National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA.
J Child Psychol Psychiatry. 2012 Nov;53(11):1149-56. doi: 10.1111/j.1469-7610.2012.02568.x. Epub 2012 Jun 1.
There is debate as to whether chronic irritability (operationalized as severe mood dysregulation, SMD) is a developmental form of bipolar disorder (BD). Although structural brain abnormalities in BD have been demonstrated, no study compares neuroanatomy among SMD, BD, and healthy volunteers (HV) either cross-sectionally or over time. Furthermore, the developmental trajectories of structural abnormalities in BD or SMD are unknown. This study provides such data in BD, SMD, and HV.
An optimized, modulated voxel-based morphometry (VBM) analysis was conducted on structural MRI scans from 201 children (78 SMD, 55 BD, and 68 HV). In addition, 92 children (31 SMD, 34 BD, and 27 HV) were rescanned after 2 years (mean interval 1.99 ± 0.94 years), to compare time-related changes among the three groups.
Cross-sectionally, the groups differed in gray matter (GM) volume in presupplementary motor area (pre-SMA), dorsolateral prefrontal cortex (DLPFC), insula, and globus pallidus. The cortical differences were driven mainly by increased GM volume in HV compared with BD and SMD. In globus pallidus, there was increased GM in BD compared with HV and SMD. Longitudinally, group-by-time interactions were evident in two clusters in the superior/inferior parietal lobule (R SPL/IPL) and in the precuneus. In both clusters, the interactions were driven by an abnormal increase in volume in BD.
Cross-sectionally, both BD and SMD are associated with structural abnormalities in frontal cortex, insula, and basal ganglia. Although some of these deficits overlap (insula and DLPFC), others differentiate SMD and BD (pre-SMA and globus pallidus). Abnormal developmental trajectories in lateral parietal cortex and precuneus are present in, and unique to, BD. Because of the high proportion of co-occurring ADHD in the SMD subjects, we could not separate effects of ADHD from those of SMD, and future research including a nonirritable ADHD group must address this issue.
慢性易怒（表现为严重的情绪失调，SMD）是否是双相情感障碍（BD）的一种发展形式存在争议。尽管已经证明 BD 存在结构性脑异常，但尚无研究比较 SMD、BD 和健康志愿者（HV）之间的神经解剖结构，无论是在横断面还是随时间变化。此外，BD 或 SMD 中结构性异常的发展轨迹尚不清楚。本研究提供了 BD、SMD 和 HV 中的此类数据。
对 201 名儿童（78 名 SMD、55 名 BD 和 68 名 HV）的结构 MRI 扫描进行了优化调制体素形态计量学（VBM）分析。此外，92 名儿童（31 名 SMD、34 名 BD 和 27 名 HV）在 2 年后（平均间隔 1.99±0.94 年）重新扫描，以比较三组之间的时间相关变化。
在横断面上，三组在补充运动前区（pre-SMA）、背外侧前额叶皮质（DLPFC）、岛叶和苍白球的灰质（GM）体积上存在差异。皮质差异主要是由于 HV 与 BD 和 SMD 相比 GM 体积增加所致。在苍白球中，BD 与 HV 和 SMD 相比 GM 体积增加。纵向来看，在顶下/顶内叶（RSPL/IPL）和楔前叶两个脑区存在组间时间交互作用。在这两个脑区，交互作用是由 BD 中体积异常增加驱动的。
在横断面上，BD 和 SMD 都与额叶皮质、岛叶和基底节的结构性异常有关。尽管其中一些缺陷重叠（岛叶和 DLPFC），但其他缺陷则将 SMD 和 BD 区分开来（pre-SMA 和苍白球）。外侧顶叶皮质和楔前叶的异常发育轨迹存在于 BD 中，且是 BD 所特有的。由于 SMD 患者中 ADHD 的比例较高，我们无法将 ADHD 的影响与 SMD 的影响分开，因此未来包括非易怒 ADHD 组的研究必须解决这个问题。
