Li Xiaobo, Branch Craig A, Bertisch Hilary C, Brown Kyle, Szulc Kamila U, Ardekani Babak A, DeLisi Lynn E
The Center for Advanced Brain Imaging at The Nathan S Kline Institute for Psychiatric Research, Orangeburg, New York 10962, United States.
Schizophr Res. 2007 Mar;91(1-3):62-72. doi: 10.1016/j.schres.2006.12.016. Epub 2007 Feb 16.
Abnormalities in language processing and the related brain structures have been reported in people with schizophrenia. It has been proposed that the brain pathways for language processing are anomalous in these individuals and form the underlying basis for the positive symptoms of the illness. If language pathway abnormalities can be detected early in people at high-risk for schizophrenia prior to the onset of symptoms, early treatment can ensue.
Fifteen young adults at high genetic risk for developing schizophrenia were compared with 15 of their siblings with schizophrenia or schizoaffective disorder and 15 age and sex matched individuals at low risk for schizophrenia using a visual lexical decision task during fMRI. The data were analyzed by contrasting activation obtained during a real word-pseudoword discrimination task to activation obtained during a nonlinguistic discrimination task, and the differential activations were examined.
Patterns of brain activation while reading and discriminating between real and pseudowords differed across groups, with more bilateral activation in schizophrenia patients and their high-risk siblings than controls. In control subjects discrimination of words from psuedowords significantly activated Brodmann's area 44 more strongly than when non-linguistic symbols were discriminated. However, high-risk subjects and their siblings with schizophrenia activated this region similarly for both language and non-language tasks.
Normal individuals can be distinguished from subjects at high genetic risk for schizophrenia and patients with schizophrenia by their more lateralized and stronger activation of Brodmann's area 44 to word compared with symbol discrimination tasks. Thus, evaluation of language processing by fMRI may be a valuable tool for use in the prediction of individual risk for developing schizophrenia.
已有报道称精神分裂症患者存在语言处理及相关脑结构异常。有人提出，这些个体的语言处理脑通路异常，并构成该疾病阳性症状的潜在基础。如果在精神分裂症高危人群出现症状之前就能早期检测到语言通路异常，便可进行早期治疗。
利用功能磁共振成像（fMRI）期间的视觉词汇判断任务，将15名具有高遗传风险患精神分裂症的年轻成年人与其15名患有精神分裂症或分裂情感性障碍的兄弟姐妹以及15名年龄和性别匹配的低精神分裂症风险个体进行比较。通过将实词 - 伪词辨别任务期间获得的激活与非语言辨别任务期间获得的激活进行对比来分析数据，并检查差异激活情况。
不同组在阅读及辨别实词和伪词时的脑激活模式存在差异，精神分裂症患者及其高危兄弟姐妹的双侧激活比对照组更多。在对照组中，辨别单词与伪词时布罗德曼44区的激活明显比辨别非语言符号时更强。然而，高危个体及其患有精神分裂症的兄弟姐妹在语言和非语言任务中对该区域的激活相似。
与符号辨别任务相比，正常个体在辨别单词时布罗德曼44区的激活更具偏侧化且更强，这可将其与精神分裂症高遗传风险个体及精神分裂症患者区分开来。因此，通过功能磁共振成像评估语言处理可能是预测个体患精神分裂症风险的一种有价值的工具。
