School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas, USA.
School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas, USA.
World Neurosurg. 2022 Dec;168:e518-e529. doi: 10.1016/j.wneu.2022.10.013. Epub 2022 Oct 10.
Chiari I malformation (CM-1), traditionally defined as a descent of the cerebellar tonsils by 5 mm or more, is surgically managed via posterior fossa decompression. However, there is currently no clear radiologic or symptomatic selection criteria for surgical intervention to indicate which patients may see the most improvement following decompression.
This retrospective pilot study included 22 patients who had symptomatic CM-1 managed via surgical decompression and 22 patients who had nonoperative management of CM-1. Tonsillar motion was assessed using phase-contrast magnetic resonance imaging and 2-dimensional fast imaging employing steady-state acquisition. Both quantitative and qualitative results that best described the CM-1 anatomy, radiologic measurements, and tonsillar motion were obtained and analyzed.
Statistical analysis suggested that clinical symptoms differ based on tonsillar motion (P = 0.0044). Surgical patients had significantly more tonsillar motion than nonsurgical patients (P = 0.0010). Among the patients who underwent suboccipital decompression, the presurgery to postsurgery change in clinical symptoms was statistically significant (P < 0.0001), with all clinical symptoms showing decreased prevalence postsurgery. Anterior flow (P = 0.0004) and posterior flow (P < 0.0001) had significant negative associations with tonsillar motion.
Tonsillar motion correlated positively with increased clinical symptoms of CM-1. Furthermore, tonsillar motion was associated with impaired cerebrospinal fluid flow that manifested in increased clinical symptoms. We recommend use of 2-dimensional fast imaging employing steady-state acquisition and assessment of cerebrospinal fluid flow as an adjunct to both clinical judgement and magnetic resonance imaging when selecting patients with CM-1 who would best benefit from surgical decompression.
Chiari I 畸形（CM-1）传统上定义为小脑扁桃体下疝 5 毫米或以上，通过后颅窝减压进行手术治疗。然而，目前对于手术干预没有明确的影像学或症状选择标准来表明哪些患者在减压后可能会有最大的改善。
本回顾性试点研究纳入了 22 例接受手术减压治疗的有症状 CM-1 患者和 22 例接受非手术治疗的 CM-1 患者。使用相位对比磁共振成像和二维快速成像采用稳态采集评估扁桃体运动。获得并分析了最佳描述 CM-1 解剖结构、影像学测量和扁桃体运动的定量和定性结果。
统计分析表明，临床症状根据扁桃体运动而有所不同（P=0.0044）。手术组患者的扁桃体运动明显多于非手术组（P=0.0010）。在接受枕下减压的患者中，手术前后临床症状的变化具有统计学意义（P<0.0001），所有临床症状的患病率在手术后均有所下降。前向流（P=0.0004）和后向流（P<0.0001）与扁桃体运动呈显著负相关。
扁桃体运动与 CM-1 增加的临床症状呈正相关。此外，扁桃体运动与脑脊液流动受损有关，表现为临床症状加重。我们建议在选择 CM-1 患者时，将二维快速成像采用稳态采集与评估脑脊液流动作为临床判断和磁共振成像的辅助手段，以确定哪些患者最受益于手术减压。
