Department of Radiology, Division of Neuroradiology, University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242, USA.
Schizophr Res. 2011 Sep;131(1-3):4-10. doi: 10.1016/j.schres.2011.05.024. Epub 2011 Jun 25.
Imaging studies of schizophrenia patients showed fronto-temporal brain volume deficits, while magnetic resonance spectroscopy (MRS) studies of patients and unaffected biological relatives have found a decrement of the neuronal marker N-acetyl-aspartate (NAA) in the hippocampus and frontal lobes, and increased choline-containing phospholipids. Using a 3T MR scanner, we determined the metabolite profile within limbic regions (anterior cingulate cortex (ACC) and left hippocampus) of 36 unaffected, adolescent/young adult relatives of schizophrenia probands (first-degree=16, second-degree=20) and 25 healthy controls with no family history of schizophrenia. Significant main effects of group were found on NAA/Cho ratios for both the left hippocampus (F = 6.11, p ≤ 0.02) and ACC (F = 4.89, p ≤ 0.03) as well as for the left hippocampus Cho/Cr ratio (F = 5.55, p ≤ 0.02). Compared to age and sex matched healthy controls without a family history of schizophrenia, first-degree relatives of probands had greater MRS metabolite deviations than second-degree relatives. Greater familial proximity to the schizophrenia proband (or higher schizophrenia susceptibility) among biological relatives was associated with stepwise lowering of NAA/Cho and elevations in Cho/Cr ratios. The observed limbic metabolite changes among young, nonpsychotic biological relatives are likely related to shared genetic vulnerability factors, and may assist in the early identification of schizophrenia for primary and secondary prevention.
精神分裂症患者的影像学研究显示额颞叶脑容量不足，而患者和未受影响的生物学亲属的磁共振波谱（MRS）研究发现海马体和额叶中的神经元标志物 N-乙酰天门冬氨酸（NAA）减少，以及含有胆碱的磷脂增加。使用 3T MR 扫描仪，我们确定了 36 名未受影响的青少年/年轻成年精神分裂症先证者亲属（一级亲属=16，二级亲属=20）和 25 名无精神分裂症家族史的健康对照者的边缘区域（前扣带回皮质（ACC）和左海马体）内的代谢物谱。发现左海马体（F=6.11，p≤0.02）和 ACC（F=4.89，p≤0.03）以及左海马体 Cho/Cr 比值（F=5.55，p≤0.02）的 NAA/Cho 比值存在显著的组间主效应。与无精神分裂症家族史的年龄和性别匹配的健康对照组相比，先证者一级亲属的 MRS 代谢物偏差大于二级亲属。亲属与精神分裂症先证者的亲缘关系越近（或精神分裂症易感性越高），NAA/Cho 和 Cho/Cr 比值就越低。在非精神病的年轻生物学亲属中观察到的边缘代谢物变化可能与共同的遗传易感性因素有关，并可能有助于精神分裂症的早期识别，以进行一级和二级预防。
