous carotid artery(PCA) and the basal turn of the cochlea, the distance between PCA and infra-cochlear vein(ICV)/cochlear aqueduct(CA), and the distance between the lower surface of basal cochlear turn and the point where the carotid artery and jugular vein(JV) meet close to the jugular foramen, were measured to be around 1.3 mm, 6 mm and 8 mm respectively, thus constituting an approximate 6?8 mm2 infra-cochlear corridor. This analysis and further study with larger samples might be helpful for operation via this corridor led to the petrous apex where cholesterol granuloma, cholesteatoma and other lesions are not uncommon.

Ephrin A2 protein expression in the regeneration and plasticity of cochlear hair cells in chicken following kanamycin ototoxicity

The results from this study showed that the thresholds of brainstem auditory-evoked potentials peak following 10 successive days of intramuscular injection of Roman chickens with kanamycin, starting 3 days after birth. Fluorescence immunohistochemistry analysis revealed few ganglion cells positively labeled for Ephrin A2 in the cochlea of experimental chickens from 2 days before until 7 days after the last kanamycin injection. The number of Ephrin A2-positive ganglion cell bodies was increased at 15 days after the last injection and was similar to that in normal chickens at 30 days following the cessation of kanamycin treatment. These experimental findings indicate that Ephrin A2 protein expression in the acoustic ganglia is synchronized with the connection damage and regeneration of cochlear hair cells after kanamycin exposure. Ephrin A2 may play an important role in the regeneration and plasticity of cochlear hair cells in the chick cochlea following kanamycin ototoxicity.

Hidden Hearing Loss: Causes, Current Knowledge, and Future Directions

Introduction: Hidden hearing loss (HHL) is a type of auditory disorder that affects the auditory neural processing and hearing sensitivity in subjects with normal hearing thresholds. Unlike central auditory processing disorders, HHL happens when the cochlea (the peripheral auditory organ) is affected. There are several known risk factors to HHL which includes noise exposure, ototoxic drugs, and peripheral neuropathies, and age. Recent studies have shed light on this type of hearing loss, its etiology, prevalence, and how it can affect the auditory acuity in humans. Methods: This paper covers the current research regarding HHL, its causes, the different mechanisms involved in this disorder, and the diagnosis and potential treatments related to it. We will delve deeply into different researches concerning HHL. 4 articles from 285 were selected focusing on normal hearing individuals with bad speech intelligibility were discussed in this paper. In addition, articles discussing the effects of noise exposure on hearing impaired individuals were not considered as this study solely aims to focus on normal hearing sensitivity individuals with HHL, resulting in 4 articles from 285. Results: Numerous literatures over the decades have suggested that HHL is due to the degeneration of cochlear ribbon synapses, or hair cells synapses without hair cell damage. Their association with HHL was noted several times through this study, whether we were studying the effect of noise exposure, of age, or of ototoxicity. In all cases, no significant hair cell damage was observed, and normal thresholds were recovered. However, a decline in the amplitude of Auditory Brainstem Response (ABR) peak I from auditory nerve (AN) responses in noise exposed subjects and a decline in compound action potential (CAP) was measured when certain drugs were applied to the round window of Guinea pigs. Conclusion: Most studies, have proven that cochlear synaptophysin is the major contributor to noise induced, age, and ototoxic related HHL. There are several audiometric tests that were used to help identify HHL including Puretone audiometry in background noise, ABR, CAP, Distortion Product Otoacoustic Emission (DPOAE).

Advances in research on labyrinth membranous barriers

Integrity of the membranous labyrinth barrier system is of critical importance, which promotes inner ear homeostasis and maintains its features. The membranous labyrinth barrier system is divided into several subsets of barriers which, although independent from each other, are interrelated. The same substance may demonstrate different permeability characteristics through different barriers and under different conditions, while different substances can have different permeability features even in the same barrier under the same condition. All parts of the mem-branous labyrinth barrier structure, including their morphology, enzymes and channel proteins, and theirs permeability characteristics under various physiological and pathological conditions are reviewed in this paper. Infections, noise exposure, ototoxicity may all increase perme-ability of the barriers and lead to disturbances in inner ear homeostasis. Copyright ? 2015 The Authors. Production & hosting by Elsevier (Singapore) Pte Ltd On behalf of PLA General Hospital Department of Otolaryngology Head and Neck Surgery. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Otolithic organ function in patients with profound sensorineural hearing loss

Profound sensorineural hearing loss (PSHL) is not uncommonly encountered in otology. In clinics, there is a high incidence of otolithic damage in patients with PSHL, but relevant reports are few. Sharing a continuous membranous structure and similar receptor cell ultrastructures, the cochlea and vestibule may be susceptible to the same harmful factors. Disorders of the inner ear may result in a variety of manifestations, including vertigo, spatial disorientation, blurred vision, impaired articulation, and hearing impairment. Considering the diversity of clinical symptoms associated with PSHL with otolithic dysfunction, it may be frequently misdiagnosed, and objective means of testing the function of otolithic organs should be recommended for hearing-impaired patients. Vestibular-evoked myogenic potentials (VEMPs) via air-conducted sound are of great importance for the diagnosis of otolithic function. Hearing devices such as cochlear implants are commonly accepted treatments for PSHL, and early identification and treatment of vestibular disorders may increase the success rate of cochlear implantation. Therefore, it is necessary to increase awareness of otolithic functional states in patients with PSHL.

Chronic otitis media and subsequent hearing loss in children from the Himalayan region residing in Buddhist Monastic schools of Nepal

Objectives:The main objective of the study was to ascertain the prevalence of chronic otitis media and determine the corresponding hearing loss in children from Nepal’s Himalayan region now residing in Buddhist Monastic schools of Nepal.Methods:The study was conducted among children at Buddhist monastic school in different parts of Nepal.A total of 3174 children aged between 5 and 15 years,who were originally from the Himalayan region of Nepal and were currently residing in monastic schools,were screened for ear problems and hearing loss.They were examined by otoscope to diagnose chronic otitis media.Hearing was evaluated by pure tone audiometer,and 0.5e4 kHz air conduction hearing threshold was measured and documented.Results:Of the total of 3174 children who were screened for ear diseases and hearing loss,monks constituted 76.21%(n?2419)and Nuns 23.78%(n?755).Chronic otitis media was the most common otoscopic finding during the screening,and it affected a total of 344(10.83%)children.Out of these 344,hearing loss of varying degrees was observed in 5.42%(n?172)children.Conclusion:There is high prevalence of chronic otitis media in children belonging to the Himalayan region of Nepal,and it is the main cause of avoidable hearing loss.Timely diagnosis and treatment of chronic otitis media could prevent unnecessary hearing loss in these children.

Evaluation of ocular and cervical vestibular evoked myogenic potentials in a conductive hearing loss model

Objective:To investigate the effects of conductive hearing loss (CHL) on vestibular evoked myogenic potentials (VEMPs) using a simulated CHL model, and to provide the basis for future studies. Methods:Twenty-one healthy subjects were recruited in this study. We measured ocular VEMPs (oVEMPs) and cervical VEMPs (cVEMPs) in these subjects by air-conduction sound (ACS) stimulation. CHL was simulated later by blocking the right external auditory canal with a soundproof earplug to evaluate its impacts on VEMPs. Subjects' responses before simulated CHL served as the control, and were compared to their responses following simulated CHL. Results: oVEMPs following simulated CHL showed decreased response rate, elevated thresholds, attenuated amplitudes and prolonged N1 latencies compared with those before simulated CHL, and the differences were statistically significant. Similarly, cVEMPs following simulated CHL also showed decreased response rate, elevated thresholds and attenuated amplitudes, with prolonged P1 latencies compared with those before simulated CHL, although only differences in response rate, threshold and amplitude were significant. Conclusions:Conductive hearing loss affects the response rate and other response parameters in oVEMPs and cVEMPs.

Getting started in endoscopic ear surgery

Endoscopic ear surgery(EES) is an exciting, rapidly developing and innovative field of otologic surgery.Technically and conceptually, EES is a significant departure from traditional microscopic transcanal approaches to the middle ear and canal that has shown very positive results with respect to patient outcomes. This review serves as a primer for the otologist and otology resident embarking on EES and discusses the theory surrounding the learning process, the optical chain for endoscopic surgery as well as other important underlying principles.

Improved hearing in noise using new signal processing algorithms with the Cochlear^(TM) Nucleus~ 6 sound processor

Objective： To demonstrate the performance benefit of the Automatic Scene Classifier （SCAN） algorithm available in the Nucleus 6 （CP900 series） sound processor over the default processing algorithms of the previous generation Nucleus 5 （CP810） and Freedom HybridTM sound processors. Methods： Eighty-two cochlear implant recipients （40 Nucleus 5 processor users and 42 Freedom Hybrid processor users） listened to and repeated AzBio sentences in noise with their current processor and with the Nucleus 6 processor. Results： The SCAN algorithm when enabled yielded statistically significant non-inferior and superior performance when compared to the Nucleus 5 and Freedom Hybrid sound processors programmed with ASC ＋ ADRO. Conclusion： The results of these studies demonstrate the superior performance and clinical utility of the SCAN algorithm in the Nucleus 6 processor over the Nucleus 5 and Freedom Hybrid processors.

Audiological characteristics of the contralateral ear in patients with unilateral physical non-explosive ear trauma

Objectives:To document the frequency of occurrence and types of symptoms experienced in the contralateral ear in patients with unilateral physical non-explosive(UPN)ear trauma and to compare the audio metric and tympano metric parameters between asymptomatic and symptomatic contralateral ears.Design:Prospective analytical clinical study Setting:Specialized(Ear,Nose,and Throat)clinic of a tertiary health institution.Participants:Patients with UPN ear trauma who presented within the first week of the incident.Main outcome measures:Otologic symptoms in the contralateral ear in UPN ear trauma Results:Eighteen out of 53 patients(34.0%)experienced symptoms in the contralateral ear.The symptoms were tinnitus in 77.8%(14/18),hearing loss in 66.7%(12/18),and ear blockage in 27.8%(5/18).There was hearing loss in 38/53(71.7%)of contralateral ears.Hearing loss type and PTAv at the low frequencies were not significantly different(p=0.142),but other audiometric parameters were significantly different between asymptomatic and symptomatic contralateral ears(p<0.05 in all).Type C tympanogram was more prominent in the symptomatic contralateral ear.There was a statistically-significant difference in the type of tympanogram between the two categories of patients(p=0.018).There was no difference in acoustic reflex between the two categories of patients(p=0.095).Conclusions:The contralateral ear may be affected in up to one-third of patients with UPN ear trauma,and experience otologic symptoms similar to those of the traumatized ears.Audiologic and audiometric parameters were abnormal in most of the contralateral ears.The two ears must be assessed thoroughly in cases of UPN ear trauma.

Development of otology specific outcome measure:Ear Outcome Survey-16 (EOS-16)

Purpose An important outcome measure of patient care is the impact on the patient’s health-related quality of life(HRQoL).Current ear-specific HRQoL instruments are designed for one diagnosis and emphasize different subdivisions such as symptoms,hearing problems,psychosocial impact,and the need for care.The optimal length of the recall period has not been studied.For these reasons,a new survey is needed that would cover most chronic ear diseases.Methods A preliminary 24-item survey(EOS-24)was created.Untreated adult patients(included n=186)with one of seven different chronic otologic conditions from all university hospitals in Finland were recruited to respond to EOS-24 and the 15D general HRQoL instrument.The recruiting otologists evaluated the severity of the disease and the disability caused by it.A control group was recruited.Based on the patients’responses in different diagnosis groups,the items were reduced according to pre-defined criteria.The resulting survey was validated using a thorough statistical analysis.Results The relevance and necessity of the original 24 items were thoroughly investigated,leading to the exclusion of 8 items and the modification of 1.The remaining 16 items were well-balanced between subdivisions and were useful in all seven diagnosis groups,thus constituting the final instrument,EOS-16.The most suitable recall period was three months.Conclusions EOS-16 has been created according to the HRQoL survey guidelines with a versatile nationwide patient population.The survey has been validated and can be used for a wide range of chronic ear diseases as a HRQoL instrument.

Self Ear Cleaning: Prevalence and Profile among School Children in Ekiti, Nigeria

Background: Self-cleaning of ears with different objects is a common practice among school children with scanty report in literature. Aim: The aim of this study was to determine the prevalence and profile of self-ear cleaning among school children. Methods: It was a cross-sectional institutional-based study which was carried out among school children in Ekiti, south western Nigeria from January 2017, to March 2017. Results: A total of 174 students participated in this study. Their age ranged between 13 and 17 years. The highest number of participant was found at the age of 15 years. One hundred and eighteen (67.8%) of them had carried out self ear cleaning. Personal hygiene was the commonest reason for self ear cleaning in 28.8% of the students. Cotton buds were mostly used by the respondents in 51.7% of them. Injury to the external auditory canal (EAC) was the most recorded complications. Conclusion: The outcome of this study shows that self-ear cleaning practices were common among school children with a prevalence of 67.8%. Cotton buds were the commonest objects used. Avoidable complications were reported among respondents. There is a need to intensify efforts on public enlightenment programme and the establishment of school health programme in our various schools.

The Impact of Age on Cochlear Implant Performance

Objective: Cochlear implantation is the emerging treatment of choice for severe and profound sensorineural hearing loss, yet there are conflicting data on outcomes in adults. There is significant variability in the literature concerning the exact effect of age on cochlear implant outcomes. We sought to evaluate the outcomes of cochlear implant performance stratified by age. Study Design: Retrospective review. Methods: Audiologic preoperative and postoperative evaluation consisted of word recognition scores (Consonant-Nucleus-Consonant). Complications were retrospectively collected after each cochlear implantation. A sub-analysis was performed comparing patients implanted at a younger (21 - 64 years) and older (65 and above) age. Results: A total of 240 patients were evaluated. Patients experienced a significant improvement in audiologic performance as seen with word recognition scores (p < 0.00001). The mean post-implant score was 44.6% (at 3 months) and 53.5% (at 24 months) at 50 dB compared to average pre-implantation aided score of 6%. There was no significant difference between postoperative performances in younger versus older patient groups. Multiple regressions showed no correlation with duration of deafness at time of implantation or age and performance. There was no significant difference in performance based on side of implantation. Conclusion: This is one of the largest series to date on hearing outcomes in adults who receive a cochlear implant. No statistical differences were noted between the younger and older groups or based on side of implantation. The audiologic benefit in the adult population is clearly demonstrated.

Acute Mastoiditis Clinical Course and Management in Patients Presented to Khartoumar Ear, Nose and Throat Hospital during the Period from November 2017 to November 2019

Introduction: Acute mastoiditis is the most common complication of Acute Otitis Media (AOM) and it’s the cause of serious morbidity. There is no standard universally agreed-upon management approach to acute mastoiditis. This study aims to view the clinical presentation and management approaches in Khartoum Ear, Nose and Throat Hospital. Methodology: This is a prospective case series and a hospital-based study conducted at Khartoum Ear, Nose and Throat Hospital during the period from November 2017 to November 2019. A total of 61 patients were included in the study. Results: The median age at presentation is 5 years old, males are more affected than females with a ratio of 1.35:1, and the mean duration of symptoms prior to hospital admission was 9.6 days. The most common presenting symptoms were otalgia (83.3%), ear discharge (83.3%) and post-auricular swelling (83.3%), and the most common signs at admission were tenderness over the mastoid (95.1%), retroauricular swelling and protrusion of the auricle (82%), and redness over the mastoid (77%). The abnormal tympanic membrane was found in all patients with central perforation being the commonest finding (73.8%), and bulging tympanic membrane (21.3%). 34.4% of patients received oral antibiotics before admission and the mean duration of symptoms prior to admission increased significantly in those who received antibiotics 12.7 days in comparison to those who didn’t 8.3 days. Only 52.5% of patients had a past history of recurrent acute otitis media, and 8.2% had a past history of acute mastoiditis. All the patients with recurrent mastoiditis had a past history of recurrent acute otitis media. Computed Tomography (CT) scans were obtained for 50.8% and 83.9% of those scans showed coalescent mastoiditis. Further evidence of intracranial extension was found in 6.5% and Magnetic Resonance Imaging (MRI) was obtained for them. Of the study group, 67.2% presented with subperiosteal abscess, 4.9% with facial nerve palsy and 3.3% with brain abscess. Thirteen patients with no complications were managed initially with injectable and topical antibiotics and were successful in only 6 of them (46%), abscess incisions and drainages were needed in 46 patients and were successful in 34 of them (73.9%). Eighteen patients (29.5%) needed mastoidectomy and all of them were managed successfully (100%). One patient (1.6%) was referred for intracranial abscess drainage in a specialized hospital, also one patient (1.6%) initially presented with intracranial abscess died on the second day of admission and 96.8% were discharged in good condition. The mean duration of hospital stay was 7.5 days. Conclusion: Patients present to the hospital after a prolonged period with a higher rate of complications, and the delayed presentation increased significantly in patients who received oral antibiotics prior to admission. Conservative medical treatment in non-complicated acute mastoiditis was ineffective in more than half of the patients and abscess incision and drainage and/or mastoidectomy are often necessary for the management.

Review of the Study of Nonlinear Atmospheric Dynamics in China (1999-2002)

Researches on nonlinear atmospheric dynamics in China (1999-2002) are briefly surveyed. This review includes the major achievements in the following branches of nonlinear dynamics: nonlinear stability theory, nonlinear blocking dynamics, 3D spiral structure in the atmosphere, traveling wave solution of the nonlinear evolution equation, numerical predictability in a chaotic system, and global analysis of climate dynamics. Some applications of nonlinear methods such as hierarchy structure of climate and scaling invariance, the spatial-temporal series predictive method, the nonlinear inverse problem, and a new difference scheme with multi-time Ievels are also introduced.