伴有中枢神经系统疾病的聋儿人工耳蜗植入效果观察

目的 探讨伴有中枢神经系统疾病的极重度感音神经性耳聋患儿人工耳蜗植入的术前评估方法和植入后效果. 方法 南方医科大学珠江医院耳鼻咽喉科自1996年1月至2009年1月对23例伴有中枢神经系统疾病的语前聋患儿实施人工耳蜗植入,包括脑白质异常13例、脑皮质发育不良4例、脑积水2例、先天性颞叶囊肿2例、秽语痉挛综合征1例、唐氏综合征1例；分析患儿术前听力、影像学检查及发育评估、手术植入方法和术后听觉言语康复情况并与同期30例接受人工耳蜗植入、无中枢神经系统疾病的极重度感音性聋患儿(对照组)的疗效进行比较. 结果 中枢系统疾病组患儿人工耳蜗植入术后均获得听觉,未出现严重并发症;术后6个月啭音声场测听平均听阈(42.89±3.5) dBHL,高于对照组[(32.4±4.5)dBHL],差异有统计学意义(P＜0.05).术后1年左右闭式词表言语识别率平均为(65.18±3.1)％,低于对照组[(81.63±3.7)％],差异有统计学意义(P＜0.05)；患儿均获得不同程度的语言交流能力,但2例重度脑白质异常和2例脑皮质发育不良患儿言语康复落后于其他患儿. 结论 伴有中枢神经系统疾病的极重度感音性聋患儿在经过术前充分评估和全面观察后可以实施人工耳蜗植入,但中枢疾病的类型与严重程度可影响术后康复效果.     

耳蜗干细胞内耳移植对感音神经性耳聋大鼠听力恢复的实验研究

目的：探讨耳蜗干细胞内耳移植能否对感音神经性耳聋大鼠听力恢复产生影响。方法：从新生大鼠耳蜗分离的组织,经原代和传代培养,鉴定后移植入感音神经性耳聋模型大鼠内耳,将感音神经性耳聋大鼠模型分为两组：耳蜗干细胞移植组;PBS移植对照组;术后分别于1个月、18个月和24个月采用听觉脑干诱发电位方法检测模型大鼠的听力恢复情况,处死大鼠,通过免疫荧光染色方法,观察移植的耳蜗干细胞在内耳存活、分化和迁移情况。结果：分离新生大鼠耳蜗组织,细胞培养后,可获得大量Nestin阳性耳蜗干细胞。制作感音神经性耳聋模型,将耳蜗干细胞移植入感音神经性耳聋模型大鼠内耳,免疫荧光检测发现在耳蜗干细胞移植组移植针道两侧可见移植的Nestin阳性细胞和Myosin ⅦA阳性细胞。对照组呈较弱的荧光反应。听觉脑干诱发电位结果显示耳蜗干细胞移植组的感音神经性耳聋模型大鼠听力恢复情况较好,对照组无明显改善。结论：耳蜗干细胞移植入内耳可存活、迁移和分化为内耳毛细胞,可促进感音神经性耳聋模型大鼠的听力恢复。     

听神经瘤术中耳蜗电图监测与听力保护

目的：评价耳蜗神经电位活动直接监护在听神经瘤手术中对保护听力的作用。方法：听神经瘤手术中施行耳蜗电图监护。结果：１６例听神经瘤手术中施行耳蜗电图监护者，术后听力保留５例（３１％），其中４例为有效听力保留。肿瘤在２厘米以下者听力保留为３８％。结论：听神经瘤手术过程中采用耳蜗电图监护，能敏感地反应即时的听神经功能状况，经术者及时的反馈信息，有助于听力保护。     

中型听神经瘤术中听力保存及影响因素

目的 探讨中型听神经瘤听力保存的影响因素.方法 回顾性研究了乙状窦后入路听神经瘤显微手术58例.其中,试图听力保存的中型肿瘤22例.术前、术后行听力学检测纯音听阈(PTA)、言语识别率(SDS)和听觉诱发电位(BAEP),进行对比分析.结果 全部58例病人中,听力得以较好保存的4例.除去未考虑听力保存的大型肿瘤,22例中型肿瘤中听力得以保存的(较好保存PTA 60dB,SDS≥50%;部分保存PTA≤60dB,SDS≥50%)9例.12例肿瘤和耳蜗神经粘连重,10例没有粘连或粘连轻.结论 肿瘤与耳蜗神经的分界面是否粘连是听力保存的重要影响因素.术中神经监测对指导肿瘤切除是有益的,但术者的局部解剖知识和显微外科技术仍是手术成功的最基本因素.     

经乙状窦后手术入路切除内听道听神经瘤的听力保留

本文报告514例各类听神经瘤完全切除术连续病例。其中399例(占病例总数的78％)取经迷路手术入路,115例(22％)取经乙状窦后手术入路,选择其中的94例占(18％)作为听力保留的实验者。其临床标准是:内听道外肿瘤最大直径1.5cm。功能听力小于或等于会话容许值(SRT)50分贝。会话辨别力评分(SDS)大于或等于60％。此94例中,26例为内听道神经瘤。术中通过耳蜗神经反应电位(CNAP)来监测术侧耳蜗神经功能,部分病例还进行了脑干听觉诱发电位监测。     

冠心病患者国产与进口雷帕霉素支架置入后早期康复训练对炎性反应的影响

背景：冠心病患者支架置入后24 h可见血清炎症因子水平升高,但支架置入后长期的血清炎症因子水平变化报道尚不多见。 目的：观察冠心病国产雷帕霉素药物洗脱支架(Partner支架)和进口雷帕霉素药物洗脱支架(Cypher)置入后早期康复训练对血清炎症因子及患者生活质量的影响。 方法：收集辽宁医学院附属第三医院2007-01/2009-12心内科介入支架治疗急性心肌梗死患者108例。根据病变及经济情况将患者分为Partner组(n=58)和Cypher组(n=50)。征询患者及家属意见,对部分患者进行早期康复训练,Partner组和Cypher组分别为34例和28例,所有患者于支架置入前、置入后3,5周抽取空腹静脉血,检测血清白细胞介素18,C-反应蛋白,肿瘤坏死因子α水平。置入后5周应用WHOQOL-BRIEF量表评估患者生活质量。 结果与结论：未进行康复训练的Cypher组患者血清白细胞介素18,C-反应蛋白和肿瘤坏死因子α水平在置入前和置入后3,5周与未康复训练+Partner组相比,差异无显著性意义(P > 0.05)。患者支架置入后5周,康复训练+Partner/Cypher组患者世界卫生组织的简明QOL测定表评分均明显高于对应的未进行康复训练组(P < 0.05)。提示进行康复训练对2种支架置入的冠心病患者血清炎症因子水平无明显影响,但却对患者生活质量有明显改善作用。     

鼠神经生长因子穴位注射联合经络导平治疗婴幼儿听力损伤疗效分析

目的研究婴幼儿听力损伤的治疗效果。方法对102例有听力损伤的婴幼儿随机分为2组,治疗组52例、84耳,对照组50例、85耳,2组均给予听力训练,6个月以上开始配予助听器。治疗组增加鼠神经生长因子听宫、风池、外关、耳门穴位注射,联合经络导平听宫穴位输气,并将治疗前后测得的脑干听觉诱发电位结果作比较。结果 2组治疗效果总有效率差异有统计学意义(P<0.05),年龄越小、损伤越轻者疗效越佳。结论鼠神经生长因子穴位注射联合经络导平可有效治疗婴幼儿听力损伤,可减轻或避免聋残儿的出现。     

听神经瘤全切的面、耳蜗神经保留——(附33例随访报告)

总结近5年61例听神经瘤手术切除的效果。肿瘤全切除45例(74%),其中面神经保留38例(84%),耳蜗神经保留17例(38%)。对面神经保留中的33例进行了随访,面神经功能恢复到Ⅳ级以上的24例;33例中,同时保留耳蜗神经15例,术后听力恢复10例,其中听力接近正常2例。术后发生耳鸣15例,其中7例耳鸣较严重。本文介绍了枕下乙状窦后入路的手术要点。     

颈交感神经阻滞治疗神经性耳聋的疗效观察

神经性耳聋临床多见，主要指中耳、外耳声音传导正常，但耳蜗或听觉神经系统发生病变的病症，病变情况在听觉皮质中枢、听神经和内耳多见，致使听觉器官不能正确感知声音，导致严重的听力损失［1］。神经性耳聋的影响因素复杂多样，部分医师和学者认为是由于内耳微循环障碍导致的组织缺氧、缺血［2］。近年来，我院采用颈交感神经阻滞方式治疗取得明显效果，报告如下。     

毒性损伤大鼠耳蜗核移植嗅球神经前体细胞的初步观察

目的体外培养大鼠嗅球神经前体细胞，并移植到谷氨酸诱导损伤的耳蜗核，观察其生存、分化过程。方法嗅球神经前体细胞取自孕15d胚胎大鼠，免疫荧光染色鉴定。耳蜗核定位注射谷氨酸制成损伤模型。伤后7d移植标记的神经前体细胞，不同时间测定听性脑干反应并取材观察移植细胞的存活及分化。结果巢蛋白阳性的嗅球神经前体细胞在体外可自我复制传代，并分化出神经元和神经胶质细胞。谷氨酸损伤和前体细胞移植均造成听性脑干诱发反应（ABR）阈值升高，并有部分的恢复。免疫荧光技术发现耳蜗核中Hoechst33342分别和神经元特异性烯醇化酶（NSE）、胶质纤维酸性蛋白（GFAP）、谷氨酸双重标记的移植细胞。结论嗅球神经前体细胞移植耳蜗核短期存活良好，所分化出的神经元可表达听觉神经递质。     

Auditory brainstem activity and development evoked by apical versus basal cochlear implant electrode stimulation in children.

OBJECTIVE: The role of apical versus basal cochlear implant electrode stimulation on central auditory development was examined. We hypothesized that, in children with early onset deafness, auditory development evoked by basal electrode stimulation would differ from that evoked more apically. METHODS: Responses of the auditory nerve and brainstem, evoked by an apical and a basal implant electrode, were measured over the first year of cochlear implant use in 50 children with early onset severe to profound deafness who used hearing aids prior to implantation. RESULTS: Responses at initial stimulation were of larger amplitude and shorter latency when evoked by the apical electrode. No significant effects of residual hearing or age were found on initial response amplitudes or latencies. With implant use, responses evoked by both electrodes showed decreases in wave and interwave latencies reflecting decreased neural conduction time through the brainstem. Apical versus basal differences persisted with implant experience with one exception; eIII-eV interlatency differences decreased with implant use. CONCLUSIONS: Acute stimulation shows prolongation of basally versus apically evoked auditory nerve and brainstem responses in children with severe to profound deafness. Interwave latencies reflecting neural conduction along the caudal and rostral portions of the brainstem decreased over the first year of implant use. Differences in neural conduction times evoked by apical versus basal electrode stimulation persisted in the caudal but not rostral brainstem. SIGNIFICANCE: Activity-dependent changes of the auditory brainstem occur in response to both apical and basal cochlear implant electrode stimulation.     

Visual stimuli can impair auditory processing in cochlear implant users

It has been shown that visual stimulation can activate cortical regions normally devoted to auditory processing in deaf individuals. This neural activity can persist even when audition is restored through the implantation of a cochlear implant, raising the possibility that cross-modal plasticity can be detrimental to auditory performance in cochlear implant users. To determine the influence of visual information on auditory performance after restoration of hearing in deaf individuals, the ability to segregate conflicting auditory and visual information was assessed in fourteen cochlear implant users with varied degree of expertise and an equal number of participants with normal-hearing matched for gender, age and hearing performance. An auditory speech recognition task was administered in the presence of three incongruent visual stimuli (color-shift, random-dot motion and lip movement). For proficient cochlear implant users, auditory performance was equal to that of controls in the three experimental conditions where visual stimuli were presented simultaneously with auditory information. For non-proficient cochlear implant users, performance did not differ from that of matched controls when the auditory stimulus was paired with a visual stimulus that was color-shifted. However, significant differences were observed between the non-proficient cochlear implant users and their matched controls when the accompanying visual stimuli consisted of a moving random-dot pattern or incongruent lip movements. These findings raise several questions with regards to the rehabilitation of cochlear implant users.     

Cochlear implants in single-sided deaf recipients: Near normal higher-order processing

ObjectiveSingle-sided deafness (SSD) is a condition where an individual has a severe to profound sensorineural hearing loss in one ear and normal hearing on the contralateral side. The use of cochlear implants in individuals with SSD leads to functional improvements in hearing. However, it is relatively unclear how sounds incoming via the cochlear implant (independent of the hearing ear) are processed and interpreted by higher-order processes in the brain.MethodsScalp electroencephalography and auditory event-related potentials were recorded monaurally from nine experienced single sided cochlear implant users. Speech-in-noise and localisation tests were used to measure functional changes in hearing.Resultscochlear implant use was associated with improvement in speech-in-noise and localisation tests (compared to cochlear implant off). Significant N2 and P3b effects were observed in both cochlear implant and normal hearing ear conditions, with similar waveform morphology and scalp distribution across conditions. Delayed response times and a reduced N2 (but not P3b) effect was measured in the CI condition.ConclusionThe brain is capable of using processes similar to those in normal hearing to discriminate sounds presented to the cochlear implant. There was evidence of processing difficulty in the cochlear implant condition which could be due to the relatively degraded signals produced by the cochlear implant compared to the normal hearing ear.SignificanceUnderstanding how the brain processes sound provided by a cochlear implant highlights how cortical responses can be used to guide implantation candidacy guidelines and influence rehabilitation recommendations.     

Using Extracochlear Multichannel Electrical Stimulation to Relieve Tinnitus and Reverse Tinnitus-Related Auditory-Somatosensory Plasticity in the Cochlear Nucleus

ObjectivesTinnitus has no reliable cure but may be significantly relieved by the usage of cochlear implants. However, not all tinnitus patients necessitate cochlear implantation that can impair hearing. This study was to investigate whether a novel extracochlear electrical stimulation (EES) strategy could relieve tinnitus of guinea pigs without hearing impairment, and the roles of auditory-somatosensory plasticity in the cochlear nucleus in the tinnitus relief.Materials and MethodsWe used a novel four-electrode extracochlear implant to electrically stimulate the cochlea of tinnitus guinea pigs. Tinnitus was assessed by the gap-prepulse inhibition of the acoustic startle reflex (GPIAS) ratios and the tinnitus index. The plasticity of auditory and somatosensory innervation in the different subdivisions of cochlear nucleus was evaluated by immunostaining of vesicular glutamate transporter 1 (VGLUT1) and VGLUT2, respectively.ResultsThe EES induced significant decreases of GPIAS ratios and the tinnitus index of tinnitus guinea pigs, indicating reductions of tinnitus behavioral manifestations. Meanwhile, the EES reversed the abnormal auditory-somatosensory innervation in the cochlear nucleus of tinnitus animals but did not change the hearing and the numbers of inner hair cell synapses.ConclusionsThis study demonstrated that the novel EES strategy could effectively relieve tinnitus without impairment to hearing and cochlear structure of tinnitus animals. The reversal of tinnitus-related auditory-somatosensory plasticity in the cochlear nucleus was correlated with the tinnitus relief induced by the EES.     

Clinical application of neurotrophic factors: the potential for primary auditory neuron protection

Sensorineural hearing loss, as a result of damage to or destruction of the sensory epithelia within the cochlea, is a common cause of deafness. The subsequent degeneration of the neural elements within the inner ear may impinge upon the efficacy of the cochlear implant. Experimental studies have demonstrated that neurotrophic factors can prevent this degeneration in animal models of deafness, and can even provide functional benefits. Neurotrophic factor therapy may therefore provide similar protective effects in humans, resulting in improved speech perception outcomes among cochlear implant patients. There are, however, numerous issues pertaining to delivery techniques and treatment regimes that need to be addressed prior to any clinical application. This review considers these issues in view of the potential therapeutic application of neurotrophic factors within the auditory system.     

Long-term monaural auditory deprivation and bilateral cochlear implants

Long-term binaural auditory deprivation is associated with poorer speech recognition outcomes after cochlear implantation, even for postlingual hearing loss. It is, however, unknown to what extent the outcomes of implantation are related to the peripheral changes occurring monaurally or to changes at a higher level in the auditory system related to binaural deafness. This retrospective study aimed to unravel peripheral and central contributions to cochlear implantation outcomes by comparing outcomes obtained in individual ears for adults with long-term monaural auditory deprivation (i.e. unilateral use of hearing aid) who received bilateral cochlear implants. Results showed that similar outcomes can be obtained with the implant placed in the auditory-deprived or in the aided ear. This suggests that the peripheral changes related to monaural auditory deprivation have little effect on outcomes of cochlear implantation.     

Cortical auditory evoked potentials in unsuccessful cochlear implant users

In some cochlear implant users, success is not achieved in spite of optimal clinical factors (including age at implantation, duration of rehabilitation and post-implant hearing level), which may be attributed to disorders at higher levels of the auditory pathway. We used cortical auditory evoked potentials to investigate the ability to perceive and discriminate auditory stimuli in 10 unsuccessful implant users aged 8–10 years (CI) and 10 healthy age-matched controls with normal hearing (NH). Pure tones (1 and 2 kHz) and double consonant-vowel syllables were applied. The stimuli were presented in an oddball paradigm that required the subjects to react consciously. The latencies and amplitudes of the P1, N1, P2, N2 and P3 waves were analyzed, in addition to reaction times and number of responses. Significant differences in the average response times and number of responses were observed between the CI and NH groups. The latencies also indicate that the CI group took longer to perceive and discriminate between tonal and speech auditory stimuli than the NH group.     

Development of hearing, speech and language in congenitally deaf infants and children after cochlear implantation

In Japan, universal newborn hearing screening has been partly introduced since 2000 in order to discover neonates with congenital deafness, and the average age at discovery was around five months; however, among infants who were not examined by the universal newborn hearing screening, the average age at discovery was around two years. After fitting hearing aids, congenitally deaf infants are educated in a preschool for speech and hearing. If hearing aids are not effective to develop hearing and speech, cochlear implant surgery is performed as modern technology. The outcome of hearing, speech and language after cochlear implantation was excellent. At the age of elementary school enrollment, most of their verbal IQ was considered to be the same as age-matched normal children. Cochlear implant is the most important treatment at present.     

Allografted fetal dorsal root ganglion neuronal survival in the guinea pig cochlea

Neural grafting is a potential strategy to help restore auditory function following loss of spiral ganglion cells. As a first step towards the reconstruction of a neural pathway from the cochlea to the brainstem, we have examined the survival of fetal dorsal root ganglion (DRG) neurons allografted into the cochlea of adult guinea pigs. In some animals implantation of DRGs was combined with a local infusion of neurotrophic substances whereas in others auditory sensory receptors were chemically destroyed prior to DRG implantation by injection of the ototoxin neomycin into the middle ear. The results show that many transplanted DRG neurons attached close to the cochlear spiral ganglion neurons. The survival of the implant was significantly increased by treatment with neurotrophic factors, but not reduced by the absence of auditory sensory structures. This study shows that implanted sensory neurons can survive heterotopic grafting immediately adjacent to the eighth cranial nerve, thereby providing a basis for further studies of the anatomical and functional influence of neural grafts in the inner ear.     

Auditory and tactile processing in a postmeningitic deaf-blind patient with a cochlear implant

The authors examined the neural function of a postmeningitic deaf-blind patient who regained his hearing with a multichannel cochlear implant. Auditory stimuli activated the temporal cortices of both sides in a manner similar to that of controls, reflecting the successful recruitment of the auditory cortex after implantation. The patient's occipital lobes were deactivated during the tactile language task, the results of which were completely different from those before cochlear implantation.