Memory Clinic, Department of Science of Elderly, Neuroscience, Head and Neck and Orthopaedics, Fondazione Policlinico A. Gemelli, IRCCS, Rome, Italy.
Department of Neuroscience, Catholic University of Sacred Heart, Rome, Italy.
J Alzheimers Dis. 2021;81(2):619-627. doi: 10.3233/JAD-201452.
The assessment of semantic memory may be a useful marker to identify individuals with mild cognitive impairment (MCI) who will progress to Alzheimer's disease (AD) in the early stages of the disease.
The aim of this five-year follow-up longitudinal study is to assess whether semantic assessment could predict progression in MCI.
A population of MCI (N = 251); mild (N = 178) and moderate AD (N = 114); and a sample of healthy participants (HP; N = 262) was investigated. The five-year follow-up of the MCI group was completed by 178 patients. Semantic and episodic memory measures were used, including a measure of the discrepancy between categorical and phonological verbal fluency, the semantic-phonological delta (SPD). The main outcome was the progression of MCI due to AD to dementia.
A general linear model showed a significant effect of diagnosis on SPD (Wilks' Lambda = 0.591; p < 0.001). The estimated marginal means were -0.91 (SE = 0.185) in HP, -1.83 (SE = 0.187) in MCI, -1.16 (SE = 0.218) in mild AD, and -1.02 (SE = 0.275) in moderate AD. Post-hoc comparisons showed a significant difference between MCI and HP (p < 0.001). The follow-up was completed by 178 MCI individuals. SPD in MCI patients who progress to dementia was significantly lower than in MCI that will not progress (p = 0.003). Together with the Mini-Mental State Examination, the SPD was the only measure with a significant predicting effect at the five-years follow-up (p = 0.016).
The SPD indicates the impairment of semantic memory in individuals with underlying AD at the MCI early stage, reflecting the early involvement of perirhinal and entorhinal cortices in the earliest stages of AD neuropathological process.
语义记忆评估可能是识别轻度认知障碍 (MCI) 患者的有用标志物，这些患者在疾病早期会发展为阿尔茨海默病 (AD)。
本为期五年的纵向研究旨在评估语义评估是否可以预测 MCI 的进展。
研究了 MCI 患者 (N=251)、轻度 AD (N=178)和中度 AD (N=114)以及健康参与者 (HP; N=262) 样本。MCI 组的五年随访由 178 名患者完成。使用语义和情景记忆测量，包括类别和语音流畅性之间差异的测量，语义语音差 (SPD)。主要结果是由于 AD 导致的 MCI 进展为痴呆。
一般线性模型显示诊断对 SPD 有显著影响 (Wilks' Lambda=0.591;p<0.001)。估计的边缘均值分别为 HP 中为-0.91(SE=0.185)，MCI 中为-1.83(SE=0.187)，轻度 AD 中为-1.16(SE=0.218)，中度 AD 中为-1.02(SE=0.275)。事后比较显示 MCI 与 HP 之间存在显著差异 (p<0.001)。178 名 MCI 患者完成了随访。进展为痴呆的 MCI 患者的 SPD 明显低于不会进展的 MCI 患者 (p=0.003)。与 Mini-Mental State Examination 一起，SPD 是唯一在五年随访中具有显著预测效果的测量指标 (p=0.016)。
SPD 表明在 MCI 早期有潜在 AD 的个体语义记忆受损，反映了边缘和内嗅皮质在 AD 神经病理学过程的最早阶段的早期参与。
