Andreasen N C, O'Leary D S, Flaum M, Nopoulos P, Watkins G L, Boles Ponto L L, Hichwa R D
Mental Health Clinical Research Centre, University of Iowa College of Medicine, Iowa City, USA.
Lancet. 1997 Jun 14;349(9067):1730-4. doi: 10.1016/s0140-6736(96)08258-x.
There have been reports that patients with schizophrenia have decreased metabolic activity in prefrontal cortex. However, findings have been confounded by medication effects, chronic illness, and difficulties of measurement. We aimed to address these problems by examination of cerebral blood flow with positron emission tomography (PET).
We studied 17 neuroleptic-naïve patients at the early stages of illness by means of image analysis and statistical methods that can detect abnormalities at the gyral level.
An initial omnibus test with a randomisation analysis indicated that patients differed from normal controls at the 0.06 level. In the follow-up analysis, three separate prefrontal regions had decreased perfusion (lateral, orbital, medial), as well as regions in inferior temporal and parietal cortex that are known to be anatomically connected. Regions with increased perfusion were also identified (eg, thalamus, cerebellum, retrosplenial cingulate), which suggests an imbalance in distributed cortical and subcortical circuits.
These distributed dysfunctional circuits may form the neural basis of schizophrenia through cognitive impairment of the brain, which prevents it from processing input efficiently and producing output effectively, thereby leading to symptoms such as hallucinations, delusions, and loss of volition.
有报道称精神分裂症患者前额叶皮质的代谢活动降低。然而，研究结果受到药物作用、慢性疾病和测量困难的影响。我们旨在通过正电子发射断层扫描（PET）检查脑血流量来解决这些问题。
我们通过图像分析和能够在脑回水平检测异常的统计方法，对17例未服用抗精神病药物且处于疾病早期的患者进行了研究。
一项采用随机分析的初步综合测试表明，患者与正常对照组在0.06水平上存在差异。在后续分析中，三个不同的前额叶区域灌注减少（外侧、眶部、内侧），以及已知在解剖学上相连的颞下皮质和顶叶皮质区域。还发现了灌注增加的区域（如丘脑、小脑、扣带回后回），这表明皮质和皮质下分布式回路存在失衡。
这些分布式功能失调回路可能通过大脑的认知障碍形成精神分裂症的神经基础，这会阻止大脑有效地处理输入并产生输出，从而导致幻觉、妄想和意志丧失等症状。
