以中文書寫任務追蹤認知障礙長者之認知變化

Abstract

背景:輕度認知障礙是指正常老化和失智症之間的過渡狀態，故對輕度認知障礙者進 行密切追蹤是早期識別失智症的關鍵，然而，現有的臨床檢查耗時或是花費高，因此針對輕度認知障礙患者的檢查追蹤，行為標記是一個可選用的評估。其中，書寫為檢測早期認知衰退的潛在行為標誌，現有研究多探討不同認知族群在橫斷面的比較，少有研究探討輕度認知退化患者在不同時間階段進行書寫評估的變化。為了促進失智症早期識別評估工具的完善發展，進一步探討輕度認知障礙患者在不同時間執行不同書 寫任務的特徵及變化是必要的。因此，本研究旨在以三種中文書寫任務(包含:抄寫 單字、抄寫水平句子及抄寫垂直句子)，追蹤探討輕度認知障礙長者之認知變化，並期望找出書寫變化的代表參數，作為認知退化的預測因子。 方法:本研究共招募25位輕度認知障礙患者及10位失智症患者，其中輕度認知障礙患者，依照臨床失智評估量表總分，將輕度認知障礙患者分成輕微及嚴重組，並分別進行四次追蹤評估，評估包含書寫評估及相關問卷評量。書寫評估主要採用本研究團隊開發之中文書寫平板評估，主要執行抄寫單字、抄寫水平句子任務及抄寫垂直句子任務，並收集分析書寫過程的動態特徵及書寫產品。本研究分為兩階段進行，首先找出用來區分不同程度認知損傷的中文書寫指標，第二階段則使用廣義估計方程式，檢驗這些指標是否能反映認知狀態的縱貫性變化，作為預測認知退化風險的潛在指標。 結果及結論:結果顯示，「書寫停頓時間比例」可穩定區分輕度認知障礙與失智症，反映失智症患者在書寫時需較多動作計畫時間，導致書寫流暢性下降;此外，句子抄寫任務中的「字距控制」也可以作為區分不同輕度認知障礙組別及輕微認知障礙與失智症的參數，顯示此種類型任務需要較高的視覺空間與動作規劃能力，有助辨識不同程度的認知退化。進一步納入追蹤時間點後發現，隨時間推移，參與者進入失智分組的機率增加，顯示長期追蹤對於認知變化的偵測具重要意義。因此，本研究發現書寫停頓時間比例與字距控制參數可作為追蹤認知退化的代表指標，且垂直句子抄寫表 現也許可以納入未來臨床縱貫式評估，有助於早期發現失智風險並介入治療。

Background: Mild Cognitive Impairment (MCI) is considered a transitional stage between normal aging and dementia. Therefore, closely monitoring individuals with MCI is crucial for the early detection of dementia. However, current clinical examinations are often time-consuming or costly. As such, behavioral markers represent a feasible alternative for evaluating and tracking individuals with MCI. Among these, handwriting has been identified as a potential early behavioral marker of cognitive impairment. While existing studies have primarily focused on cross-sectional comparisons among different cognitive groups, there is a lack of research investigating handwriting changes in individuals with MCI across multiple time points. Accordingly, this study aimed to examine changes and differences in the handwriting processes of MCI patients during different handwriting tasks—including character copying, horizontal sentence copying, and vertical sentence copying—and to identify representative handwriting parameters that could serve as predictors of cognitive impairment. Methods: This study recruited 25 individuals with MCI and 10 with dementia. Based on the Clinical Dementia Rating Scale (CDR-SB), MCI participants were further classified into mild and severe groups. All participants underwent four follow-up assessments, including handwriting tasks and related questionnaires. A tablet-based Chinese handwriting assessment developed by our team was used to evaluate character copying, horizontal sentence copying, and vertical sentence copying. Both handwriting dynamics and final written products were analyzed. The study was conducted in two phases: Phase 1 identified key handwriting indicators for differentiating cognitive impairment levels, and Phase 2 applied Generalized Estimating Equations (GEE) to examine whether these indicators could reflect longitudinal cognitive changes and serve as predictors of cognitive decline. Results and Conclusion: The results showed that the still time ratio during handwriting could distinguish between MCI and dementia, reflecting reduced motor fluency and increased planning demands in dementia patients. Additionally, space control in sentence-copying tasks differentiated between MCI subgroups and between mild MCI and dementia, suggesting higher demands on visuospatial and motor planning abilities. After incorporating follow-up time points, an increased likelihood of transitioning to dementia was observed over time, highlighting the importance of longitudinal monitoring. Overall, still time ratio and character spacing emerged as key indicators for tracking cognitive decline, with vertical sentence copying showing potential for future clinical use in early detection and intervention.