磁共振成像在人工耳蜗植入术中的应用进展

人工耳蜗 (cochlearimplant,CI)模拟人的耳蜗功能 ,绕过无效的毛细胞 ,直接刺激残余的螺旋神经节细胞 ,产生听觉 ,可使重度、极重度聋患者回到有声世界。CI植入术手术径路通常是面隐窝径路 ,去除圆窗龛前缘 ,将电极由圆窗植入鼓阶。常用的植入装置有 3种 :Nucleus2 4、MedEl40     

CT与磁共振成像在儿童人工耳蜗植入术前研究

目的　评价CT与磁共振成像 (magneticresonanceimaging ,MRI)在儿童人工耳蜗植入术前的诊断作用 ,以及对手术选择的影响。方法　 71例 ( 142耳 )双耳重度耳聋、拟行人工耳蜗植入的患儿进行术前CT与MRI检查。结果　CT与MRI均发现 ,12例 ( 2 2耳 )患者有前庭水管扩大 ( 15 5 % ) ;14例 ( 2 5耳 )患儿有Mondini畸形 ( 17 6% ) ;3例 ( 5耳 )患儿有内耳道扩大 ( 3 5 % ) ;2例 ( 4耳 )患者有可疑内耳道底骨质缺损 ( 2 8% )。MRI发现有 5例 ( 5耳 )患者单侧耳蜗纤维化 ( 3 5 % ) ,而CT未见异常。1例 ( 2耳 )患儿的CT显示面神经裸露 ( 1 4% ) ,MRI正常。结论　人工耳蜗植入术前应该进行CT与MRI检查。对于发现前庭水管综合征、Mondini畸形、内耳道扩张及内耳道底骨质缺损有重要意义。这二种影像学检查结果可以相互补充诊断耳蜗纤维化与面神经裸露。对手术适应证的选择以及保证手术正常进行有重要意义     

人工耳蜗植入者颅脑磁共振成像检查一例

人工耳蜗术后行磁共振成像(magnetic resonance imaging MRI)一直被视为禁忌。近年来国外学者研究发现一定条件下，耳蜗植入者行颅脑MRI检查是安全的。我们对1例人工耳蜗植入患者行颅脑MRI扫描，报道如下。     

CT与磁共振成像在儿童人工耳蜗植入术前研究

目的 评价CT与磁共振成像（magnetic resonance imaging,MRI)在儿童人工耳蜗植入术前的诊断作用，以及对手术选择的影响。方法 71例（142耳）双耳重度耳聋、拟行人工耳蜗植入的患儿进行术前CT与MRI检查。结果 CT与MRI均发现，12例（22耳）患者有前庭水管扩大（15.5%)；14例（25耳）患儿有Mondini畸形（17.6%)；3例（5耳）患儿有内耳道扩大（3.5%)；2例（4耳）患者有可疑内耳道底骨质缺损（2.8%)。MRI发现有5例（5耳）患者单侧耳蜗纤维化（3.5%)，而CT未见异常。1例（2耳）患儿的CT显示面神经裸露（1.4%)，MRI正常。结论 人工耳蜗植入术前应该进行CT与MRI检查。对于发现前庭水管综合征、Mondini畸形、内耳道扩张及内耳道底骨质缺损有重要意义。这二种影像学检查结果可以相互补充诊断耳蜗纤维化与面神经裸露。对手术适应证的选择以及保证手术正常进行有重要意义。     

内听道狭窄的人工耳蜗植入术效果观察并文献复习

摘要：目的通过观察一例内听道狭窄患者人工耳蜗植入术后的远期康复效果,结合文献复习探讨该类畸形的手术选择指标。方法收集患儿术前听力学资料以及颞骨薄层CT资料,分别于术后半年、2年、4年时进行声场测试、MAIS量表评分、言语识别率测试分析患者康复疗效。并以内听道狭窄、蜗神经管狭窄、蜗神经孔狭窄以及蜗神经发育不良为关键词搜索与人工耳蜗康复的相关文献。结果半年时声场测试500、1 000、2 000、4 000 Hz分别为35、40、40、45 dBHL,2年时MAIS量表评分24分,4年时言语识别率80%,患儿于术后3年时言语理解能力进步明显,康复效果优于文献搜索结果。结论存在内听道狭窄的患者,人工耳蜗植入前对影像学及听力测试结果的综合分析非常重要,选择耳蜗神经发育相对较好侧以及助听效果较好侧手术,同时需坚持术后康复治疗。     

内听道重复畸形影像学评估

目的　分析内听道重复畸形（duplication of the internal auditory canal,DIAC）患者CT及MRI影像学表现,提高对该畸形的认识,为人工耳蜗植入提供术前依据。方法　回顾性观察20例（24耳）DIAC患者内耳多层螺旋CT（MSCT）及MRI资料,测量并分析病变组与对照组内听道及蜗神经孔宽度。结果　DIAC均为内听道狭窄及合并其他颞骨畸形。MSCT示21耳、MRI水成像示16耳内听道由骨性分隔成双管。MRI水成像示前庭蜗神经纤细。病变、对照组内听道宽度及蜗神经孔宽度均有统计学差异（P <0.001）。6例（8耳）行人工耳蜗植入术后听力均有不同程度恢复。结论　DIAC均显示内听道狭窄,MSCT所示骨性分隔为其特征性征象,MRI水成像示前庭蜗神经发育不良,联合两种影像检查方法可为本病诊断和人工听觉植入提供客观参考依据。     

蜗神经发育不良患者人工耳蜗术前影像学评估技术及临床应用

蜗神经发育不良(Cochlear nerve deficiency,CND)是先天性极重度耳聋的原因之一,指蜗神经缺失或蜗神经纤细.CND的诊断主要依靠在3D-核磁中判断蜗神经状态,而由于技术限制,蜗神经往往显示不清.与非CND患者相比,CND患者的人工耳蜗术后效果较差,且部分患者无法从中获益.因此,提高术前CND的诊...     

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。     

人工耳蜗植入术前耳蜗神经及后通路功能评估

人工耳蜗植入（CI）是重度、极重度感音神经性聋且助听器验配无效或效果不佳患者有效地干预方法之一,CI术前对耳蜗神经及后通路功能的准确评估尤为重要,是一项涉及听力学、影像学和遗传学的综合评估。当常规听力学检测无听觉反应和（或）常规影像学检查提示耳蜗神经可能发育不良时,需重点评估耳蜗神经及后通路功能,可完善大功率助听器条件下测听、皮层听觉诱发电位（CAEP）、电诱发听性脑干反应（EABR）、电诱发听神经复合动作电位（ECAP）等特殊听力学检测,以及功能性磁共振成像（fMRI）、正电子发射断层显像（positron emission tomography,PET）等功能性影像学检查,判断是否有CI手术适应证和禁忌证,进而选择合适的人工耳蜗植入体、预估手术难度,并制订具体手术方案和并发症预案,同时可预估CI手术疗效。     

Cavernous hemangioma of the internal auditory canal

Hemangiomas rarely occur in the internal auditory canal. These tumors originate from the capillary bed of the epineurium surrounding the nerve and can either compress or infiltrate the nerve. Depending on location and the nerve of origin, these lesions can cause severe and progressive sensorineural hearing loss, tinnitus, facial nerve palsy, or vertigo even when they are relatively small. The presence of a small contrast-enhancing tumor in the internal auditory canal accompanied by severe sensorineural hearing loss and facial nerve palsy, should raise the suspicion of a hemangioma. Early recognition and surgical intervention in these benign tumors may improve the chance of preserving the functional integrity of the facial nerve and provides better results after nerve reconstruction. Due to their relative small size, the temporal bone CT-scan may show no evidence of pathological widening of the internal auditory canal or the typical intralesional calcifications at the time of presentation. MRI with Gadolinium is the imaging method of choice and a high index of clinical suspicion is necessary for the diagnosis of these tumors. In this paper we report about a 51-year-old male presented with right-sided sensory-neural deafness and facial nerve palsy, accompanied by severe tinnitus and ipsilateral loss of vestibular function due to a cavernous hemangioma in the internal auditory canal.     

The bony cochlear nerve canal in children with absent or hypoplastic cochlear nerves

Objective

To correlate presence and size of the bony cochlear nerve canal [BCNC] with size of the internal auditory meatus [IAM] on CT in children with absent or hypoplastic cochlear nerves [CNs] as compared to age matched controls.

Methods

This retrospective case-notes review was based in the departments of Cochlear Implantation and Neuroradiology at a tertiary paediatric hospital. Twenty-five ears of fifteen children (subjects) with profound sensorineural deafness (SND) and absent or hypoplastic CN on MRI scan were compared to age matched controls. Two groups of controls were included; a control group of nineteen ears of twelve children with normal hearing or conductive hearing loss [control group 1] and a second control group of twenty one ears of eleven children with severe to profound hearing loss related to GJB2 mutations [control group 2]. Both control groups had evidence of the presence of the CN. Two neuroradiologists independently assessed presence and size of BCNC and IAM on CT and presence of CN on MRI in subjects and controls. The BCNC and IAM size was compared between subjects and both control groups. The presence of BCNC was correlated with the IAM size on CT, presence/absence of CN on MRI and audiological evaluation in subjects.

Results

The mean IAM width was significantly smaller in subjects as compared to controls. The BCNC was absent in 17/25 subject ears and present in all control ears. Absent BCNC correlated with a narrow IAM in 13/17 subject ears. Presence of the BCNC supported presence of a CN although this was not seen on MRI. However, BCNC absence may be associated with presence of a CN as was seen in two subject ears. Five subject ears out of 22 [22%] with absent CN on MRI had other evidence of a present cochlear nerve.

Conclusions

BCNC is an additional parameter to assess presence of the cochlear branch of the CN. Presence of the BCNC may indicate cochlear nerve presence. Caution should be used in assessing candidacy of cochlear implants based on MRI alone and a combination of imaging and audiological tests should be used to assess presence of the CN.     

Rare tumors of the internal auditory canal

The study was performed to identify the incidence and histology of rare tumors with growth restricted to the internal auditory canal (IAC) that are different from vestibular schwannoma (VS). Furthermore, the question was addressed whether a preoperative diagnosis would be possible in these cases. A series of 351 patients that were operated on for IAC tumors through a transtemporal or translabyrinthine approach was investigated retrospectively. Cases with a tumor entity other than VS were analyzed for symptoms, radiological diagnosis, intraoperative findings and postoperative histolopatology to determine if a differential diagnosis to the common VS can be established prior to surgery. In 15 out of 351 cases (4.3%), uncommon processes of the IAC were determined by histology (6 lipomas, 3 hemangiomas, 2 neurofibromas, 2 menigiomas, 1 facial neuroma and 1 case of bilateral malignant lymphoma). The symptoms and the clinical manifestations were typical for patients with VS so that a preoperative differential diagnosis was not possible in the majority of cases. An analysis of the operation reports revealed that in 10 out of the 15 cases the surgeon suspected an unusual tumor of the IAC during surgery. The results of the present investigation suggest that rare lesions of the IAC can be expected in less than 5% of the cases and that preoperative diagnosis of rare IAC tumors is difficult. Intraoperative findings such as adhesion to cranial nerves and consistency of the tumor often indicate unusual processes, but histological analysis of the removed tissue is essential for the definite diagnosis.     

人工耳蜗植入术前的影像学检查

目的 :探讨CT和MRI检查对人工耳蜗植入术前评估的价值。方法 :对 2 6例感音性耳聋患者均采用颞骨轴位高分辨率CT螺旋扫描、MR水成像及内耳三维重建。结果 :1 8例先天性感音性耳聋患儿中检出Mondini畸形Ⅰ型 1例 (2耳 ) ,Ⅱ型 1例 (2耳 ) ,内耳纤维化 1例 (2耳 ) ;5例语后聋患者中检出慢性化脓性中耳炎 1例 (2耳 ) ,内耳骨化 1例 (2耳 )。结论 :对于人工耳蜗植入术的术前评估 ,CT检查具有重要价值 ,必不可少 ,MRI检查是必要的补充。对内耳的三维重建 ,MRI优于CT。     

Cholesteatoma invasion into the internal auditory canal

Cholesteatoma invasion into the internal auditory canal (IAC) is rare and usually results in irreversible, complete hearing loss and facial paralysis on the affected side. This retrospective study examines the clinical characteristics of seven patients with cholesteatoma invading the IAC, analyzes possible routes of the cholesteatoma’s extension and describes the surgical approaches used and patient outcome. Extension to the IAC was via the supralabyrinthine route in most patients. A subtotal petrosectomy, a translabyrinthine approach or a middle cranial fossa approach combined with radical mastoidectomy were required for the complete removal of the cholesteatoma. All seven patients presented with some preoperative facial nerve palsy. The facial nerve was decompressed in four patients and facial nerve repair was performed in three others, two by hypoglossal-facial anastomosis and one by a greater auricular nerve interposition grafting. All patients ended up with total deafness in the operate ear. At 1 year following surgery, the facial nerve function was House–Brackmann grade III in six cases and grade II in one. In conclusion, cholesteatoma invading the IAC is a separate entity with characteristic clinical presentations, require a unique surgical approach, and result in significant morbidity, such as total deafness in the operated ear and impaired facial movement.     

听神经病及蜗神经发育不良儿童人工耳蜗植入的有效性

目的 通过问卷量表评估,探讨听神经病及蜗神经发育不良儿童的人工耳蜗植入效果.方法 实验组为2004年1月至2010年10月期间接受人工耳蜗植入的符合听神经病或蜗神经发育不良诊断标准、且术前至少佩戴3个月助听器并接受语言训练的患儿,共21例,其中听神经病9例,蜗神经发育不良12例.植入对照组为20例同期植入人工耳蜗的感音神经性聋患儿.所有人工耳蜗植入患儿均开机使用6个月以上.正常听力对照组为42例听力正常的儿童,按年龄分为正常听力A组(年龄在24个月以下)18例、正常听力B组(年龄24～ 48个月)16例和正常听力C组(年龄在48个月以上)8例.采用听觉行为分级(Categories of Auditory Performance,CAP)和言语可懂度分级(Speech Intelligibility Rating,SIR)两个量表进行评分,使用SPSS16.0软件对实验组得分与植入对照组和正常听力对照组进行比较.结果 听神经病组、蜗神经发育不良组、感音神经性聋组以及三组正常听力儿童的CAP得分(x±s,下同)分别为(4.44±1.50)分、(4.83±1.69)分、(4.55±1.66)分、(5.22±1.11)分、(6.75±0.45)分和(7.00±0.00)分,SIR得分分别为(2.66±1.11)分、(2.33±1.15)分,(2.40±0.75)分,(2.56±1.04)分、(4.12±0.81)分和(5.00±0.00)分.CAP和SIR得分在六组受试者间差异均具有统计学意义(x2=35.481,P＜0.001;x2 =40.549,P＜0.001);组内两两比较,听神经病组/蜗神经发育不良组与感音神经性聋组及正常听力A组得分比较,差异无统计学意义(P值均＞0.05),而与正常听力B组及C组相比,差异具有统计学意义(P值均＜0.01).结论 听神经病和蜗神经发育不良儿童接受人工耳蜗植入后,同感音神经性聋患儿一样,能够获得听觉及言语能力的进步,但落后于听力正常的同龄儿童.人工耳蜗提高此类患儿听觉及言语能力的远期效果还有待进一步随访和评估.     

Usefulness of radiological findings for predicting cochlear implantation outcomes in children with cochlear nerve deficiency: a pilot study

Conclusion: Children with CND received limited benefits from CIs and their results varied. The size of the vestibulocochlear nerve relative to the facial nerve could potentially be used as a predicator for CI outcomes in children with CND.

Objective: This study aimed to (1) retrospectively review the outcomes of cochlear implants (CIs) in children with cochlear nerve deficiency (CND) and (2) evaluate the clinical usefulness of radiological findings as predictors for post-implantation outcomes.

Methods: Study participants included 10 children with bilateral CND and profound sensorineural hearing loss. The preoperative magnetic resonance imaging and temporal bone computed tomography scans were evaluated. Auditory processing capability and speech perception performance were measured with Categories of Auditory Performance (CAP) and Speech Intelligibility Rating (SIR) scales. Aided hearing thresholds with CI were measured. The relationships between CI outcomes and the sizes of vestibulocochlear nerve and cochlear nerve canal (CNC) were analysed.

Results: Although post-operative CAP scores and hearing thresholds significantly improved in children with CND, their results were worse than those measured in implanted children with normal cochlear nerve. No significant correlation was found between the CI outcomes and the vestibulocochlear nerve diameters or the CNC diameters in children with CND. However, children with larger vestibulocochlear-nerve-to-facial-nerve-ratios got better results.     

Drilling and control of the internal auditory canal by fixed endoscope

Preservation of vestibular structures, particularly the posterior semicircular canal, is essential to ensure hearing preservation in addition to complete tumour resection during retrosigmoid surgical resection of a vestibular schwannoma. Drilling of the internal auditory canal (IAC) is a delicate step, during which these structures can be accidentally perforated. The orientation of the IAC results in the formation of poorly visible zones that can predispose to perforation of these structures when drilling is performed with a microscope. Hand-held endoscopy exposes all of the operative field, but immobilizes one of the surgeon's hands, making this surgery even more delicate. Fixed endoscopy is a solution that gives the surgeon greater freedom of movement, while ensuring precise control of the surgical procedure. It allows identification and avoidance of vestibular structures, while allowing resection as close as possible to the tumour. The schwannoma can be entirely cleaved when the fundus of the IAC is correctly controlled, while sparing the facial and cochlear nerves.     

人工耳蜗植入术前听神经完整性的评估

目的 探讨、评估人工耳蜗植入候选者术前听神经完整性的检查方法;在对侧耳人工耳蜗植入术前,客观检查耳蜗发育及病变状态的检查方法。方法 对12例人工耳蜗植入候选者进行检查,根据本小组建立的人工耳蜗植入术前耳蜗影像学检查方法、术前听神经完整性检查方法及评估标准、以及术后植入电极位置的早期检查方法,结合11例人工耳蜗植入术后听觉康复疗效进行分析。结果 11例患儿满足本小组制定的人工耳蜗植入遴选标准而接受了多导人工耳蜗植入,包括1例对侧耳(第2耳)人工耳蜗植入。一例患儿因评估结果为听神经发育障碍,未作人工耳蜗植入。所有人工耳蜗植入患儿术后听觉能力皆明显改善。结论 MRI头轴位及听神经轴位和颞骨CT薄层扫描、膜迷路表层实时三维重建及膜迷路实时重建等影像学方法,结合听力学及外耳道电刺激测听反应阈与不适阈差值的电生理方法来评估听神经的完整性,对术前预测人工耳蜗植入后患儿听觉康复的可能疗效,有非常重要的意义。术后早期反斯氏位X线摄片观察蜗内植入电极部位及植入电极形态,可作为人工耳蜗电极植入成功性直观、简捷的评估方法。     

Electrode array misplacement into the superior semicircular canal: As a rare complication of cochlear implantation

Objective

To report electrode array misplacement into the superior semicircular canal occurring as an rare complication of cochlear implantation through round window insertion, and to explore the causative association between electrode array misplacement and cochlear implantation surgical techniques.

Methods

A chart review of the electrode array misplacement into the superior semicircular canal and their management in 695 patients undergoing cochlear implantation was undertaken from January 2003 and January 2014 in Anhui Provincial Hospital.

Results

There were two children of electrode array misplacement into the superior semicircular canal complication, and the rate was 0.28%.

Conclusions

Electrode array misplacement into the superior semicircular canal associated with cochlear implantation is rare. Surgeons should be aware of that the smaller round window maybe the reason of electrode array misplacement through round window insertion. Intra-operative neural response telemetry and X-ray can alert the surgeon the problem with the array's misplacement, which can be identified by postoperative CT.