Differential diagnosis of parkinsonian syndromes is considered one of the most challenging in neurology. Quantitative MR planimetric measurements were reported to discriminate between progressive supranuclear palsy (PSP) and non-PSP-parkinsonism. Several studies have used midbrain to pons ratio (M/P) and the Magnetic Resonance Parkinsonism Index (MRPI) in distinguishing PSP patients from those with Parkinson's disease. The current meta-analysis aimed to compare the performance of these measures in discriminating PSP from multiple system atrophy (MSA). A systematic MEDLINE review identified 59 out of 2984 studies allowing a calculation of sensitivity and specificity using the MRPI or M/P. Meta-analyses of results were carried out using random effects modelling. To assess study quality and risk of bias, the QUADAS-2 tool was used. Eight studies were suitable for analysis. The meta‐analysis showed a pooled sensitivity and specificity for the MRPI of PSP versus MSA of 79.2% (95% CI 72.7–84.4%) and 91.2% (95% CI 79.5–96.5%), and 84.1% (95% CI 77.2–89.2%) and 89.2% (95% CI 81.8–93.8%), respectively, for the M/P. The QUADAS-2 toolbox revealed a high risk of bias regarding the methodological quality of patient selection and index test, as all patients were seen in a specialized outpatient department without avoiding case control design and no predefined threshold was given regarding MRPI or M/P cut-offs. Planimetric brainstem measurements, in special the MRPI and M/P, yield high diagnostic accuracy for the discrimination of PSP from MSA. However, there is an urgent need for well-designed, prospective validation studies to ameliorate the concerns regarding the risk of bias.

帕金森综合征的鉴别诊断被认为是神经病学中最具挑战性的诊断之一。据报道，定量 MR 平面测量可区分进行性核上性麻痹 (PSP) 和非 PSP 帕金森病。几项研究使用中脑与脑桥比 ( M / P ) 和磁共振帕金森病指数 (MRPI) 来区分 PSP 患者和帕金森病患者。目前的荟萃分析旨在比较这些措施在区分 PSP 和多系统萎缩 (MSA) 方面的性能。一项系统的 MEDLINE 审查确定了 2984 项研究中的 59 项，允许使用 MRPI 或M / P计算敏感性和特异性. 使用随机效应模型对结果进行荟萃分析。为了评估研究质量和偏倚风险，使用了 QUADAS-2 工具。八项研究适合分析。荟萃分析显示 PSP 与 MSA 的 MRPI 的汇总敏感性和特异性分别为 79.2%（95% CI 72.7–84.4%）和 91.2%（95% CI 79.5–96.5%）和 84.1%（95% CI 77.2 M / P分别为 –89.2%) 和 89.2% (95% CI 81.8–93.8%) 。QUADAS-2 工具箱显示，在患者选择和指标测试的方法学质量方面存在很高的偏倚风险，因为所有患者都在专门的门诊就诊，没有避免病例对照设计，并且没有给出关于 MRPI 或M / P的预定义阈值截止。平面脑干测量，特别是 MRPI 和M / P，为区分 PSP 和 MSA 提供了很高的诊断准确性。然而，迫切需要精心设计的前瞻性验证研究，以减轻对偏倚风险的担忧。