[Analysis of the anatomical features of vestibular nerve canal based on 10 µm otology CT].

Objective: To analysis the anatomical features of normal vestibular nerve canal based on 10 µm otology CT. Methods: Sixty-seven patients (103 ears) underwent 10 µm otology CT examinations in Department of Radiology, Beijing Friendship Hospital, Capital Medical University from September 2020 to March 2021 were retrospectively recruited. There were 24 males and 43 females, aged from 18 to 70 (40±17) years. According to the morphology of the inferior vestibular nerve canal, it can be divided into four types as follows: uniform straight type, curved type, ampullary type and direct connection. The anatomical variables of the superior vestibular nerve canal (external orifice, isthmus and internal orifice widths, canal length, angle with labyrinthine segment of the facial nerve) and inferior vestibular nerve canal (widths of the externaland internal orifice, canal length, angles with long axis of the vestibule and the modiolus) between the different sides, genders and canal morphologies were analyzed and compared, respectively. Results: 100% superior vestibular nerve canals and 75.7% (78/103) inferior vestibular nerve canals are clearly depicted by otology CT. The left-side ear presented with larger internal orifice diameter of the superior vestibular neve canal [(1.46±0.47) mm vs (1.31±0.41) mm], and a smaller angle between the inferior vestibular neve canal and the modiolus [(41.6±16.9)° vs (51.6±21.0)°] than the right-side ear (all P<0.05, respectively), respectively. Compared to females, males demonstrated larger internal orifice of the superior vestibular nerve canal [(1.55±0.37) mm vs (1.28±0.36) mm, P<0.05]. The uniform straight type of the inferior vestibular nerve canal was the most common type (62.1%, 64/103), followed by the direct connection (19.4%, 20/103), and the ampullary type was the least common type (4.9%, 5/103). There were significant differences in external diameter and angles with the long axis of the vestibule and the modiolus between the four morphologies of the superior vestibular nerve canal (all P<0.05, respectively). Conclusion: Ten µm otology CT is capable of depicting normal vestibular nerve canal clearly. Quantitative measurement of the normal vestibular nerve canal can provide references for the imaging diagnosis and preoperative evaluation of lesions in this area.

[Analysis of spatial location of the malleus in patients with chronic otitis media based on 10 µm otology CT].

Objective: To assess the changes of the spatial location of the malleus in patients with chronic otitis media (COM) using 10 µm otology CT. Methods: Forty-five patients with COM (COM group, 45 ears) and 55 patients without external and middle ear disease (control group, 89 ears), who underwent 10 µm otology CT examination in Department of Radiology, Beijing Friendship Hospital, Capital Medical University from October 2020 to March 2021, were retrospectively collected during the same period. In the COM group, there are 20 males and 25 females, aged from 20 to 78 (40±14) years. In the control group, 29 were males and 26 were females, with age of 19 to 57 (32±11) years. The shortest distance between the malleus head and the upper wall, the distance between the outer edge of the malleus neck and the scutum, the distance between the outer edge of the malleus neck and the pars flaccida of the tympanic membrane, the shortest distance between the malleus head and the anterior wall, the shortest distance between the anterior process and the anterolateral wall, the shortest distance between the tip of the malleus handle and the promontory, and the shortest distance between the malleus head and the tympanic segment of the facial nerve were measured and compared between the two groups. Results: Compared with the control group, the head-upper wall distance (M (Q1, Q3)) (0.81 (0.48, 1.21) mm vs 0.57 (0.33, 0.90) mm) and the neck-scutum distance (1.79 (1.54, 2.13) mm vs 1.65 (1.48, 1.83) mm) were larger in the COM group (all P<0.05), and the neck-tympanic membrane distance (1.32 (1.15, 1.49) mm vs 1.45 (1.31, 1.59) mm) and the handle-promontory distance (1.56 (1.33, 2.09) mm vs 2.10 (1.74, 2.43) mm) were reduced in the COM group (all P<0.05, respectively). The neck-tympanic membrane distance on the left was larger than those on the right in the COM group (1.39 (1.19, 1.51) mm vs 1.21 (0.87, 1.31) mm, P<0.05). Conclusion: There are changes in the relative position of the malleus in patients with COM, which are helpful for further understanding the imaging manifestations in patients with COM.

[Application of 10 µm otology CT on evaluation of isolated malleus fixation in patients with conductive hearing loss].

Objective: To evaluate the application of 10 µm otology CT on evaluation of isolated malleus fixation (IMF) in patients with conductive hearing loss. Methods: A total of 19 patients (25 sides) with idiopathic hearing loss, including 8 males and 11 females, aged between 4 to 50 years, who underwent 10 µm otology CT examination in Department of Radiology, Beijing Friendship Hospital, Capital Medical University from October 2020 to July 2021, were retrospectively collected. For those patients with idiopathic hearing loss, there were 5 cases (6 sides), including 2 males and 3 females, with an average age of 18-70 [65(20,68)] years, with bony connection between malleus and tympanum wall. Eighteen sex-and age-matched cases with normal hearing group, including 6 males and 12 females, with an average age of 20-68 (39±14) years, as the ratio of 1∶3, were included as the controls. The distances of the tegmen tympani between malleus head and horizontal semicircular canal, as well the distances between malleus head and horizontal semicircular canal were retrospectively measured and further compared between the two groups. Results: The incidence of IMF in patients with idiopathic conductive hearing loss without other etiologies was 24.0% (6/25). The specificity of 10 µm otology CT in diagnosing IMF was 100%. The distances of tegmen tympani between horizontal semicircular canal and malleus head in IMF patients were significantly smaller compared with the controls [-0.65(-1.21, -0.35) mm vs 1.34(0.04, 1.68) mm;0.92(0.51, 1.49) mm vs 2.82(1.76, 3.53) mm](both P<0.05, respectively). There was no significant difference in distances between malleus head and horizontal semicircular canal [-1.30 (-1.90, -0.46)mm vs -0.42 (-1.15, 0.05),P=0.057]. Conclusions: IMF is not uncommon in conductive hearing loss without other causes, which can be clearly shown by 10 µm otology CT. Its occurrence is related to the local downward shift of tegmen tympani above the malleus, without upwards displacement of the malleus.

[Study on the relationship between the morphology of the isthmus of the vestibular aqueduct and Meniere's disease based on 10 µm otology CT].

Objective: To evaluate the morphology of isthmus of the vestibular aqueduct (VA) and its relationship with the occurrence, course of Meniere's disease (MD) and the degree of hearing loss based on 10 µm otology CT. Methods: A total of 13 patients with MD in Beijing Friendship Hospital, Capital Medical University from October 2020 to July 2021, including 4 males and 9 females, age from 16 to 77 (56±16) years, were prospectively enrolled. All patients underwent 10 µm otology CT examination. The included lesion side was the MD affected group (14 sides), and the non-lesion side was the MD healthy group (12 sides). According to the 1∶2 side, 16 sex-and side matched cases (28 sides) without external and middle ear disease were included in the control group, including 4 males and 12 females, age from 16 to 77 (56±14) years. The horizontal semicircular canal showed on the largest plane was considered as the standard cross-section, and continuous observation was made on this image. According to the display type of isthmus of the VA, it was divided into Ⅰ to Ⅳ grades. Kruskal Wallis test was used to compare the morphological differences of VA isthmus among the affected group, the healthy group and the control group. The degree of hearing impairment was assessed by pure tone audiometry (PTA) results, which were divided into normal/mild/moderate/moderately severe/severe/extremely severe hearing impairment. Spearman correlation analysis was used to compare the correlation between the morphological rating of VA isthmus on the affected side and age, course of disease and the results of pure tone audiometry (PTA). Results: The proportions of VA isthmic morphology GRADE Ⅰ,Ⅱ,Ⅲ,Ⅳ in the MD affected group were 28.6% (4/14), 42.9% (6/14), 21.4% (3/14), 7.1% (1/14), those in the MD healthy group were 0 (0/12), 33.3% (4/12), 33.3% (4/12), 33.3% (4/12), and those in the control group were 0 (0/28), 7.1% (2/28), 64.2% (18/28), 28.6% (8/28). The VA isthmus scores [M (Q1, Q3)] of MD affected group was lower than that of MD healthy group [2 (1, 3) vs 3 (2, 4)] and control group [2 (1, 3) vs 3 (3, 4)] (all P<0.05, respectively). The morphology of the VA isthmus on the affected side of MD was negatively correlated with age (r=-0.81, P=0.002), and there was no correlation with the course of disease and degree of hearing impairment (r=-0.40, r=-0.26; all P>0.05, respectively). Conclusion: The stenosis of the VA isthmus in MD was a possible anatomical factor for the occurrence of MD.

[Analysis of the imaging characteristics of otosclerosis based on 10 µm otology CT].

Objective: To evaluate the imaging features of otosclerosis based on10 µm otology CT. Methods: Data of 27 patients with otosclerosis (51 sides) in Beijing Friendship Hospital, Capital Medical University from October 2020 to July 2021 were retrospectively collected, including 9 males and 18 females age ffrom 22 to 70 (42±12) years. All patients underwent 10 µm otology CT examination and surgical treatment. The types, amounts and involved sites of otosclerosis were analyzed and the sensitivity of 10 µm otology CT in diagnosing otosclerosis were evaluated. Results: Fenestral type accounted for 49.0% (25/51 sides), and diffuse type accounted for 51.0% (26/51 sides),and he retrofenestral type without fenestral lesion was not seen. Single lesions accounted for 45.1% (23/51 sides) and multiple lesions accounted for 54.9% (28/51 sides). The incidence of involvement of the fissula ante fenestram and annular ligaments were both 100%. The incidence of involvement of stapes footplate, vestibule, cochlea, round window, inner auditory canal wall, facial nerve canal, stapes muscle and semicircular canal was 60.8% (31 sides), 33.3% (17/51 sides), 21.6% (11/51 sides), 17.6% (9/51 sides), 13.7% (7/51 sides), 9.8% (5/51 sides), 7.8% (4/51 sides) and 5.9% (3/51 sides), respectively. The sensitivity of 10 µm otology CT in diagnosis of otosclerosis was 100%. Conclusion: 10 µm otology CT can fully display the imaging features of otosclerosis, and has the potential to be an effective routine method for otosclerosis.

[Effect of malleostapedotomy procedure on 17 cases of congenital middle ear malformation].

Objective: To conclude the clinical features and the postoperative efficacy of congenital middle ear malformation treated with Malleostapedotomy (MS), and to explore the security and effectiveness of MS surgery. Methods: The clinical data of 17 patients (18 ears) with congenital middle ear malformation undergoing MS procedure were analyzed. There were 10 males (11 ears) and 7 females (7 ears), aged from 7 to 48 years. The imaging examination, pure-tone audiometry, intraoperative findings and postoperative hearing improvement of these patients were analyzed and summarized, and software SPSS23.0 was used for statistical analysis. Rusults All the 17 patients (18 ears) presented with hearing loss since childhood on the affected sides. Preoperative high resolution CT (HRCT) of the temporal bone revealed definite malformations in 9 ears (6 ears with incus long process dysplasia and 3 ears with anterior and posterior crus dysplasia). Before surgery, the mean bone conductive hearing threshold at 500, 1 000, 2 000 and 4 000 Hz was (15.6±10.2) dB HL, the mean air conductive hearing threshold was (60.6±9.7) dB HL, and the mean air-bone gap was (45.0±8.9) dB. During the surgery, all 18 ears were found to be accompanied by absence or hypoplasia of incus long process. 12 ears had stapes fixation, 6 ears had oval window atresia. All patients were treated with MS procedure by using Piston. The patients were followed up for 3 months to 1 year. The mean bone conductive hearing threshold was (14.7±8.8) dB HL. The mean air conductive hearing threshold was (37.7±11.6) dB HL, and the mean air-bone gap was (23.0±8.0) dB. There were statistically significant differences in the mean air conductive hearing threshold and mean air-bone gap before and after surgery (P<0.05). While there were no statistically significant differences in the mean bone conductive hearing threshold before and after surgery (P=0.550). Conclusions: MS procedure is safe and reliable in patients with congenital middle ear malformation of incus long process dysplasia, stapes fixation or oval window atresia. HRCT is useful in evaluating the major deformity of ossicular chain and facial nerve deformity. However, it is not enough to evaluate the joint of incus-stapes and oval window atresia. MS surgery in middle ear malformation requires advanced surgical experience and skills. The hearing improvement can be significant, even though some air-bone gap after surgery exist.

[Clinical management strategies of pulsatile tinnitus with transverse sinus stenosis].

Objective: To study the clinical diagnosis and treatment strategies for vein-related pulsatile tinnitus patients with transverse sinus stenosis. Methods: The clinical data of patients with vein-related pulsatile tinnitus, from January 2015 to August 2019, were collected,whose digital subtraction angiography showing transverse sinus stenosis. Taking December 2019 as the last follow-up time, we analyzed the clinical characteristics, CT angiography and digital subtraction angiography results, lumbar puncture pressure and cerebrospinal fluid composition, and other auxiliary examination results (pure tone audiometry, fundus examination of papilledema, carotid ultrasonography, bone density screening, endocrinous test), as well as tinnitus handicap inventory, treatment options and follow-up results. Results: 83 patients were enrolled with female of 89.2% (74/83) and male of 10.8%(9/83); 65.1% (54/83) with right tinnitus, 31.3% (26/83) with left tinnitus, and 3.6% (3/83) with bilateral tinnitus; 67.5% (56/83) with right dominant sinus, 19.3% (16/83) with left dominant sinus, 13.3% (11/83) with bilateral equalization; Bilateral and ipsilateral stenosis accounted for 55.4% and 44.6% respectively; BMI was overweight or obese in 41 cases (49.4%, 41/83). Patients with tinnitus handicap inventory level three or above accounted for 79.5% (66/83). Eventually, 33 patients chose conservative observation (39.8%, 33/83), 40 patients (48.2%), 8 patients (9.6%) and 2 patients (2.4%) received sigmoid sinus-related surgery, interventional surgery, or emissary vein occlusion respectively. The mean follow-up time of 74 patients was 26.2 months. The data of 48 surgery patients showed that the pressure differences of venous sinus among the recurrent patients were more obvious; Interventional surgery with simultaneous stenting placement was effective. Tinnitus did not decrease in two patients with emissary vein occlusion. Analysis of 26 patients with lumbar puncture revealed eight cases of normal cranial pressure and 18 cases of high cranial pressure. The sinus pressure difference between the two groups was different (P=0.025), but the difference of age of onset, concomitant symptoms, BMI, proportion of empty sella or papilledema was not statistically significant (P>0.05). Conclusions: The evaluation of patients with vein-related pulsatile tinnitus requires a standardized procedure. Papilledema cannot be used as a sensitive indicator in patients with early intracranial hypertension. Venous sinus pressure difference may be one of the indicators of intracranial hypertension, and the lumbar puncture is the gold standard for the diagnosis. Weight loss can be used as a conservative treatment during the observation period. Significant sinus stenosis is a risk factor for recurrence in patients undergoing sigmoid sinus surgery. Interventional stenting is an effective treatment for tinnitus secondary to transverse sinus stenosis.

Research progress on flat epithelium of the inner ear.

Sensorineural hearing loss and vertigo, resulting from lesions in the sensory epithelium of the inner ear, have a high incidence worldwide. The sensory epithelium of the inner ear may exhibit extreme degeneration and is transformed to flat epithelium (FE) in humans and mice with profound sensorineural hearing loss and/or vertigo. Various factors, including ototoxic drugs, noise exposure, aging, and genetic defects, can induce FE. Both hair cells and supporting cells are severely damaged in FE, and the normal cytoarchitecture of the sensory epithelium is replaced by a monolayer of very thin, flat cells of irregular contour. The pathophysiologic mechanism of FE is unclear but involves robust cell division. The cellular origin of flat cells in FE is heterogeneous; they may be transformed from supporting cells that have lost some features of supporting cells (dedifferentiation) or may have migrated from the flanking region. The epithelial-mesenchymal transition may play an important role in this process. The treatment of FE is challenging given the severe degeneration and loss of both hair cells and supporting cells. Cochlear implant or vestibular prosthesis implantation, gene therapy, and stem cell therapy show promise for the treatment of FE, although many challenges remain to be overcome.

[Clinical analysis of missed diagnostic congenital cholesteatoma].

Objective:The clinical symptoms, imaging features and surgical treatment of congenital cholesteatoma are reported. Method:The clinical data of 20 patients with congenital cholesteatoma diagnosed and treated in our hospital from January 2016 to May 2018 were retrospectively analyzed, including the age of onset, clinical symptoms, signs, audiology, HRCT of temporal bone, surgical methods and so on. Result:In 20 patients with congenital cholesteatoma, the clinical manifestations were hearing loss in the affected ears, including 5 cases with ear fullness and 4 cases with tinnitus. There were 13 cases of local yellow-white shadow of tympanic membrane, 5 cases of normal tympanic membrane and 2 cases of tympanic membrane bombe. Pure tone audiometry showed conductive deafness in 14 cases and mixed deafness in 6 cases. CT scan of temporal bone showed that 15 cases had pneumatic type of mastoid, 4 cases had diploectic type and 1 case had sclerostic type. There were 15 cases of interspersed flocculent shadow and 5 cases of mass shadow. Among the 20 cases of chronic otitis media with cholesteatoma, 6 have cholesteatoma in epitympanum, 4 in tympanic cavity, 3 in tympanic cavity and epitympanum, 2 in mastoid and tympanic antrum, 1 in mastoid, tympanic antrum and tympanic cavity, 1 in tympanic antrum, tympanic cavity and petrous apex, 1 in tympanic cavity, hypotympanum, posterior tympanum and ostium tympanicum tubae auditivae, 1 in aditus ad antrum, epitympanum and posterior tympanum, 1 in tympanic cavity, epitympanum and posterior tympanum. Intact canal wall mastoidectomy and tympanoplasty were performed in 7 cases, open mastoidectomy and tympanoplasty in 5 cases, middle ear exploration and tympanoplasty in 4 cases, atticotomy with reconstruction and tympanoplasty in 3 cases and subtotal temporal bone resection in 1 case. Conclusion:For patients with intact tympanic membrane presenting with hearing loss, the tympanic membranes should be carefully examined, and thin-section CT and MRI of temporal bone should be performed in time to avoid missed diagnosis of congenital cholesteatoma. Once diagnosed, surgery should be performed as soon as possible.

Exposure to sodium salicylate disrupts VGLUT3 expression in cochlear inner hair cells and contributes to tinnitus.

To examine whether exposure to sodium salicylate disrupts expression of vesicular glutamate transporter 3 (VGLUT3) and whether the alteration in expression corresponds to increased risk for tinnitus. Rats were treated with saline (control) or sodium salicylate (treated) Rats were examined for tinnitus by monitoring gap-pre-pulse inhibition of the acoustic startle reflex (GPIAS). Auditory brainstem response (ABR) was applied to evaluate hearing function after treatment. Rats were sacrificed after injection to obtain the cochlea, cochlear nucleus (CN), and inferior colliculus (IC) for examination of VGLUT3 expression. No significant differences in hearing thresholds between groups were identified (p>0.05). Tinnitus in sodium salicylate-treated rats was confirmed by GPIAS. VGLUT3 encoded by solute carrier family 17 members 8 (SLC17a8) expression was significantly increased in inner hair cells (IHCs) of the cochlea in treated animals, compared with controls (p<0.01). No significant differences in VGLUT3 expression between groups were found for the cochlear nucleus (CN) or IC (p>0.05). Exposure to sodium salicylate may disrupt SLC17a8 expression in IHCs, leading to alterations that correspond to tinnitus in rats. However, the CN and IC are unaffected by exposure to sodium salicylate, suggesting that enhancement of VGLUT3 expression in IHCs may contribute to the pathogenesis of tinnitus.

[Experience of revision cochlear implantation].

Objective:To analyse the characteristics of the revision cochlear implantation （RCI）patients，the cause of the cochlear malfunction，and the choice of RCI operative approach. Method:A total of 39 patients with RCI were enrolled in this study. The cochlear use time, cause of failure and reoperation procedure are recorded and analyzed retrospectively. Result:There were 39 patients accepted cochlear reoperation，the ages ranges from 1 to 28，average age was 7.8 years, median age was 5 years old. The cochlear use time ranges from 1 month to 7 years，average was 2.2 years, median time was 1 year. Thirty-seven patients underwent RCI,30 cases right side and 7 cases left side. The reason of RCI contains device failure (28 cases)，infection (5 cases)，incorrect electrode implantation (3 cases)，facial nerve stimulation (2 cases)，and electrode prolapse (1 case).The choice of RCI procedure was dependent on the first operation procedure,contains facial nerve recess approach (35 cases) and mastoid approach (2 cases).Contralateral implantation was performed in 5 cases, the rest were ipsilateral. Conclusion:RCI has a variety causes and the common reason is trauma and device failure，the RCI should be completed as early as possible to avoid the ossified cochlear and hearing or speech stagnation，the electrode implantation through previous approach is the best method.