Glastonbury Christine M, Davidson H Christian, Harnsberger H Ric, Butler John, Kertesz Thomas R, Shelton Clough
Department of Radiology, University Hospital, Salt Lake City, UT, USA.
AJNR Am J Neuroradiol. 2002 Apr;23(4):635-43.
High-resolution T2-weighted fast spin-echo MR imaging provides excellent depiction of the cisternal and intracanalicular segments of the vestibulocochlear and facial nerves. Absence or reduction in caliber of the cochlear nerve (deficiency) has been described in association with congenital sensorineural hearing loss (SNHL). Depiction of cochlear nerve integrity may be important for diagnosis and management of SNHL.
We retrospectively reviewed high-resolution T2-weighted fast spin-echo MR images of 22 patients examined for SNHL who had deficiency of the cochlear nerve. Images were evaluated for the presence and comparative size of the component nerves (facial, cochlear, superior vestibular, and inferior vestibular nerves), relative size of the internal auditory canal (IAC), and any associated inner ear abnormalities. The clinical history, results of the clinical examination, and audiometric findings were reviewed for each patient.
Deficiency of the cochlear nerve was observed in 12 patients with congenital SNHL and in 10 patients with acquired SNHL. Hypoplasia of the IAC was observed in association with congenital deficiency of the cochlear nerve in 11 of 12 patients. Deficiency of the cochlear nerve was observed in association with acoustic schwannoma in two cases and with acquired labyrinthine abnormalities in seven cases. Hypoplasia of the IAC was not observed in association with acquired SNHL.
Deficiency of the cochlear nerve can be shown by high-resolution T2-weighted fast spin-echo MR imaging. Deficiency may be observed in association with congenital or acquired SNHL and may be important in the assessment of patients for cochlear implantation. Hypoplasia of the IAC is an indicator of congenital cochlear nerve deficiency.
高分辨率T2加权快速自旋回波磁共振成像能出色地显示前庭蜗神经和面神经的脑池段及内耳道段。耳蜗神经缺如或管径变细（发育不全）已被描述与先天性感音神经性听力损失（SNHL）相关。显示耳蜗神经的完整性对于SNHL的诊断和治疗可能很重要。
我们回顾性分析了22例因SNHL接受检查且存在耳蜗神经发育不全的患者的高分辨率T2加权快速自旋回波磁共振图像。评估图像中各组成神经（面神经、耳蜗神经、上前庭神经和下前庭神经）的存在情况及相对大小、内耳道（IAC）的相对大小以及任何相关的内耳异常。回顾了每位患者的临床病史、临床检查结果和听力测定结果。
在12例先天性SNHL患者和10例获得性SNHL患者中观察到耳蜗神经发育不全。在12例先天性耳蜗神经发育不全患者中的11例中观察到IAC发育不全。在2例中观察到耳蜗神经发育不全与听神经瘤相关，在7例中与获得性迷路异常相关。在获得性SNHL患者中未观察到IAC发育不全。
高分辨率T2加权快速自旋回波磁共振成像可显示耳蜗神经发育不全。发育不全可能与先天性或获得性SNHL相关，在评估患者是否适合人工耳蜗植入时可能很重要。IAC发育不全是先天性耳蜗神经发育不全的一个指标。
