Niznikiewicz M, Donnino R, McCarley R W, Nestor P G, Iosifescu D V, O'Donnell B, Levitt J, Shenton M E
Laboratory of Neuroscience, Department of Psychiatry, VA Medical Center, Harvard Medical School, Brockton, MA 02301, USA.
Am J Psychiatry. 2000 Mar;157(3):428-37. doi: 10.1176/appi.ajp.157.3.428.
Few studies have evaluated the parietal lobe in schizophrenia despite the fact that it has an important role in attention, memory, and language-all functions that have been reported to be abnormal in schizophrenia. The inferior parietal lobule, in particular, is of interest because it is not only part of the heteromodal association cortex but also is part of the semantic-lexical network, which also includes the planum temporale. Both the inferior parietal lobule, particularly the angular gyrus of the inferior parietal lobule, and the planum temporale are brain regions that play a critical role as biological substrates of language and thought. The authors compared volume and asymmetry measures of the individual gyri of the parietal lobe by means of magnetic resonance imaging (MRI) scans.
MRI scans with a 1. 5-Tesla magnet were obtained from 15 male chronic schizophrenic and 15 comparison subjects matched for age, gender, and parental socioeconomic status.
Inferior parietal lobule volumes showed a leftward asymmetry (left 7.0% larger than right) in comparison subjects and a reversed asymmetry (left 6.3% smaller than right) in schizophrenic subjects. The angular gyrus accounted for this difference in asymmetry, with the left angular gyrus being significantly larger (18.7%) than the right in comparison subjects, a finding that was not observed in schizophrenic patients. A further test of angular gyrus asymmetry showed a reversal of the normal left-greater-than-right asymmetry in the schizophrenic patients.
Patients with schizophrenia showed a reversed asymmetry in the inferior parietal lobule that was localized to the angular gyrus, a structure belonging to the heteromodal association cortex as well as being part of the semantic-lexical network. This finding contributes to a more comprehensive understanding of the neural substrates of language and thought disorder in schizophrenia.
尽管顶叶在注意力、记忆和语言（据报道在精神分裂症中这些功能均存在异常）方面起着重要作用，但很少有研究对精神分裂症患者的顶叶进行评估。尤其是顶下小叶备受关注，因为它不仅是异模态联合皮质的一部分，还是语义 - 词汇网络的一部分，该网络还包括颞平面。顶下小叶，特别是顶下小叶的角回，以及颞平面都是作为语言和思维生物学基础发挥关键作用的脑区。作者通过磁共振成像（MRI）扫描比较了顶叶各个脑回的体积和不对称性测量值。
对15名男性慢性精神分裂症患者以及15名在年龄、性别和父母社会经济地位相匹配的对照受试者进行了1.5特斯拉磁共振成像扫描。
对照受试者的顶下小叶体积显示出左侧不对称（左侧比右侧大7.0%），而精神分裂症患者则呈现相反的不对称（左侧比右侧小6.3%）。角回导致了这种不对称差异，在对照受试者中，左侧角回明显比右侧大（18.7%），而在精神分裂症患者中未观察到这一现象。对角回不对称性的进一步测试表明，精神分裂症患者正常的左侧大于右侧的不对称性发生了反转。
精神分裂症患者的顶下小叶出现了不对称反转，且这种反转定位于角回，角回是异模态联合皮质的一部分，也是语义 - 词汇网络的一部分。这一发现有助于更全面地理解精神分裂症中语言和思维障碍的神经基础。
