Oestreich Lena K L, Pasternak Ofer, Shenton Martha E, Kubicki Marek, Gong Xue, McCarthy-Jones Simon, Whitford Thomas J
School of Psychology, UNSW Australia, NSW, Australia; Queensland Brain Institute, University of Queensland, St Lucia, QLD 4072, Australia.
Department of Psychiatry, Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
Neuroimage Clin. 2016 Aug 4;12:405-14. doi: 10.1016/j.nicl.2016.08.004. eCollection 2016.
There is growing evidence to suggest that delusions associated with schizophrenia arise from altered structural brain connectivity. The present study investigated whether structural changes in three major fasciculi that interconnect the limbic system - the cingulum bundle, uncinate fasciculus and fornix - are associated with delusions in chronic schizophrenia patients.
Free-water corrected Diffusion Tensor Imaging was used to investigate the association between delusions and both microstructural changes within these three fasciculi and extracellular changes in the surrounding free-water. Clinical data and diffusion MRI scans were obtained from 28 healthy controls and 86 schizophrenia patients, of whom 34 had present state delusions, 35 had a lifetime history but currently remitted delusions, and 17 had never experienced delusions.
While present state and remitted delusions were found to be associated with reduced free-water corrected fractional anisotropy (FAT) and increased free-water corrected radial diffusivity (RDT) in the cingulum bundle bilaterally, extracellular free-water (FW) in the left cingulum bundle was found to be specifically associated with present state delusions in chronic schizophrenia. No changes were observed in the remaining tracts.
These findings suggest that state and trait delusions in chronic schizophrenia are associated with microstructural processes, such as myelin abnormalities (as indicated by decreased FAT and increased RDT) in the cingulum bundle and that state delusions are additionally associated with extracellular processes such as neuroinflammation or atrophy (as indicated by increased FW) in the left cingulum bundle.
越来越多的证据表明，与精神分裂症相关的妄想源于大脑结构连接的改变。本研究调查了连接边缘系统的三个主要纤维束——扣带束、钩束和穹窿——的结构变化是否与慢性精神分裂症患者的妄想有关。
使用自由水校正扩散张量成像来研究妄想与这三个纤维束内的微观结构变化以及周围自由水的细胞外变化之间的关联。从28名健康对照者和86名精神分裂症患者中获取临床数据和扩散磁共振成像扫描，其中34人有当前状态的妄想，35人有终生病史但目前妄想已缓解，17人从未经历过妄想。
虽然发现当前状态和缓解期妄想与双侧扣带束中自由水校正分数各向异性（FAT）降低和自由水校正径向扩散率（RDT）增加有关，但发现左侧扣带束中的细胞外自由水（FW）与慢性精神分裂症的当前状态妄想特别相关。其余纤维束未观察到变化。
这些发现表明，慢性精神分裂症的状态和特质妄想与微观结构过程有关，如扣带束中的髓鞘异常（以FAT降低和RDT增加表示），并且状态妄想还与左侧扣带束中的细胞外过程有关，如神经炎症或萎缩（以FW增加表示）。
