Differentiation of neuropsychological features between posterior cortical atrophy and early onset Alzheimer\u2019s disease

Jieying Li,Aihong Zhou,Yi Xing,Jianping Jia,Fen Wang,Yi Tang,Liyong Wu

doi:10.1186/s12883-018-1068-6

Abstract

BackgroundPosterior cortical atrophy (PCA) is a group of clinical syndromes characterized by visuospatial and visuoperceptual impairment, with memory relatively preserved. Although PCA is pathologically almost identical to Alzheimer’s disease (AD), they have different cognitive features. Those differences have only rarely been reported in any Chinese population. The purpose of the study is to establish neuropsychological tests that distinguish the clinical features of PCA from early onset AD (EOAD).MethodsTwenty-one PCA patients, 20 EOAD patients, and 20 healthy controls participated in this study. Patients had disease duration of ≤4 years. All participants completed a series of neuropsychological tests to evaluate their visuospatial, visuoperceptual, visuo-constructive, language, executive function, memory, calculation, writing, and reading abilities. The cognitive features of PCA and EOAD were compared.ResultsAll the neuropsychological test scores showed that both the PCA and EOAD patients were significantly more impaired than people in the control group. However, PCA patients were significantly more impaired than EOAD patients in visuospatial, visuoperceptual, and visuo-constructive function, as well as in handwriting, and reading Chinese characters.ConclusionsThe profile of neuropsychological test results highlights cognitive features that differ between PCA and EOAD. One surprising result is that the two syndromes could be distinguished by patients’ ability to read and write Chinese characters. Tests based on these characteristics could therefore form a brief PCA neuropsychological examination that would improve the diagnosis of PCA.

Highlights

Posterior cortical atrophy (PCA) is a group of clinical syndromes characterized by visuospatial and visuoperceptual impairment, with memory relatively preserved
+, positive Pittsburgh compound B (PIB) Positron emission tomography (PET) scan; −, negative PIB PET scan aChi-square test bOne-way ANOVA cMann-Whitney test d9 of the PCA patients refused the PIB-PET scan there was no significant difference in the disease duration (p = .602) between PCA and early onset AD (EOAD) patients (Table 1)
Clinical characteristics of PCA patients Clinical characteristics of PCA patients were found to be consistent with the core features of PCA (Table 2)

Summary

Introduction

Posterior cortical atrophy (PCA) is a group of clinical syndromes characterized by visuospatial and visuoperceptual impairment, with memory relatively preserved. PCA is pathologically almost identical to Alzheimer’s disease (AD), they have different cognitive features. Those differences have only rarely been reported in any Chinese population. The purpose of the study is to establish neuropsychological tests that distinguish the clinical features of PCA from early onset AD (EOAD). The main clinical features, besides space perception (visuospatial) and object perception (visuoperceptual) deficits, include alexia, Balint syndrome Neuropathological studies have indicated demonstrated that most cases of PCA are identical to Alzheimer’s disease [4,5,6]. For a clearer understanding of the pathogenesis in AD, it is crucial to distinguish the

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