Characteristics of responsiveness of cochlear nerve to electrical stimulation in patients with cochlear nerve deficiency / 中华耳鼻咽喉头颈外科杂志

Objectives: This study aimed to evaluate the responsiveness of cochlear nerve to electrical stimulation in patients with cochlear nerve deficiency(CND), to compare their results with those measured in implanted children with normal-sized cochlear nerves, and to investigate the characteristics of the cochlear nerve injury of children with CND. Methods: Participants were children who underwent cochlear implantation at Shandong Provincial ENT Hospital from January 2012 to January 2020, including CND group and control group. The CND group included 51 subjects (male:20; female: 31) who were diagnosed with CND and had normal cochlea. For the CND group, four children had been bilaterally implanted, the mean implantation age was (2.7±1.5) years old. The control group included 21 subjects (male:10; femal:11) who had normal-sized cochlear nerve and normal cochlea. For the control group, all children had been unilaterally implanted except one, and the mean implantation age was (3.0±1.9)years old. Three subjects in the CND group used CI422 electrode arrays, and all the other subjects used CI24RECA/CI512 electrode arrays. The electrically evoked compound action potentials (ECAP) had been tried to record for each electrode using Custom Sound EP software (v. 4.3, Cochlear Ltd.) at least six months post first activation. Furthermore, ECAP amplitude growth functions (AGF) were measured at multiple electrode locations across the electrode array. Generalized linear mixed effect models with the subject group and electrode location as the fixed effects and subjects as the random effect were used to compare results of ECAP measurements. Results: In the control group, ECAP could been recorded at all electrodes (100%), but it could only be recorded in 71% (859/1 210) electrodes in the CND group. Additionally, the percentage of electrodes with measurable ECAP decreased from electrode 1 to electrode 22 in the CND group. Compared to the control group, the ECAP thresholds significantly increased, the ECAP amplitudes and AGF slopes significantly decreased, and the ECAP latency significantly increased in the CND group (P<0.01). GLMM showed that the stimulating site had a significant effect on the ECAP threshold, maximum amplitude, and AGF slope (P<0.01), but had no significant effect on the ECAP latency (P>0.05) in the CND group. However, the stimulating site had no significant effects on the ECAP measurements in the control group. Furthermore, the functional status of cochlear nerve varied greatly among CND group. From electrode 1 to electrode 22, the ECAP thresholds gradually increased, the ECAP maximum amplitudes and AGF slopes gradually decreased in the CND group. Conclusion: Compared with patients with normal-sized cochlear nerve, not only the number of residual spinal ganglion neurons reduce,but also the function of spinal ganglion neurons damages in CND patients. The degree of cochlea nerve deterioration varies greatly among CND patients. Generally, the deterioration of cochlear nerve tends to increase from the basal to the apical site of the cochlea.

The imaging characteristics and prognosis of patients with cochlear implants whose cochlear nerves are not shown on MRI / 中华耳鼻咽喉头颈外科杂志

Objective: To analyze the temporal bone CT and inner ear magnetic resonance imaging characteristics of cochlear implant patients with no cochlear nerve display in the inner auditory canal under MRI. To retrospectively analyze the long-term hearing and speech rehabilitation effects of such patients after cochlear implant. And to analyze the correlation between the results of imaging examinations and the postoperative effects of cochlear implant patients with this type of cochlear nerve deficiency. Methods: A total of 88 children with cochlear nerve deficiency, who underwent cochlear implantation in Shandong Provincial ENT Hospital from May 2014 to October 2018, were enrolled. Patients with cochlear malformations were excluded,only the patients with cochlear nerve deficiency whose cochlear structure was normal and no cochlear nerve displayed in inner auditory canal under MRI were enrolled. There were 64 patients, including 4 bilaterally implanted, 68 ears in total, with an average age of (2.8±1.7) years (range 1-6 years) at the time of implantation. The implanted product was Cochlear, including 24RECA and 512 models. All patients underwent inner ear magnetic resonance imaging and temporal bone CT scan before operation. Auditory speech function assessments were performed at 12 months, 24 months, and 36 months after surgery, including categories of auditory performance (CAP), speech intelligibility rating (SIR) and hearing aid threshold test. The imaging evaluation content included the width of the cochlear nerve canal of temporal bone CT, the width of the internal auditory canal, the width of the auditory nerve at the cerebellopontine angle of the inner ear MRI, and the ratio of the facial nerve to the width of the auditory nerve at the cerebellopontine angle. The correlations between the results of postoperative hearing aid hearing threshold, CAP, SIR and imaging results were analyzed. Results: Among the 64 cases of cochlear nerve not shown under MRI, 56 ears with CT data showed that the width of the cochlear nerve canal in temporal bone CT was (0.72±0.30) mm (mean±standard deviation, the same below), and the width of the internal auditory canal was (4.07±1.10) mm; 66 ears with MRI data showed that the diameter of the auditory nerve at the cerebellopontine angle of the inner ear MRI was (1.58±0.27) mm, the diameter of the facial nerve was (1.57±0.27) mm, and the ratio of the diameter of the facial nerve to the auditory nerve was (1.02±0.23). The average hearing thresholds at 12, 24, and 36 months after surgery were (46.8±2.5) dB HL, (40.7±0.8) dB HL, and (36.8±1.5) dB HL, respectively. The preoperative and postoperative CAP scores at 12, 24 and 36 months were (1.0±1.0), (3.8±1.4), (4.5±1.4) and (5.1±0.7) points, respectively. The preoperative and postoperative SIR scores at 12, 24, and 36 months were (1.1±0.3), (1.9±0.9), (2.5±0.9), and (2.9±0.6) points, respectively. The hearing threshold at 24 months after surgery was negatively correlated with the width of the internal auditory canal of temporal bone CT (r=-0.349, P=0.037), and the hearing threshold at 36 months after surgery was positively correlated with the ratio of the diameter of the facial nerve to the auditory nerve at the cerebellopontine angle of the inner ear MRI (r=0.740, P=0.001). Conclusions: Children with cochlear implants whose cochlear nerves are not shown on MRI can benefit from cochlear implantation, and their speech and auditory functions can improve significantly after surgery. The width of the internal auditory canal in the temporal bone CT and the ratio of the diameter of the facial nerve to the auditory nerve at the cerebellopontine angle of the inner ear MRI may be related to the long-term hearing threshold after surgery.

Multi-center study on the treatment for intermediate and high-frequency sudden sensorineural hearing loss / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To analyze the therapeutic effect of treatment for intermediate and high-frequency sudden sensorineural hearing loss (SSNHL).</p><p><b>METHODS</b>A prospective clinical multicentre research was conducted using international standardized approach of clinical research. SSNHL Cases with intermediate and high-frequency hearing loss, that accepted no medication from onset of hearing loss within two weeks duration and ages ranged between 18 and 65, were collected. All patients were treated by one of four treatments plans chosen by unified random table.</p><p><b>RESULTS</b>141 patients with intermediate and high-frequency SSNHL were recruited in the research. Twenty subjects were treated with lidocaine, 21 cases with lidocaine and hormone, 40 cases with Ginaton, and 60 cases with Ginaton and hormone. 42 out of 141 (29.79%) patients were total recovery, 24 (17.02%)achieved excellent recovery, 27 (19.15%)achieved partial recovery, and 48 (34.04%) were ineffective. The total effective rate was 65.96%. In lidocaine group, the total effective rate was 55.00%, 66.67% in lidocaine and hormone group, 67.50% in Ginaton group, and 68.33% in Ginaton and hormone group. Considering the total effective rate, there was no statistical difference between four groups (P > 0.05). However, the recovery rate in Ginaton group was significant difference comparing with that in lidocaine group (P = 0.0496). 119 had concomitant symptom of tinnitus, and the tinnitus was improved in patients of 81.51%. With regard to total effective rate of tinnitus in four treatment groups, it was 57.89% (11/19) in lidocaine group, 100.00% (18/18) in lidocaine and hormone group, 88.57% (31/35) in Ginaton group, 78.72% (37/47) in Ginaton and hormone group. There was significant ascendancy in lidocaine and hormone group versus that in lidocaine group (P = 0.002) and Ginaton and hormone group (P = 0.029). And the difference between lidocaine and Ginaton groups was statistical significance (χ(2) = 6.705, P < 0.05). In 43 patients with muffled symptom in aural region, 90.70% was partial recovery. There was no statistical difference between each groups (χ(2) = 5.97,P = 0.74). There were 17 with dizziness or vertigo improved in all cases. Another 10 patients accompanied other complaints all improved.</p><p><b>CONCLUSIONS</b>for the treat of intermediate and high-frequency SSNHL, the therapeutic effect in hearing has no significantly different between single and combined drug therapies. Considering the recovery rate, there is an obvious advantage in Ginaton group compared with lidocaine group. Tinnitus is the major concomitant symptom in intermediate and high-frequency SSNHL, and lidocaine and hormone therapy should be used.</p>