Lucas-Jiménez Olaia, Ojeda Natalia, Peña Javier, Cabrera-Zubizarreta Alberto, Díez-Cirarda María, Gómez-Esteban Juan Carlos, Gómez-Beldarrain María Ángeles, Ibarretxe-Bilbao Naroa
Department of Methods and Experimental Psychology Faculty of Psychology and Education University of Deusto Bilbao Spain.
OSATEK MR Unit Hospital of Galdakao Galdakao-Usansolo Spain.
Ann Clin Transl Neurol. 2018 May 25;5(7):803-814. doi: 10.1002/acn3.578. eCollection 2018 Jul.
Apathy is a common nonmotor symptom in Parkinson's disease (PD) affecting 40% of patients. The aim of the study was to investigate brain changes and correlates of frontal, striatal, and limbic pathways related to subclinical symptoms of apathy in PD patients.
Thirty-two PD patients divided into low-subclinical symptoms of apathy (LSA) ( = 18) and high-subclinical symptoms of apathy (HSA) ( = 14) and 25 healthy controls (HC) underwent a T1-weighted, diffusion-weighted, and resting-state functional MRI. Apathy was evaluated with the Lille Apathy Rating Scale. Voxel-based morphometry, tract-based spatial statistics, and resting-state functional connectivity (FC) analyses were performed with a region-of-interest approach.
HSA-PD showed increased white matter axial and mean diffusivity compared with HC and increased white matter axial diffusivity compared with LSA-PD. HSA-PD showed decreased fronto-striatal and fronto-limbic FC compared with HC and decreased fronto-striatal FC compared with LSA-PD. LSA-PD showed decreased fronto-limbic but increased fronto-striatal FC (hyperconnectivity) compared with HC. No significant differences in grey matter were found. Fronto-striatal FC and white matter axial and mean diffusivity were associated with symptoms of apathy in HSA-PD. The fronto-striatal hyperconnectivity was associated with lower symptoms of apathy in LSA-PD.
Findings suggest distinct brain alterations in PD groups with subclinical symptoms of apathy. The increased pattern of activation in LSA-PD, accompanied with lower apathetic symptomatology, might be the initial manifestation of compensatory mechanisms for dysfunctional limbic pathway. The same pattern of hyperconnectivity has been found in other pathologies and the implication of these abnormalities as a cross-disease model for initial apathy symptomatology is further discussed.
淡漠是帕金森病（PD）常见的非运动症状，影响40%的患者。本研究旨在调查与PD患者淡漠亚临床症状相关的大脑变化以及额叶、纹状体和边缘系统通路的相关性。
32例PD患者分为低淡漠亚临床症状组（LSA）（n = 18）和高淡漠亚临床症状组（HSA）（n = 14），以及25名健康对照者（HC），接受了T1加权、扩散加权和静息态功能磁共振成像检查。采用里尔淡漠评定量表评估淡漠情况。采用基于体素的形态学测量、基于纤维束的空间统计学和静息态功能连接（FC）分析，并结合感兴趣区方法进行研究。
与HC相比，HSA-PD组白质轴向扩散率和平均扩散率增加，与LSA-PD组相比，白质轴向扩散率增加。与HC相比，HSA-PD组额叶-纹状体和额叶-边缘系统FC降低，与LSA-PD组相比，额叶-纹状体FC降低。与HC相比，LSA-PD组额叶-边缘系统FC降低，但额叶-纹状体FC增加（超连接）。未发现灰质有显著差异。额叶-纹状体FC以及白质轴向扩散率和平均扩散率与HSA-PD组的淡漠症状相关。额叶-纹状体超连接与LSA-PD组较低的淡漠症状相关。
研究结果表明，有淡漠亚临床症状的PD组存在明显的大脑改变。LSA-PD组激活模式增加，同时淡漠症状较低，这可能是边缘系统通路功能障碍的代偿机制的初始表现。在其他疾病中也发现了相同的超连接模式，并进一步讨论了这些异常作为初始淡漠症状的跨疾病模型的意义。
