Axon P R, Temple R H, Saeed S R, Ramsden R T
Department of Otolaryngology, Manchester Royal Infirmary, United Kingdom.
Am J Otol. 1998 Nov;19(6):724-9.
This study aimed to assess the pathologic processes that result in ossification of the cochlear lumen after bacterial meningitis.
The study design was a retrospective case review.
The study was conducted at a tertiary referral center.
Profoundly deaf postmeningitic patients who underwent cochlear implantation were studied.
Diagnostic and therapeutic observations were performed.
The extent of cochlear ossification is classified and related to age at which infection occurred, cerebrospinal fluid leukocyte count, Gram's stain, organism, and delay between meningitis and implantation. The extent of ossification noted on high-definition computed tomographic (CT) scan is compared with surgical findings and related to the time delays between meningitis, imaging, and surgery.
Ossification fell into three groups: gross ossification of the scala tympani and variable amounts of the scala vestibuli; partial ossification localized to the basal turn of the scala tympani; and no ossification. There was no correlation between the extent of ossification and the age when infected, type of pathogen, cerebrospinal fluid leukocyte count, and time delay between meningitis and implantation. Visualization of bacteria on Gram's stain was a highly sensitive measure of ossification (0.93) but was not specific (0.6) with positive and negative predictive values of 0.76 and 0.86, respectively. High-definition CT underestimated the extent of ossification in 50% of cases when performed within 6 months of meningitis.
Ossification is either gross or localized to the basal turn of the scala tympani. If ossification does occur, it is rapid and complete within a few months of infection. The visualization of bacteria on Gram's stain is a sensitive indicator for the presence of ossification but has low specificity. High-definition CT, if performed within the first 6 months of meningitis, can be an inaccurate diagnostic tool and therefore should be performed as close to the date of surgery as possible.
本研究旨在评估细菌性脑膜炎后导致蜗管骨化的病理过程。
本研究设计为回顾性病例分析。
研究在一家三级转诊中心进行。
对接受人工耳蜗植入的重度感音神经性聋的脑膜炎后患者进行研究。
进行诊断和治疗观察。
蜗管骨化程度进行分类，并与感染发生时的年龄、脑脊液白细胞计数、革兰氏染色、病原体以及脑膜炎与植入之间的时间间隔相关。将高分辨率计算机断层扫描（CT）上显示的骨化程度与手术结果进行比较，并与脑膜炎、影像学检查和手术之间的时间延迟相关。
骨化分为三组：鼓阶的广泛骨化以及前庭阶不同程度的骨化；局限于鼓阶基底转的部分骨化；无骨化。骨化程度与感染时的年龄、病原体类型、脑脊液白细胞计数以及脑膜炎与植入之间的时间延迟无关。革兰氏染色上细菌的可视化是骨化的高度敏感指标（0.93），但不具有特异性（0.6），阳性预测值和阴性预测值分别为0.76和0.86。在脑膜炎后6个月内进行高分辨率CT检查时，50% 的病例低估了骨化程度。
骨化要么广泛存在，要么局限于鼓阶基底转。如果确实发生骨化，在感染后的几个月内会迅速且完全形成。革兰氏染色上细菌的可视化是骨化存在的敏感指标，但特异性较低。如果在脑膜炎后的前6个月内进行高分辨率CT检查，可能是一种不准确的诊断工具，因此应尽可能接近手术日期进行检查。
