I review 14-year-achievements from Department of Physiology, Yamanashi University. Awake cat A1 has phasic and sustained cells. Phasic cells with short (<2.5 ms) integration time encode temporal information by short excitation followed by inhibition. Sustained cells with long (20 ms) integration time encode spectral information by side band inhibition adjacent to excitation spectrum. A1 encodes a wide range of sound parameters by functional complementarity of both cells. The higher auditory fields select only the A1 information fitting to behavior objective. A1 encodes sound information regardless of individual behavior, whereas the higher auditory fields are active only when the individual acts toward a goal.

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The staging system for congenital cholesteatoma developed by Potsic PW et al. in 2002 has been applied in several studies. In this staging system, we had not been able to evaluate the condition of auditory ossicle. In this study, we evaluated clinical features of the congenital cholesteatoma based on Potsic staging system (Potsic) and the staging criteria for cholestiatoma 2010 Japan (2010 cholesteatoma). Between 2001 and 2012, 52 patients (53 ears) with congenital cholesteatoma underwent surgery at our hospital. In stage III and IV in Potsic, success rates of hearing improvement were 80% (12/15) of S0, 100% (6/6) of S1, 62% (13/21) of S2 in 2010 cholesteatoma. These results suggested that the condition of stapes is important for hearing improvement.
We concluded that the staging criteria for cholesteatoma 2010 might be useful to calculate hearing improvement in congenital cholesteatoma.

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The endoscopic approach and endaural incision for localized congenital cholesteatoma have been reported in the literature, but the high residual and recurrence rates are problematic. In order to clarify the surgical indicators for endaural incision and tympanoplasty for congenital cholesteatomas, we retrospectively reviewed data in our hospital.
From 2005 to 2012, there were 16 cases of congenital cholesteatoma in children who were treated surgically in our hospital and followed up for an average of 52 months. Endaural incision was undertaken for localized cholesteatomas in the anterior part of the tympanic cavity, and tympanoplasty for advanced cases. Potsic's staging system was used for classification, in which stages I and II are localized and III and IV are advanced. Cholesteatoma was classified into the closed and open types. Efficacy was assessed according to recurrence rate and hearing results.
As the results: the cases of stages I, II, III and IV were comprised of 3, 3, 8, and 2 patients, respectively. Endural incision was undertaken in four patients, two stage I (both closed type) and two stage II patients (one closed and open, respectively) with cholesteatomas in the anterior part of the tympanic cavity, and the recurrence rate was 0% and 100% for stages I and II, respectively. Two cases with recurrent cholesteatomas were found around the tendon of the tensor tympani, and the complete removal of cholesteatoma was difficult because of the blind area behind the malleus handle. The remaining 12 cases underwent tympanoplasty, (single-stage ossicular chain reconstruction in 5 closed type patients, staged tympanoplasty in 7 open type patients), and recurrence rates were 0% for stages I and II, 25% for Stage III, and 100% for Stage IV. After excluding two cases due to a short follow-up period and one case without postoperative hearing test, the postoperative AB gap was 0-10dB in 10 cases, 11-20dB in 2 cases and 21-30dB in one case.
Conclusion: Potsic's stage I, and closed type congenital cholesteatoma in the anterior part of the tympanic cavity are surgical candidate for endaural incision, but a care must be taken for residual cholesteatoma around the tendon of the tensor tympani. Stage II to IV cholesteatoma are good surgical candidates for tympanoplasty, including staged surgery for open type cholesteatomas. Our results indicated that congenital cholesteatomas have better postoperative hearing results compared to the acquired form.

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We retrospectively reviewed the data of 35 patients with pars tensa cholesteatoma who underwent tympanoplasty at Kurashiki Central Hospital between December 2004 and April 2013. Each case was classified according to the 2010 Japan Otological Society Classification and Staging of Cholesteatoma guidelines. Type of surgical procedure, postoperative hearing outcomes and recurrence rate were analyzed.
Postoperative hearing outcomes were satisfactory in 79%, and the recurrence rate was 3%. Surgical procedure varied in concordance with Classification and Staging of Cholesteatoma guidelines. Postoperative hearing outcome deteriorated according to the extent of stapedial abnormality.

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External auditory canal cholesteatoma (EACC) is comparatively a rare disease with an uncertain etiology. If conservative therapy is inadequate to control otalgia and otorrhea or destruction of the external auditory canal (EAC) reaches into the mastoid or temporomandibular joint, surgical treatment is required. We operated 18 cases of EACC between January 2009 and December 2013. The average age of patients was 57.1 years old (ranged from 27 to 92 years old). There were 11 males and 6 females, and the side of EACC was left in 10 cases, right in 6 cases and bilateral in 1 case. Idiopathic etiology was in 14 cases, followed by traumatic in 2 cases, postoperative in 1 case, and secondary in 1 case. CT showed the bony destruction limited to the external canal wall in 6 cases, mastoid involvement in 7 cases and the temporo-mandibular joint involovement in 5 cases, respectively. Canaloplasty was performed in both 6 cases with limited lesion to the EAC wall and 5 cases with temporo-mandibular joint involvement, followed by canal wall down tympanomastoidectomy with canal wall reconstruction in 6 cases and canal wall down tympanomastoidectomy in 1 case. In the surgical technique of EACC, it is important to reconstruct the smooth and flat external auditory canal after complete resection of keratinized products, cholesteatoma and eroded bone. EAC was epithelized in 65.6 days averagely after surgery (ranged from 10 to 164 days). The recurrence was found in 2 cases (11.1%). Of these cases, conservative therapy was performed in one case, and it was necessary to perform the revision surgery in the one case. We must check carefully the epithelization of the canal wall and the recurrence of EACC.

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To determine a treatment strategy for intractable otitis media may sometimes be time consuming, and the disease may progress before the definite diagnosis is made. Thus, early diagnosis and treatment are desirable. Even if the otitis media related to ANCA associated vasculitis is suspected, some cases do not fall into its category.
We reported 8 cases (15 ears) of refractory otitis media with ANCA associated vasculitis (AAV). Five cases met the criteria of granulomatosis with polyangiitis, two cases met the criteria of microscopic polyangiitis and seven cases met proposed diagnostic criteria of otitis media with ANCA associated vasculitis (OMAAV). One case did not meet any of the diagnostic criteria. After making diagnosis by exclusion for the case, we treated with oral steroids and the condition was improved. In another case, however, facial nerve palsy and bilateral deafness developed during the course, and the patient terminated in death. After considering various differential diagnoses of intractable otitis media, we should refer to OMAAV diagnostic criteria and treat them at early stages in order to improve the prognosis.

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Twelve adult patients with acute otitis media associated with bone conduction hearing loss were clinically evaluated between April 2010 and March 2013. The average age of the patients was 49 years (range, 21-66 years), and they complained of otalgia, hearing loss, vertigo, ear fullness, and tinnitus. All patients showed mixed hearing loss in pure-tone audiometry. Nine of the 12 patients showed high-frequency hearing loss, 2 showed pan-frequency hearing loss, and 1 showed high and low-frequency hearing loss. All patients were treated in the hospital with the systemic administration of antibiotics, steroids, vitamins, and myringotomy. Nine of 12 patients achieved complete recovery. The median duration of recovery was 44.5 days. Thus, pure-tone audiometry can be helpful for adult patients with acute otitis media for the detection of bone conduction hearing loss. Aggressive treatment, including myringotomy, is necessary from the early stage to improve inner ear disorders.

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A patient with skull base osteomyelitis due to fungal infection was treated with drip infusion of an antifungal drug and hyperbaric oxygen therapy, and the symptoms disappeared. However, after 9 months, the disease recurred, and was accompanied by peripheral facial palsy. After administration of the antifungal drug that was effective on the first admission and hyperbaric oxygen therapy, the symptoms rapidly disappeared. The treatment effects were evaluated using the β-D glucan level as a parameter. Since no recurrence was observed until 2 years after the end of treatment, the β-D glucan level may be useful as a parameter for evaluating treatment effects on skull base osteomyelitis due to fungal infection.

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Over 20 years have passed since cochlear implantation introduced in Japan. Most of cochlear implantations are safe procedures, but some complications could occur during their long follow-up period. We investigated and reported post-operative complications of cochlear implantations performed in Sapporo Medical University Hospital between 1988 and May 2013.
The total number of cochlear implantations was 248 ears (adults: 159 ears, children: 89 ears and male: 106 ears, female: 142 ears).
The complications defined as what required any medical interventions were found in 92 ears (37%). The major complications required surgical interventions were found in 12 ears (4%). In minor complications, the incidence of vertigo and tinnitus was higher in adults than in children.
In our research, the incidence of postoperative complications was similar to those reported in the literature.
We considered that a long time follow-up of the patients received implantation in their hospital is the most important to prevent any postoperative complications.

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In order to investigate the rate of hearing decline in neurofibromatosis type 2 (NF2) patients conservatively managed in Japan, we retrospectively reviewed the charts of 25 NF2 patients who were treated at Keio University Hospital between 1985 and 2014. Nineteen patients (30 ears) with at least 1 year of follow-up were selected.
The mean length of follow-up was 7.1 ± 6.3 years (range, 1-25 years). Mean hearing decline rate was 4.9 ± 5.8 dB/year in pure tone average (PTA) and 4.0 ± 8.0 % in speech discrimination score (SDS). The rate of ears with useful hearing function reduced from 90% at presentation to 55% at the end of follow-up defined by the American Academy of Otolaryngology- Head and Neck Surgery classification. Deterioration of SDS at presentation and tumor growth rate (1.4 ± 2.3 mm/year) were significantly related to the hearing decline rate.
Although this report was based on the largest number of patients among reports about natural history of hearing function in NF2 patients in Japan, the number was relatively small. More studies are needed to elucidate long-term prognosis of hearing function in NF2 patients in Japan.

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Neuroma is a generally benign neoplastic tumor of nerve fibers and Schwann cells, and formation is usually post-traumatic. This pathology differs from schwannoma in that it consists of a diffuse outgrowth of neurofilaments, myelin sheaths and Schwann cells. Acoustic schwannoma is a commonly known intratympanic tumor, but little has been reported on intratympanic neuroma. We report a rare case of this pathology herein.
The patient was a 45-year-old man who presented to the hospital with a 6-month history of general malaise, headache. And he was incidentally found a tumor-like mass in the tympanic cavity on magnetic resonance imaging at the previous hospital. The right tympanic membrane appeared thin and recessed and the peripheral tissue was calcified. Audiogram showed moderate conductive hearing loss in the right ear. Computed tomography demonstrated a tumor-like mass in the tympanic cavity. Middle ear cholesteatoma was suspected and the intratympanic tumor resection was performed. The tumor was located at the back of the long process of the incus displacing the superstructure of the stapes towards the direction of the mesotympanum and it was attached to the facial nerve. Acoustic schwannoma was suspected, but pathological examination revealed neuroma. Postoperatively, no facial weakness was evident and hearing was improved, and follow-up is being continued on an outpatient basis with no signs of recurrence.
This case illustrates that intratympanic neuroma can occur without preceding trauma. The patient reported no previous injury. One report suggested that a long history of chronic inflammation in the middle ear without trauma could be related to the formation of intratympanic neuroma, but this has not been confirmed. Additional cases are needed to clarify the relationship, and further research on this topic appears warranted.

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Approximately one in every 1,000 infants is born bilaterally deaf, and early hearing detection and intervention is important for communication, cognition and educational development. The Toyama prefectural government decided to implement newborn hearing screening tests for all infants in 2005. Fortunately, a Child Developmental Support Center was established in Toyama in the early 1980's, and professionals such as otolaryngologists, pediatric neurologists and speech-language-hearing therapists have been working in conjunction very well in the early intervention system for providing service. The start of prefectural business made it possible for obstetricians to get involved in this system. Currently, more than 97% of newborn infants receive hearing screenings shortly after birth. If some degree of hearing loss is identified, the baby is fitted with hearing aids as soon as possible, within 3?4 months in most cases. The Child Developmental Support Center, Koshi Tsuen Center, has played an important role in this area for more than 30 years and will continue to do so in the future.

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