Psychiatry Neuroimaging Laboratory.
Cereb Cortex. 2014 May;24(5):1389-96. doi: 10.1093/cercor/bhs422. Epub 2013 Jan 10.
The normal human brain is characterized by a pattern of gross anatomical asymmetry. This pattern, known as the "torque", is associated with a sexual dimorphism: The male brain tends to be more asymmetric than that of the female. This fact, along with well-known sex differences in brain development (faster in females) and onset of psychosis (earlier with worse outcome in males), has led to the theory that schizophrenia is a disorder in which sex-dependent abnormalities in the development of brain torque, the correlate of the capacity for language, cause alterations in interhemispheric connectivity, which are causally related to psychosis (Crow TJ, Paez P, Chance SE. 2007. Callosal misconnectivity and the sex difference in psychosis. Int Rev Psychiatry. 19(4):449-457.). To provide evidence toward this theory, we analyze the geometry of interhemispheric white matter connections in adolescent-onset schizophrenia, with a particular focus on sex, using a recently introduced framework for white matter geometry computation in diffusion tensor imaging data (Savadjiev P, Kindlmann GL, Bouix S, Shenton ME, Westin CF. 2010. Local white geometry from diffusion tensor gradients. Neuroimage. 49(4):3175-3186.). Our results reveal a pattern of sex-dependent white matter geometry abnormalities that conform to the predictions of Crow's torque theory and correlate with the severity of patients' symptoms. To the best of our knowledge, this is the first study to associate geometrical differences in white matter connectivity with torque in schizophrenia.
正常人类大脑的解剖结构具有明显的不对称性。这种模式被称为“扭矩”，与性别二态性有关：男性大脑的不对称性比女性更明显。这一事实，加上众所周知的大脑发育方面的性别差异（女性更快）和精神病发病（男性更早且结果更差），导致了这样一种理论，即精神分裂症是一种障碍，其中与语言能力相关的大脑扭矩发育中的性别依赖性异常导致大脑半球间连接的改变，这与精神病有因果关系（Crow TJ、Paez P、Chance SE。2007. 胼胝体连接不良与精神病的性别差异。国际精神药理学评论。19(4):449-457.）。为了提供支持这一理论的证据，我们使用一种新的扩散张量成像数据中白质几何计算框架（Savadjiev P、Kindlmann GL、Bouix S、Shenton ME、Westin CF。2010. 从扩散张量梯度中获取局部白质几何结构。神经影像。49(4):3175-3186.），对青少年发病的精神分裂症的半球间白质连接的几何结构进行分析，特别关注性别因素。我们的结果揭示了一种与 Crow 的扭矩理论预测相符的、依赖于性别的白质几何异常模式，并且与患者症状的严重程度相关。据我们所知，这是首次将白质连接的几何差异与精神分裂症中的扭矩联系起来的研究。
