From the Department of Neuroradiology (J.C.B., K.K., J.I.L.)
From the Department of Neuroradiology (J.C.B., K.K., J.I.L.).
AJNR Am J Neuroradiol. 2019 Aug;40(8):1402-1405. doi: 10.3174/ajnr.A6133. Epub 2019 Jul 11.
The prevalence of patent facial nerve canals and meningoceles along the facial nerve course is unknown. This study aimed to assess the frequency of such findings in asymptomatic patients.
A retrospective review was completed of patients with high-resolution MR imaging of the temporal bone whose clinical presentations were unrelated to facial nerve pathology. Facial nerve canals were assessed for the presence of fluid along each segment and meningoceles within either the labyrinthine segment (fluid-filled distention, ≥1.0-mm diameter) or geniculate ganglion fossa (fluid-filled distention, ≥2.0-mm diameter). If a meningocele was noted, images were assessed for signs of CSF leak.
Of 204 patients, 36 (17.6%) had fluid in the labyrinthine segment of the facial nerve canal and 40 (19.6%) had fluid in the geniculate ganglion fossa. Five (2.5%) had meningoceles of the geniculate ganglion fossa; no meningoceles of the labyrinthine segment of the canal were observed. No significant difference was observed in the ages of patients with fluid in the labyrinthine segment of the canal or geniculate ganglion compared with those without fluid ( = .177 and = .896, respectively). Of the patients with a meningocele, one had a partially empty sella and none had imaging evidence of CSF leak or intracranial hypotension.
Fluid within the labyrinthine and geniculate segments of the facial nerve canal is relatively common. Geniculate ganglion meningoceles are also observed, though less frequently. Such findings should be considered of little clinical importance without radiologic evidence of CSF otorrhea, meningitis, or facial nerve palsy.
沿面神经走行存在面神经管和脊膜膨出的患病率尚不清楚。本研究旨在评估无症状患者中此类发现的频率。
对颞骨高分辨率磁共振成像的患者进行了回顾性研究，这些患者的临床表现与面神经病变无关。评估面神经管各段是否存在液体，并评估迷路段（充满液体的扩张，直径≥1.0 毫米）或膝状神经节窝（充满液体的扩张，直径≥2.0 毫米）内是否存在脊膜膨出。如果发现脊膜膨出，则评估图像是否有脑脊液漏的迹象。
在 204 例患者中，36 例（17.6%）面神经管迷路段有液体，40 例（19.6%）膝状神经节窝有液体。5 例（2.5%）有膝状神经节窝脊膜膨出；未观察到面神经管迷路段脊膜膨出。迷路段或膝状神经节窝有液体的患者与无液体的患者年龄无显著差异（ =.177 和 =.896，分别）。在有脊膜膨出的患者中，1 例部分空蝶鞍，无一例有影像学证据表明存在脑脊液漏或颅内低血压。
面神经管迷路段和膝状神经节段内的液体较为常见。也观察到膝状神经节脊膜膨出，但较少见。如果没有脑脊液耳漏、脑膜炎或面神经瘫痪的放射学证据，此类发现应被认为临床意义不大。
