首发精神分裂症患者的前联合白质完整性对认知功能的影响

摘要

Objective To investigate the relationship between the white matter fiber connectivity of the anterior commissure (AC) and schizophrenia, and to explore the role of AC connectivity in cognitive functions in first-episode schizophrenia. Methods Twenty-four patients with first-episode schizophrenia and 29 healthy controls underwent diffu-sion tensor imaging (DTI) to measure fractional anisotropy (FA). Fiber tracking was then used to reconstruct the white matter fiber connectivity of AC to examine the white matter integrity. We also analyzed the relationship between AC integ-rity and cognitive function. Results Compared to healthy controls, patients with first-episode schizophrenia had a signifi-cant reduction in mean FA of AC tracts [(0.48±0.07) vs. (0.54±0.05),P=0.002],longer completion time in trail making test(TMT)[TMT_A: (55.19 ± 19.15) vs. (36.61 ± 11.72), P<0.001;TMT_B: (88.84 ± 38.92) vs. (53.75 ± 23.41), P<0.001] and worse performance in logical memory test [immediate logical memory score:(6.12±3.85) vs. (11.69±3.68), P<0.001;delay logical memory score:(3.33±3.16) vs. (9.83±4.15), P<0.001]. In addition, there was negatively correlation of mean FA of AC tracts with TMT_A completion time (r=-0.458, P=0.037) or TMT_B completion time (r=-0.541, P=0.011) in patients with schizophrenia, but not in controls. Conclusion This study supports the disconnection hypothesis of schizo-phrenia. The deficit of AC microstructure integrity may be partly responsible for impaired executive functions in schizo-phrenia, suggesting that the integrity of white matter fiber is an important endophenotype of schizophrenia.%目的：研究首发精神分裂症患者前联合白质纤维完整性与精神分裂症的关系及其对认知功能的影响。方法对24例首发精神分裂症患者和29名正常对照者行弥散张量成像（diffusion tensor imaging，DTI）扫描，使用纤维束追踪的方法重建前联合纤维，并研究前联合纤维连接异常与认知功能间的关系。结果患者组前联合平均部分各向异性（fractional anisotropy，FA）值较对照组下降[（0.48±0.07）vs.（0.54±0.05），P=0.002]，连线测验（trail making test，TMT）完成时间延长[TMT_A：（55.19±19.15）vs.（36.61±11.72），P<0.001；TMT_B：（88.84±38.92）vs.（53.75±23.41），P<0.001]，逻辑记忆测试分数低于对照组[即刻逻辑记忆分数：（6.12±3.85）vs.（11.69±3.68），P<0.001；延时逻辑记忆：（3.33±3.16）vs.（9.83±4.15），P<0.001]。且患者组的FA值与TMT_A测验时间（r=-0.458，P=0.037）和TMT_B测验时间（r=-0.541，P=0.011）分别呈负相关，但在对照组未发现此相关性。结论本研究支持精神分裂症的脑功能连接异常假说，前联合白质纤维微结构受损可能是精神分裂症患者执行功能受损的原因之一，提示白质纤维完整性是精神分裂症的一个重要内表型。