BACKGROUND AND OBJECTIVES Clinical diagnosis of multiple system atrophy (MSA) is challenging. In 2022, new diagnostic criteria for MSA were proposed. We hypothesized that the positive predictive value (PPV) of clinical diagnosis of MSA improved because of advanced diagnostic tools, including brain MRI. This study aimed to understand temporal changes in PPV of MSA. METHODS We conducted a retrospective analysis of patients clinically diagnosed with MSA whose brains were examined in the Mayo Clinic brain bank from 2008 to 2022. PPV was compared between 2 periods (2008-2017 and 2018-2022) and successively with a 4-year moving average. PPV for each clinical subtype (parkinsonism type [MSA-P] and cerebellar type [MSA-C]) was assessed. RESULTS This study included 321 patients (136 women, age at death 68 ± 9 years) with a clinical diagnosis of MSA. Among them, 225 were pathologically confirmed as MSA, resulting in an overall PPV of 70%. The remaining 30% had alternative pathologic diagnoses including Lewy body disease (18%), progressive supranuclear palsy (4%), cerebrovascular disease (1%), corticobasal degeneration (1%), and others (6%). PPV improved from 63% in 2008-2017 to 78% in 2018-2022 (odds ratio [OR] 2.0 [1.2-3.5], p = 0.005). Linear analysis also demonstrated increased PPV over time (r = 0.66 [0.14-0.89], p = 0.02). Brain MRI scans were more frequently performed in 2018-2022 compared with 2008-2017 (91% vs 80%; OR 2.4 [1.2-5.0], p = 0.012). PPV was higher in patients with brain MRI compared with those without (73% vs 52%; OR 2.5 [1.3-4.9], p = 0.0057). PPV for MSA-C was similar in both groups (87% in 2008-2017 and 93% in 2018-2022), while that for MSA-P improved from 59% in 2008-2017 to 72% in 2018-2022 (OR 1.8 [1.0-3.2], p = 0.04). DISCUSSION This study demonstrates an improvement in the PPV of MSA in recent years, potentially attributed to the increased use of brain MRI. Nevertheless, it also highlights that it remains difficult to make a correct diagnosis for some patients based on their clinical presentation. These findings provide a baseline for future clinicopathologic research on MSA.

中文翻译：

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多系统萎缩临床诊断现状：2008 年至 2022 年的 15 年分析。


背景和目的 多系统萎缩 （MSA） 的临床诊断具有挑战性。2022 年，提出了 MSA 的新诊断标准。我们假设 MSA 临床诊断的阳性预测值 （PPV） 由于先进的诊断工具（包括脑部 MRI）而有所改善。本研究旨在了解 MSA PPV 的时间变化。方法 我们对 2008 年至 2022 年在梅奥诊所脑库中检查大脑的临床诊断为 MSA 的患者进行了回顾性分析。在 2 个时期（2008-2017 年和 2018-2022 年）之间比较 PPV，并先后与 4 年移动平均值进行比较。评估每种临床亚型 （帕金森综合征型 [MSA-P] 和小脑型 [MSA-C]）的 PPV。结果 本研究包括 321 例临床诊断为 MSA 的患者 （136 名女性，死亡年龄 68 ± 9 岁）。其中，225 例经病理证实为 MSA，总体 PPV 为 70%。其余 30% 有其他病理诊断，包括路易体病 （18%） 、进行性核上性麻痹 （4%）、脑血管疾病 （1%）、皮质基底节变性 （1%） 和其他 （6%）。PPV 从 2008-2017 年的 63% 提高到 2018-2022 年的 78% （比值比 [OR] 2.0 [1.2-3.5]，p = 0.005）。线性分析还显示 PPV 随时间增加 （r = 0.66 [0.14-0.89]，p = 0.02）。与 2008-2017 年相比，2018-2022 年脑部 MRI 扫描更频繁（91% 对 80%;或 2.4 [1.2-5.0]，p = 0.012）。与无脑部 MRI 的患者相比，有脑部 MRI 的患者 PPV 更高 （73% 对 52%;或 2.5 [1.3-4.9]，p = 0.0057）。两组 MSA-C 的 PPV 相似 （2008-2017 年为 87%，2018-2022 年为 93%），而 MSA-P 的 PPV 从 2008-2017 年的 59% 提高到 2018-2022 年的 72% （OR 1.8 [1.0-3.2]，p = 0.04）。 讨论 本研究证明近年来 MSA 的 PPV 有所改善，这可能归因于脑部 MRI 使用的增加。然而，它也强调，根据一些患者的临床表现做出正确的诊断仍然很困难。这些发现为未来 MSA 的临床病理学研究提供了基线。