By just preserving the nerve anatomically, function of a cochlear nerve which is a central nerve cannot be saved. In order to save the function of the cochlear nerve, we thought that a highly sensitive continued stable monitoring which can visualize the change occurring in the nerve function that cannot be detected by the eye. Therefore, we produced the hearing preservation operation using new technologies called intraoperative continuous cochlear monitoring and cochlear mapping.
What is most characteristic in our nerve monitoring surgery is to operate while monitoring the condition of the nerve function every several seconds without stopping the operation manipulation. The auditory brainstem response which is the traditional way of monitoring the auditory sensation is a convenient method but requires five hundred (30sec) to one thousand times in adding numbers, making is difficult for monitoring in real time. It is also susceptive to electromagnetic wave or had a flaw in that measurements could not be made in a case where the audibility level was bad.
Cochlear nerve action potential was a lot sensitive than the auditory brainstem response and had a lot of improvements made to those faults on auditory brainstem response, but the stability of the electrode was not good and had a flaw in that the electrode interfered with the surgery. In order to improve the flaw in the cochlear nerve action potential, we came up with an idea to place the electrode more on the inner side at the nuclei. The electric potential obtained was named DNAP. There was a significant improvement in the hearing preservation rate by the help of DNAP and cochlear mapping.
We can now check after the surgery, by reviewing the trend graph, which reactions took place at which timing. So, with more experience, the surgeon becomes aware of the needless surgical procedure and what the invasive surgical manipulations are. These really are the other significant merits for the surgeon.

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The ear surgery of chronic otitis media or choleateatoma needs very important operations training for ear nose and throat (ENT) residents. They are common ear diseases and so young doctors should get a standard skill of ear surgery. However, stapes surgery is relatively uncommon. It is also important training program for them. They need to learn normal anatomy of the middle ear and treat ossicular conduction.
We performed questionnaire survey to explore training conditions of ear surgery for young ENT doctors. List of questions were sent to the committee members of the Japan Otological Society. Questions consisted of the number of annual stapes surgery and operators, when to start ear surgery training, necessary or disadvantage items for their training, what ear surgery is appropriate for young doctors and so on. More than ninety percent leading doctors answered our survey. This seemed to show the result how important they were thinking ear surgery training.
In Japan, total number of ENT doctors has been decreasing and hospitals available for ear surgery have been also limited recently. Even in this adverse circumstance, training for residents to learn ear surgery is very important and they should experience hearing improvement of patients after ear surgery. Therefore, in normal middle ear anatomy operation like stapes surgery can be very useful training course for young ENT residents.

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We have constructed that three dimensional movies and images on temporal bone anatomy as teaching aids for students and young doctors.
We showed the young doctors the 3D movies of surgical approaches, via middle fossa and translabyrinthine approach. Afterwards, the questionnaire survey demonstrated that the first year experienced doctors could understand the facial nerve very well and the four years or more experienced doctors could newly understand the anatomy of inner auditory meatus.
We also divided the medical students into two groups. One group was lectured by 2D CT imagesalone for 60 minutes, but another group was lecturedby 3D movies for 15 minutes. There was no significant difference between two groups. Through the 3D movies based lecture, the students could understand for shorter time than 2D images based lecture.
These studies demonstrated that introduction of 3D moviecan be useful for understanding temporal bone anatomy medical students and young doctors.
This article also introduced the tentative guidelines for human body dissection for clinical anatomy education and research and commentary in Japan.
We discussed the issues of cadaver training and education of clinical anatomy.

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For the purpose of effective instruction of ear surgery, we made an educational progrum for young ear surgeons. This program is aimed to establish the knowledge of temporal bone anatomy with reference to radiological images, especilally computed tomography (CT). Dicom data of temporal bone CT taken from healthy adult subject on 0.167 mm slice thickness are supplied to trainees. Trainees can observe each slices on their personal computer. Then, each structures in the temporal bone, such as the eustacian tube, ossicles, vessels, facial nerves, labyrinth, etc., are observed on cosecutive images. Through this progrum, trainees can study three-dimensional anatomy of the temporal bone elsewhere. Trainees also experience a cadaver dissection and study an appropriate use of the microscope and drill. After these experience, trainee can perform ear surgery. Their manupilation are recorded on video and trainee must review and edit briefly. This video recording and editing are also instructive for trainees. The program also containes partcipation to the lateral skull base surgery which is useful in recognition of through temporal bone anatomy. We believe, our progrum is complehensive and wothry for education in ear specialists.

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To obtain safe, excellent results in otologic surgery, physicians require a systematic education. The author has developed a system for teaching otologic surgery to physicians at Osaka Medical College over the past 15 years. The anatomy of the human temporal bone is fundamental to otologic surgery. At our college, anatomy is taught using human temporal bone serial specimens under a microscope and high-resolution computed tomography (CT). In addition, cadaver dissection under a surgical microscope is extremely useful for young physicians, not only for understanding the surgical anatomy but also for learning how to use surgical instruments like drills and forceps. In the operating room, each operation is divided into several parts, e.g., mastoidectomy, lesion removal, ossiculoplasty, and tympanic membrane reconstruction, and young physicians perform one or two of these procedures while senior doctors perform the rest. Young doctors are not allowed to perform the entire surgery until they have amassed experience over a sufficient time. The senior doctors must check the operating records and hospitalization summaries. This education system has resulted in low rates of surgical complications and excellent outcomes. In addition, the amount of otologic surgery performed at Osaka Medical College has increased markedly.

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Little was known about difficulties of life and psychological problems in cases with unilateral hearing loss in Japan. Herein I report about my experiments and my parents' care in the disease.
I have right unilateral hearing loss due to right external ear canal obstruction combined with right microtia. In my childhood, my parents talked to me and show me TV programs for improving the delayed acquisition. When I was two years old, they felt regret for taking me to swim in the sea because I had left otitis media, therefore, they forbid me to swim. They asked my school teachers to let me sit at the right front side of classrooms, and not to hit me on the right normal hearing ear. In my university age, I felt the difficulties in the clinical medical practices, small meetings and parties because I could not listen from the right side in a small voice. In the clinical medical practice of otolaryngology, hearing examination and CT revealed that I had severe conduction hearing loss, and the professor recommended an operation. Despite of my parents' objection, I had the operation, resulting in improvement of hearing loss, earfulness and shoulder stiffness. At the present I have right moderate hearing loss and some difficulties; 1) I sometimes do not listen to the microphone sounds in giving my presentation. 2) It is hard to talk with a diseased side person in the small meeting and party, and considering the order of seating place. 3) I sometimes give up listening to the conversation.
Patients with congenital diseases may not know correct information about their disease although having the difficulties in their social life. Therefore, they need to be informed about the disease at the proper time.

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Anatomical studies in humans have reported changes in the middle ear with age, however, the functional changes with age remain an open issue. In the present study, we analyzed the data from the National Institute for Longevity Sciences - Longitudinal Study of Aging (NILS-LSA) to assess the ten-year transition observed in tympanometric measurements. We analyzed the static admittance (comparable to compliance: SC), tympanometric peak pressure (PP), resonance frequency (RF), as variables associated with middle ear function, in 950 subjects who participated in both the 1st (1997-2000 survey) and 6th (2008-2010 survey) investigation of the NILS-LSA [Analysis 1], subsequently, in 3333 subjects who took part in the NILS-LSA between 1997 and 2010, regardless of repetitive visits [Analysis 2]. In Analysis 1, statistical analysis was done to treat the follow-up values at the 6th survey, as a dependent variable, using a multiple regression model in which independent variables were age, sex, and the initial values at the 1st survey. In Analysis 2, repeated measures analysis of variance was performed using a mixed model. The follow-up values in SC, PP, and RF obtained at the 6th survey were significantly correlated with values at the 1st survey in Analysis 1 (p< 0.0001). It suggested that the individual features of middle ear function were not much different from those of a decade ago. However, the direction of aging effect on RF observed in Analysis 1 and Analysis 2 appeared to be incompatible. Whereas in Analysis 1 higher RF was seen in the older middle ear, in Analysis 2 chronological change was directed towards lower frequency. The present finding could be explained by previous studies showing anatomical changes inconsistent for age-related middle-ear stiffness, such as more rigid, and less elastic changes with age in ossicular joints and in the tympanic membrane, and also a reduction in tonic middle-ear muscle contraction, which all affect middle-ear stiffness. As these anatomical changes contribute to middle ear in varying degrees over time, middle-ear stiffness with age may become increased or decreased at an individual level.

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We present the clinical results in 30 patients with unilateral congenital cholesteatoma who underwent surgical operation in our department between 1992 and 2010. They had postoperative follow-up of more than 1 year. The diagnosis was made at the age of less than 10 years in 80 % of the patients. In 25 ears the cholesteatoma was located only in the tympanic cavity. The majority had a posterosuperior quadrant in origin. One-staged and two-staged operations were performed in 26 and 4 ears, respectively. Twenty-seven patients underwent canal wall up tympanoplasty. The transtympanic resection was performed in 3 cases. The success rate for ossicular reconstruction was 100.0% (n=10) in type I, 50.0% (n=4) in type IIIc, 54.5% (n=11) in type IVi and 75.0% (n=5) type IVc with the overall success rate of 66.7% (n=30). Residual recurrence was observed in 5 ears with one-staged tympanoplasty. Residual cholesteatoma was found during the second operation in all 4 ears with two-staged tympanoplasty. In most younger patients congenital cholesteatoma was found during the treatment for acute otitis media or otitis media with effusion. The development and clinical introduction of optical devices would facilitate the detection of congenital cholesteatoma at an earlier age resulting in better therapeutic results.

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A 50-year-old woman complained of no symptoms except for fullness of the left ear. Her physical examination revealed a white mass visible through the left intact tympanic membrane, although her pure tone audiogram was within normal limits. CT and MRI showed a solitary mass in the left middle ear. In order to confirming the diagnosis, we performed a trans-mastoid tumor biopsy, and the tumor was microscopically diagnosed as meningioma.
Later, the tumor was successfully removed by combined approach technique, and the canal wall up tympanoplasty type III-i (interposition) was performed. The patient was undergoing regular follow-ups, and for 18 months after her surgery, she was free of any recurrent meningioma and retained good hearing.
There will be arguments both for and against operations in similar cases. Surgery, follow-ups (Wait-and-scan), and radiation can be recommended. To make a decision, further verification and the informed consent are important.

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Cochlear implantation is widely regarded as safe procedure, but there are always some risks of complication. We must ensure that every effort is taken to decrease the risk of complications. Before implantation, patients should be informed about potential problems especially the possibility of revision surgery. In this article, we investigated late complications of cochlear implantation performed at Osaka University Hospital between January 1991 and March 2011. The total number of implantation was 494 (adults: 319, children: 175). Of these operations, 27 cases (8.5%) received revision surgery in adults, and 20 cases (11.4%) in children. The reasons for revision surgery were device failure (8 cases), poor sound reaction (11 cases), electrode extrusion (6 cases), skin flap infection (5 cases) and the others. In children, it was characteristic that the reasons for revision surgery included trauma (2 cases), gusher (1 case) and the facial spasm (1 case). Reimplantation was the most common procedure in revision surgery. In some cases, patients required the removal of cholesteatoma, translocation of the receiver, or removal of the cochlear implant. There were also some cases where multiple revision surgeries were required. The revision rate was considerably higher in children than in adults because of cholesteatoma or skin flap infections. Furthermore, the rate of postoperative complications in patients with middle ear disease was higher than that of patients without middle ear disease.
We must provide patients with adequate informations to prevent flap breakdown. We must have special considerations for surgical procedure in patients with middle ear disease. Long-term follow-up is important because complications such as cholesteatoma will typically occur several years after implantation.

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A retrospective two-years' review was conducted in 95 patients (146 impaired ears) who considered to have steroid unresponsive autoimmune inner ear disease (AIED) and on all patients positive for antibody for a 68kDa bovine inner ear antigen. Pure tone average (PTA) at 250Hz, 500Hz, 1 kHz, 2 kHz and 4 kHz was used as objective measure of outcome. The patients were treated with cyclophosphamide (CPM).
At the initial treatment, 73 of 146 impaired ears (50%) exhibited a positive response to therapy. 41patients (64 impaired ears) treated with CPM had recurrence hearing loss. Positive response to CPM therapy at the end of study was seen in 46% of patients and was not significantly different as compared with the reaction of the initial CPM treatment. However, 16% of impaired ears with recurrence hearing loss were worsened. The PTA of the patients demonstrated with those normal recoveries and marked recovery was significantly low level as compared with those of patients who resulted in better, stable and worsened hearing.
In recovery rate by disease type, acute low tone sensory neural hearing loss was 69% and followed by 55% of Meniere's disease, 49% of sudden deafness, 25% of contralateral endolymphatic hydrops and 22% of idiopathic sensory neural hearing loss. 31 patients with rotatory vertigo attack were significantly recovered.
No significant difference in the improvement of hearing loss was seen between patients with or without vertigo.
In conclusion, intermittent low dose of CPM therapy to patients with steroid unresponsive AIED showed in 46% improvement rate of hearing loss, though 41patients (64 impaired ears) had reactivated in two years.

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The term 'pneumolabyrinth' was first used by Mafee in 1984, and refers to the presence of air within the cochlea or vestibule. Most of pneumolabyrinth cases reported in the literature were associated with fracture of the temporal bone. In other cases, pneumolabyrinth associated with stapes surgery, cholesteatoma, neoplasm of the middle ear and deformity has been reported. We treated four cases of pneumolabyrinth without trauma. In one case, it was caused by the Valsalva maneuver performed on a mountain top. This patient was treated conservatively at first, but needed exploratory tympanotomy due to deteriorating hearing loss and vertigo. The other three cases were associated with cholesteotoma and were all treated conservatively. The symptoms were various types of hearing loss, vertigo, tinnitus, and aural fullness. High resolution computed tomography (HRCT) is helpful for diagnosis because it allows for visualization of air trapped in the vestibule or the cochlea. It has been reported that the presence of air within the inner ear can disturb the propagation of the sound waves traveling within the cochlea. The air may also disturb the movement of the stapes and cause conductive hearing loss. Patients who have experienced episodes of implosive and/or explosive force may need HRCT for diagnosis. The treatment options for pneumolabyrinth comprise observation with bed rest and head elevation, medication and surgery. Exploratory tympanotomy is recommended for patients who show progressive hearing loss and continuous vertigo but severe hearing loss rarely improves without surgery.

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Two cases of hypertrophic pachymeningitis associated with bilateral mixed hearing loss are reported. Both patients initially presented with repeated otitis media with effusion that improved with steroid therapy. Bone conduction threshold worsening was observed during follow-up periods, and a diagnosis of hypertrophic pachymeningitis was made based on MRI with Gd enhancement. Both patients were MPO-ANCA-positive. Biopsy of the thickened dura mater performed for the first patient showed no pathological findings indicating vasculitis. Dural thickening improved following high-dose steroid therapy, but hearing did not improve in the ear which had already gone deaf for the first patient. Hearing improved following high-dose steroid therapy in the second patient, who had been diagnosed at a relatively early stage.
Hypertrophic pachymeningitis should be considered in patients with refractory otitis media with effusion accompanied by an increase in the bone conduction threshold and MPO-ANCA-positive. In addition, early treatments with steroid at an appropriate dose would be necessary to prevent irreversible hearing loss.

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We reported a case of suspected perilymphphatic oozer. The patient visited our hospital 3 years after head trauma and complained of refractory watery otorrhea from the left ear and moderate mixed hearing loss, but no vertigo/dizziness. Her otorrhea was positive for CTP (cochlin-tomoprotein), which is a perilymph-specific protein. Because CTP can be used as a diagnostic marker of perilymph leakage, the diagnosis of perilymphatic fistula was made in the patient. In addition, her otorrhea contained high concentration of glucose and radionuclide cisternography showed its accumulation in the left ear. Therefore, the diagnosis of cerebrospinal fluid (CSF) leakage was also made in the patient. These findings suggest that traumatic perilymphatic fistula caused the leakage of perilymph from the cochlea, which was made up with a CSF flowing through the cochlear aqueduct. Consequently, the mixture of perilymph and CSF was leaked from the labylinthine window of the patient but her inner ear function was preserved. Therefore, we could diagnose her with perilymphatic oozer, which is characterized by a mild welling-type of perilymph leakage and different from perilymphatic gusher.

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