Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah, United States of America.
Division of Pediatric Neurosurgery, Primary Children's Hospital, Salt Lake City, Utah, United States of America.
PLoS One. 2024 Jan 16;19(1):e0296260. doi: 10.1371/journal.pone.0296260. eCollection 2024.
The fibrous posterior atlanto-occipital membrane (PAOM) at the craniocervical junction is typically removed during decompression surgery for Chiari malformation type I (CM-I); however, its importance and ultrastructural architecture have not been investigated in children. We hypothesized that there are structural differences in the PAOM of patients with CM-I and those without.
In this prospective study, blinded pathological analysis was performed on PAOM specimens from children who had surgery for CM-I and children who had surgery for posterior fossa tumors (controls). Clinical and radiographic data were collected. Statistical analysis included comparisons between the CM-I and control cohorts and correlations with imaging measures.
A total of 35 children (mean age at surgery 10.7 years; 94.3% white) with viable specimens for evaluation were enrolled: 24 with CM-I and 11 controls. There were no statistical demographic differences between the two cohorts. Four children had a family history of CM-I and five had a syndromic condition. The cohorts had similar measurements of tonsillar descent, syringomyelia, basion to C2, and condylar-to-C2 vertical axis (all p>0.05). The clival-axial angle was lower in patients with CM-I (138.1 vs. 149.3 degrees, p = 0.016). Morphologically, the PAOM demonstrated statistically higher proportions of disorganized architecture in patients with CM-I (75.0% vs. 36.4%, p = 0.012). There were no differences in PAOM fat, elastin, or collagen percentages overall and no differences in imaging or ultrastructural findings between male and female patients. Posterior fossa volume was lower in children with CM-I (163,234 mm3 vs. 218,305 mm3, p<0.001), a difference that persisted after normalizing for patient height (129.9 vs. 160.9, p = 0.028).
In patients with CM-I, the PAOM demonstrates disorganized architecture compared with that of control patients. This likely represents an anatomic adaptation in the presence of CM-I rather than a pathologic contribution.
颅颈交界区的纤维性后寰枕膜（PAOM）在 Chiari 畸形 I 型（CM-I）减压手术中通常被切除；然而，其在儿童中的重要性及其超微结构尚未得到研究。我们假设在 CM-I 患者和无 CM-I 患者的 PAOM 中存在结构差异。
在这项前瞻性研究中，对因 CM-I 接受手术和因后颅窝肿瘤接受手术的儿童的 PAOM 标本进行了盲法病理分析（对照组）。收集了临床和影像学资料。统计分析包括 CM-I 组和对照组之间的比较以及与影像学指标的相关性。
共有 35 名儿童（手术时平均年龄 10.7 岁；94.3%为白人）纳入了有活性标本评估：24 名 CM-I 患者和 11 名对照组。两组间无统计学差异。有 4 名儿童有 CM-I 家族史，5 名儿童有综合征。两组的扁桃体下疝、脊髓空洞症、颅底至 C2 和髁突至 C2 垂直轴的测量均相似（均 p>0.05）。CM-I 患者的齿状突-轴位角较低（138.1 度 vs. 149.3 度，p = 0.016）。形态上，CM-I 患者的 PAOM 显示出统计学上更高比例的组织结构紊乱（75.0% vs. 36.4%，p = 0.012）。PAOM 脂肪、弹性蛋白和胶原蛋白的百分比总体上没有差异，且男女患者的影像学和超微结构发现也没有差异。CM-I 患儿的后颅窝容积较低（163234mm3 vs. 218305mm3，p<0.001），在按患者身高校正后仍存在差异（1299mm3 vs. 1609mm3，p = 0.028）。
与对照组患者相比，CM-I 患者的 PAOM 表现出组织结构紊乱。这可能代表了 CM-I 存在时的解剖适应，而不是病理贡献。
