Utility of deep learning for the diagnosis of cochlear malformation on temporal bone CT.

OBJECTIVE: Diagnosis of cochlear malformation on temporal bone CT images is often difficult. Our aim was to assess the utility of deep learning analysis in diagnosing cochlear malformation on temporal bone CT images. METHODS: A total of 654 images from 165 temporal bone CTs were divided into the training set (n = 534) and the testing set (n = 120). A target region that includes the area of the cochlear was extracted to create a diagnostic model. 4 models were used: ResNet10, ResNet50, SE-ResNet50, and DenseNet121. The testing data set was subsequently analyzed using these models and by 4 doctors. RESULTS: The areas under the curve was 0.91, 0.94, 0.93, and 0.73 in ResNet10, ResNet50, SE-ResNet50, and DenseNet121. The accuracy of ResNet10, ResNet50, and SE-ResNet50 is better than chief physician. CONCLUSIONS: Deep learning technique implied a promising prospect for clinical application of artificial intelligence in the diagnosis of cochlear malformation based on CT images.

Variation of the stapes and its surrounding anatomical structures based on micro-computed tomography.

BACKGROUND: Stapedotomy is the most efficient treatment for otosclerosis. The anatomical structure of the operation area is complex, but it has a great impact on the postoperative effect. We measure the anatomical parameters of the stapes and its surrounding structures to provide an anatomical reference for stapes surgery in otosclerosis. MATERIALS AND METHODS: Fifteen adult cadaver heads (30 samples) were scanned using micro-CT. The stapes, facial nerve and external auditory canal were reconstructed by image processing. The stapes parameters and relationships between the stapes and surrounding structures were measured using a three-dimensional reconstruction model. RESULTS: The length, width and thickness of the stapes footplate were 2.93 ± 0.17 mm, 1.46 ± 0.08 mm and 0.30 ± 0.11 mm, respectively. The distance between the stapes footplate and long process of the incus was 3.79±0.39 mm. The angle of the incudostapedial joint was 88.29 ± 11.58°. The distance from the center of the stapes footplate to the facial canal was 1.60 ± 0.34 mm. In simulated stapes surgery, the minimum depth of the external auditory canal to be removed was 2.17 ± 0.91 mm, and no significant difference was found between the left and right sides and between men and women (P > 0.05). CONCLUSIONS: A three-dimensional model of the stapes bone and its surrounding anatomical structures was established based on Micro-CT imaging. Anatomical parameters of the stapes bone and its surrounding structures were measured using the model. In stapedotomy, the implanted piston diameter should be around 0.6mm, with a length of approximately 4.6mm. Care should be taken to protect the facial nerve canal during the surgery. These data provide reference for otologists.

Application of UNETR for automatic cochlear segmentation in temporal bone CTs.

OBJECTIVE: To investigate the feasibility of a deep learning method based on a UNETR model for fully automatic segmentation of the cochlea in temporal bone CT images. METHODS: The normal temporal bone CTs of 77 patients were used in 3D U-Net and UNETR model automatic cochlear segmentation. Tests were performed on two types of CT datasets and cochlear deformity datasets. RESULTS: Through training the UNETR model, when batch_size=1, the Dice coefficient of the normal cochlear test set was 0.92, which was higher than that of the 3D U-Net model; on the GE 256 CT, SE-DS CT and Cochlear Deformity CT dataset tests, the Dice coefficients were 0.91, 0.93, 0 93, respectively. CONCLUSION: According to the anatomical characteristics of the temporal bone, the use of the UNETR model can achieve fully automatic segmentation of the cochlea and obtain an accuracy close to manual segmentation. This method is feasible and has high accuracy.

Safety and Effectiveness of Diode Laser Used in Stapes Surgery.

Objective: We comprehensively assessed the safety and effectiveness of a 980-nm diode laser with fiberoptic delivery in stapes surgery by laser energy use, complications, and audiometric outcomes. Materials and methods: We retrospectively reviewed 116 primary stapes surgery cases. A high-power (30-40 W), short-pulse (60 msec), 980-nm diode laser was used for superstructure removal and footplate fenestration in the diode laser group (DLG) and, the hook and drill method in the conventional technique group (CTG). Data on complications and surgical diode laser use were collected; audiometric results within 6 months postoperatively were included in the analysis. Results: In DLG, the median fenestration and superstructure resection energy were 4.80 and 18.23 J, respectively. Footplate floating occurred in two ears (2/128, 1.56%) with manual fenestration, although none in the DLG (p = 0.07). Six CTG patients (6/26, 23.08%) underwent inevitable stapedectomy owing to footplate dislocation, which was higher than that in the DLG (2.11%, p < 0.01). No patients in the DLG experienced sensorineural hearing loss, and bone conduction (BC) improved at 1 (preoperative and postoperative means: 23.69 and 20.93 dB, respectively; p = 0.003) and 2 kHz (preoperative and postoperative means: 35.28 and 31.40 dB, respectively; p < 0.001), whereas changes in BC at 0.5 and 3 kHz were stable (p > 0.05). Four DLG patients (4/107, 3.74%) experienced transient facial nerve palsy postoperatively. Laser energy analysis showed shorter superstructure vaporization intervals in patients with transient facial nerve palsy (mean, 11.65 sec; median of control, 24.57 sec; p = 0.037). Conclusions: High-power, short-pulse, 980-nm diode laser is safe and effective in stapes surgery.

Auditory brainstem response after electrolytic lesions in the unilateral medial geniculate body of tree shrews.

OBJECTIVES: This study aimed to assess the processing of clicks and tone pips in the auditory brainstem of tree shrews and analyze the long-term evolution of postlesion plasticity in the auditory system and its ability to self-repair. METHODS: The auditory brainstem response (ABR) was measured in the normal control group (n=10) and the electrolytic damage group (n=10) before and 0 h, 24 h, 48 h, 72 h, and 25 d after electrolytic damage. Recordings were performed under closed-field conditions using clicks and tone pips, followed by statistical analysis of the ABR threshold, amplitude and latency. RESULTS: The results were as follows: (1) After electrolytic damage to the tree shrew medial geniculate body (MGB), the latency and amplitude of ABR waveforms from the left ear changed from 0 h to 25 d. All parameters were lower at 25 d than they were preoperatively. The amplitude of ABR wave VI (using click sound stimulation) decreased or disappeared in both ears. (2) The ABR threshold was significantly different in both ears at 72 h postoperatively compared with preoperatively (0 h) (P < 0.05) but recovered by 25 d. CONCLUSION: Based on these results, we conclude the following: (1) The origin of wave VI in tree shrews may be associated with the MGB. After electrolytic damage to the MGB, the changes in the ABR waveforms at different frequencies indicated that the MGB nucleus had a certain characteristic frequency. (2) Unilateral injury to the MGB can lead to similar levels of hearing impairment in both ears.

Analysis of the clinical and genetic characteristics of a Chinese family with osteogenesis imperfecta type I.

BACKGROUND: Osteogenesis imperfecta type I (OI-I) is a rare genetic disorder characterized by skeletal deformity, bone fragility, blue sclerae, dentinogenesis imperfecta, and hearing loss. The current study aimed to confirm the clinical diagnosis and genetic cause of OI-I in a four-generation Chinese family. METHODS: Clinical investigation and pedigree analysis were conducted to characterize the phenotypic manifestations of a Chinese family with OI-I. Follow-up audiometry and imaging tests were used to evaluate the postoperative outcomes of stapes surgery in the proband with otosclerosis. Whole-exome sequencing (WES) and Sanger sequencing were used to identify the pathogenic gene variants and for cosegregating analysis. RESULTS: We described in detail the clinical features of the collected family with autosomal dominant OI-I, and firstly identified a pathogenic splicing variant (c.2344-1G>T) in intron 33 of COL1A1 in a Chinese family. The molecular analysis suggested that the mutation might cause splice site changes that result in a loss of gene function. The proband, who suffered from otosclerosis and presented two-side middle-severe conductive hearing loss, benefitted significantly from successive bilateral middle ear surgery. CONCLUSIONS: The diagnosis of OI-I in a Chinese family was established by clinical and genetic investigation. A heterozygous pathogenic splicing variant in COL1A1 was directly responsible for the bone fragility and hearing loss of this family. Otosclerosis surgery should be suggested to rehabilitate conductive hearing impairment in OI patients.

A Novel Eustachian Tube Test: Preliminary Research of Sonotubometry With Nasopharynx Under Pressure.

OBJECTIVES: The aim of this study was to develop a novel Eustachian tube (ET) test consisting of sonotubometry with nasopharynx under pressure to measure opening of the ET. We assessed the advantages of this novel approach compared with those of sonotubometry only or tubomanometry only and explored the possibility of quantifying ET patency. STUDY DESIGN: This was a prospective clinical study at a tertiary referral center. METHODS: Sonotubometry, tubomanometry, and sonotubometry with nasopharynx under pressure were performed on a total of 106 ears. The ET-opening detection rates of the different test methods were compared with McNemar's test or Fisher's exact test. The correlation between the ET-opening latency index (R value) and nasopharyngeal pressure, as well as the correlation between the sound pressure of the external ear canal and the nasopharyngeal pressure, was assessed via Spearman's correlation coefficients. RESULTS: ET openings were detected most frequently during sonotubometry with nasopharynx under pressure, with opening rates of 93.40, 98.10, and 98.10% at 30, 40, and 50 mbar, respectively, which were significantly higher than those of sonotubometry (80.20%) and tubomanometry (74.50, 86.80, and 90.60% at 30, 40, and 50 mbar, respectively). Both R values and sound pressures were significantly different at pressures of 30, 40, and 50 mbar; the R value decreased with the increase of nasopharyngeal pressure (r = -0.298, p  = 0.000), while the sound pressure increased with nasopharyngeal pressure (r = 0.251, p  = 0.000). CONCLUSIONS: Sonotubometry with nasopharynx under pressure represents a novel hybrid ET test that our findings suggest is superior to sonotubometry only and tubomanometry only in detecting ET openings in healthy ears. Sound pressure resulting from sonotubometry with nasopharynx under pressure may be useful for quantifying the degree of openness of the ET. However, further validation in both healthy subjects and patients with ET dysfunction is required before this novel ET test may be recommended for clinical use.

Clinical application of MIIRMR as a salvage method in gadolinium-enhanced MRI after intra-tympanic injection.

BACKGROUND: Three-dimensional fluid-attenuated inversion-recovery (3 D-FLAIR) and real inversion-recovery (3 D-real IR) sequences are used to detect endolymphatic hydrops (EH), but medium inversion-time inversion-recovery imaging with magnitude reconstruction (MIIRMR) may be more sensitive. AIMS: We investigated the inner-ear visualisation success rate and EH detection rates of 3 D-FLAIR and 3 D-real IR, and whether salvage MIIRMR could improve EH detection. MATERIALS AND METHODS: Fifty-one patients (102 ears) with episodic or chronic vestibular syndrome were injected intra-tympanically with 8-fold diluted gadolinium, and 3 D-FLAIR and 3 D-real IR images obtained 24-h post-injection. If 3 D-FLAIR inner-ear visualisation failed, additional MIIRMR was performed. The success and EH detection rate increase by MIIRMR was calculated. The diagnostic performance of combined MIIRMR + 3D-FLAIR + 3D-real IR for Meniere's disease (MD) was evaluated. RESULTS: The success rates of 3 D-FLAIR and 3 D-real IR were 88.90% and 72.55%, respectively. MIIRMR increased the success and EH detection rates by 11.10% and 6.86%, respectively. In MD, MIIRMR increased these rates by 10.53% and 10.53%, respectively. 3 D-FLAIR + 3D-real IR + MIIRMR had 92.11% sensitivity, 79.68% specificity, 72.92% positive-predictive value, and 94.44% negative-predictive value for MD diagnosis. CONCLUSION AND SIGNIFICANCE: MIIRMR can improve success and EH detection rates when 3 D-FLAIR fails. Combined MIIRMR + 3D-FLAIR + 3D-real IR is more valuable for diagnosing MD than conventional sequences.

Observation in inner ear of tree shrew using scanning electron microscope and the Atoh1 distribution in cochlea.

This study aimed to observe the ultrastructure on the surface of the inner ear of a normal tree shrew using scanning electron microscope (SEM). The specimens of cochlea, macula utriculi, macula sacculi, and crista ampullaris of the normal adult tree shrew were collected and observed by SEM. We used immunofluorescence for cochlear protein Atoh1 staining. We observed that cochlea of the tree shrew is centered on the cochlear axis, circling about 3.5 times from bottom to top of the cochlea. The organ of Corti is located between medial and lateral grooves, including inner and outer hair cells as well as supporting cells. Maculae staticae include macula of saccule and macula of utricle, and the surface of macula is covered with a large number of otoliths. We found a gelatinous layer below the otoliths, followed by the layer of the honeycomb structure. The hair cell cilia of macula and crista ampullaris include one kinocilium and more stereocilia. There is no obvious cross structure but numerous hair cell cilia on semicircular canal crista ampullaris. Immunofluorescence staining showed that protein Atoh1 is mainly distributed in the nucleus of the cochlea's inner and outer hair cells. The observation of the inner ear structure under SEM elucidate the fine surface morphological structure of the entire cochlea, the vestibular maculae staticae, and crista ampullaris, providing new insight into the structure and function of the inner ear of tree shrew. HIGHLIGHTS: This article is the first to describe the inner ear ultrastructure of a small primate tree shrew by scanning electron microscopy (SEM). Under an SEM, the phalangeal processes of Deiter cells in tree shrews were observed to be connected to the tip of a neighboring hair cell, which was different from that of Deiters' cells in guinea pigs, and this crossed one hair cell, and connected to the tip of the third hair cell. It was observed that the crista ampullaris of tree shrews were horseshoe-shaped, and similar to that of humans and monkeys, this had no obvious "cross-shaped hump" structure. Tree shrew's ABR threshold value curve conforms to the mammalian U-shaped curve, wave III is the main wave of ARB, its sensory frequency may be higher 8 kHz, and the characteristics of the stereocilia of tree shrew we have observed may be related to the perception of higher frequency hearing.

[Value of cone-beam computer tomography in the middle and inner ear observation].

Objective:To identified the feasibility and normal range of cone beam computer tomography（CBCT） in the measurement of temporal bone. Methods:15 formalin fixed human cadaver head specimens were scanned by CBCT, high resolution CT, and Micro CT, respectively. Morphological parameter measurements of the middle and inner ear structures including ossicular chain, cochlea, semicircular canal and facial nerve were performed, and the results measured by the three scanning methods were compared. Results:None of the parameters measured by the three scanning methods were statistically significant except the thickness of stapes footplate（P<0.01） and the diameter of cochlear basal turn（P<0.01）. CBCT was superior in detecting facial nerve bony canal dehiscence. Conclusion:CBCT has the advantages of short scanning time, low radiation dose and high resolution. It can accurately display the morphological characteristics of the temporal bone structures, and is a reliable evaluation method for otological surgery.

[Progress of research on cone beam CT in cochlear implantation].

Cochlear implant, as the most successful artificial auditory implant, brings tens of thousands of patients with severe or profound sensorineural hearing loss back to the world of sound every year. With the expansion of surgical indications, a large number of difficult cases bring new challenges for cochlear implantation. As a new technology, cone beam CT has the double advantages of high spatial resolution and low radiation. It is considered as the second revolution of CT technology, which shows unique value in the application of cochlear implantation. This article reviews the basic principles of cone beam CT and its application and research progress in cochlear implantation.

A de novo mutation of the SOX10 gene associated with inner ear malformation in a Guangxi family with Waardenburg syndrome type II.

OBJECTIVE: Waardenburg syndrome type 2 (WS2) is a rare neural-crest disorder, characterized by heterochromic irides or blue eyes and sensorineural hearing loss. The aim of this study was to analyze the clinical features and investigate the genetic cause of WS2 in a small family from Guangxi Zhuang Autonomous region. METHODS: Whole-exome sequencing and mutational analysis were used to identify disease-causing genes in this family. RESULTS: A de novo missense mutation, C.355C > T (p. Arg119Cys), in exon 2 of SOX10 was related to inner ear malformation in the proband and identified by whole exon sequencing, but this mutation was absent in normal controls and any public databases. According to nucleic acid sequence and protein bioinformatic analysis, this mutation is considered the cause of WS2 without neurologic involvement in the proband. CONCLUSIONS: Our findings provide an accurate genetic diagnosis, counseling, and rehabilitation for family members and may contribute to further genotype-phenotype correlation studies of the SOX10 gene.

Comparison of sonotubometry, impedance, tubo-tympano-aerography, and tubomanometry to test eustachian tube function.

PURPOSE: There is currently no gold standard for the diagnosis of eustachian tube (ET) dysfunction. To provide an objective basis for the clinical diagnosis of ET dysfunction, we explored the characteristics of sonotubometry, impedance, tubo-tympano-aerography (TTAG), and tubomanometry (TMM) in volunteers with healthy ETs. MATERIALS AND METHODS: Sonotubometry, impedance, TTAG, and TMM tests were performed in 110 healthy ears of 55 volunteers, and the characteristics of each ET test were compared and discussed. RESULTS: The ET opening rate was compared between sonotubometry with dry swallowing, impedance with the Valsalva maneuver, TTAG with the Valsalva maneuver, and TMM with a nasopharyngeal pressure of 50 mbar in 100 (90.9%), 102 (92.7%), 99 (90.0%), and 104 (94.5%) ears, respectively; there was no significant difference among the four methods (P = 0.575). In sonotubometry, both dry swallowing and the Valsalva maneuver were superior to wet swallowing in terms of detecting ET opening (P = 0.000). In TMM, both the opening rate and the external auditory canal pressure were positively correlated with the nasopharyngeal pressure. Specifically, the opening rate and external auditory canal pressure increased with an increase in the nasopharyngeal pressure (r = 0.271, P = 0.000; r = 0.315, P = 0.000, respectively). CONCLUSIONS: Sonotubometry, impedance, TTAG, and TMM have their own advantages and disadvantages. In clinical practice, the appropriate ET function test should be chosen on the basis of the patient's specific condition.

Adverse effects of semicircular circle angles variation on Epley repositioning procedure: a study on reconstruction of Micro-CT images 3D.

Background: For patients with posterior semicircular canal (PSC) BPPV, Epley re-position maneuver and some improvement methods are the most efficient treatment methods. But there were still 9.43% patients who were not benefit from Epley re-position maneuver.Objective: To measure the angles of semicircular canals and evaluate its effect on Epley maneuver.Methods: Fifteen skull specimens, containing 30 temporal bone specimens were included. After Micro-CT scanning, 3D reconstruction was loaded with the CT image. The angles between each semicircular canal and each standard skull plane were measured. Furthermore, the angles' effect on Epley maneuver was evaluated according to the three-dimension (3D) model.Results: Angles of PSC plane: Frankfurt plane was 71.54 ± 6.51, sagittal plane was 53.77 ± 5.36°, and the coronal plane was 43.33 ± 3.56°. Angles between PSC and the sagittal plane of skulls had an adverse effect on Epley maneuver, when it was less than 45°.Conclusion: 1. Variation could be found in angles between the semicircular canals and the standard planes of skulls, which meant variation of semicircular canals' location existing in skulls. 2. The variation of angles between PSC and sagittal plane could have an adverse effect on the Epley maneuver when the angle was less than 45°, which may cause the Epley maneuver to be invalid.

The characterization of auditory brainstem response (ABR) waveforms: A study in tree shrews (Tupaia belangeri).

To characterize the patterns of ABR waves in tree shrews, we must understand the hearing sensitivity and auditory function of healthy adult tree shrews. Fifteen tree shrews (30 ears) were stimulated with clicks and tone-pips at 11 different frequencies from 1 to 60 kHz. The ABR waves were recorded and analyzed. The ABR consisted of five to seven positive waves in the first 10 ms after a click stimulus, and the average hearing threshold of component III was 27.86 ±â€¯3.78 dB SPL. Wave III was the largest and most clear. The ABR threshold was related to the tone-pip sitmulus by a "U" shaped curve. The sensitive frequency was approximately 8 kHz in tree shrews. The latencies systematically decreased with increasing stimulus frequencies. The ABR amplitudes of wave III increased as the sound pressure level increased. All of these results provide an empirical basis for future studies of hearing diseases in tree shrews.

Micro-CT study of the human cochlear aqueduct.

OBJECTIVE: The anatomic structure of the cochlear aqueduct (CA) in human temporal bone specimens was observed using micro-computed tomography (CT). MATERIALS AND METHODS: Micro-CT scanning of 18-µm-thick slices was performed on 30 slides of human temporal bone specimens to observe the CA structure and its relationship with its surroundings. The length, internal and external apertures, and the narrowest width of the CA were measured. The differences in CAs were compared between high jugular bulb (HJB) specimens and normal specimens. RESULTS: A large number of CA images were acquired using Micro-CT scanning, which clearly displayed the basic anatomic structures, stereotactic localizations, and adjacent relationships of the CAs. The whole course of a CA was 12.31 ± 3.60 mm, the diameter of the internal aperture was 465 ± 242 µm, the diameter of the external aperture was 2.88 ± 1.06 mm, the narrowest diameter was 601 ± 335 µm, the diameter of the opening of inferior cochlear vein (ICV) was 151 ± 50 µm, the distance between the internal aperture and ICV was 270 ± 197 µm, and the distance between the inferior margin of the internal acoustic meatus (IAM) and the top most part of the external aperture of the CA was 6.783 ± 2.15 mm. No bony obstruction of the CA or CA enlargement was observed in the specimens. A total of 28 CAs had one accompanying bony canal in the surroundings. The length and travelling of the CA were not affected by the level of the jugular bulb (JB). The variation of the travelling of the ICV was larger than that of the CA. CONCLUSION: Micro-CT adequately displayed the bony CA canal and provided a new method for anatomical studies of the CA and a basis for functional studies.

Anatomical Variations of the Human Cochlea Determined from Micro-CT and High-Resolution CT Imaging and Reconstruction.

Understanding the anatomical variations in the human cochlea is important for cochlear implants. This study examined these variations using a reconstructed fusion model of the skull and temporal bone. The three-dimensional (3D) digital model of the temporal bone was reconstructed from multiple axial micro-computed tomography (CT) scans of temporal bone and high resolution CT of the skull from 15 cadavers. A skull model was reconstructed and merged with the reconstructed temporal bone. The 3D relationship between the cochlea and the skull's mid-sagittal plane was analyzed. The α and ß angles of the cochlear autogenous rotation and bottom position, respectively, further subdivided the cochlear spatial orientation. The relationship between the base of the cochlea and the round window was evaluated with the Φ angle. Cochlear size was measured and the relationship was statistically analyzed. Cochlear implant electrode arrays were observed in five cases of right-temporal bone specimens. The α, ß, and Φ angles were 46.01 ± 9.65, 56.79 ± 3.58, and 44.41 ± 7.23, respectively. The α angle varied greatly and was negatively correlated to the Φ angle (correlation coefficient = -0.211, P < 0.05). Among the five specimens, the α and Φ angle of the 2R and 4R cochlear specimens was lower and higher than the mean value, respectively. These measurements revealed variations in the size and position of the cochlea. Some of these variations may require surgical adjustments for insertion of electrodes with cochlear implants and present a greater challenge for implantation of cochlear electrode implantation. These data also provide a better understanding of variations in human cochlear anatomy. Anat Rec, 301:1086-1095, 2018. © 2017 Wiley Periodicals, Inc.

The diagnostic value of measurement of cochlear length and height in temporal bone CT multiplanar reconstruction of inner ear malformation.

CONCLUSION: The cochlear length (CL) and cochlear height (CH) measured through MPR will provide for more accurate quantitative diagnosis of inner ear malformation, and are subsequently convenient for calculating cochlear duct length (CDL) before cochear implant. OBJECTIVES: Qualitative and quantitative diagnosis of inner ear malformation in deaf patients through multiplanar reconstruction (MPR) was performed to provide a reference for cochlear implants. METHODS: One hundred and two cases without sensorineural deafness and 560 patients with sensorineural deafness had MPR of temporal bone computed tomography performed to obtain the standardized cochlear-view and oblique coronal-view images. The inner ear radial lines were measured to formulate normal values for inner ear malformation diagnosing, and the CDL was estimated based on CL. RESULTS: The normal range values of inner ear radial lines were measured and formulated, of which CL was 8.1-9.59 mm and CH was 3.28-3.90 mm. According to inner ear morphology and the normal values measured above, 61 cases of incomplete partition-type II (IP-II) and a high percentage (27/110, 24.5%) of hypoplasia of cochlea (HC) were diagnosed. The HC group was further divided into 1-turn, 1.5-turn, and 2-turn sub-groups, which had CDL of 15.98 ± 1.48 mm, 21.36 ± 0.96 mm, and 26.56 ± 0.60 mm, respectively.

Electrophysiological change in the tensor veli palatini muscle after radiotherapy.

CONCLUSION: Electromyography of the tensor veli palatine (TVP) was abnormal and showed mainly myogenic impairment in patients with nasopharyngeal carcinoma (NPC) with secretory otitis media (SOM) after radiotherapy. The diseased ears showed impairment in opening functions of the eustachian tubes (ETs). OBJECTIVES: To characterize electrophysiology of the TVP muscle using electromyography (EMG) in patients with SOM after radiotherapy of NPC. METHODS: Twenty healthy volunteers and 20 patients with NPC and SOM after radiotherapy were chosen for assessment of EMG of the TVP during swallowing. RESULTS: The measurements of average duration and amplitude of action potential, swallowing contraction duration, and peak voltage in NPC patients with both SOM (n = 25) and healthy ears (n = 6) were significantly lower than those of ears (n = 38) in healthy controls (p < 0.01). In patients with NPC, the average action potential duration and swallowing contraction duration in ears with SOM were lower than those of subjects with healthy ears (p < 0.05), whereas no significant difference was found in average amplitude of action potential and peak voltage between them.

The effects of the auditory brainstem response before and after fluoro-gold injection in medial geniculate body.

OBJECTIVE: This study aimed to use the tree shrew as an otological model, not only to verify the location of the auditory pathway in tree shrews by fluoro-gold (FG) but also to elucidate the effects of the auditory brainstem response (ABR) before and after FG injection. METHODS: FG was injected into the medial geniculate body (MGB) of experimental group (n=10).The normal group (n=10) was inserted the microsyringe, which was not perfused FG. Hearing was assessed by testing ABRs before and after the operation. RESULTS: FG-labelled neurons were primarily distributed in the ipsilateral MGB, the ipsilateral and contralateral nuclei of the inferior colliculus (NIC), the superior olivary nucleus (SON), the dorsal cochlear nucleus (DCN), and the ventral cochlear nucleus (VCN). The ABR after FG injection caused a significant decrease in the wave amplitudes at 24 h that recovered by 72 h. However, the wave I-VI interpeak latencies in the right ear were shortened at 0 and 24 h post-surgery, whereas after 48 h, the interpeak latencies were prolonged. CONCLUSIONS: The FG retrograde tracing technique accurately displays the anatomical location of the auditory pathway in the tree shrew. The change in ABR waves suggested that there was a functional abnormality in the central auditory pathway after FG injection. The auditory thalamus may have self-regulating properties.