Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, United States.
Schizophr Res. 2013 Jan;143(1):172-8. doi: 10.1016/j.schres.2012.10.014. Epub 2012 Nov 11.
White matter alterations in schizophrenia are associated with deficits in neurocognitive performance. Recently, across task within-individual variability (WIV) has emerged as a useful construct for assessing the profile in cognitive performance in schizophrenia. However, the neural basis of WIV has not been studied in patients with schizophrenia.
Twenty-five patients with schizophrenia (SZ) and 27 healthy comparison subjects (HC) performed a computerized neurocognitive battery (CNB) and underwent diffusion tensor imaging (DTI). WIV for performance accuracy and speed on the CNB was calculated across-tasks. Voxel-wise group comparisons of white matter fractional anisotropy (FA) were performed using tract-based spatial statistics (TBSS). The relationship between accuracy and speed WIV on the CNB and white matter FA was examined within the regions that differentiated patients and healthy comparison subjects.
SZ had higher WIV for performance accuracy and speed as compared to HC. FA in SZ compared to HC was reduced in bilateral frontal, temporal and occipital white matter including a large portion of the corpus callosum. In white matter regions that differed between patients and comparison subjects, higher FA in the left cingulum bundle and left fronto-occipital fasciculus were associated with lower CNB speed WIV for HC, but not SZ. Accuracy WIV was not associated with differences in white matter FA between SZ and HC.
We provide evidence that WIV is greater in patients with SZ and that this greater within-individual variability in performance in patients is associated with disruptions of WM integrity in specific brain regions.
精神分裂症患者的白质改变与神经认知表现缺陷有关。最近,个体内跨任务变异性(WIV)作为评估精神分裂症认知表现特征的有用构建体已经出现。然而,精神分裂症患者的 WIV 神经基础尚未得到研究。
25 名精神分裂症患者(SZ)和 27 名健康对照组(HC)进行了计算机神经认知测试(CNB)和弥散张量成像(DTI)。通过跨任务计算 CNB 性能准确性和速度的 WIV。使用基于束的空间统计学(TBSS)对全脑白质各向异性分数(FA)进行组间比较。在区分患者和健康对照组的区域内,检查了 CNB 准确性和速度 WIV 与白质 FA 之间的关系。
与 HC 相比,SZ 的 WIV 更高。与 HC 相比,SZ 的 FA 降低,双侧额颞顶枕叶白质包括胼胝体的大部分区域。在患者与对照组之间存在差异的白质区域中,左侧扣带束和左侧额枕束的 FA 较高与 HC 的 CNB 速度 WIV 较低有关,但与 SZ 无关。准确性 WIV 与 SZ 和 HC 之间的白质 FA 差异无关。
我们提供的证据表明,SZ 患者的 WIV 更大,并且患者在表现方面更大的个体内变异性与特定脑区 WM 完整性的破坏有关。