Piolino Pascale, Chételat Gaël, Matuszewski Vanessa, Landeau Brigitte, Mézenge Florence, Viader Fausto, de la Sayette Vincent, Eustache Francis, Desgranges Béatrice
Inserm-EPHE-Université de Caen Basse-Normandie, Unité E0218, Caen, France.
Neuropsychologia. 2007 Sep 20;45(12):2730-43. doi: 10.1016/j.neuropsychologia.2007.04.013. Epub 2007 Apr 19.
Patients suffering from frontal variant of frontotemporal dementia (fv-FTD) undergo autobiographical amnesia encompassing all time periods. We previously demonstrated in a group of 20 fv-FTD patients that this impairment involved deficits in executive function and semantic memory for all periods as well as new episodic learning and behavioural changes for the most recent period covering the last 12 months [Matuszewski, V., Piolino, P., de la Sayette, V., Lalevée, C., Pélerin, A., Dupuy, B., et al. (2006). Retrieval mechanisms for autobiographical memories: Insights from the frontal variant of frontotemporal dementia, Neuropsychologia, 44, 2386-2397]. The aim of the present study was to unravel the neural bases of this impairment by mapping in a subgroup of patients correlations between resting-state brain glucose utilization measured by FDG-PET and measures of autobiographical memory (AM) using the TEMPau task which is designed to gauge personal event recollection across five life time periods. Like in our previous report, the group of patients was impaired regardless of time periods compared to healthy subjects providing generic memories instead of event specific sensory-perceptual-affective details, i.e., episodic memories. New data showed that the patients were also impaired in sense of reliving and self-perspective during retrieval. The cognitivo-metabolic correlations between the AM score and resting normalized FDG-Uptake were computed using statistical parametric mapping (SPM2) and controlling for age and dementia severity. They revealed that AM deficits were mainly subserved by the dysfunction of left-sided orbitofrontal and also temporal neocortical areas whatever the period. Additional analysis showed that specific memories were associated with left orbitofrontal areas whereas generic memories were mainly associated with the left temporal pole. This study supports the view that fv-FTD patients undergo a breakdown of generative processes which relies regardless of the remoteness on the left orbitofrontal cortex and temporal neocortex to gain access to AM.
患有额颞叶痴呆额叶变异型（fv-FTD）的患者会经历涵盖所有时间段的自传体失忆。我们之前在一组20名fv-FTD患者中证明，这种损害涉及所有时间段的执行功能和语义记忆缺陷，以及最近12个月这一时间段的新情景学习和行为变化[马图谢夫斯基，V.，皮奥里诺，P.，德拉塞耶特，V.，拉莱韦，C.，佩勒兰，A.，迪皮伊，B.等（2006年）。自传体记忆的检索机制：来自额颞叶痴呆额叶变异型的见解，《神经心理学》，44，2386 - 2397]。本研究的目的是通过在一组患者中绘制静息态脑葡萄糖利用情况（通过FDG-PET测量）与自传体记忆（AM）测量值之间的相关性，来揭示这种损害的神经基础，使用TEMPau任务来评估五个生命时间段内的个人事件回忆。与我们之前的报告一样，与提供一般记忆而非特定事件的感觉-感知-情感细节（即情景记忆）的健康受试者相比，该组患者在各个时间段均存在损害。新数据表明，患者在检索过程中的重温感和自我视角方面也存在损害。使用统计参数映射（SPM2）并控制年龄和痴呆严重程度，计算了AM评分与静息态标准化FDG摄取之间的认知-代谢相关性。结果显示，无论在哪个时间段，AM缺陷主要由左侧眶额和颞叶新皮质区域的功能障碍所导致。进一步分析表明，特定记忆与左侧眶额区域相关，而一般记忆主要与左侧颞极相关。本研究支持这样一种观点，即fv-FTD患者经历了生成过程的崩溃，无论时间远近，这一过程都依赖于左侧眶额皮质和颞叶新皮质来获取自传体记忆。
