Pagarkar Waheeda, Gunny Roxana, Saunders Dawn E, Yung Wai, Rajput Kaukab
Department of Audiovestibular Medicine, NHS City and Hackney and Royal National Throat Nose and Ear Hospital, United Kingdom.
Int J Pediatr Otorhinolaryngol. 2011 Jun;75(6):764-73. doi: 10.1016/j.ijporl.2011.02.017. Epub 2011 Apr 16.
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.
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.
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.
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.
在耳蜗神经缺如或发育不全的儿童中，对比与年龄匹配的对照组，通过CT观察骨蜗神经管（BCNC）的存在情况及大小与内耳道（IAM）大小之间的关系。
本回顾性病例笔记研究基于一家三级儿科医院的人工耳蜗植入科和神经放射科。将15名患有重度感音神经性耳聋（SND）且MRI扫描显示耳蜗神经缺如或发育不全的儿童（受试者）的25只耳，与年龄匹配的对照组进行比较。纳入两组对照组；第一组对照组为12名听力正常或患有传导性听力损失儿童的19只耳[对照组1]，第二组对照组为11名与GJB2基因突变相关的重度至极重度听力损失儿童的21只耳[对照组2]。两组对照组均有耳蜗神经存在的证据。两名神经放射科医生独立评估受试者和对照组CT上BCNC和IAM的存在情况及大小，以及MRI上耳蜗神经（CN）的存在情况。比较受试者与两组对照组之间BCNC和IAM的大小。在受试者中，将BCNC的存在情况与CT上IAM的大小、MRI上CN的存在与否以及听力评估进行关联分析。
与对照组相比，受试者的平均IAM宽度明显更小。25只受试耳中有17只BCNC缺如，所有对照耳中BCNC均存在。17只受试耳中有13只BCNC缺如与IAM狭窄相关。BCNC的存在支持耳蜗神经的存在，尽管在MRI上未观察到。然而，如在两只受试耳中所见，BCNC缺如可能与耳蜗神经的存在有关。22只MRI显示CN缺如的受试耳中有5只[22%]有其他存在耳蜗神经的证据。
BCNC是评估CN耳蜗支存在情况的一个额外参数。BCNC的存在可能表明耳蜗神经存在。在仅基于MRI评估人工耳蜗植入候选资格时应谨慎，应结合影像学和听力测试来评估CN的存在情况。
