小儿蜗神经发育不良

目的报道一组蜗神经发育不良(cochlear nerve deficiency,CND)小儿的临床特征,以提高对本病的认识。方法回顾性分析2007年1月到2008年4月就诊的、内耳MRI及听力学资料完整的20例(37耳)CND小儿(其中男13例,女7例,年龄10个月到4岁)的影像学、听力学表现及人工耳蜗植入效果。结果 85%(17/20)的患儿为双侧发病,15%(3/20)为单侧发病;16.22%(6/37)合并前庭神经发育异常,8.11%(3/37)合并面神经发育异常。根据是否伴有内耳畸形分为三组:32.43%(12/37)伴耳蜗畸形或同时伴有前庭畸形(第一组);13.51%(5/37)仅伴前庭畸形(第二组);54.05%(20/37)独立发病,不伴内耳畸形(第三组)。听力学测试结果:86.49%(32/37)ABR最大输出(100 dB nHL)无反应,13.51%(5/37)在非常高的刺激强度仅有分化不良的波Ⅴ;9耳有行为听阈结果者均为极重度感音神经性聋;第一组12耳DPOAE和CM均未引出,第二组60%(3/5)DPOAE和CM均未引出,40%(2/5)DPOAE和/或CM引出;第三组45%(9/20耳)DPOAE和CM均未引出,55%(11/20耳)DPOAE和/或CM引出。人工耳蜗植入效果:2例术前、术后资料完整者中1例术后开机一年婴幼儿有意义听觉整合量表(infant and toddler meaningful auditory integration scale,IT-MAIS)评估得分与蜗性聋儿相当,另1例无效。结论 CND患儿多无特殊病史,根据是否伴有内耳畸形及内耳畸形的种类,其听力学表现多样,诊断主要依据影像学检查,应注意鉴别诊断,以便制定合理有效的干预措施。     

小儿听神经病的误诊和漏诊

目的:探讨小儿听神经病的临床表现。方法:对一组年龄为4～68个月,听力学检查表现为听神经病患儿的临床资料进行回顾性研究。受试者的入选标准为短声听觉脑干反应(ABR)严重异常而畸变产物耳声发射(DPOAE)和(或)耳蜗微音电位(CM)正常。分析其短声ABR、DPOAE、行为听力测试、声导纳以及内耳MRI等结果。结果:①40例听力学表现为双侧听神经病,8例为单侧;②68.2%耳(60/88)在短声ABR的最大输出强度100dBnHL无反应,而有些耳仅在很高的测试强度有波形分化较差的Ⅴ波;③所有耳均可记录到CM,而只有41.5%能记录到DPOAE;④该组患儿的行为听力结果各种各样,为从轻度到极重度的听力损失;⑤4例经内耳MRI诊断为蜗神经发育不全。结论:在听力学表现为听神经病的儿童:①CM的诊断敏感度较DPOAE高;②各种客观听力测试无法预估行为听力;③需作内耳MRI检查,以除外蜗神经发育不全。     

蜗神经发育不良患者的听力学特征分析

目的探讨蜗神经发育不良(cochlear nerve deficiency,CND)患者的听力学特征。方法以30例(54耳)(男14例,女16例,年龄6月~29岁,平均4.9岁)内听道斜矢状位磁共振成像示蜗神经发育不良的患者为研究对象,回顾性分析患者的纯音测听或行为测听、声导抗、耳声发射、听性脑干反应(ABR)、听性稳态反应等听力学检测结果及颞骨高分辨CT(HRCT)结果,分析蜗神经发育异常者的听力学特征。结果 30例54耳蜗神经发育不良患者中,双侧24例(80%),单侧6例(20%),其中蜗神经缺如33耳,蜗神经细小21耳。54耳中,共有25耳(46.29%)伴内耳畸形,而单侧蜗神经发育不良者的对侧6耳中,50%(3耳)伴内耳畸形。纯音测听或行为测听和听性稳态反应结果均提示蜗神经发育不良患耳呈重度-极重度听力损失,且蜗神经缺如耳较蜗神经细小耳的听力损失程度更重。11耳(20.37%,11/54)蜗神经发育不良耳可在80~100 dB nHL高强度声刺激下引出听性脑干反应;6例双侧蜗神经发育不良者(20.0%,6/30)中7耳(1例双耳,5例单耳)全部频率或部分频率引出DPOAE,但其中5耳未引出ABR,2耳分别于100和90 dB nHL刺激声强下引出ABR。结论蜗神经发育不良患者常表现为重度-极重度听力损失,近一半伴内耳畸形,部分患耳可引出DPOAE,而ABR严重异常或缺失。     

耳蜗神经发育不良听神经病谱系障碍患者听力学分析

目的分析中国听神经病谱系障碍患者蜗神经的发育情况,进一步探讨中国听神经病谱系障碍患者的相关影像学特征。方法本研究以19例行内听道斜矢状位高分辨核磁共振成像的听神经病谱系障碍患者为研究对象,进行详细的病史采集和听力学检测。纯音测听检测、声导抗检测、听性脑干反应、DPOAE检测、言语识别率检测等,回顾性分析听神经病谱系障碍患者的蜗神经影像学特征,并探讨蜗神经发育异常患者的听力学特征。结果本研究的19例听神经病谱系障碍患者中,共发现4例蜗神经发育异常的患者,所占比例为21.05(4/19)。4例患者在内听道斜矢状位MRI上均表现为双侧蜗神经细小。其中,2例患者有耳聋家族史,1例患者伴有共济失调障碍。4例蜗神经发育异常的患者听力曲线类型各异:2例患者表现为全频中度下降的平坦型听力曲线,1例表现为中重度低频上升型听力曲线,另外1例表现为中重度的高频下降型听力曲线。4人(8耳)的言语识别率均较差,除1耳外,其余7耳的言语识别率均低于40%。结论对于听神经病谱系障碍的患者,若条件允许的情况下,应常规行内听道斜矢状位高分辨核磁共振成像,以评价蜗神经粗细及发育情况,对于了解听神经病谱系障碍患者的病变部位和病因。     

蜗神经发育不良患者的人工耳蜗植入

目的:观察蜗神经发育不良的患儿人工耳蜗植入术后的效果,探讨术前HRCT和MRI对蜗神经发育不良的诊断及评估价值。方法:回顾性分析10例蜗神经发育不良患儿的术前影像学资料及人工耳蜗植入术后对声音的反应和语训效果。结果:3例(6耳)HRCT提示双侧内耳道狭窄,耳蜗、前庭和半规管发育正常,MRI提示蜗神经发育不良。7例(14耳)HRCT提示双侧内耳道正常,其中1例IP-Ⅰ型,伴前庭半规管发育不良,6例双侧耳蜗、前庭和半规管发育正常;7例MRI提示蜗神经发育异常。10例患儿均行人工耳蜗植入,经过12～32个月的随访,3例学会简单语言,MAIS量表、CAP分数及SIR分级较前提高;1例虽能讲话,但口齿含糊;4例对声音有反应,仅能说"爸爸"、"妈妈"等单音节词;2例无反应(1例取出)。10例蜗神经发育不良患儿同其他蜗神经发育正常儿童相比,术后康复情况明显落后。结论:对蜗神经缺陷患儿,术前仅做颞骨HRCT检查易漏诊,结合内耳道MRI(含内耳道斜矢状位重建)已成必须。若发现疑似病例,应慎重筛选,告知行人工耳蜗植入效果不佳的巨大可能性,严格掌握手术指征。     

1例耳蜗前庭神经畸形患者耳蜗植入术前的功能性磁共振评估并文献复习

目的:探讨功能性磁共振(fMRI)评价耳蜗前庭神经畸形患者是否有人工耳蜗植入指征的可能性。方法:对1例15岁双侧耳聋患者,在人工耳蜗植入前进行听力学、影像学检查及fMRI综合评估。结果:纯音测听和听觉脑干反应显示患者为双侧极重度感音神经性聋,瞬态诱发性耳声发射双侧均未引出。颞骨薄层CT显示内耳畸形(不全分隔Ⅰ型),MRI斜矢状位重建显示耳蜗前庭神经畸形。fMRI显示左耳给声,1000Hz100dBHL,右侧听皮层被激活;右耳给声,双侧听皮层均未见激活。左侧人工耳蜗植入术后1个月开机,患者对声音有反应。结论:结合听力学和影像学检查,fMRI可评估人工耳蜗植入候选者,尤其是在影像学检查显示患者耳蜗前庭神经发育畸形时,更是一种有效的评估方法。     

蜗神经磁共振成像在感音神经性聋中的应用

目的探讨蜗神经磁共振成像在感音神经性聋(SNHL)中的应用价值。方法采用GE TwinExct1.5T磁共振扫描仪对130例(260耳)SNHL患者进行蜗神经磁共振成像及内耳水成像。蜗神经成像序列为斜矢状位FRFSET2加权像,内耳水成像为3DFIESTA序列。结果 90例大于等于18岁的患者中,85例170耳显示蜗神经、迷路正常;1例2耳前庭导水管扩大;1例1耳蜗神经信号缺失;3例6耳蜗神经细小;40例小于18岁的患者中,19例38耳显示蜗神经、迷路正常;2例3耳Michel畸形;6例12耳Mondini畸形;1例2耳共腔畸形;12例24耳前庭导水管扩大;21例畸形中7例14耳蜗神经信号缺失。2例4耳显示内听道狭窄伴蜗神经细小。结论磁共振内耳成像对诊断SNHL有着重要的价值,对判断患者内耳蜗神经发育情况及内耳畸形有着不可替代的作用,是这类患者进行人工耳蜗植入术前必要检查。     

耳蜗性耳硬化症人工耳蜗植入的应用研究

分析耳蜗性耳硬化症患者的临床特点、人工耳蜗植入术中情况及人工耳蜗植入术后听觉言语康复效果,为该疾病的诊治提供参考。方法分析4例耳蜗性耳硬化症患者病史资料、听力学检查结果及影像学结果,观察人工耳蜗植入手术的术中所见,并定期对4例患者进行听力学及影像学随访。结果①所有患者人工耳蜗电极均经圆窗膜径路完全植入鼓阶。其中1例于术中发现镫骨完全固定,导致术中鼓阶开孔时外淋巴波动不明显;1例发现圆窗膜骨化,术中鼓阶开孔定位困难;其余2例患者镫骨活动好,圆窗结构清晰。所有患者术中电极阻抗检测均正常,且引出标准的神经反应遥测波形;②术后随访1~5年无术后并发症出现,声场测听示平均听阈为40.8 dBHL,平均言语识别率为77.3%,言语及交流能力较术前提高;颞骨高分辨率CT提示双侧内耳病变范围无明显进展。结论耳蜗性耳硬化症进展缓慢,严重时可导致重度/极重度感音神经性聋,当使用助听器无效时,人工耳蜗植入能帮助患者获得较满意的听觉康复效果。     

听神经病谱系障碍患者的临床及听力学特征分析

目的探讨听神经病谱系障碍(auditory neuropathy spectrum disorder,ANSD)的临床和听力学特征。方法分析14例(22耳)ANSD患者的临床资料及听力学检查结果,14例均行声导抗测试、听性脑干反应(auditory brainstem re-sponse,ABR)测试及畸变产物耳声发射(distortion product otoacoustic emission,DPOAE)测试,9例行纯音听阈测试,6例行听性稳态反应(auditory steady-state response,ASSR)测试。5例行颞骨薄层CT检查,9例行MRI检查。结果 14例(22耳)患者中,双侧ANSD 8例,单侧ANSD 6例。9例(14耳)行纯音测听的患者听力图以低频损失为主呈上升型7耳(占50%),覆盆型2耳(占14.29%),平坦型1耳(占7.14%),下降型1耳(占7.14%),全聋型3耳(占21.43%)。低频组(250Hz、500Hz)的平均阈值较中(1k Hz、2k Hz)、高频组(4k Hz、8k Hz)明显升高。声导抗鼓室图均为A型,镫骨肌反射消失。11例(6例单侧ANSD,共16耳)ABR未引出;其余3例(共6耳)ABR严重异常。14例DPOAE均正常引出。6例(9耳)ASSR结果均为极重度聋。结论 ANSD的临床表现具有明显的个体差异,这种个体差异产生的原因目前尚无法确定。对疑似ANSD的感音神经性聋患者,应行全面的听力学检查以明确诊断,对确诊的患者应定期随访。     

听神经病人工耳蜗植入术中EABR监测及其疗效评估

目的:探讨听神经病的病变部位并观察听神经病人工耳蜗植入术后的疗效。方法:选择在我院行人工耳蜗植入术的8例听神经病患者,同时筛选背景接近的8例非听神经病极重度聋人工耳蜗植入患者作为对照组进行配对。回顾性分析2组患者术前听力学资料;术中耳蜗植入前采用自制电极行电刺激听性脑干诱发反应(EABR)评估听觉通路;植入后检测神经反应遥测(NRT)、EABR;并随访术后调机T、C值,采用听觉行为分级标准(CAP)、言语可懂度分级标准、言语识别率评估术前和开机后1年时听力言语情况。结果:8例听神经病患者术中植入前均可引出EABR波形,但是波形较正常有变异,需要刺激量加大或者调整参数,Ⅴ波潜伏期长短不一;植入耳蜗后NRT反应好,EABR和术中测试波形接近。术后开机均有听性反应,随访开机T、C值与对照组差异无统计学意义;听神经病组患者术前及开机1年CAP分别为6.50±0.94和6.90±0.77,言语识别率(双字词)分别为(85.00±11.66)%和(89.50±9.02)%,与对照组比较差异无统计学意义。结论:术前EABR可以做为评估听神经病(听同步不良患者)听觉通路的有效工具,筛选合适植入者;人工耳蜗可以帮助听神经病患者提高听力及言语能力。     

Idiopathic Intracranial Hypertension Presenting as Auditory Neuropathy Hearing Disorder in a Child

Otologic manifestations are known to occur in patients with idiopathic intracranial hypertension (IIH), but the occurrence of sensorineural hearing loss, especially in pediatric populations, has been addressed in only a few reports. Here, we describe a pediatric patient who presented with IIH and severe bilateral hearing loss. The patient's hearing loss was diagnosed as a form of auditory neuropathy (AN) and resolved after prompt treatment of the increased intracranial pressure. This case points to a possible association between IIH and AN and suggests that IIH may potentially be a reversible cause of AN spectrum disorder. Laryngoscope, 129:E407–E411, 2019     

Consequences of neural asynchrony: A case of auditory neuropathy

Abstract The neural representation of sensory events depends upon neural synchrony. Auditory neuropathy, a disorder of stimulus-timing-related neural synchrony, provides a model for studying the role of synchrony in auditory perception. This article presents electrophysiological and behavioral data from a rare case of auditory neuropathy in a woman with normal hearing thresholds, making it possible to separate audibility from neuropathy. The experimental results, which encompass a wide range of auditory perceptual abilities and neurophysiologic responses to sound, provide new information linking neural synchrony with auditory perception. Findings illustrate that optimal eighth nerve and auditory brainstem synchrony do not appear to be essential for understanding speech in quiet listening situations. However, synchrony is critical for understanding speech in the presence of noise.     

The auditory characteristics of children with inner auditory canal stenosis

Conclusions This study shows that the prevalence of auditory neuropathy spectrum disorder (ANSD) in the children with inner auditory canal (IAC) stenosis is much higher than those without IAC stenosis, regardless of whether they have other inner ear anomalies. In addition, the auditory characteristics of ANSD with IAC stenosis are significantly different from those of ANSD without any middle and inner ear malformations. Objectives To describe the auditory characteristics in children with IAC stenosis as well as to examine whether the narrow inner auditory canal is associated with ANSD. Method A total of 21 children, with inner auditory canal stenosis, participated in this study. A series of auditory tests were measured. Meanwhile, a comparative study was conducted on the auditory characteristics of ANSD, based on whether the children were associated with isolated IAC stenosis. Results Wave V in the ABR was not observed in all the patients, while cochlear microphonic (CM) response was detected in 81.1% ears with stenotic IAC. Sixteen of 19 (84.2%) ears with isolated IAC stenosis had CM response present on auditory brainstem responses (ABR) waveforms. There was no significant difference in ANSD characteristics between the children with and without isolated IAC stenosis.     

Auditory and speech performance in cochlear implanted ANSD children

Background: Auditory neuropathy spectrum disorder (ANSD) is a distinct type of SNHL that is characterized by the presence of otoacoustic emissions and/or cochlear microphonics. Cochlear implantation was initially not recommended for ANSD children, later studies showed variable outcomes among those subjects.

Objective: To assess the auditory and speech performance of cochlear implanted children with auditory neuropathy spectrum disorder (ANSD) and to compare these results to those obtained from cochlear implanted children with sensorineural hearing loss (SNHL)

Material and methods: 18 cochlear implanted children with ANSD and 40 cochlear implanted children with SNHL were included in this study. Auditory and speech performance results were compared across both subject groups using the Category of Auditory Performance (CAP) and Speech Intelligibility Rate (SIR) tests, with measurements recorded one year post implantation.

Results: Cochlear implanted children with ANSD showed clinically significant improvements that were comparable to those observed from cochlear implanted subjects without ANSD.

Conclusions: Children with ANSD benefit from early cochlear implantation and can reach similar auditory and speech performance results as that achieved by children without ANSD.     

Practical guidelines to minimise language and cognitive confounds in the diagnosis of CAPD: a brief tutorial

Objective: To provide audiologists with strategies to minimise confounding cognitive and language processing variables and accurately diagnose central auditory processing disorder (CAPD). Design: Tutorial. Study sample: None. Results: Strategies are reviewed to minimise confounding cognitive and language processing variables and accurately diagnose CAPD. Conclusions: Differential diagnosis is exceedingly important and can be quite challenging. Distinguishing between two or more conditions presenting with similar symptoms or attributes requires multidisciplinary, comprehensive assessment. To ensure appropriate interventions, the audiologist is a member of the multidisciplinary team responsible for determining whether there is an auditory component to other presenting deficits or whether one condition is responsible for the symptoms seen in another. Choice of tests should be guided both by the symptoms of the affected individual, as established in an in-depth interview and case history, the individual’s age and primary language, and by the specific deficits reported to be associated with specific clinical presentations. Knowing which tests are available, their strengths and limitations, the processes assessed, task and response requirements, and the areas of the central auditory nervous system (CANS) to which each test is most sensitive provides the audiologist with critical information to assist in the differential diagnostic process.     

A Dominantly Inherited Progressive Deafness Affecting Distal Auditory Nerve and Hair Cells

We have studied 72 members belonging to a large kindred with a hearing disorder inherited in an autosomal dominant pattern. We used audiological, physiological, and psychoacoustic measures to characterize the hearing disorders. The initial phenotypic features of the hearing loss are of an auditory neuropathy (AN) with abnormal auditory nerve and brainstem responses (ABRs) and normal outer hair cell functions [otoacoustic emissions (OAEs) and cochlear microphonics (CMs)]. Psychoacoustic studies revealed profound abnormalities of auditory temporal processes (gap detection, amplitude modulation detection, speech discrimination) and frequency processes (difference limens) beyond that seen in hearing impairment accompanying cochlear sensory disorders. The hearing loss progresses over 10–20 years to also involve outer hair cells, producing a profound sensorineural hearing loss with absent ABRs and OAEs. Affected family members do not have evidence of other cranial or peripheral neuropathies. There was a marked improvement of auditory functions in three affected family members studied after cochlear implantation with return of electrically evoked auditory brainstem responses (EABRs), auditory temporal processes, and speech recognition. These findings are compatible with a distal auditory nerve disorder affecting one or all of the components in the auditory periphery including terminal auditory nerve dendrites, inner hair cells, and the synapses between inner hair cells and auditory nerve. There is relative sparing of auditory ganglion cells and their axons.     

Activity influences on neuronal connectivity within the auditory pathway

HYPOTHESIS: Sensorineural hearing loss may be associated with altered patterns of neuronal connections within the central auditory pathway. STUDY DESIGN: The cat auditory system was used to address the relative importance of impulse traffic within the auditory nerve in maintaining central nervous system connections. METHODS: Acute, unilateral deafness was induced by tetrodotoxin intoxication of cochlear hair cells. Analysis focused on the structural patterns of contact between auditory nerve endings called end bulbs of Held and their target neurons. Specifically, end bulb morphology and target cell size within the cochlear nucleus were examined. Highly specialized synaptic contacts at this junction provide a powerful site for study. RESULTS: The principal finding was that abolished activity in the auditory nerve caused nerve endings to assume a different shape, typified by more branching and smaller terminal swellings. The new shape is one typically associated with only a subpopulation of fibers in normal-hearing cats--those exhibiting a high-threshold, low-spontaneous activity profile. This result implies that abolished activity alters patterns of nerve fiber contact with second-order neurons. Tetrodotoxin produced differential effects on subpopulations of target neurons within the brainstem and is interpretable on the basis of "weighing" synaptic inputs. Second-order neurons that receive large axosomatic inputs from their parent fiber were significantly smaller than neurons that receive small, axodendritic terminals. Thus, attenuated auditory activity may produce differential effects across the auditory pathway, thereby disrupting the normal balance of inputs into synaptic stations. CONCLUSIONS: Impulse traffic is a critical factor in the interaction between the ear and central auditory stations and appears necessary for the maintenance of key synapses. As hearing disorders with impaired comprehension may be modeled by studies of auditory deafferentation, these observations extend the possibility that changes in central neuronal connections underlie reduced capabilities for processing restored auditory input.     

听神经病谱系障碍患者的内科药物综合治疗及疗效分析

目的：分析听神经病谱系障碍患者经内科药物综合治疗的临床疗效以及相关因素对预后的影响。方法：对11例（22耳）经纯音测听、声导抗、畸变产物耳声发射、听性脑干反应测试确诊为听神经病谱系障碍者（治疗组）予以内科药物综合治疗,同时选取同期就诊但未接受治疗的11例听神经病谱系障碍患者作为对照组,分析比较治疗组治疗前后和对照组患者随诊前后的纯音听阈和言语识别率变化,并分析患者的性别、年龄和伴随症状与疗效的关系。统计数据应用SPSS19．0行配对样本t检验、独立样本t检验和Pearson相关分析。结果：经内科药物综合治疗后,治疗组22耳中,治疗有效13耳,有效率为59．09％。治疗组22耳平均纯音听阈由治疗前的（53．92±18．86）dBHI。提升至（47．44±14．98）dBHL,差异有统计学意义（t=5．20,P〈0．05）;而对照组听力无明显变化（P〉0．05）。治疗组言语识别率治疗前后分别为（29．20±25．80）％和（41．60±22．90）％,平均提高（12．40±13．80）％,差异有统计学意义（t=4．02,P〈0．05）。伴有耳鸣症状者疗效较无耳鸣症状者差（t=-3．85,P〈0．05）,发病年龄和疗效呈负相关（r=-6．72,P〈0．05）,而疗效未见性别差异（P〉0．05）。结论：听神经病谱系障碍患者应用糖皮质激素等内科药物综合治疗可有效改善其纯音听阈和言语识别率,内科药物综合治疗可作为听神经病谱系障碍治疗的可选方案。