Clin Nucl Med. 2018 Apr;43(4):e103-e108. doi: 10.1097/RLU.0000000000002018.
Primary progressive aphasia (PPA) is a neurological syndrome in which language functions become progressively impaired with relative sparing of memory and other instrumental functions. The pathologic causes of PPA are heterogeneous, but studies suggest that logopenic PPA (LPA) is underpinned by Alzheimer disease (AD) pathology in a high proportion of cases. The purposes of this descriptive and retrospective study were to characterize F-florbetapir PET imaging in a group of patients with a clinical syndrome of PPA, to determine the value of clinical characterization based on language phenotype in predicting the underlying pathology of PPA with F-florbetapir, and to quantify amyloid load in PPA subjects classified as "positive" F-florbetapir scans. Then, we compare the quantification and distribution of F-florbetapir uptake with those of typical, predominantly amnestic AD patients.
We conducted a PET study with F-florbetapir in a cohort of 12 right-handed patients diagnosed with PPA: 3 patients with semantic-variant PPA, 5 with nonfluent PPA, 1 with LPA, and 3 unclassifiable patients. We evaluated amyloid deposition between APP groups and 11 patients with typical amnestic AD.
Among the 12 patients with PPA syndrome, 8 (66.7%) were considered as amyloid positive. One of the 3 patients with semantic-variant PPA was F-florbetapir positive. In contrast, 4 of the 5 nonfluent-variant PPA, 2 of the 3 unclassifiable cases and the single patient with LPA were F-florbetapir positive. A significantly higher F-florbetapir uptake was observed in PPA F-florbetapir-positive patients compared with typical AD patients. This difference was observed in all regions of interest, except in posterior cingulate and temporal cortex.
These results suggest that F-florbetapir PET may be useful in a routine clinical procedure to improve the reliability of identifying AD pathology in patients with PPA syndrome, with different clinical subtypes of the PPA syndrome.
原发性进行性失语症（PPA）是一种以语言功能逐渐受损为特征的神经综合征，而记忆和其他工具性功能相对保留。PPA 的病理原因具有异质性，但研究表明，在很大比例的病例中，-logopenic PPA（LPA）是由阿尔茨海默病（AD）病理学引起的。本描述性和回顾性研究的目的是描述一组 PPA 临床综合征患者的 F-氟比他滨 PET 成像，确定基于语言表型的临床特征在预测 PPA 潜在病理学方面的价值，以及量化分类为“阳性”的 PPA 受试者的淀粉样蛋白负荷 F-氟比他滨扫描。然后，我们比较了 F-氟比他滨摄取的定量和分布与典型、主要为遗忘型 AD 患者的定量和分布。
我们对 12 名右利手 PPA 患者进行了 F-氟比他滨 PET 研究：3 名语义变异型 PPA 患者、5 名非流利型 PPA 患者、1 名 LPA 患者和 3 名无法分类的患者。我们评估了 APP 组与 11 名典型遗忘型 AD 患者之间的淀粉样蛋白沉积情况。
在 12 名 PPA 综合征患者中，8 名（66.7%）被认为是淀粉样蛋白阳性。3 名语义变异型 PPA 患者中有 1 名 F-氟比他滨阳性。相比之下，5 名非流利变异型 PPA 患者中有 4 名、3 名无法分类的病例中有 2 名和 1 名 LPA 患者中有 1 名 F-氟比他滨阳性。与典型 AD 患者相比，PPA F-氟比他滨阳性患者的 F-氟比他滨摄取明显更高。这种差异在所有感兴趣的区域都观察到，除了后扣带回和颞叶皮质。
这些结果表明，F-氟比他滨 PET 可能有助于在常规临床程序中提高识别 PPA 综合征患者 AD 病理学的可靠性，特别是在 PPA 综合征的不同临床亚型中。
