The extracellular matrix（ECM）is a complex network structure composed of collagen，glycoproteins，and proteoglycans.It not only provides structural support and viscoelasticity to tissues but also participates in cell signaling，responding to environmental forces and signals to mediate tissue remodeling in response to environmental cues. Due to the intricate and precise functions of the inner ear，the perception and transmission of sound rely on the complex interactions between cochlear cell structures and the ECM. In the inner ear，the ECM not only constitutes key structures such as the basilar membranes（BM）and tectorial membranes（TM），which are essential for sound perception，but also regulates cell shape，adhesion，and migration.Certain ECM components interact with cell surface receptors to activate signaling pathways that regulate gene expression.Additionally，the ECM modulates the storage and diffusion of ions and secreted factors, creating concentration gradients.These functions are critical for inner ear development，repair，and function.Thus，the ECM plays a vital role in auditory processes，and abnormalities in ECM are a cause of certain hereditary hearing loss.This review primarily summarizes the ECM genes that lead to hearing loss.
Humans ; Extracellular Matrix/genetics* ; Hearing Loss/genetics* ; Mutation ; Cochlea ; Extracellular Matrix Proteins/genetics*

Objective:The research is to study the expression and distribution of matrix metalloproteinase (MMPs)-2 and -9 in the guinea pig cochlea after noise exposure, and to explore the role of MMPs in the blood-labyrinth-barrier (BLB). In addition, the role of MMPs inhibitor doxycycline in noise-induced BLB trauma was studied as well, which provides the basis for further studies and prophylaxis of noise-induced hearing loss.Methods:A total of 45 healthy adult guinea pigs were randomly divided into the control group (15 received intraperitoneal injection of 0.9% saline for 4 consecutive days), the noise-exposure group (15 exposed by 120 dB SPL white noise for 4 h per day for continuous 2 d, intraperitoneal injection of normal saline for 4 consecutive days) and the noise-exposure + doxycycline group (15 exposed by 120 dB SPL white noise exposure for 4 h per day for 2 consecutive days, and intraperitoneal injection of doxycycline 50 mg/kg/d for 4 consecutive days), respectively. Immunofluorescence staining, western blot, and real-time quantitative PCR were used to analyze the distribution and differential expression of MMP-2 and -9 in the stria vascularis of guinea pigs in comparison with the normal control group, noise only group, and noise & doxycycline treatment group. Immunofluorescence staining was used to observe the changes in tight junction (TJ) protein ZO-1 in stria vascularis in three groups and to investigate the effect of acoustic injury on TJs. And ABR tests were utilized to detect the hearing function of guinea pigs in the three groups. Intravenous Evans blue was administrated intravenously as an indicator of vascular leakage among three groups to study the changes in BLB permeability in context of acoustic injury. SPSS 22.0 was used for statistical analysis.Results:There was no significant difference in hearing function between the noise-exposure group and the noise & doxycycline group two hours after noise exposure. After seven, 14 and 28 days noise exposure, the hearing recovery of the noise & doxycycline treatment group was significantly greater than that of the noise-exposure group ( P<0.05) . Immunofluorescence staining showed that there was only a small amount of MMP-2 and -9 in the stria vascular in the normal control group, and ZO-1 showed dense linear expression. While, in the noise-explore group, MMP-2 and -9 in the stria vascular was significantly elevated ( P<0.05), and the configuration of ZO-1 became loose and discontinuous. However, the MMP-2 and -9 in the noise & doxycycline treatment group were not significantly different from the normal control group ( P>0.05), which were significantly less than that in the noise-exposure group, and just a little break of ZO-1 was observed, however, the overall structure remained dense. The leakage of Evans blue from stria vascular capillary in the noise-exposure group was significantly increased, and the difference between the other two groups did not show any statistical significance ( P>0.05). Conclusions:The damage of tight junction structure induced by MMP-2 and -9 may play an important role in BLB destruction. In addition, doxycycline can inhibit MMPs secretion, thereby, to some extent, protecting the integrity of BLB from acoustic injury, and contributing to the long-term hearing recovery.

Congenital facial palsy is unilateral or bilateral facial nerve palsy at birth due to genetic or different pathogenic factors. It can be divided into syndromic type and non-syndromic type according to its accompanying symptom. The pathogeny and symptom of each type are different, in part with genetic heterogeneity. Congenital facial palsy cannot recover spontaneously. Different types of congenital facial palsy have different treatment schemes. The treatment is significant to the improvement of life quality and physical and mental development of children with congenital facial palsy.

Objective: To elucidate the clinical behavior, causes of misdiagnosis, surgical management, and outcomes of facial nerve schwannomas (FNS). Methods: A retrospective review in Chinese People′s Liberation Army General Hospital from January 1, 2002 to December 31, 2015 was carried out and evaluated 110 patients with FNS, including 50 males and 60 females, aged 16-67 years old. The appropriate surgical strategy was selected based on each patient′s clinical manifestations, facial nerve function, and imaging characteristics. After surgery, patients received follow-up visits to assess their facial nerve functions, with the effect of treatment compared to the reality before surgery. The Kruskal-Wallis H test was used to distinguish between the pre- and post-operation facial nerve functions in patients who had different facial nerve functions before the operations. Results: 110 cases of FNS mainly presented with facial paralysis, hearing loss, tinnitus, otalgia, dizziness, and facial spasm. 20 of the cases were misdiagnosed as Bell′s Palsy, 6 were mistaken for chronic otitis media/cholesteatoma with radical mastoidectomy, 3 were mistaken for Meniere′s disease, 1 was misdiagnosed as petrous bone cholesteatoma, and 4 were mistaken for acoustic neuroma. 81.8 % (90/110) of the patients had multiple segments of the facial nerve, including the vertical segment of the facial nerve, accounting for 65.5% (72/110), followed by the labyrinthine/geniculate segment, for 61.8% (68/110), and the horizontal segment, for 55.5% (61/110). The appropriate surgical approaches were chosed based on the sizes and scopes of the tumors evaluated by imaging: transmastoid approach in 73 cases, translabyrinthe approach in 14 cases, middle cranial fossa approach in 13 cases, retrosigmoid approach in 3 cases, transmastoid-middle cranial fossa approach in 3 cases, and transmastoid-neck approach in 4 cases, with all the patients undergoing a total/subtotal resection of the tumor. Eighty-seven patients had their facial nerves reconstructed. Among them, 6 received facial nerve end-to-end anastomosis, 55 received great auricular nerve graft, and 26 were subjected to facial nerve-hypoglossal nerve anastomosis. Because of long histories, facial muscle atrophies, or other reasons, the remaining patients were not received facial nerve reconstruction. The House-Brackmann(H-B) grading scale was used to evaluate the facial nerve function pre- and post-operation. Patients with better facial nerve functions and shorter history of facial paralysis before operation would get relatively better facial nerve function. The before and after operation comparisons revealed that the recovery of the facial nerve functions in patients with H-B Ⅰ-Ⅲ was better than the improvement in patients with H-B Ⅳ-Ⅴ. The difference was statistically significant (Kruskal-Wallis H test, H=8.508, P<0.05). Conclusions The diagnosis of patients with unknown facial paralysis, hearing loss, and tinnitus should take into account the possibility of FNS. CT and other imaging examinations of the temporal bone can avoid misdiagnosis and determine the tumor size and extent of lesions, as well as provide the basis for the choice of the surgical approach. After tumors have been completely resected, facial nerve reconstruction can be performed simultaneously, according to the defect of the nerve.

Objective To study the effects of epigallocatechin-3-gallate(EGCG) on noise-induced cochlear injuries.Methods A total of 45 guinea pigs were divided into three groups: the EGCG+noise exposure group, the normal saline+noise exposure group, and the control group.15 Guinea pigs in each group.For EGCG administration, the guinea pigs were given abdominal injection (25 mg/1 000 g) 1 day before and 1 hour before noise exposure (120 dB SPL, 4 h),where for the control group, the guinea pigs received nothing.The hearing function was detected by the auditory brainstem response (ABR) recording after noise exposure immediately, and at 1,3,7, and 14 days after noise exposure.On the 14th day, the cochlea were isolated, and the cells morphology of basal membrane and vascular stria, the outer hair cell movement protein (Prestin), and the 3-nitrotyrosine (3-NT) were examined by immunohistochemistry staminy.Results After noise exposure, ABR thresholds in the EGCG group were higher than that of in the control group(P<0.05), but lower than the normal saline group(P<0.05),though the differences between the other two groups became smaller from day 3.Immunohistochemistry (IHC) staining showed that the three rows of outer hair cells of the control group with Prestin protein stained were arranged neatlyand lack of cell absent, and 3-NT was mainly distributed in the cytoplasm and epidermis.Compared with the normal saline + noise group, after noise exposure, the outer hair cells of EGCG + noise group were in better shape, and prestin staining was clear.Besides, the basal membrane and vascular stria were slightly damaged, the cells arranged neatly and the 3-NT distribution was decreased.Conclusion Preventive intraperitoneal injection of EGCG may reduce cochlea damage caused by noise.

Objective: To investigate the choice of surgical approach of petrous bone cholesteatoma (PBC)and surgical outcomes. Methods: A retrospective study was performed on 90 patients diagnosed and treated for PBC from January 2000 to December 2014 by the Chinese People′s Liberation Army General Hospital otolaryngologists. According to Sanna′s classification, 40 out of the 90 cases were supralabyrinthine, five infralabyrinthine, four infralabyrinthine-apical, 25 massive and 16 apical. Five cases underwent transmastoid and retrolabyrinthine approach, translabyrinthine approach was performed on six patients, 19 cases underwent subtotal petrosectomy, seven cases underwent transotic approach, 41 cases underwent middle fossa approach, combined transmastoid/middle fossa approach was performed on 11 cases, translabyrinthine and sphenoid sinus approach were performed on one case. Supralabyrinthine cases mainly applied middle fossa approach (77.5%, 31/40) and combined transmastoid and middle-fossa approach(20.0%, 8/40). Combined transmastoid-retrolabyrinthine approach were applied for all the infralabyrinthine cases (100.0%, 5/5). Infralabyrinthine-apical cases mainly applied subtotal petrosectomy (75.0%, 3/4). Massive cases mainly applied subtotal petrosectomy (60.0%, 15/25), transcochlear approach (20.0%, 5/25), and translabyrinthine approach (16.0%, 4/25). Apical cases mainly applied middle fossa approach (62.5%, 10/16). Results: Ninty percent (18/20) of the patients who had preoperative grade Ⅰ facial nerve function maintained in the postoperative period. Out of 90 cases, only 11 cases received open cavity, and the rest cases received cavityobliteration. There were three cases of recurrence, four cases of cavity infection, three cases of cerebrospinal fluid leakage, and one case of epidural hematoma, who all received surgeries. Conclusions Sanna′s classification should be used to classify different kinds of PBC cases, choose the best surgical approach for different cases, and preserve or repair facial function during removal of PBC, and thus reduce recurrence and complications.

OBJECTIVETo analyze the clinical characteristics of unilateral conductive hearing loss with intact tympanic membrane, and summarize the key diagnostic points, differential diagnosis and observe the effects of surgical treatment.

METHODSWe reviewed data from 82 patients with unilateral conductive hearing loss with intact tympanic membranes who accepted the exploratory tympanotomy from April 2011 to September 2013. There were 41 males and 41 females, aged from 7 to 66( averaged 26.5±13.7)years, with a history of one month to 50 years. The history, clinical symptoms, audiological evaluation, high resolution temporal bone CT, the results of surgical exploration and hearing reconstruction were analyzed.

RESULTSThe exploratory tympanotomy revealed 43 cases of congenital middle ear malformations (52.4%), 22 cases of otosclerosis (26.8%), eight cases of congenital cholesteatoma (9.8%), six cases of trauma induced conductive hearing loss (7.3%), three cases of congenital ossicular malformations with congenital cholesteatoma (3.7%). Progressive hearing loss was common in patients with otosclerosis and congenital cholesteatoma, and patients with congenital middle ear malformations described their hearing loss since childhood. High resolution temporal bone CT of congenital middle ear malformation, trauma induced conductive hearing loss, congenital cholesteatoma diagnosis rate was 40.0%, 50.0%, and 83.3% respectively. The preoperative air-conductive threshold of patients with absence of the oval window were increased to (66.9±1.1)dBHL, the preoperative bone-conductive threshold achieved (28.3±10.4)dBHL at 2 000 Hz. While patients with stapes fixation and that with ossicular chain discontinuity were (27.2±9.7)dBHL and (17.8±8.8)dBHL(P=0.000)respectively. Through the tympanic exploration with endaural incision under the microscope, different hearing reconstruction were applied according to different lesions. After the operation, the hearing level of 52 patients with return visit were improved, the mean air-conductive threshold were decreased from (60.0±11.4)dBHL to (32.2±12.1)dBHL(P=0.000); and the mean ABG were decreased from (43.2±12.0)dB to (16.3±9.4)dB(P=0.000).

CONCLUSIONSCongenital middle ear malformations, otosclerosis, congenital cholesteatoma are the most common causes in unilateral conductive hearing loss with an intact tympanic membrane. The diagnosis rate can be improved by analyzing the clinical features. Through exploratory tympanotomy and hearing reconstruction, we can clarify the diagnosis and achieve a satisfying hearing recover.

Adolescent ; Adult ; Aged ; Audiometry ; Child ; Cholesteatoma ; congenital ; pathology ; Diagnosis, Differential ; Ear Ossicles ; pathology ; Ear, Middle ; abnormalities ; Female ; Hearing Loss, Conductive ; pathology ; surgery ; Humans ; Male ; Middle Aged ; Middle Ear Ventilation ; Otosclerosis ; pathology ; Tympanic Membrane ; Young Adult

Objective To analyze the medical and audiological features of trauma induced stapes fracture ,and to summarize the key diagnostic points and to observe the effects of surgical treatment .Methods Five patients with trauma induced stapes fracture confirmed by the surgical exploration from January 1995 to October 2013 were retro_spectively reviewed .Ossicular chain reconstruction was performed on each patient .The preoperative and postopera_tive pure-tone thresholds were compared to judge the effects of surgical treatment .ResuIts The surgical explora_tion revealed 4 cases of stapes feet fracture ,1 case of stapes neck fracture with temporal bone fracture and peripheral paralysis of the facial nerve .Different types of ossicular reconstruction were performed according to the exploration results:2 cases with autogenous stapes remodeling ,1 case with allogenous stapes remodeling ,1 case with bone piece of external acoustic meatus ,and 1 case with artificial auditory ossicle(TORP) implanting .Additionally ,the case of peripheral paralysis of the facial nerve received facial nerve decompression .After the operation ,5 patients felt that their hearing was improved .The mean postoperative pure-tone threshold was 30 .7 dB HL ,and the mean ABG(air-bone-gap) was 18 dB HL while the mean preoperative pure-tone threshold was 61 dB HL(t=6 .725 ,P<0 .05) and the mean ABG was 38 .7 dB HL(t=3 .616 ,P<0 .05) .The facial nerve functions of the case with facial paralysis recovered to House-Brackmann Grade I three months after receiving facial nerve decompression .ConcIu_sion Stapes fractures are rare .Being different from the general conductive hearing loss ,patients with stapes fracture usu_ally have the acoustic stapedius reflex .Through ossicular reconstruction ,we can yield a satisfying hearing recovery .

OBJECTIVE: To analyze the diagnosis, therapy and prognosis of the rare cases of malignant tumors in external auditory canal. METHOD: Eight cases of rare malignant tumors in external auditory canal were collected except squamous cell carcinoma and adenoid cystic carcinoma. The clinical manifestation, staging, surgical method, secondary treatment and prognosis were analysed. RESULT: There were 5 cases of basal cell carcinoma and 2 cases of mucoepidermoid carcinoma and 1 case of myoepithelial carcinoma. Three cases of the 5 basal cell carcinoma in external auditory canal have been misdiagnosed for a long time. After admission, 4 of the 5 basal cell carcinoma were T1 stage and cured only by a complete resection of tumor. One case of T2 stage basal cell carcinoma was found recurrence 2 years later after the first excision of tumor, and was treated with radiotherapy. Tumor was controlled. Two cases of mucoepidermoid carcinoma had been misdiagnosed as a benign tumor and received a resection. One case was found metastasis to the parapharyngeal space and nasopharynx and was treated with concurrent chemotherapy. Tumor was also controlled after 5-years follow-up. Another case was found metastasis to parotid gland and received an expanding tumor resection. No recurrence was detected after a 1-year followed up. One case of T4 stage myoepithelial carcinoma in external auditory canal was a metastasis of parotid and received a partial temporal bone resection. No-recurrence was found 1 year later. CONCLUSION Because the tumors above have a very low incidence in external ear canal and the location of tumors are hidden, they are often misdiagnosed and delayed in treatment. Therefore, otologists should pay more attention to avoid the misdiagnosis. To the treatment, complete surgical resection of early-stage tumor is important and for late-stage tumor, a supplemented by chemoradiotherapy may be needed.
Carcinoma, Adenoid Cystic ; diagnosis ; surgery ; Carcinoma, Basal Cell ; diagnosis ; surgery ; Carcinoma, Squamous Cell ; diagnosis ; surgery ; Ear Canal ; pathology ; Ear Neoplasms ; diagnosis ; surgery ; Humans ; Neoplasm Recurrence, Local ; Neoplasm Staging ; Parotid Gland ; pathology ; Prognosis ; Retrospective Studies ; Temporal Bone ; surgery

OBJECTIVE: To investigate the clinical features of labyrinthine fistula and obtain the diagnosis, treatment and prognosis of different types of fistula. METHOD: A retrospective analysis of 42 cases (43 ears) with labyrinthine fistula in our hospital from January 2007 to November 2014 was conducted. Data of preoperative clinical manifestation, auditory function, CT image, operative findings, treatment and postoperative recovery were collected and statistically analysed. RESULT: Thirty-nine cases (40 ears) of the 42 cases (43 ears) which were diagnosed as labyrinthine fistula according to operative findings occurred in the lateral semicircular canal, 1 case occurred in the posterior semicircular canal, 1 case occurred in the superior semicircular canal, and 1 case occurred both in lateral and posterior semicircular canal. Before operation, 24 ears (55.8% ) experienced vertigo and 14 ears (32.6%) showed impaired bone conduction hearing threshold. According to Dornhoffer classification standard, 22 cases (23 ears) were diagnosed as type I fistula, 9 cases as type II fistula and 11 cases as type III fistula. There was no statistical difference among the 3 groups on type of hearing loss, vertigo, CT, facial nerve canal damage before operation and bone conduction hearing threshold, vertigo after operation. CONCLUSION An accurate diagnosis of labyrinthine fistula relies on the operative findings rather than preoperative clinical manifestation, auditory function or CT The surgical intervention should be individualized. There is no significant difference on postoperative recovery among different types of labyrinthine fistula.
Bone Conduction ; Cholesteatoma, Middle Ear ; complications ; Deafness ; Facial Nerve Injuries ; Fistula ; etiology ; Humans ; Labyrinth Diseases ; etiology ; Otitis Media ; complications ; Postoperative Period ; Prognosis ; Retrospective Studies ; Vertigo