CHRU de Tours, Tours, France.
J Alzheimers Dis. 2013;33(3):775-80. doi: 10.3233/JAD-2012-121267.
Posterior cortical atrophy (PCA) is characterized by progressive higher-order visuo-perceptual dysfunction and praxis declines. This syndrome is related to several underlying diseases, including Alzheimer's disease (AD), sometimes involving an amyloidogenic process. The aims of the study were to 1) define cerebrospinal fluid (CSF) biomarker profiles in PCA patients compared to AD patients and 2) explore the amyloidogenic process through the Aβ(42)/Aβ(40) ratio in PCA patients to elucidate the underlying disease in vivo. CSF biomarker analysis (t-tau, p-tau, Aβ(42), and Aβ(42)/Aβ(40) ratio) and neuropsychological examination were performed in 22 PCA patients and compared with those of age-matched AD patients. Associated clinical neurological signs were investigated (e.g., extrapyramidal motor signs, myoclonus). CSF biomarker profiles did not differ significantly between the PCA and AD groups; 82% of patients with PCA fulfilled the biological criteria for typical AD with abnormal levels of the three markers and 18% of PCA patients presented atypical CSF profiles. All PCA patients with associated clinical neurological signs presented typical AD CSF profiles. The clinical presentations of these patients were similar to other PCA subjects. The Aβ(42)/Aβ(40) ratio for all PCA patients, including those with atypical CSF profiles, was decreased. Most PCA syndromes were associated with CSF biomarkers suggestive of AD, even in cases with associated clinical neurological signs. The amyloidogenic process was confirmed by the decreased Aβ(42)/Aβ(40) ratio for all patients. This analysis avoids misdiagnosis in the presence of physiologically high or low amyloid peptide production rates and provides information in vivo to improve understanding of the underlying disease in PCA.
后部皮质萎缩症（PCA）的特征是进行性高级视知觉功能障碍和动作执行能力下降。这种综合征与几种潜在疾病有关，包括阿尔茨海默病（AD），有时涉及淀粉样蛋白形成过程。本研究的目的是 1）定义 PCA 患者与 AD 患者相比的脑脊液（CSF）生物标志物谱，2）通过 PCA 患者的 Aβ（42）/Aβ（40）比值探索淀粉样蛋白形成过程，以阐明体内潜在疾病。对 22 例 PCA 患者进行了 CSF 生物标志物分析（t-tau、p-tau、Aβ（42）和 Aβ（42）/Aβ（40）比值）和神经心理学检查，并与年龄匹配的 AD 患者进行了比较。研究了相关的临床神经体征（如锥体外系运动体征、肌阵挛）。PCA 和 AD 组之间的 CSF 生物标志物谱无显著差异；82%的 PCA 患者符合典型 AD 的生物学标准，即三种标志物水平异常，18%的 PCA 患者表现出非典型 CSF 谱。所有伴有相关临床神经体征的 PCA 患者均表现出典型 AD 的 CSF 谱。这些患者的临床表现与其他 PCA 患者相似。所有 PCA 患者（包括 CSF 谱不典型的患者）的 Aβ（42）/Aβ（40）比值均降低。大多数 PCA 综合征与提示 AD 的 CSF 生物标志物有关，即使在伴有相关临床神经体征的情况下也是如此。淀粉样蛋白形成过程通过所有患者（包括 Aβ（42）/Aβ（40）比值降低）得到证实。该分析避免了在生理上高或低淀粉样肽产生率存在的情况下的误诊，并提供了体内信息，以改善对 PCA 中潜在疾病的理解。
