Department of Psychiatry, Marqués de Valdecilla University Hospital, Spain.
Am J Psychiatry. 2010 Apr;167(4):451-8. doi: 10.1176/appi.ajp.2009.09050716. Epub 2010 Feb 16.
Impaired cognitive function has been identified as a core feature of schizophrenia. However, a significant proportion of patients do not show any cognitive deficits. The aim of this study was to assess if there were differences in white matter integrity between patients with and without cognitive impairment.
A diffusion tensor imaging study and neurocognitive assessment were conducted in 49 patients with first-episode psychosis and 41 healthy comparison subjects. Subjects were assessed using the Continuous Performance Test, the Grooved Pegboard Test, the Rey Auditory Verbal Learning Test, and the Trail Making Test Part B. For each test, the patient sample was subdivided according to performance, with those scoring more than one standard deviation below the normative mean categorized as impaired. For each cognitive domain, white matter fractional anisotropy in deficit and nondeficit subgroups was compared using a voxel-based analysis. A nonparametric statistical method, controlling for multiple comparisons, was applied.
Impairment on the Trail Making Test Part B was associated with reduced fractional anisotropy in the right/left anterior thalamic radiation and inferior fronto-occipital fasciculus, forceps minor, and left superior and inferior longitudinal fasciculi. Patients exhibiting Grooved Pegboard Test impairment showed reduced fractional anisotropy in the forceps minor, inferior fronto-occipital fasciculus, anterior thalamic radiation, and corticospinal and corticopontine tracts. Impaired performance on the Rey Auditory Verbal Learning Test and Continuous Performance Test was not associated with significant differences in fractional anisotropy.
Deficits in executive and motor functioning in patients with first-episode psychosis are associated with reductions in white matter integrity in the major fasciculi that connect the frontal and temporal cortices as well as in pathways connecting cortical and subcortical regions. Their presence at the onset of illness, in minimally medicated patients, indicates that these findings are not attributable to effects of chronic illness or its treatment.
认知功能障碍已被确定为精神分裂症的核心特征。然而，相当一部分患者没有表现出任何认知缺陷。本研究旨在评估首次发作的精神病患者中是否存在有认知障碍和无认知障碍患者之间的白质完整性差异。
对 49 例首发精神病患者和 41 例健康对照者进行弥散张量成像研究和神经认知评估。采用连续操作测试、槽钉板测试、 Rey 听觉言语学习测试和 Trail Making 测试 B 部分对受试者进行评估。对于每个测试，根据表现将患者样本进行细分，将得分低于正常均值一个标准差以上的患者归类为受损。对于每个认知域，使用基于体素的分析比较缺陷亚组和非缺陷亚组的白质各向异性分数。应用一种非参数统计方法，控制多重比较。
Trail Making 测试 B 的损伤与右侧/左侧前丘脑辐射和下额枕束、小内囊、左侧上下纵束的各向异性分数降低有关。Grooved Pegboard 测试损伤的患者显示小内囊、下额枕束、前丘脑辐射、皮质脊髓束和皮质脑桥束的各向异性分数降低。Rey 听觉言语学习测试和连续操作测试的表现受损与各向异性分数无显著差异相关。
首发精神病患者的执行和运动功能障碍与连接额颞皮质的主要束以及连接皮质和皮质下区域的通路的白质完整性降低有关。这些发现出现在疾病发作时，且处于未经药物治疗的患者中，表明这些发现并非归因于慢性疾病或其治疗的影响。
