Primary progressive aphasias (PPAs) are a group of neurodegenerative diseases presenting with insidious and relentless language impairment. Three main PPA variants have been described: the non-fluent/agrammatic variant (nfvPPA), the semantic variant (svPPA), and the logopenic variant (lvPPA). At the time of diagnosis, patients and their families’ main question pertains to prognosis and evolution, but very few data exist to support clinicians’ claims. The objective of this study was to review the current literature on the longitudinal changes in cognition, behaviours, and functional abilities in the three main PPA variants. A comprehensive review was undertaken via a search on PUBMED and EMBASE. Two authors independently reviewed a total of 65 full-text records for eligibility. A total of 14 group studies and one meta-analysis were included. Among these, eight studies included all three PPA variants. Eight studies were prospective, and the follow-up duration was between one and five years. Overall, svPPA patients showed more behavioural disturbances both at baseline and over the course of the disease. Patients with lvPPA showed a worse cognitive decline, especially in episodic memory, and faster progression to dementia. Finally, patients with nfvPPA showed the most significant losses in language production and functional abilities. Data regarding the prodromal and last stages of PPA are still missing and studies with a longer follow-up observation period are needed.

中文翻译：

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原发性进行性失语症三种主要变体的认知、行为和功能能力的纵向变化：文献综述


原发性进行性失语症（PPA）是一组神经退行性疾病，表现为隐匿且持续的语言障碍。已经描述了三种主要的 PPA 变体：非流利/语法变体（nfvPPA）、语义变体（svPPA）和语词减少变体（lvPPA）。在诊断时，患者及其家属的主要问题涉及预后和演变，但很少有数据支持临床医生的主张。本研究的目的是回顾当前关于三种主要 PPA 变体认知、行为和功能能力纵向变化的文献。通过对 PUBMED 和 EMBASE 的搜索进行了全面审查。两位作者独立审查了总共 65 条全文记录的资格。总共纳入 14 项小组研究和一项荟萃分析。其中，八项研究涵盖了所有三种 PPA 变体。八项研究是前瞻性的，随访时间为一年到五年。总体而言，svPPA 患者在基线和病程中表现出更多的行为障碍。 lvPPA 患者的认知能力下降更严重，尤其是情景记忆，并且进展为痴呆的速度更快。最后，患有 nfvPPA 的患者在语言产生和功能能力方面表现出最显着的损失。有关 PPA 前驱期和末期的数据仍然缺失，需要进行更长随访观察期的研究。