Laisney Mickaël, Matuszewski Vanessa, Mézenge Florence, Belliard Serge, de la Sayette Vincent, Eustache Francis, Desgranges Béatrice
U 923, Inserm-EPHE-Université de Caen/Basse-Normandie, GIP Cyceron, CHU Côte de Nacre, Caen, France.
J Neurol. 2009 Jul;256(7):1083-94. doi: 10.1007/s00415-009-5073-y. Epub 2009 Apr 14.
Verbal fluency tasks are commonly used to explore semantic memory and executive functions. The aim of this study was to gain a better understanding of the cognitive and neural mechanisms underlying verbal fluency impairment in the frontal variant of frontotemporal dementia (fv-FTD) and in semantic dementia (SD). Semantic and phonemic fluency tasks were performed by 36 fv-FTD and SD patients and 18 elderly controls. We also carried out a neuropsychological investigation of semantic memory, working memory and shifting and updating processes. We performed correlative and regression analyses of fluency scores and neuropsychological data. In addition, patients underwent a resting positron emission tomography examination, and statistical parametric mapping was used to establish correlations between resting-state FDG uptake in the whole brain and fluency scores for each patient group. Both patient groups displayed impaired performances on both fluency tasks compared with controls, but with different patterns. While fv-FTD patients scored higher than SD patients on semantic fluency, their performances on the phonemic task did not differ. Correlation and regression analyses clearly demonstrated that the fv-FTD patients' performances on both fluency tasks depended on their executive abilities, while those of the SD patients were hampered by the impairment of their semantic memory store. Correlations with resting FDG uptake were consistent with the results of the cognitive study. In fv-FTD, both fluency performances were related to the metabolism of the frontal lobes, while we observed significant correlations between performances on both fluency tasks and the left temporal lobe metabolism in SD.
言语流畅性任务通常用于探索语义记忆和执行功能。本研究的目的是更好地理解额颞叶痴呆（fv-FTD）的额叶变异型和语义性痴呆（SD）中言语流畅性受损的认知和神经机制。36名fv-FTD和SD患者以及18名老年对照者完成了语义和音素流畅性任务。我们还对语义记忆、工作记忆以及转换和更新过程进行了神经心理学调查。我们对流畅性得分和神经心理学数据进行了相关性和回归分析。此外，患者接受了静息正电子发射断层扫描检查，并使用统计参数映射来确定每个患者组全脑静息态FDG摄取与流畅性得分之间的相关性。与对照组相比，两个患者组在两项流畅性任务上的表现均受损，但模式不同。虽然fv-FTD患者在语义流畅性方面得分高于SD患者，但他们在音素任务上的表现没有差异。相关性和回归分析清楚地表明，fv-FTD患者在两项流畅性任务上的表现取决于他们的执行能力，而SD患者的表现则受到其语义记忆存储受损的阻碍。与静息FDG摄取的相关性与认知研究结果一致。在fv-FTD中，两项流畅性表现均与额叶代谢有关，而在SD中，我们观察到两项流畅性任务的表现与左颞叶代谢之间存在显著相关性。
