Department of Otolaryngology, Hacettepe University School of Medicine, Ankara, Turkey.
Department of Otolaryngology, Ondokuz Mayıs University School of Medicine, Samsun, Turkey.
Laryngoscope. 2020 Nov;130(11):E696-E703. doi: 10.1002/lary.28596. Epub 2020 Mar 5.
OBJECTIVES/HYPOTHESIS: The objective of this study was to classify anomalous facial nerve (FN) routes and to determine their association with inner ear malformations (IEMs).
Retrospective cross sectional study.
The computed tomography images of 519 patients (796 ears) with IEMs were retrospectively evaluated, and the abnormal routes of the FN were classified as: Meatal segment: type 1, normal internal auditory canal (IAC); type 2, narrow IAC; type 3, facial canal (FC) only; type 4: separate FC/duplicated IAC. Labyrinthine segment (LS): type 1, normal; type 2a/b/c, mild/moderate/severe anterior displacement; type 3, superior displacement; type 4: straight LS. Tympanic segment (TS): type 1, normal; type 2, superiorly displaced TS; type 3, TS at the oval window; type 4: TS inferior to the oval window; type 5: unclassified. Mastoid segment: type 1, normal facial recess (FR)/normal mastoid segment; type 2: narrow FR; type 3, unclassified.
In meatal segment classification, a narrow IAC was common in ears with cochlear hypoplasia (CH) (76.1%), and only FC was common in ears with severe IEMs (62.7%) such as Michel deformity, common cavity, and cochlear aplasia. Incomplete partition-III has its unique superiorly displaced LS (100%). CH-IV also has its unique mild anterosuperior displacement. Ears with a superiorly displaced TS usually (93.1%) had aplastic or hypoplastic semicircular canals. The FR is likely to be narrow in CH and severe IEMs.
The FN route is affected in IEMs, which must be kept in mind when operating on ears with IEMs. Especially in CH cases, all segments of the FN can be abnormal.
4 Laryngoscope, 130:E696-E703, 2020.
目的/假设：本研究的目的是对异常面神经（FN）走行进行分类，并确定其与内耳畸形（IEM）的关系。
回顾性横断面研究。
回顾性评估了 519 例（796 耳）IEM 患者的 CT 图像，并将 FN 的异常路径分为：外段：1 型，正常内听道（IAC）；2 型，IAC 狭窄；3 型，仅面神经管；4 型：面神经管单独/重复 IAC。迷路段（LS）：1 型，正常；2a/b/c 型，轻度/中度/重度前移位；3 型，上移位；4 型：直 LS。鼓室段（TS）：1 型，正常；2 型，TS 上移位；3 型，TS 位于卵圆窗；4 型：TS 位于卵圆窗下；5 型：未分类。乳突段：1 型，正常面神经隐窝（FR）/正常乳突段；2 型：FR 狭窄；3 型，未分类。
在外段分类中，耳蜗发育不全（CH）患者的 IAC 狭窄较常见（76.1%），而严重 IEM 患者（如 Michel 畸形、共同腔和耳蜗发育不全）仅面神经管常见（62.7%）。不完全分隔-III 有其独特的上移位 LS（100%）。CH-IV 也有其独特的轻度前上移位。TS 上移位的耳朵通常（93.1%）有发育不良或发育不全的半规管。CH 和严重 IEM 中 FR 可能变窄。
FN 路径在 IEM 中受到影响，在对 IEM 患者进行手术时必须牢记这一点。特别是在 CH 病例中，FN 的所有节段都可能异常。
4 级喉镜，130：E696-E703，2020 年。
