Thakar Sumit, Sivaraju Laxminadh, Jacob Kuruthukulangara S, Arun Aditya Atal, Aryan Saritha, Mohan Dilip, Sai Kiran Narayanam Anantha, Hegde Alangar S
1Department of Neurological Sciences, Sri Sathya Sai Institute of Higher Medical Sciences, Bangalore; and.
2Department of Psychiatry, Christian Medical College, Vellore, India.
J Neurosurg Spine. 2018 Jan;28(1):23-32. doi: 10.3171/2017.5.SPINE17264. Epub 2017 Nov 10.
OBJECTIVE Although various predictors of postoperative outcome have been previously identified in patients with Chiari malformation Type I (CMI) with syringomyelia, there is no known algorithm for predicting a multifactorial outcome measure in this widely studied disorder. Using one of the largest preoperative variable arrays used so far in CMI research, the authors attempted to generate a formula for predicting postoperative outcome. METHODS Data from the clinical records of 82 symptomatic adult patients with CMI and altered hindbrain CSF flow who were managed with foramen magnum decompression, C-1 laminectomy, and duraplasty over an 8-year period were collected and analyzed. Various preoperative clinical and radiological variables in the 57 patients who formed the study cohort were assessed in a bivariate analysis to determine their ability to predict clinical outcome (as measured on the Chicago Chiari Outcome Scale [CCOS]) and the resolution of syrinx at the last follow-up. The variables that were significant in the bivariate analysis were further analyzed in a multiple linear regression analysis. Different regression models were tested, and the model with the best prediction of CCOS was identified and internally validated in a subcohort of 25 patients. RESULTS There was no correlation between CCOS score and syrinx resolution (p = 0.24) at a mean ± SD follow-up of 40.29 ± 10.36 months. Multiple linear regression analysis revealed that the presence of gait instability, obex position, and the M-line-fourth ventricle vertex (FVV) distance correlated with CCOS score, while the presence of motor deficits was associated with poor syrinx resolution (p ≤ 0.05). The algorithm generated from the regression model demonstrated good diagnostic accuracy (area under curve 0.81), with a score of more than 128 points demonstrating 100% specificity for clinical improvement (CCOS score of 11 or greater). The model had excellent reliability (κ = 0.85) and was validated with fair accuracy in the validation cohort (area under the curve 0.75). CONCLUSIONS The presence of gait imbalance and motor deficits independently predict worse clinical and radiological outcomes, respectively, after decompressive surgery for CMI with altered hindbrain CSF flow. Caudal displacement of the obex and a shorter M-line-FVV distance correlated with good CCOS scores, indicating that patients with a greater degree of hindbrain pathology respond better to surgery. The proposed points-based algorithm has good predictive value for postoperative multifactorial outcome in these patients.
目的 尽管先前已确定了I型Chiari畸形（CMI）合并脊髓空洞症患者术后结局的各种预测因素，但在这种广泛研究的疾病中，尚无已知的用于预测多因素结局指标的算法。作者使用CMI研究中迄今为止最大的术前可变数组之一，试图生成一个预测术后结局的公式。方法 收集并分析了82例有症状的成年CMI患者的临床记录数据，这些患者伴有后脑脑脊液流动改变，在8年期间接受了枕骨大孔减压、C-1椎板切除术和硬脑膜成形术治疗。对构成研究队列的57例患者的各种术前临床和放射学变量进行双变量分析，以确定它们预测临床结局（根据芝加哥Chiari结局量表[CCOS]测量）和最后一次随访时脊髓空洞症消退情况的能力。在双变量分析中有意义的变量在多元线性回归分析中进一步分析。测试了不同的回归模型，并在25例患者的亚组中确定了对CCOS预测最佳的模型并进行了内部验证。结果 在平均±标准差为40.29±10.36个月的随访中，CCOS评分与脊髓空洞症消退之间无相关性（p = 0.24）。多元线性回归分析显示，步态不稳、闩部位置和M线-第四脑室顶点（FVV）距离与CCOS评分相关，而运动功能缺损的存在与脊髓空洞症消退不良相关（p≤0.05）。从回归模型生成的算法显示出良好的诊断准确性（曲线下面积为0.81），得分超过128分表明临床改善（CCOS评分为11或更高）的特异性为100%。该模型具有出色的可靠性（κ = 0.85），并在验证队列中以合理的准确性得到验证（曲线下面积为0.75）。结论 步态失衡和运动功能缺损的存在分别独立预测后脑脑脊液流动改变的CMI减压手术后较差的临床和放射学结局。闩部下移和较短的M线-FVV距离与良好的CCOS评分相关，表明后脑病变程度较高的患者对手术反应更好。所提出的基于点数的算法对这些患者术后的多因素结局具有良好的预测价值。
