Since newborn hearing screening has prevailed in Japan in the last decade, children with severe hearing loss were found and processed for education and treatment earlier in their life. Moreover, much more infants have been diagnosed as having bilateral mild or moderate hearing loss, or unilateral severe or profound hearing loss by newborn hearing screening. Regarding differential diagnosis on pediatric hearing loss, genetic tests and imaging studies have been found to be useful in addition to audiological evaluation such as auditory brainstem response and otoacoustic emission. Although recent technological progresses of imaging studies including computed tomography (CT) and magnetic resonance imaging are remarkable, the ideal imaging algorithm in pediatric hearing loss is still under debate. In this study, we conducted retrospective chart review on the results of temporal bone CT in 60 cases of infants with unilateral or bilateral moderate to profound hearing loss. In particular, we focused on the following points; 1) role of temporal bone CT on differential diagnosis of moderate to severe hearing loss, 2) comparison of temporal bone CT results between unilateral and bilateral profound hearing loss, and 3) correlation between the results of audiological tests and anomalies in the inner ear and internal acoustic meatus. Out of 31 cases with moderate to severe hearing loss, 28 cases showed abnormal findings on temporal bone CT, indicating the importance of temporal bone CT on differential diagnosis for moderate to severe hearing loss. It was of interest that 10 out of 16 cases with unilateral profound hearing loss were diagnosed as having a stenosis of the bony cochlear nerve canal. In addition, the results of temporal bone CT in 16 cases with unilateral profound hearing loss were quite distinct from those in 11 cases with bilateral profound hearing loss, which suggested that etiopathology in bilateral profound hearing loss is not only duplication of that in unilateral profound hearing loss. While infants with cochlear and vestibular malformation or bony cochlear nerve canal stenosis demonstrated profound hearing loss, there was no correlation observed between hearing levels and single semicircular canal dysplasia. On the basis of the results of this review, we can make the general suggestions that infants with unilateral profound hearing loss or bilateral moderate to severe hearing loss should have a temporal bone CT study as the initial imaging test because of a high prevalence of positive findings, which leads clinicians to have an effective follow-up of hearing and prediction of audiological prognosis.
Secondary cholesteatoma, defined as acquired cholesteatom of which epithelial invasion occurred from the edge of tympanic membrane (TM) perforation, is relatively rare. We investigated 111 ears that underwent surgical treatment after the diagnosis of acquired cholesteatoma in our institution from 2005 to 2010, and found 7 ears with secondary cholesteatoma with TM perforation. Six of 7 cases had no recurrence of the cholesteatoma. The remaining cases underwent staged tympanoplasty had residual choleseatoma on the footplate. The postoperative hearing improvement rate was 85.7% (6/7cases). Although secondary cholesteatoma would commonly be developed from the edge of TM perforation around the malleus handle, there were two atypical cases of secondary cholesteatoma extending from the edge of TM perforation onto the long process of the incus and migrating directly to the medial surface of the perforation probably due to aberrant migration process.
Glomus tympanicum tumors are relatively rare, and the first Japanese case was reported in 1956. We have performed a retrospective study of four patients who received total removal of a glomus tympanicum tumor within the period from May 2006 to December 2013 in our department. All four patients were female. They all experienced pulsatile tinnitus, and three of them complained of hearing loss. Tumor resections were performed under general anesthesia, and tympanoplasty type I was carried out in three cases, and tympanoplasty type IIIc was carried out in the remaining case. All operations could be completed successfully with no preoperative embolization and a little perioperative blood loss. All cases were pathologically diagnosed with paragangliomas. During surgery for a glomus tympanicum tumor, it is important to decide on an appropriate surgical procedure based on the preoperative imaging findings. It is also important to perform hemostasis of the feeding vessels and to reduce the tumor size using bipolar cautery, which also functions to widen the surgical field. There has been no sign of tumor recurrence in any of the four cases.
GJB2 gene mutation is most frequent cause for hereditary deafness. GJB2 encodes connexin26 (Cx26), a component in cochlear gap junction. To elucidate the molecular pathway for the gap junction dysfunction, biochemical analysis of gap junction plaques (GJPs) with multiple Cx26 mutant mouse models are needed. Recently, we demonstrated a biochemical pathogenesis caused by abnormal cochlear GJPs with GJB2 mutations using two different mouse models. This machinery can be a new target for drag design of hereditary deafness.
Endolymph, the extracellular solution in the cochlea of the inner ear, exhibits a unique potential of +80 mV called endocochlear potential (EP). We previously identified by electrophysiological experiments that the EP depends on two K+-diffusion potentials in the two epithelial layers in the stria vascularis that comprises inner and outer epithelial layers, and also showed by theoretical approach that the electrochemical environment in the cochlea including the endolymph is maintained by the K+-circulation throughout this organ. Ion-transport mechanism in the basolateral surface of the outer layer, which consisted primarily of fibrocytes of spiral ligament, remains unknown. Na+, K+-ATPase and Na+, K+, 2Cl- cotransporter (NKCC) that occur together in this membrane domain and have been believed to be involved in the K+-circulation. However, our recent study strongly suggests that the Na+, K+-ATPase functionally dominates but NKCC's contribution is limited. Based on the experimental data, we will develop a new mathematical model to reconstitute the EP and K+-circulation in silico and account for the relationship between the two.
In the auditory epithelia of the cochlea, the sensory hair cells and supporting cells are arranged in a checkerboard-like pattern, but the mechanism underlying this cellular patterning was unknown. We recently found that mouse hair cells and supporting cells express the immunoglobulin-like adhesion molecules nectin-1 and -3, respectively, and that their interaction mediates the heterotypic adhesion between these two cell types. Nectins, a family of immunoglobulin-like molecules, comprising four members (nectin-1, -2, -3, and -4), promote both homophilic and heterophilic interactions between the members. Their heterophilic interactions are stronger than their homophilic interactions. When cells expressing either nectin-1 or -3 were co-cultured, they arranged themselves into a mosaic pattern. Genetic removal of nectin-1 or -3 disrupted the checkerboard pattern, inducing aberrant attachment between hair cells. These results indicate that the heterophilic interactions between nectin-1 and -3 are critical for establishing the checkerboard-like pattern of hair cells and supporting cells.
Sensorineural hearing loss (SNHL) is one of the most common features of congenital disorders. There are over a hundred loci associated with SNHL in humans. To date, 53 loci of DFNA, the gene locus responsible for autosomal dominant nonsyndromic SNHL, have been identified and 30 genes have been defined as DFNA-causative. 76 loci of DFNB, the gene locus responsible for autosomal recessive deafness, have been identified, and 55 genes have been defined as DFNB-causative. In addition, 15 mitochondrial DNA mutations associated with SNHL have been discovered. However, it is difficult to detect the causative mutation for each patient with SNHL because of the genetic heterogeneity. Usami et al. have developed an effective screening strategy (Invader assay) for hereditary hearing loss. Using this assay, we can check 46 known mutations in 13 known deafness genes frequently found in Japanese patients with SNHL. Since 2012, this testing has been covered by the social health insurance. We can identify the causative gene mutations in approximately 40% patients with SNHL using the Invader assay. If we cannot identify the mutation by this method, we can add the TaqMan PCR method for checking 55 known mutations in 6 known deafness gene. We can also use massively parallel DNA sequencing (MPS) technology to discover rare causative genes through the multicenter research project. We would need approval from the ethics committee for the multicenter research program. It is important to perform genetic counseling and get written informed consent when conducting genetic testing for congenital SNHL. We can use the results of genetic testing when designing a patient's clinical course of treatment. GJB2 is the gene most frequently associated with congenital SNHL. The c.235delC mutation in this gene, the most frequent allele, is known to be associated with profound deafness. In addition, better speech performance after cochlear implantation can be observed in patients with GJB2-related profound SNHL. If the homozygous c.235delC mutation in the GJB2 gene is identified in patients with profound SNHL, we can recommend cochlear implantation at an early age. Thus, we can select the most suitable clinical course for each patient through genetic counseling by detecting the causative gene mutation.
A new standard for cochlear implantation for children (2014) are summarized. The surgical indication is > 1 year of the age and 8kg in body weight, >45dB and >90dB of the hearing threshold with and without hearing aid respectively, and speech perception is < 50%. Patients with a gene mutation associated severe hearing loss and patients who can not develop intelligible pronounciation due to hearing loss at the range of high frequencies, provide considerable factors for surgical indication of cochlear implant. In addition, bilateral cochlear implant are considered to be benefittical for some children.
After the new indication for pediatric cochlear implantation in Japan was announced, several points emerged to be considered during cochlear implantation surgery in young children. The main changes in the new indication are setting the lowest age of implantation as 1 year old, setting the lowest weight of the patient as 8 kg, and approving the bilateral implantation. In this article, four points are discussed from the viewpoints of surgical techniques. The first point to be considered is about bleeding. Young children have mastoid cavity with less pneumatization and more bone marrow causing much bleeding during mastoidectomy. Considering that young children have small amount of total circulating blood volume and can cause hypovolemic shock with less blood loss than adult, careful hemostasis is necessary in mastoidectomy of young children. To achieve good hemostasis, it is recommended to use diamond bur and bone wax and to complete mastoidectomy in a short time. Second, skin incision should not be extended toward a mastoid tip in younger children. Stylo-mastoid foramens exist in a more lateral position in young children due to poor development of mastoid tips. Therefore, extended skin incision toward a mastoid tip may cause facial nerve injury in younger children. Third, careful manipulation is necessary for fixation of the receiver-stimulator. Most surgeons create a bony well for receiver-stimulator and also create small holes for the tie-down suture to secure the receiver-stimulator onto the cranium. However, younger children have thin cranial bone thickness. Therefore, sometimes it is stressful to make suture-retaining holes because this manipulation requires the exposure of dura mater in younger children. One of the resolutions for this problem is to use self-drilling screws to anchor sutures. With 3 mm-length screws, sufficient stability is available even on 1.5 mm thick cranial bone by inserting screws in oblique fashion. Fourth, bilateral cochlear implantation limits the usage of monopolar cautery due to electrical current passing the body. Instead of monopolar cautery, heated scalpel is useful in the second cochlear implant surgery. Bilateral surgery may cause bilateral vestibular dysfunction, which result in severe dysequilibrium problems. It is possible to avoid these problems by applying minimally invasive cochlear implant surgery including round window approach and usage of a soft and slim electrode array. In conclusion, cochlear implantation for young children can be performed safely with well understanding of pitfalls of the surgery and with appropriate surgical techniques.
Facial nerve paralysis due to Bell's palsy or Ramsay Hunt syndrome usually recovers spontaneously, but some of them suffer from sequelae such as facial contracture and pathological synkinesis. On the contrary, complete facial palsy frequently stays prolonged in cases with temporal bone trauma and neoplastic origin. Management of such cases with incomplete recovery is presented in this paper. Rehabilitation with muscle relaxation is applied to cases with poor prognosis, which is assessed by electroneuronography (ENoG), during 6-12 months after the onset of facial palsy. Botulinum toxin is introduced to cases which have facial contracture and pathological synkinesis stable prior to rehabilitation similar to the above. Maximum dose of the single administration on the paralyzed face is 25-30 units. For cases with prolonged complete facial nerve paralysis due to temporal bone fracture or localized benign tumor such as facial neuroma and neurofibroma, late decompression surgery alone can be expected to obtain fair recovery up to House-Brackmann's grade III or IV. In most cases with advanced tumor surrounding the facial nerve, e.g. large facial schwannoma, temporal bone carcinoma, and complicated petrous bone cholesteatoma (epidermoid), nerve transection cannot be avoided. For those cases, either the cable graft using the great auricular nerve/sural nerve or hypoglossal-facial nerve anastomosis is selected based on the proximal stump condition of the facial nerve. Facial function usually reaches House-Brackmann's grade III or IV 1-1.5 year after these surgical interventions.
Current state of usage of the Classification and Staging System of Cholesteatoma proposed by the Japan Otological Society was evaluated by reviewing articles in which the system was used. Number of use of the system in articles gradually increased and the utilization purpose ranged widely, suggesting that this system has potentials to estimate pathogenesis, surgical indication and postoperative result of the cholesteatoma by common standard. Continuous revision and consensus development of the system should be required for the universalistic usage.
We reported the clinical utility of the staging criteria of cholesteatoma proposed by Japan otological society, 2010. This criteria indicates detail existence of middle ear pathologies and established common language for the otological surgeons. As this criteria consists of simple components, it makes the operational concepts more accessible for medical staffs and even patients.
We retrospectively investigated 118 cases of middle ear cholesteatoma which were operated in 2009, 2010 in Seirei Yokohama Hospital. They are categorized into 65 ears of “pars-flaccida” (55.1%), 20ears of “pars-tensa” (16.9%), 10 ears of “secondary” (8.5%), 11 ears of “congential” (9.3%) and 12 ears of “unclassifiable” (10.2%). ‘Unclassifiable’ cases are divided into following 3 groups. 1; ‘mixed’, combined case of “pars-flaccida” and “pars-tensa”, 2; ‘multiple’ , in which we could find discontinuous cholesteatomas and 3; ‘others’. We presented one ‘mixed’ case and one ‘multiple’ case. We considered about causes of middle ear cholesteatoma showing the answers of audience by analyzer.
Objective: To analyze the practicality of staging criteria of acquired cholesteatoma (2010). Methods: A total of 350 surgical cases of acquired cholesteatoma between 2009 and 2010 at five institutes were analyzed using staging criteria of acquired cholesteatoma (2010). Results: All cases were classified as pars flaccida (249 cases, 71%), pars tensa (74 cases, 21%), or combined group (27 cases, 8%) according to eardrum status. The rate of postoperative air-bone gap (ABG) less than 20dB was 73% for the pars flaccida group, 62% for the pars tensa group, and 31% for the combined group. These rates decreased with increasing degree of cholesteatoma staging. Residual diseases at second look peaked out at 12 months postoperatively, while those after single-stage operation appeared 24-36 months postoperatively. The recurrences were distributed equally between 6 months and 36 months. Every type of recurrence increased in accordance with degree of staging. Conclusion: The severity of staging is proportional to hearing results and recurrence rate. This practical surgical classification facilitates the comparison and collection of data from different sources.
We considered whether the cholesteatoma progress level classification how can take advantage of the future. For that the first problem in the current cholesteatoma surgery is not possible to grasp the number of surgical cases nationwide, the second is that there is no performance on a national scale of recurrence and hearing prognosis, and the third surgery of cholesteatoma that the appropriate technical evaluation has not been made. And proposed the cases registered on a national scale by utilizing the database by multicenter study that has been carried out in our group from a few years ago. And we suggested to whether unable evaluation of expertise in cholesteatoma surgery procedures. Finally we think also for further future prospects.
ANCA - associated vasculitis (AAV) often involves initially middle ear and intractable otitis media is possible to be OMAAV. However, clinical characteristics of OMAAV have not been clarified yet. In this study, we aimed to describe a series of OMAAV patients and underline the difficulties involved in diagnosing and treating this challenging disease. In this multicenter study, we assigned 297 patients (86 males and 211 females) with OMAAV from 65 departments of otolaryngology in Japan. Their age were ranged from 13 to 89 years. At the initial visit, ear, nose, other upper respiratory tract, lung, and kidney lesions were involved in 294 (97%), 95 (32%), 24 (6%), 80 (27%), 55 (18%) patients, respectively. Facial nerve palsy and hypertrophic pachymeningitis were observed in 54 (18%) and 44 (15%) patients at the initial visit, respectively. Serum PR3-ANCA and MPO-ANCA were detected in 76 (27%) and 169 (59%) patients, respectively. A definitive histological diagnosis of AAV could be done in only 54 (30%) patients. All patients responded to treatments with prednisolone and/or immunosuppression therapy. Three (1%) patients died from subarachnoid hemorrhage due to vasculitis of basiar artery. It is difficult to make definitive diagnosis of OMAVV. We found that facial nerve palsy, hypertrophic pachymeningitis and MPO-ANCA positivity are characteristic in OMAAV. We proposed the diagnostic criteria of OMAAV from these findings.
Objective: Otitis media with ANCA (antineutrophil cytoplasmic antibody) associated vasculitis (OMAAV) is intractable conditions that are resistant to conventional conservative treatment. In the present study, we examined the clinical differences according to ANCA subtype and the serological study of ANCA negative patients were performed. Methods: A total of 297 patients were enrolled in the nationwide surveys. Patients were divided into three groups: PR3-ANCA positive group 67 (23%), MPO-ANCA positive group 159 (54%) and ANCA double negative group 52 (17%). ANCA double positive 15 (5%) and ANCA unmeasured patients 4 (1%) were excluded. Clinical data were collected and compared among the three groups. Plasma sample of ANCA negative AAV patients were tested for the presence of ANCA with 5 detection methods (3 PR3-ANCA kits (direct-ELISA, capture ELISA, anchor ELISA), 2 MPO-ANCA kits (direct-ELISA, capture ELISA) and Indirect immunofluorescence (IIF) technique. The other ANCA serotype (azurocidin, BPI, capthepsin G, elastase, lactoferrin, lysozyme) were also tested by ELISA technique. Results: No significant differences among groups were found in the clinical otological findings and the major clinical symptoms on the initial visit. Over the whole course of the follow-up period, PR3-ANCA positive group had significantly higher rate of the nose involvement and the lung involvement, while ANCA negative group had significantly higher rate of hypertrophic pachymeningitis. Rate of relapes was significantly higher in PR3-ANCA positive group. Of 16 cliniacally ANCA negative patients, 1 patient was positive for PR3-ANCA and 3 were positive for MPO-ANCA with combined ELISA methods. Two patients were positive for P-ANCA in IIF. Furthermore, 1 patient was positive for BPI-ANCA and one was positive for elastase-ANCA. Conclusion: Over the course of the follow-up period, PR3-ANCA positive group had significant higher rate of nose and lung involvement, and had a higher rate of relapse. ANCA negative group had significantly higher rate of hypertrophic pachymeningitis. These findings may allow for better characterization of pathologies and eventually assist in improving the clinical utility of OMAAV diagnostic criteria. To the ANCA negative cases, ANCA should also be tested by a different technique such as new generation ELISA and IIF. Additionally, presence of other ANCA serotype should also be considered.
Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is characterized by systemic necrotizing vasculitis. Recently, reports of otitis media with AAV (OMAAV) with bone-conduction hearing loss have increased and there is increasing recognition of OMAAV. Facial nerve palsy and hypertrophic pachymeningitis are symptoms that are frequently associated with OMAAV. We investigated the clinical features of OMAAV, particularly facial nerve palsy and hypertrophic pachymeningitis. Additionally, we examined the characteristics of relapse cases. Of 297 cases, patients with facial nerve palsy numbered 94 (32%) and patients with hypertrophic pachymeningitis numbered 70 (24%). Many patients with facial nerve palsy had otorrhea, otalgia and headache as initial symptoms. The patients with hypertrophic pachymeningitis were also similar results. It was found that facial nerve palsy and hypertrophic pachymeningitis were relevant with otitis media due to vasculitis, in other words OMAAV. Concerning about multiple organ disorder, lung disorder was less in the patients with hypertrophic pachymeningitis and kidney disorder was less in the patients with facial nerve palsy. OMAAV with facial nerve palsy and/or hypertrophic pachymeningitis had different features from typical systemic GPA. There were 125 cases (43%) with relapse in their clinical course. Relapsed cases had no characteristic symptom in this study. Although it was not examined in detail in this study, the relapsed organ was not necessarily coincided with the organ which impaired at the first time. There is a possibility that the various symptoms appear during the course. Therefore it is necessary to follow up taking care of the multiple organ symptoms after the initial treatment. Concerning treatment, patients treated with steroid therapy without immunosuppressive drugs relapsed more than patients treated with steroid and immunosuppressive drugs. Facial nerve palsy and hypertrophic pachymeningitis were relatively common symptoms in OMAAV. These findings might be a key for the diagnosis. Furthermore, it was revealed that OMAAV can easily relapse. Initial immunosuppression therapy that includes corticosteroid is therefore essential for achieving long-term remission for OMAAV.
Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) presents the otologic symptom as an initial symptom. In this study, audiological features and hearing outcome after immunosuppressive therapy were evaluated. A total 284 cases 480 ears audiologically evaluated at pre- and post-treatment in the nationwide surveys were enrolled in this study. Hearing outcomes were compared among the following factors: 1. hearing loss type (conductive, sensorineural or mixed), 2. otitis media type (secretion or granulation), 3. ANCA subtype, 4. another organ involvements (nose, lung, facial palsy, hypertrophic pachymeningitis), 5. immunosuppressive therapy; prednisolone (PSL) only or PSL and cyclophosphamide(CPA). The overall hearing outcome was as follows: complete recovery in 30%, partial recovery (<10dB) in 30%, no change or worse in 40%. The completely deaf could not be recovered. The hearing outcome of ANCA negative group showed worse than that of another group. No significant difference of hearing recovery among nose, lung involvement. On the other hand, the patients combined with facial palsy showed significantly worse hearing outcome compared with no facial palsy patients. Patients treated by the immunosuppressive therapy with both PSL and CPA showed significantly better hearing outcome compared with PSL only (odds ratio 2.21).