Ugwu Izuchukwu D, Amico Francesco, Carballedo Angela, Fagan Andrew J, Frodl Thomas
Adelaide and Meath Hospital Incorporating the National Children's Hospital, Tallaght, Dublin 24, Dublin, Ireland.
Brain Struct Funct. 2015 Jul;220(4):1997-2009. doi: 10.1007/s00429-014-0769-x. Epub 2014 Apr 18.
Previous diffusion tensor imaging (DTI) studies have shown that various factors can affect white matter (WM) tract diffusivity. The aim of the present study was to investigate the effects of childhood adversity (CA), age and gender on WM diffusivity in tracts that are thought to be involved in emotional regulation in individuals with major depressive disorder (MDD) and healthy controls (HC). DTI was obtained from 46 subjects with MDD and 46 HC subjects. Data were pre-processed and deterministic tractography was applied in the cingulum, uncinate fasciculus (UF), fornix, superior longitudinal fasciculus (SLF) and fronto-occipital fasciculus (FOF). In subjects with a history of CA, fractional anisotropy (FA) was greater in the rostral cingulum (RC) and dorsal cingulum, whereas radial diffusivity (RD) was smaller in the RC when compared with subjects with no history of CA. In the UF, FOF and parahippocampal cingulum, FA was greater in the left hemisphere in the subjects with CA when compared with those without CA. Age affected FA, longitudinal diffusivity and RD in the UF, fornix, FOF and SLF, reflecting axonal and myelin degeneration with increasing age. Depression or gender did not have any effects on the diffusivity measures. Due to the cross-sectional nature of the study, a recall bias for CA and possible effects of medical treatment on diffusivity measures could have played a role. CA and age could increase the likelihood to develop WM microstructural anomalies in the brain affective network. Moreover, subjects with CA could be more vulnerable to FA changes.
既往的扩散张量成像（DTI）研究表明，多种因素可影响白质（WM）束的扩散率。本研究旨在探讨童年逆境（CA）、年龄和性别对重度抑郁症（MDD）患者和健康对照（HC）中被认为参与情绪调节的白质束扩散率的影响。对46例MDD患者和46例HC受试者进行了DTI检查。对数据进行预处理，并在扣带束、钩束（UF）、穹窿、上纵束（SLF）和额枕束（FOF）中应用确定性纤维束成像。有CA病史的受试者，与无CA病史的受试者相比，其喙侧扣带束（RC）和背侧扣带束的分数各向异性（FA）更大，而RC中的径向扩散率（RD）更小。在UF、FOF和海马旁扣带束中，有CA的受试者左半球的FA比无CA的受试者更大。年龄影响UF、穹窿、FOF和SLF中的FA、纵向扩散率和RD，反映了随着年龄增长轴突和髓鞘的退变。抑郁或性别对扩散率测量没有任何影响。由于本研究的横断面性质，CA的回忆偏差和药物治疗对扩散率测量的可能影响可能起到了一定作用。CA和年龄可能增加大脑情感网络中发生WM微结构异常的可能性。此外，有CA的受试者可能更容易出现FA变化。
