Schizophrenia has long been framed as a disorder of altered brain connectivity, with dysfunction in thalamocortical circuity potentially playing a key role in the development of the illness phenotype, including psychotic symptomatology and cognitive impairments. There is emerging evidence for functional and structural hypoconnectivity between thalamus and prefrontal cortex in persons with schizophrenia spectrum disorders, as well as hyperconnectivity between thalamus and sensory and motor cortices. However, it is unclear whether thalamocortical dysconnectivity is a general marker of vulnerability to schizophrenia or a specific mechanism of schizophrenia pathophysiology. This study aimed to answer this question by using diffusion-weighted imaging to examine thalamocortical structural connectivity in 22 persons with schizophrenia or schizoaffective disorder (SZ), 20 siblings of individuals with a schizophrenia spectrum disorder (SIB), and 44 healthy controls (HC) of either sex. Probabilistic tractography was used to quantify structural connectivity between thalamus and six cortical regions of interest. Thalamocortical structural connectivity was compared among the three groups using cross-thalamic and voxel-wise approaches. Thalamo-prefrontal structural connectivity was reduced in both SZ and SIB relative to HC, while SZ and SIB did not differ from each other. Thalamo-motor structural connectivity was increased in SZ relative to SIB and HC, while SIB and HC did not differ from each other. Hemispheric differences also emerged in thalamic connectivity with motor, posterior parietal, and temporal cortices across all groups. The results support the hypothesis that altered thalamo-prefrontal structural connectivity is a general marker of vulnerability to schizophrenia, whereas altered connectivity between thalamus and motor cortex is related to illness expression or illness-related secondary factors.

长期以来，精神分裂症一直被认为是一种大脑连接改变的疾病，丘脑皮质回路功能障碍可能在疾病表型的发展中发挥关键作用，包括精神病症状和认知障碍。有新的证据表明，精神分裂症谱系障碍患者的丘脑和前额叶皮层之间存在功能和结构上的低连接，以及丘脑与感觉和运动皮层之间的高度连接。然而，尚不清楚丘脑皮质连接障碍是精神分裂症易感性的一般标志还是精神分裂症病理生理学的特定机制。本研究旨在通过使用扩散加权成像检查 22 名精神分裂症或分裂情感障碍 (SZ) 患者、20 名精神分裂症谱系障碍 (SIB) 患者的兄弟姐妹和 44 名健康对照 (HC) 来回答这个问题任何性别。概率纤维束成像用于量化丘脑和六个感兴趣的皮质区域之间的结构连接。使用跨丘脑和体素方法比较了三组之间的丘脑皮质结构连接性。相对于 HC，SZ 和 SIB 的丘脑前额叶结构连接性降低，而 SZ 和 SIB 彼此没有差异。相对于 SIB 和 HC，SZ 的丘脑运动结构连接性增加，而 SIB 和 HC 彼此没有差异。所有组的丘脑与运动、后顶叶和颞叶皮质的连接也出现了半球差异。结果支持这样的假设，即改变的丘脑前额叶结构连接是精神分裂症易感性的一般标志，而丘脑和运动皮层之间的连接改变与疾病表达或疾病相关的次要因素有关。