Narrative discourse in Persian-speaking patients with mild Alzheimer’s disease

ABSTRACT. Despite the significance of discourse impairments, they have not been thoroughly investigated in Persian-speaking patients with Alzheimer’s disease (AD). Objective: the aim of this study was to perform a multi-level analysis of narrative discourse in Persian-speaking patients with mild AD and to compare them with healthy elderly. Methods: the study included 14 older adults with mild AD and a matched group of 14 healthy elderly. Using a storytelling task based on serial pictures, both macro- and micro-linguistic aspects of narrative discourse were assessed. Cohesion ratio and coherence were investigated as macrolinguistic dimensions of discourse. The studied microlinguistic features included syntactic complexity and verbal errors (mostly involving phonological and semantic paraphasias and mazes). Severity of AD was determined using the Cognitive Dementia Rating (CDR). Results: there were significant differences between the groups regarding cohesion ratio (0.9 ± 0.34 vs. 1.29 ± 0.45, p = 0.02) and coherence scores (2.43 ± 0.41 vs. 3.02 ± 0.81, p = 0.03). Verbal errors and syntactic complexity did not differ significantly between the groups. Conclusion: Persian-speaking patients with mild AD show macrolinguistic impairments in producing discourses based on picture description. Therefore, intervention protocols should focus on the ability to organize information on a specific subject and also to connect sentences produced using appropriate cohesive ties.摘要。尽管话语障碍具有重要临床意义，但目前针对波斯语阿尔茨海默病（AD）患者的此类障碍尚未得到充分研究。研究目的：本研究旨在对轻度AD波斯语患者的叙事话语进行多维度分析，并与健康老年人进行对照比较。研究方法：本研究纳入14名轻度AD老年患者，以及14名人口学匹配的健康老年对照组。研究采用基于系列图片的叙事任务，对叙事话语的宏观语言学与微观语言学层面均进行评估。其中，话语的宏观语言学维度涵盖衔接比率与连贯性；微观语言学特征则包括句法复杂度与言语错误（主要涉及语音性错语、语义性错语及语流卡顿）。AD病情严重程度通过临床痴呆评定量表（Cognitive Dementia Rating, CDR）进行评定。研究结果：两组受试者在衔接比率（0.9±0.34 vs. 1.29±0.45，p=0.02）与连贯性评分（2.43±0.41 vs. 3.02±0.81，p=0.03）上存在显著差异；而言语错误与句法复杂度在两组间无显著差异。研究结论：轻度AD波斯语患者在基于图片描述生成话语时，存在宏观语言学层面的功能障碍。因此，相关干预方案应着重训练患者组织特定主题信息的能力，以及运用恰当衔接手段连接语句的能力。