Department of Geriatric Psychiatry, Affiliated Nanjing Brain Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
Department of Neurology, Affiliated Nanjing Brain Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
Prog Neuropsychopharmacol Biol Psychiatry. 2019 Mar 8;89:427-434. doi: 10.1016/j.pnpbp.2018.10.012. Epub 2018 Oct 24.
Previous studies suggested likely mechanisms underlying the dysfunction of the default mode network (DMN) in schizophrenia. However, altered patterns of the intrinsic activity of the DMN in both deficit schizophrenia (DS) and non-deficit schizophrenia (NDS) patients, as well as the neurocognitive relationships among them, remain unknown. This study explores the resting-state characteristics of the DMN activity in both DS and NDS patients, and further investigates correlations with neurocognitive features.
Demographic, resting-state functional MRI, and neurocognitive data were collected in 37 DS and 38 NDS patients, as well as in 38 matched healthy control subjects (HCs). Independent component analysis was conducted to investigate the characteristics of DMN activity and to further distinguish between common and specific altered regions. In addition, partial correlation analysis was conducted to examine associations between the activity of altered regions and neurocognitive assessments.
Overlapping altered brain activity was observed in both DS and NDS patients in the left middle frontal gyrus (MFG), the left angular gyrus (ANG), and the calcarine sulcus (CAL) region. Furthermore, compared to HCs, DS patients showed less activity in the right inferior temporal gyrus, the right para-hippocampal gyrus / hippocampus (PHP / HIP), and the left precuneus (PCUN), while they showed increased activity in the posterior cingulate cortex (PCC). Notably, NDS patients showed less activity in the bilateral middle occipital gyrus. Correlation analysis indicated that, in the DS group, both Trail Making Test (TMT)-B and spatial processing scores were positively associated with the activities of the left PCUN and the right PHP / HIP, while the Stroop color scores were negatively associated with PCC activity. In the NDS group, the TMT-B scores were associated with activities of the left MFG and CAL regions, while the scores of the Wechsler adult intelligence scale (Chinese revision) were negatively associated with CAL region activity.
The present study demonstrates convergent and divergent altered patterns of the DMN in both DS and NDS patients. Importantly, the specific altered regions of the DMN in DS patients may be associated with extensive deficient neurocognition, indicating novel insights into the pathogenesis of cognitive impairment in schizophrenia.
先前的研究提出了精神分裂症默认模式网络（DMN）功能障碍的可能机制。然而，缺陷型精神分裂症（DS）和非缺陷型精神分裂症（NDS）患者的 DMN 内在活动模式的改变，以及它们之间的神经认知关系仍然未知。本研究探讨了 DS 和 NDS 患者的 DMN 活动的静息状态特征，并进一步研究了与神经认知特征的相关性。
收集了 37 名 DS 患者、38 名 NDS 患者和 38 名匹配的健康对照组（HCs）的人口统计学、静息态功能磁共振成像和神经认知数据。采用独立成分分析（ICA）来研究 DMN 活动的特征，并进一步区分共同和特定的改变区域。此外，进行偏相关分析以检验改变区域的活动与神经认知评估之间的关联。
DS 和 NDS 患者均在左侧额中回（MFG）、左侧角回（ANG）和楔前回（CAL）区域观察到重叠的改变脑活动。此外，与 HCs 相比，DS 患者的右侧颞下回、右侧海马旁回/海马（PHP/HIP）和左侧楔前叶（PCUN）的活动减少，而后扣带回皮层（PCC）的活动增加。值得注意的是，NDS 患者双侧中枕叶的活动减少。相关性分析表明，在 DS 组中，连线测试 B 部分（TMT-B）和空间处理评分与左侧 PCUN 和右侧 PHP/HIP 的活动呈正相关，而 Stroop 颜色评分与 PCC 活动呈负相关。在 NDS 组中，TMT-B 评分与左侧 MFG 和 CAL 区域的活动相关，而韦氏成人智力量表（中国修订版）的评分与 CAL 区域的活动呈负相关。
本研究表明 DS 和 NDS 患者的 DMN 存在会聚和发散的改变模式。重要的是，DS 患者 DMN 的特定改变区域可能与广泛的认知缺陷有关，这为精神分裂症认知障碍的发病机制提供了新的见解。
