Institute of Psychiatry, King's College London, London, United Kingdom.
Biol Psychiatry. 2011 Mar 1;69(5):495-503. doi: 10.1016/j.biopsych.2010.10.004. Epub 2010 Dec 8.
It is not known whether regional brain N-acetyl aspartate (NAA) changes in the progression from prodrome to chronic schizophrenia. We used effect size meta-analysis to determine which brain regions show the most robust reductions in NAA first episode and chronic schizophrenia as measured by proton magnetic resonance spectroscopy and to determine whether these changes are present in individuals at high risk of developing schizophrenia.
We identified 131 articles, of which 97 met inclusion criteria. Data were separated by stage of illness (at risk, first episode schizophrenia, chronic schizophrenia) and by brain region. For each region, mean and SD of the NAA measure was extracted.
Significant reductions in NAA levels were found in frontal lobe, temporal lobe, and thalamus in both patient groups (effect size > .3; p < .01). In individuals at high risk of schizophrenia (of whom approximately 20% would be expected to undergo transition to psychosis), significant NAA reductions were present in thalamus (effect size = .78; p < .05), with reductions at trend level only in temporal lobe (effect size = .32; p < .1), and no reductions in frontal lobe (effect size = .05; p = .5).
These data suggest that schizophrenia is associated with loss of neuronal integrity in frontal and temporal cortices and in the thalamus and suggest that these changes in the frontal and temporal lobe might occur in the transition between the at-risk phase and the first episode.
目前尚不清楚从前驱期到慢性精神分裂症的进展过程中，区域性大脑 N-乙酰天冬氨酸（NAA）是否会发生变化。我们采用效应量荟萃分析来确定质子磁共振波谱测量的首发精神分裂症和慢性精神分裂症患者的哪些脑区 NAA 减少最明显，并确定这些变化是否存在于有发展为精神分裂症风险的个体中。
我们共识别出 131 篇文章，其中 97 篇符合纳入标准。根据疾病阶段（高危、首发精神分裂症、慢性精神分裂症）和脑区对数据进行分组。对于每个脑区，提取 NAA 测量的均值和标准差。
在两组患者的额叶、颞叶和丘脑都发现了 NAA 水平的显著降低（效应量>0.3；p<.01）。在有精神分裂症高风险的个体中（其中约 20%预计会发展为精神病），丘脑的 NAA 降低具有统计学意义（效应量=0.78；p<.05），而颞叶仅呈降低趋势（效应量=0.32；p<.1），额叶未见降低（效应量=0.05；p=0.5）。
这些数据表明，精神分裂症与额叶和颞叶以及丘脑的神经元完整性丧失有关，并且提示这些额叶和颞叶的变化可能发生在高危阶段向首发期的转变过程中。
