Background:Corticobasal syndrome (CBS) is the usual clinical presentation of patients with corticobasal degeneration pathology. Nevertheless, there are CBS individuals with postmortem neuropathology typical of Alzheimer’s disease (AD). Objective:In this study, we aim to detect FDG-PET metabolic signatures at the single-subject level in a CBS sample, also evaluated with cerebrospinal fluid (CSF) markers for AD pathology. Methods:21 patients (68.9±6.4 years; MMSE score = 21.7±6.3) fulfilling current criteria for CBS were enrolled. All underwent a clinical-neuropsychological assessment and an instrumental evaluation for biomarkers of neurodegeneration, amyloid and tau pathology (i.e., FDG-PET imaging and CSF Aβ42 and tau levels) at close intervals. CBS subjects were classified according to the presence or absence of CSF markers of AD pathology (i.e., low Aβ42 and high phosphorylated tau levels). Optimized voxel-based SPM procedures provided FDG-PET metabolic patterns at the single-subject and group levels. Results:Eight CBS had an AD-like CSF profile (CBS-AD), while thirteen were negative (CBS-noAD). The two subgroups did not differ in demographic characteristics or global cognitive impairment. FDG-PET SPM t-maps identified different metabolic signatures. Namely, all CBS-AD patients showed the typical AD-like hypometabolic pattern involving posterior cingulate cortex, precuneus and temporo-parietal cortex, whereas CBS-noAD cases showed bilateral hypometabolism in fronto-insular cortex and basal ganglia that is typical of the frontotemporal lobar degeneration spectrum. Discussion:These results strongly suggest the inclusion of FDG-PET imaging in the diagnostic algorithm of individuals with CBS clinical phenotype in order to early identify functional metabolic signatures due to different neuropathological substrates, thus improving the diagnostic accuracy.

中文翻译：

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皮质基底动脉综合征中的个体脑代谢特征。

背景：肾上腺皮质综合征（CBS）是患有肾上腺皮质变性病的患者的常见临床表现。尽管如此，仍有一些CBS个体具有典型的阿尔茨海默氏病（AD）的验尸神经病理学。目的：在这项研究中，我们旨在检测CBS样本中单受试者水平的FDG-PET代谢信号，并使用脑脊液（CSF）标记物评估AD病理。方法：纳入符合CBS标准的21例患者（68.9±6.4岁； MMSE评分= 21.7±6.3）。所有患者均以近乎间隔的时间接受了神经变性，淀粉样蛋白和tau病理学生物标志物（即FDG-PET成像和CSFAβ42和tau水平）的临床神经心理学评估和仪器评估。根据是否存在AD病理学CSF标记对CBS受试者进行分类（即 低的Aβ42和高的磷酸化tau水平）。优化的基于体素的SPM程序在单受试者和组水平上提供了FDG-PET代谢模式。结果：8例CBS具有AD样CSF特征（CBS-AD），而13例呈阴性（CBS-noAD）。这两个亚组在人口统计学特征或整体认知障碍方面没有差异。FDG-PET SPM t图鉴定出不同的代谢特征。即，所有CBS-AD患者均表现出典型的AD样代谢型，包括扣带后皮质，前突神经和颞顶皮质，而CBS-noAD病例则表现为额颞叶皮层和基底神经节双侧代谢减少，这是额颞叶典型的变性光谱。讨论：