听觉脑干置入用于双侧听神经瘤全聋患者的听力康复(附1例报告)

目的：探讨听觉脑干置入（ABI）用于双侧听神经瘤全聋患者的听力康复。方法：对1例双侧听神经瘤全聋患者，在经乙状窦枕下径路切除第2侧听神经瘤时，同期将12道听觉脑干装置的电极阵置入第4脑室的侧隐窝内，术中行第Ⅶ、Ⅸ脑神经监测，并且记录电刺激脑干诱发电位，以确定和校正电极位置。术后2个月开通电极并作调试。结果：术后头颅X线侧位片示电极位置正确，术后开通调试发现电刺激12个电极均能引起听觉反应，无一电极引起非听觉反应。结论：多道ABI能让双侧听神经瘤全聋患者产生有意义的听觉。术中电极阵准确地置入到脑干耳蜗核是手术成功的关键。     

多道听觉脑干植入的临床应用

目的　探讨多道听觉脑干植入的手术方法及其对恢复双侧听神经瘤所致全聋患者听力的效果。方法　 7例双侧听神经瘤患者 ,在肿瘤摘除后将 2 1道听觉脑干植入 (auditorybrainstemimplant,ABI)电极植入于第四脑室外侧隐窝内 ,直接刺激脑干耳蜗核 ,术中以面神经电图、舌咽神经肌电图及电诱发听觉脑干反应 (electricallyevokedauditorybrainstemresponses,EABR)确定电极的正确位置。术后 6周开通装置并调试 ,定期行言语识别能力测试。结果　 6例患者术中均能准确定位外侧隐窝 ,并能记录到典型的EABR ;术后均能获得不同程度的言语识别能力 ,其中 2例获得开放句识别能力。另 1例患者术中解剖定位困难 ,术中未能记录到EABR。术后电极刺激 1例无非听觉反应、5例部分电极产生非听觉反应、1例全部电极均产生非听觉反应 ,有非听觉反应的相应电极被关闭。结论　多道听觉脑干植入能使因双侧听神经瘤而全聋的患者产生有意义的听觉 ,术中正确定位脑干耳蜗核为手术成功的关键。     

多道听觉脑干植入的临床应用

目的 探讨多道听觉脑干植入的手术方法及其对恢复双侧听神经瘤所致全聋患者听力的效果。方法 ７例双侧听神经瘤患者,在肿瘤摘除后将２１道听觉脑干植入（ａｕｄｉｔｏｒｙ ｂｒａｉｎｓｔｅｍ ｉｍｐｌａｎｔ,ＡＢＩ）电极植入于第四脑室外侧陷内,直接刺激脑干耳蜗术休中以面神经电图,舌咽神经肌电图及电诱发听觉脑干反应（ｅｌｅｃｔｒｉｃａｌｌｙ ｃｖｏｋｅｄ ａｕｄｉｔｏｒｙ ｂｒａｉｎｓｔｅｍ ｒｅｓｐｏｎｓｅ     

听觉脑干植入的临床应用

听觉脑干植入 (auditorybrainstemimplant,ABI)可使听神经损伤患者有效恢复听力 ,本文从发展历史、装置组成、病例选择、手术操作、术后效果、发展前景等方面对ABI做一综述。ABI由语言处理器、接受 /刺激器、脑干电极组成 ,双侧听神经瘤患者是主要植入者 ;因解剖位置特殊 ,ABI术中须做电生理监测以辅助电极放置 ;在术后言语处理器编程中 ,着重对非听感觉和电极特异性听觉进行调试处理 ;插入式电极是以后ABI电极的发展方向     

神经纤维瘤病 Ⅱ 型的临床特点及听觉脑干植入

目的 探讨神经纤维瘤病Ⅱ型(neurofibromatosis type 2,NF2)的临床特点、治疗方法以及听觉脑干植入(auditory brainstem implant,ABI)后的效果.方法 回顾性分析1例双侧听神经瘤(NF2)患者的诊疗经过及ABI术后6、9、12、24、36个月的听力言语康复效果.结果 患者,男,13岁,因右耳听力下降及耳鸣3年伴步态不稳,声音嘶哑就诊,患者曾接受过腰椎椎管内神经纤维瘤切除病史,MRI检查示双侧桥小脑角区占位病变,临床诊断为NF2;经fishey入路分次切除双侧听神经瘤,术后病理诊断均为神经鞘膜瘤,术后2年行左耳ABI手术,ABI术后又先后接受过气管神经纤维瘤、腹膜后细胞性神经鞘瘤切除术.ABI术后开机调试时所有电极均能引出听觉反应,随着康复时间的延长,患者对自然环境声响、元音、单音节词的正确识别率均呈上升趋势,纯音听阈值逐渐降低,术后6、9、12、24、36个月元音的正确识别率分别为14%、18%、20%、24%、35%,单字词的正确识别率分别为5%、7%、10%、14%、20%;但双音节词及开放语句识别率均为0.结论 NF2多发生在青少年,治疗应遵循个体化原则,手术切除双侧听神经瘤仍是首选的方法,ABI对于双侧听神经瘤切除术后患者听力重建是一种很好的选择,术中准确定位耳蜗核是手术成功的关键.     

听觉脑干植入

听觉脑干植入(ABI)是人工耳蜗植入技术的一种进展,其工作原理与人工耳蜗类似,不同的是人工耳蜗通过电极刺激耳蜗内的听神经纤维而获得听觉,而ABI是将电极越过耳蜗和听神经直接刺激脑干耳蜗核复合体的听神经元产生听觉.就ABI的适应证及禁忌证、手术入路及手术方法、手术并发症以及植入后听力改善的效果等方面进行概述.     

听觉脑干电极植入

听觉脑干电极植入(ABI)为一些因失去完整的蜗神经功能而不适于电子耳蜗植入的深度耳聋患者,如二型神经纤维瘤病继发听神经瘤的患者,提供了一种安全、有效的听力康复手段。目前世界上已有约150例患者接受了多导ABI植入。ABI可为这些耳聋患者提供有用的听觉信息,多数患者植入ABI后可感知环境声音,其交流能力和言语识别力得到改善,一些患者对开放性言语亦可获得一定的理解能力。ABI在其病例选择、植入方式、装置的启动及随访等方面均与电子耳蜗植入有所不同,本文将就此进行概述。     

神经纤维瘤病型的中枢听觉通路电刺激

神经纤维瘤病型(NF2)通常表现为双侧前庭神经鞘膜瘤、疾病本身发展或由手术引起耳蜗神经损害而导致完全性耳聋。在某些病例有可能通过部分切除肿瘤而保留部分听力,但这也只是权宜之计。下面介绍一种较新的治疗手段,即通过类似人工耳蜗的听觉脑干植入(ABI),以直接刺激中枢听觉通路而重新获得听觉。该手段已取得较明显的效果。House于80年代初首次将一个单导ABI装置植入体内,取得一定效果。以后发展为多通道ABI。目前的多通道ABI装置主要有两种型号:欧洲型和美国型。两者主要区别在于电极的数目不同。美国型的装置有8个电极;而欧洲型有2…     

人工听觉的过去现在和未来

电诱发人工听觉(简称人工听觉)通过电刺激听觉神经来恢复、提高或重建人的听觉功能。电刺激听神经包括早期使用的单电极及目前使用的多电极人工耳蜗植入，以及结合低频残存声听觉的短电极耳蜗植入。人工耳蜗植入的工作原理是绕过已损伤的毛细胞、直接电刺激残存的听神经纤维来达到恢复、重建听觉的目的。也可以将电刺激直接作用于听觉脑干和听觉皮层，适用于听神经发生病变的患者，例如听神经瘤患者。     

听觉中脑植入

听觉中脑植入是将一特制的电极植入到下丘中心核,刺激不同的频率层,从而产生听觉的听力重建方法.神经纤维瘤病二型患者由于耳蜗核受到破坏,听觉脑干植入效果差,听觉中脑植入技术渴望成为这类患者的福音.本文就近年来有关听觉中脑植入的研究进展做一综述.     

Clinical application of the multichannel auditory brainstem implant]

OBJECTIVE: To investigate the surgical techniques and speech performance of multichannel auditory brainstem implant (ABI) in patients with bilateral acoustic neuromas (neurofibromatosis type 2). METHODS: The nucleus 21 channel auditory brainstem implant was implanted into the lateral recess of the fourth ventricle through the translabyrinthine approach in 7 patients after removal of the tumor. The accurate placement of electrode array was ensured by the electromyogram monitoring of the 7th and 9th nerves and the electrically evoked auditory brainstem responses (EABR). Initial switch-on occurred six weeks postoperatively. Speech evaluation was performed every 3 months for the first year and annually thereafter. RESULTS: During the surgery, the lateral recess could be found and the typical EABR could be recorded in 6 cases. They later reported a significant benefit from the device. Two of the cases have achieved functional open-set speech understanding. In contrast, one patient with no EABR because of difficulty of the anatomic location during the surgery had no sensations postoperatively. CONCLUSION: The multichannel ABI could effectively restore auditory sensations in patients deafened by bilateral acoustic neuromas. The accurate location of the cochlear nucleus complex during surgery was the key factor for the success of the operation.     

An auditory brainstem implant system

Neurofibromastosis type II (NF2) is a condition that may result in bilateral acoustic neuromas. The tumors and their removal may cause profound bilateral deafness. Because the auditory nerve is compromised, people with NF2 are unable to receive a cochlear implant to restore a sensation of hearing. Electrical stimulation of the auditory pathway can provide hearing in such people. This is possible by means of an auditory brainstem implant (ABI). This article focuses on the MED-EL high-rate multichannel ABI system. The system consists of the implanted and external components. Appropriate placement of the ABI is dependent on electrical auditory brainstem response testing performed intra-operatively. Data on a group of European patients implanted with the MED-EL ABI are presented. Results are promising and include some open-set speech ability.     

Auditory brainstem and cochlear implants: functional results obtained after one year of rehabilitation

Very little information has been published on the clinical outcome of auditory brainstem implants (ABI). The present paper evaluates results obtained in a patient affected by a bilateral acoustic neuroma in type II neurofibromatosis who received an implant during removal of the residual tumor. One year later surgical revision of the ABI was necessary because no auditory sensation was obtained after ABI activation. Twelve months after the surgical revision, 12 electrodes out of 15 evoked auditory sensation. The results of rehabilitation were compared with those obtained in a group of eight postlingually deaf patients with cochlear implants (CI). Twelve months postoperatively the CI patients identified 97.7 ± 5.1% of bisyllabic words in a closed set while the ABI patient identified 86%. CI patients recognized 87.1 ± 11.3% of sentences and 81.3 ± 14.8% of words with contextual cues while the ABI patient recognized 75% and 65% respectively. Speech recognition improved more slowly in the ABI patient than in the CI patients and his scores for open-set words and sentences without lip reading and contextual cues were poorer. Although the results obtained in the ABI patient were not as good as those obtained in the CI patients, the ABI patient said his quality of life was improved. Received: 19 September 2000 / Accepted: 28 September 2000     

Multichannel auditory brainstem implantation: the Australian experience

The multichannel auditory brainstem implant (ABI) provides the potential for hearing restoration in patients with neurofibromatosis type 2 (NF2). Programmes for auditory brainstem implantation have been established in two Australian centres. Eight patients have been implanted under the protocol of an international multi-centre clinical trial. Three patients had ABI insertion at the time of first side tumour removal, four at second side tumour removal and one after previous bilateral surgery where there was some residual tumour. The translabyrinthine approach was used in all cases. Successful positioning of the electrode array was achieved in seven of eight patients, all of whom achieved auditory perception with electrical stimulation. Intra-operative electrically evoked auditory brainstem response testing was successful in four patients and was useful in confirming correct electrode position. In six cases post-operative psychophysical and auditory perception testing demonstrated that useful auditory sensations were achieved. Five of these patients regularly used the implant. In one patient electrode placement was unsuccessful and only non-auditory sensations occurred on stimulation. In the remaining patients non-auditory sensations were minimal and avoidable by selective electrode programming. Auditory brainstem implantation should be considered in patients with NF2. The greatest benefit is seen in patients without debilitating disease who have non-aidable hearing in the contralateral ear.     

Normal auditory brainstem response in patients with acoustic neuroma

Auditory brainstem response testing has been a major breakthrough in audiologic screening for acoustic neuroma because of its high degree of sensitivity. Although it is not uncommon for other cerebellopontine angle masses to present with normal ABR findings, reports of eighth nerve tumors with false-negative auditory brainstem response tests are quite rare. A series of 120 acoustic neuromas resected at the University of Michigan was reviewed and revealed two such patients. These two patients presented with asymmetric sensorineural hearing loss and unilateral tinnitus and were found to have completely normal auditory brainstem response. The diagnosis of acoustic neuroma would have been delayed if a comprehensive evaluation had not been pursued.     

Auditory brainstem implantation: The first Indian experience

Multichannel auditory brainstem implants (ABI) are currently indicated for patients with neurofibromatosis type II (NF2) involving both vestibulocochlear nerves. The ABI helps bypass the damaged cochlear nerves and restores a level of auditory sensation via the electrical stimulation of the cochlear nucleus. The implant is usually placed in the lateral recess of the fourth ventricle at the time of tumor resection to stimulate the cochlear nucleus. We report a case of ABI done on a 15-year-old girl with bilateral vestibular schwannomas.