Benito Menni CASM, Barcelona, Spain.
Psychol Med. 2012 Jan;42(1):73-84. doi: 10.1017/S0033291711001073. Epub 2011 Jul 7.
It is not known whether first-episode psychosis is characterized by the same prefrontal cortex functional imaging abnormalities as chronic schizophrenia.
Thirty patients with a first episode of non-affective functional psychosis and 28 healthy controls underwent functional magnetic resonance imaging (fMRI) during performance of the n-back working memory task. Voxel-based analyses of brain activations and deactivations were carried out and compared between groups. The connectivity of regions of significant difference between the patients and controls was also examined.
The first-episode patients did not show significant prefrontal hypo- or hyperactivation compared to controls. However, they showed failure of deactivation in the medial frontal cortex. This area showed high levels of connectivity with the posterior cingulate gyrus/precuneus and parts of the parietal cortex bilaterally. Failure of deactivation was significantly greater in first-episode patients who had or went on to acquire a DSM-IV diagnosis of schizophrenia than in those who did not, and in those who met RDC criteria for schizophrenia compared to those who did not.
First-episode psychosis is not characterized by hypo- or hyperfrontality but instead by a failure of deactivation in the medial frontal cortex. The location and connectivity of this area suggest that it is part of the default mode network. The failure of deactivation seems to be particularly marked in first-episode patients who have, or progress to, schizophrenia.
首发精神病是否具有与慢性精神分裂症相同的前额叶皮层功能影像学异常尚不清楚。
30 例首发非情感性功能性精神病患者和 28 例健康对照者在执行 n 回工作记忆任务时接受了功能磁共振成像（fMRI）检查。对脑激活和失活的体素进行了分析，并对两组进行了比较。还检查了患者与对照组之间存在显著差异的区域之间的连通性。
首发患者与对照组相比，前额叶区未见明显的低激活或高激活。然而，他们在前额内侧皮层表现出失活失败。该区域与后扣带回/楔前叶和双侧顶叶皮层的部分区域显示出较高的连接性。与未发生或未发展为精神分裂症的首发患者相比，首发患者中符合 DSM-IV 诊断标准的精神分裂症患者和符合 RDC 标准的精神分裂症患者的失活失败更为明显。
首发精神病不是以低或高前额叶为特征，而是以额内侧皮层失活失败为特征。该区域的位置和连接性表明它是默认模式网络的一部分。失活失败在患有或进展为精神分裂症的首发患者中尤为明显。
