Division of Psychiatry, University of Edinburgh, Royal Edinburgh Hospital, Edinburgh, United Kingdom.
Brain Mapping Unit, Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom.
Biol Psychiatry. 2015 Sep 15;78(6):413-20. doi: 10.1016/j.biopsych.2014.12.030. Epub 2015 Feb 7.
Schizophrenia is associated with structural brain abnormalities that may be present before disease onset. It remains unclear whether these represent general vulnerability indicators or are associated with the clinical state itself.
To investigate this, structural brain scans were acquired at two time points (mean scan interval 1.87 years) in a cohort of individuals at high familial risk of schizophrenia (n = 142) and control subjects (n = 36). Cortical reconstructions were generated using FreeSurfer. The high-risk cohort was subdivided into individuals that remained well during the study, individuals that had transient psychotic symptoms, and individuals that subsequently became ill. Baseline measures and longitudinal change in global estimates of thickness and surface area and lobar values were compared, focusing on overall differences between high-risk individuals and control subjects and then on group differences within the high-risk cohort.
Longitudinally, control subjects showed a significantly greater reduction in cortical surface area compared with the high-risk group. Within the high-risk group, differences in surface area at baseline predicted clinical course, with individuals that subsequently became ill having significantly larger surface area than individuals that remained well during the study. For thickness, longitudinal reductions were most prominent in the frontal, cingulate, and occipital lobes in all high-risk individuals compared with control subjects.
Our results suggest that larger surface areas at baseline may be associated with mechanisms that go above and beyond a general familial disposition. A relative preservation over time of surface area, coupled with a thinning of the cortex compared with control subjects, may serve as vulnerability markers of schizophrenia.
精神分裂症与结构性脑异常有关，这些异常可能在疾病发作前就存在。目前尚不清楚这些异常是代表一般的易感性指标，还是与临床状态本身有关。
为了研究这一问题，我们对一组处于精神分裂症高家族风险的个体（n=142）和对照组（n=36）进行了两次结构性脑扫描。使用 FreeSurfer 生成皮质重建。将高风险队列分为在研究期间保持良好状态的个体、有短暂精神病症状的个体和随后患病的个体。比较了基线测量值和厚度及表面积的纵向变化以及叶间值，重点比较了高风险个体和对照组之间的总体差异，然后比较了高风险队列内的组间差异。
在纵向研究中，与高风险组相比，对照组的皮质表面积明显减少。在高风险组中，基线时的表面积差异预测了临床病程，随后患病的个体的表面积明显大于研究期间保持良好状态的个体。对于厚度，与对照组相比，所有高风险个体的额叶、扣带回和枕叶的额叶、扣带回和枕叶的纵向减少最为明显。
我们的研究结果表明，基线时较大的表面积可能与超越一般家族倾向的机制有关。与对照组相比，表面积随时间的相对保留，加上皮质变薄，可能是精神分裂症的易感性标志物。
