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。

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