Department of Psychology, Milano-Bicocca University, Milan, Italy.
Behav Neurol. 2011;24(3):229-36. doi: 10.3233/BEN-2011-0334.
Posterior cortical atrophy (PCA) is an uncommon presentation of Alzheimer's disease (AD), characterised by prevalent anatomo-functional involvement of posterior cortical areas. Accordingly, the main clinical features at onset are disorders of high-order visual processing, such as alexia and impairments of visuo-spatial and visuo-constructional abilities. The clinical features in the early stages of disease are variable, and they have been suggested to stem from prevalent ventral or dorsal brain pathology, and/or asymmetric hemispheric involvement. With disease progression, these differences tend to blur with the increasing severity of neuropsychological dysfunction. We report two PCA patients showing different patterns of reading impairment (respectively, letter-by-letter reading and neglect dyslexia). A follow-up study suggested that the qualitative features of alexia remain distinctive with disease evolution. In addition, single photon emission tomography (SPECT) studies revealed different patterns of hypoperfusion, consistent with the alexia types. A careful reading assessment can provide important insights to the pattern of progression of the disease in patients with PCA up to the late stages of the pathology.
后部皮质萎缩症（PCA）是阿尔茨海默病（AD）的一种不常见表现，其特征为后部皮质区域的解剖-功能普遍受累。因此，发病时的主要临床特征为高级视觉处理障碍，如失读症和视空间及视构能力损伤。疾病早期的临床特征具有变异性，据推测这些特征源于腹侧或背侧大脑病理学以及/或不对称的半球受累。随着疾病的进展，这些差异往往会因神经心理功能障碍的严重程度增加而变得模糊。我们报告了 2 例 PCA 患者，他们表现出不同类型的阅读障碍（分别为逐字阅读和忽视性失读症）。一项随访研究表明，失读症的定性特征在疾病进展过程中仍然具有特征性。此外，单光子发射断层扫描（SPECT）研究显示出不同类型的灌注不足，与失读症类型一致。仔细的阅读评估可以为 PCA 患者直至疾病晚期的疾病进展模式提供重要的见解。
