Heitz Camille, Noblet Vincent, Phillipps Clélie, Cretin Benjamin, Vogt Natacha, Philippi Nathalie, Kemp Jennifer, de Petigny Xavier, Bilger Mathias, Demuynck Catherine, Martin-Hunyadi Catherine, Armspach Jean-Paul, Blanc Frédéric
Neuropsychology Unit, Memory Resource and Research Centre (CMRR), Department of Neurology, University Hospital of Strasbourg, Strasbourg, France.
ICube Laboratory, IMIS Team, University of Strasbourg, CNRS, FMTS, Strasbourg, France.
Alzheimers Res Ther. 2016 Mar 16;8(1):10. doi: 10.1186/s13195-016-0179-9.
Theory of mind (ToM) refers to the ability to attribute mental states, thoughts (cognitive component) or feelings (affective component) to others. This function has been studied in many neurodegenerative diseases; however, to our knowledge, no studies investigating ToM in dementia with Lewy bodies (DLB) have been published. The aim of our study was to assess ToM in patients with DLB and to search for neural correlates of potential deficits.
Thirty-three patients with DLB (DLB group) and 15 patients with Alzheimer's disease (AD group), all in the early stage of the disease, as well as 16 healthy elderly control subjects (HC group), were included in the study. After a global cognitive assessment, we used the Faux Pas Recognition (FPR) test, the Reading the Mind in the Eyes (RME) test and Ekman's Facial Emotion Recognition test to assess cognitive and affective components of ToM. Patients underwent cerebral 3-T magnetic resonance imaging, and atrophy of grey matter was analysed using voxel-based morphometry. We performed a one-sample t test to investigate the correlation between each ToM score and grey matter volume and a two-sample t test to compare patients with DLB impaired with those non-impaired for each test.
The DLB group performed significantly worse than the HC group on the FPR test (P = 0.033) and the RME test (P = 0.015). There was no significant difference between the AD group and the HC group or between the DLB group and the AD group. Some brain regions were associated with ToM impairments. The prefrontal cortex, with the inferior frontal cortex and the orbitofrontal cortex, was the main region, but we also found correlations with the temporoparietal junction, the precuneus, the fusiform gyrus and the insula.
This study is the first one to show early impairments of ToM in DLB. The two cognitive and affective components both appear to be affected in this disease. Among patients with ToM difficulties, we found atrophy in brain regions classically involved in ToM, which reinforces the neuronal network of ToM. Further studies are now needed to better understand the neural basis of such impairment.
心理理论（ToM）是指将心理状态、思想（认知成分）或情感（情感成分）归因于他人的能力。这种功能已在许多神经退行性疾病中得到研究；然而，据我们所知，尚未发表关于路易体痴呆（DLB）患者心理理论的研究。我们研究的目的是评估DLB患者的心理理论，并寻找潜在缺陷的神经关联。
本研究纳入了33例DLB患者（DLB组）、15例阿尔茨海默病患者（AD组），均处于疾病早期，以及16名健康老年对照者（HC组）。在进行全面认知评估后，我们使用失言识别（FPR）测试、读心术（RME）测试和埃克曼面部表情识别测试来评估心理理论的认知和情感成分。患者接受了3-T脑磁共振成像检查，并使用基于体素的形态计量学分析灰质萎缩情况。我们进行单样本t检验以研究每个心理理论得分与灰质体积之间的相关性，并进行两样本t检验以比较DLB患者在每项测试中受损与未受损的情况。
DLB组在FPR测试（P = 0.033）和RME测试（P = 0.015）中的表现明显差于HC组。AD组与HC组之间或DLB组与AD组之间没有显著差异。一些脑区与心理理论损伤有关。前额叶皮质，包括额下回和眶额皮质，是主要区域，但我们也发现与颞顶交界区、楔前叶、梭状回和脑岛存在相关性。
本研究首次表明DLB患者存在心理理论的早期损伤。这种疾病的认知和情感成分似乎均受到影响。在存在心理理论困难的患者中，我们发现经典的参与心理理论的脑区出现萎缩，这强化了心理理论的神经网络。现在需要进一步研究以更好地理解这种损伤的神经基础。
