听神经病患者的临床听力学特点

目的探讨听神经病患者的临床听力学特点。方法自2003年1月～2007年5月共收集到22例听神经病患者的病例。总结听神经病患者的病史、纯音测听、鼓室曲线图、镫骨肌声反射、言语测听、听性脑干反应（auditory brainstem response，ABR）、耳蜗电图（electrocochleogram，ECochG）、畸变产物耳声发射（distortion product otoacoustic emission，DPOAE）及对侧白噪声抑制试验特点。其中10例患者行颅脑核磁共振成像（magnetic resonance imaging，MRI）检查。结果男性患者9例，女性患者13例，发病年龄为10～20岁，表现为进行性双耳听力下降，7例患者伴有耳鸣，最突出的表现是言语识别率差，无噪声接触史和耳毒性药物应用史，无家族史。22例患者听力曲线包括上升型13例，平坦型7例，高频听力下降型2例；鼓室曲线图均为A型；镫骨肌声反射均消失。所有听神经病患者ABR不能引出；全部病例均可记录到DPOAE，但不能被对侧白噪声抑制。耳蜗电图显示17例患者-SP／AP〉0．4，5例患者动作电位（action potential，AP）消失或振幅很小，颅脑MRI检查无异常发现。结论听神经病患者听力学检查有以下共同特点：①双耳进行性听力下降，青少年发病，言语辨别能力甚差，听力损失程度不同，多为轻度到重度，少数为极重度，纯音听力大多为低频下降为主的感音神经性聋，一部分表现为平坦型、甚至高频下降型；②声导抗为“A”型鼓室曲线，镫骨肌声反射引不出；③DPOAE均可引出，耳声发射对侧抑制消失；④ABR引不出或严重异常；⑤影像学检查无任何阳性发现。听神经病的确定目前仍停留于功能性诊断，尚不能确定其病因、病变部位，详尽的听力学检查、典型的听力学表现有助干临床诊断。     

27例听神经病患者的临床特征分析

目的总结探讨听神经病（auditory neuropathy,AN）患者的临床特点和听力学特征。方法回顾性分析27例听神经病患者,并总结其临床资料、纯音听阈、声导抗测试、听性脑干反应与畸变产物耳声发射结果。结果 27例患者中,25例表现为双耳渐进性听力减退,1例表现为渐进性左侧听力下降,1例为查体发现。其中23例伴间断性或持续性耳鸣,3例伴头晕。纯音听力图示上升型感音神经性听力损失。21例患者镫骨肌反射同侧及交叉声反射均未引出,6例镫骨肌反射阈值提高。27例听神经病患者听性脑干反应53耳自波Ⅰ起全部未引出（〉100 dB SPL）。畸变产物耳声发射全部可引出。结论听神经病是一临床表现特殊的感音神经性聋,其病变部位可能位于听神经传入通路,或伴有脑干内侧橄榄耳蜗系统的传出神经通路病变;听神经病的病因及发病机制需进一步探讨研究。     

正常听力耳鸣患者静态导纳值对镫骨肌声反射阈的影响

目的了解声导抗测试法中听力正常耳鸣患者的静态导纳值分布范围,探讨静态导纳值对镫骨肌反射阈的影响。方法将各频率纯音听阈≤15dB HL的听力正常者分为两组：正常组,无耳鸣者114例（228耳）;耳鸣组,有耳鸣者104例（208耳）,分别行鼓室声导纳和镫骨肌反射阈值的测试。结果正常组静态导纳值范围0.16～1.80ml,其中86.84%分布在0.20～1.0ml之间。耳鸣组静态导纳值为0.12～3.08ml,其中74.3%分布在0.20～1.0ml之间。在此范围内,正常组97.37%可引出镫骨肌反射,大部分各频率完全引出。耳鸣组78.83%可引出镫骨肌反射,少部分完全引出,多数仅单个频率引出,或阈值升高。结论正常听力者静态导纳值主要分布在0.20～1.0ml之间,镫骨肌反射完全引出。当静态导纳值超过1.0ml时,随静态导纳值的升高镫骨肌反射引出率下降或存在某些不确定性。     

镫骨肌反射在蜗后病变诊断中的意义

为了确定镫骨肌反射在蜗后病变诊断中的意义,作者对98例听神经鞘瘤患者采用镫骨肌反射进行检查,并与104例蜗内聋患者比较。肿瘤侧镫骨肌反射全部正常5例(5％);1种以上异常93例(95％);所有频率无反射(除外全聋)40例(41％);1～3个频率无反射38例(39％);有反射,但反射阈不对称和/或音衰试验阳性15例(15％)。44％重度耳聋     

以突聋为首发表现的颅内肿瘤病例临床特征分析

目的 描述以突聋为表现的颅内肿瘤病例临床特征,探讨听力学、影像学及实验室检查指标,以便更好的指导临床鉴别诊断,早期确定有效治疗方案.方法 对4例以突聋为首发表现的颅内肿瘤患者的临床资料进行系统性分析,包括临床表现、听力学检查、影像学检查及治疗方法和疗效评估等,归纳总结该病发生发展及转归的特点.结果 4例患者中有3名男性,1名女性,均无明显诱因出现突发性听力下降.其中2例伴有持续高调耳鸣,1例伴有耳鸣及眩晕,1例无耳鸣及眩晕表现.听力学检查结果显示:4例患者颅内占位侧听力均表现为重度或极重度感音神经性聋,镫骨肌声反射均不能引出;3例患者听性脑干反应高低刺激和耳声发射均未引出,声发射均未引出;1例仅见Ⅰ波,耳声发射部分引出反应.前庭功能检查示:1例右侧水平半规管功能低下,1例正常,2例未查.核磁共振检查发现:1例为左侧后颅窝良性肿瘤性病变,表皮样囊肿可能性大;1例为右侧颞叶囊肿;2例为右侧听神经鞘瘤.经系统的耳内科保守治疗后,1例听力基本恢复正常,眩晕症状消失,耳鸣缓解;1例耳鸣缓解;2例无效.结论 在接诊以突发性听力损失为首发症状的患者时,要考虑到有颅内占位性病变的可能性.ABR、声反射检查、言语识别率和前庭功能检查均有重要的提示意义.对于微小听神经瘤,早期可以通过耳内科治疗缓解症状.颅内占位病变的确诊还要依赖CT和MRI检查.     

听神经病听力学分析

目的 探讨听神经病的听觉电生理特点。方法 总结了10例听神经病患者的病史、纯音测听、镫骨肌反射、听性脑干反应（auditory brainstem response,ABR)、耳蜗电图、畸变产物耳声发射（distortion product otoacoustic emission,DPOAE)及对侧白噪声抑制试验、中潜伏期反应和慢皮层反应。5例患者作了颅脑CT或磁共振成像（magnetic resonance imaging,MRI)。结果 患者男女兼有，平均年龄为20．3岁，10余岁的青少年占多数。9例主诉双耳听力下降，1例双耳鸣。纯音测听示19耳为轻度至中度的低频下降型感音神经性听力损失，听力损失最严重的频率为0．5kHz或（和）0．25kHz；1耳听力正常。19耳镫骨肌反射消失，1耳纯音测听为上升型曲线者反射阈提高。ABR不能引出或仅出现波V和（和）波1。全部病例均可记录到DPOAE，但不能被对侧噪声抑制。耳蜗电图示大部分病例动作电位（action potential,AP)消失或振幅很小，负总和电位（negative summating potential,-SP)振幅绝对平均值为0．595μV，慢皮层反应皆正常，6例测中潜伏期反应5例正常。CT或MRI无异常发现。结论 听神经病早期纯音测听可正常，但其镫骨肌反射和ABR消失或阈值升高，其确切病变部位尚不明了，可能位于脑干平面以下的听觉系统。     

各种耳病的镫骨肌肌电描记

镫骨肌反射可通过声阻抗检查获得,但它常随仪器的时间常数、刺激声压及镫骨肌反射通路中的病变而变化。为了得到声反射潜伏期的精确数值,作者对患有面瘫、听神经瘤、分泌性中耳炎、美尼尔氏病、感觉神经性聋及慢性中耳炎的病人,进行了镫骨肌肌电图描记研究。镫骨肌肌作图是通过耳蜗电图平均技术记录下来的。正常的镫骨肌肌电图在声刺激后8～13ms出现一双相波形。与阻抗法测量镫骨肌潜伏期相比,镫骨肌肌电图潜伏期较稳定。对不能用阻抗法测定镫骨肌反射的病人,如鼓膜     

Van der Hoeve综合征导致传导性耳聋1例

1临床资料患者,男,17岁,于2年前无明显诱因出现双耳听力下降,左耳下降为主,呈进行性加重,伴间断性低调耳鸣,无眩晕、恶心、呕吐,无外耳道流水史,自述右下肢骨折4次,左上肢骨折2次,最后1次骨折为4年前。2005年1月来我科就诊,检查：患者发育正常,营养良好,双眼巩膜呈淡蓝色,瞳孔等大等圆,对光反射灵敏,双外耳廓无畸形,双耳道宽敞,双侧鼓膜完整,标志清楚,鼓膜活动好,音叉检查C256：韦伯试验偏左：任内试验左耳（-）右耳（＋）：盖莱实验阴性：纯音听力测试左耳骨导10dB,气导45dB,气骨导差为35dB;右耳骨导10dB,气导30dB,气骨导差为20dB;声导抗左耳为“As”型图,右耳为“A”型图：左耳镫骨肌反射未引出,颞骨CT未见明显异常。患者母亲检查为双巩膜淡蓝色,听力检查正常,自述四肢和肋骨曾多处骨折。诊断Vander Hoeve综合征,又称耳聋、蓝巩膜、脆骨病综合征。于2005年2月在局麻下行镫骨钻孔活塞术,     

婴幼儿单侧听神经瘤

目的：探讨婴幼儿单侧听神经病（AN）神经生理学特点。方法：对3例单侧AN患儿在采集病史和耳科检查的基础上,行系统的听力学检查,包括声阻抗、镫骨肌反射、听性脑干反应（ABR）、耳蜗微音电位（CM）、诱发耳声发射（EOAE）、中潜伏期反应（MLR）和事件相关电位（ERP）以及CT和（或）MRI及周围神经系统检查。结果：3例患儿鼓室图均呈“A”型,健耳的同侧和交叉镫骨肌反射可正常引出,而患耳的同侧和交叉镫骨肌反射未引出。3例患儿双侧EOAE有效引出,健耳的ABR正常引出,思耳的ABR未引出,但CM均正常。3例患儿双耳均记录到MLR及ERP。影像学和周围神经系统未见异常。结论：单侧AN与双侧AN有相似的神经生理学特点。对婴幼儿单侧AN的诊断应着重分析其神经生理学特点,建议联合应用EOAE、ABR、CM和影像学检查。应对AN患儿定期随访。     

听神经病听力学分析

目的　探讨听神经病的听觉电生理特点。方法　总结了 10例听神经病患者的病史、纯音测听、镫骨肌反射、听性脑干反应 (auditorybrainstemresponse ,ABR)、耳蜗电图、畸变产物耳声发射(distortionproductotoacousticemission ,DPOAE)及对侧白噪声抑制试验、中潜伏期反应和慢皮层反应。 5例患者作了颅脑CT或磁共振成像 (magneticresonanceimaging ,MRI)。结果　患者男女兼有 ,平均年龄为 2 0 3岁 ,10余岁的青少年占多数。 9例主诉双耳听力下降 ,1例双耳鸣。纯音测听示 19耳为轻度至中度的低频下降型感音神经性听力损失 ,听力损失最严重的频率为 0 5kHz或 (和 ) 0 2 5kHz;1耳听力正常。 19耳镫骨肌反射消失 ,1耳纯音测听为上升型曲线者反射阈提高。ABR不能引出或仅出现波Ⅴ或 (和 )波Ⅰ。全部病例均可记录到DPOAE ,但不能被对侧噪声抑制。耳蜗电图示大部分病例动作电位 (actionpotential,AP)消失或振幅很小 ,负总和电位 (negativesummatingpotential,-SP)振幅绝对平均值为 0 5 95 μV ,慢皮层反应皆正常 ,6例测中潜伏期反应 5例正常。CT或MRI无异常发现。 结论听神经病早期纯音测听可正常 ,但其镫骨肌反射和ABR消失或阈值升高 ,其确切病变部位尚不明了 ,可能位于脑干平面以下的听觉系统     

Influence of acoustic deprivation on recovery of hair cells after acoustic trauma

The purpose of this study was to investigate how the recovery of the cochlea, after acoustic trauma, might be influenced by acoustic stimulation or deprivation. In anaesthetized adult chinchillas, both ears were simultaneously exposed to a traumatizing acoustic stimulus (2 kHz tone, at 117 dB SPL for 15 min). Probe microphones positioned in both bullae were used to ensure identical exposure to the two ears; this was important because the experiment relies on within-animal controls. Cochlear action potential thresholds across frequency (CAP audiograms) were used to verify the similarity of threshold shifts to the two ears. Immediately following, a unilateral ossiculectomy was performed which resulted in one cochlea being acoustically deprived during the recovery period, whilst the other was not. In groups of animals with recovery periods of 1, 3, 6 and 12 weeks, both the acoustically deprived and the normally stimulated cochleas were examined with scanning electron microscopy. To quantify hair cell damage, we used a damage scale based on stereociliar integrity; for each cochlea, a standard region 5.5–8.5 mm from the apex was studied in detail. We found that after acoustic trauma, hair cell damage to the cochlea which is deprived of sound during the recovery period, is significantly greater compared with that in the normally stimulated, contra-lateral cochlea. Our results suggest that mechanical activation of the inner ear acts to inhibit long-term degenerative processes, or influence repair of partially damaged hair cells.     

Management of acoustic schwannoma

PURPOSE: To discuss the optimal management for patients with acoustic schwannoma. MATERIALS AND METHODS: Review of the pertinent literature. RESULTS: Microsurgery, stereotactic radiosurgery, and fractionated radiotherapy result in cure rates that approximate 90% at 5 years. Depending on tumor extent and surgical approach, the morbidity of microsurgery may exceed that of stereotactic radiosurgery and fractionated radiotherapy. Patients with useful hearing before treatment may have a higher likelihood of hearing preservation after radiotherapy compared with radiosurgery. CONCLUSION: Both microsurgery and radiosurgery are good options for patients with tumors less than 3 cm. Depending on tumor extent and the surgical approach, the morbidity of microsurgery may exceed that of radiosurgery. Patients with useful hearing may have a higher likelihood of hearing preservation after radiotherapy. Microsurgery is preferred for patients in whom the disease progresses after initial irradiation and in patients with tumors larger than 3 cm.     

Accuracy of acoustic rhinometry

OBJECTIVES: The objective of this study was to evaluate the ability of acoustic rhinometry (AR) (Rhin2100, Rhinometrics, Lynge, Denmark) to accurately determine the dimensions (cross-sectional areas and volumes) of the curved and complex slit-like geometry of the nasal airway. MATERIALS AND METHODS: A plastic model representing the replicate of a decongested nasal airway was produced by stereolithographic techniques from a 3-D MRI-scan. The exact dimensions of this model was determined from a high resolution CT-scan. Dimensions perpendicular to the curved course of the acoustic pathway were compared with dimensions inferred from parallel sections. The impact of sound loss to the paranasal sinuses and the ability to detect posterior volume changes was tested in the same model. RESULTS: The error in volume determination was < 14% for the MCA and < 8% for the volumes, whereas the error reached 52% for dimensions calculated from parallel sections in the coronal plane. The influence of the simulated maxillary sinuses depend primarily on the size of the ostia and may represent an important source of error for posterior measurements, in particular after decongestion. CONCLUSIONS: The accuracy of acoustically derived dimensions of the 3-D model depend on the orientation of the planes used to calculate the dimensions of the model. Volume estimates based on the smallest cross-sectional areas in points along the acoustic pathway correlate well with acoustically derived volumes, whereas single cross-sectional areas are more susceptible to error. Sound leakage to patent sinus ostia reduce the accuracy of posterior measurements.     

Epidemiology of acoustic neuromas

In Denmark one surgical team, during the last 7 years, has performed about 80 per cent of all acoustic neuroma surgery. Because of this centralization, in such a limited population as that of Denmark, we have attempted to make a epidemiological survey of all diagnosed tumours in the period from 1976 to 1983. Systematic and prospective records were made by the authors of all patients with translabyrinthine operations, and data on patients with suboccipital operations were collected retrospectively from the six neurosurgical departments in Denmark. The average annual incidence was 8 tumours per million inhabitants, with the highest incidence of approximately 13 tumours per million occurring in Copenhagen County. The incidence reported in previously published autopsy series is 800-900 times higher and the following may serve as an explanation for this enormous difference: Autopsy series are in all probability based on highly selected cases; they are predominantly based on elderly people and the incidence is not directly applicable to the population at large. Several of the silent tumours from the autopsy series were located in the cochlea or in the labyrinth and not in the internal ear canal. The conclusion from our study is that both the knowledge and data available at present are insufficient to serve as a basis for an actual calculation of incidence and prevalence of acoustic neuromas.(ABSTRACT TRUNCATED AT 250 WORDS)