Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
Schizophr Bull. 2010 Jul;36(4):778-87. doi: 10.1093/schbul/sbn161. Epub 2008 Nov 27.
In the pathophysiology of schizophrenia, aberrant connectivity between brain regions may be a central feature. Diffusion tensor imaging (DTI) studies have shown altered fractional anisotropy (FA) in white brain matter in schizophrenia. Focal reductions in myelin have been suggested in patients using magnetization transfer ratio (MTR) imaging but to what extent schizophrenia may be related to changes in MTR measured along entire fiber bundles is still unknown.
DTI and MTR images were acquired with a 1.5-T scanner in 40 schizophrenia patients and compared with those of 40 healthy participants. The mean FA and mean MTR were measured along the genu of the corpus callosum and the left and right uncinate fasciculus.
A higher mean MTR of 1% was found in the right uncinate fasciculus in patients compared with healthy participants. A significant negative correlation between age and mean FA in the left uncinate fasciculus was found in schizophrenia patients but not in healthy participants.
Decreased FA in the left uncinate fasciculus may be more prominent in patients with longer illness duration. The increased mean MTR in the right uncinate fasciculus could reflect a compensatory role for myelin in these fibers or possibly represent aberrant frontotemporal connectivity.
在精神分裂症的病理生理学中，大脑区域之间的异常连接可能是一个核心特征。弥散张量成像（DTI）研究表明，精神分裂症患者的白质部分各向异性分数（FA）发生改变。利用磁化传递率（MTR）成像已经发现患者的髓鞘有局部减少，但到何种程度精神分裂症可能与沿整个纤维束测量的 MTR 变化有关尚不清楚。
使用 1.5-T 扫描仪对 40 名精神分裂症患者和 40 名健康对照者进行 DTI 和 MTR 成像，并进行比较。在胼胝体膝部和左侧及右侧钩束上测量平均 FA 和平均 MTR。
与健康对照组相比，患者右侧钩束的平均 MTR 高 1%。在精神分裂症患者中发现左侧钩束的 FA 与年龄呈显著负相关，但在健康对照组中未发现这种相关性。
左侧钩束的 FA 降低可能在病程较长的患者中更为明显。右侧钩束的平均 MTR 增加可能反映了这些纤维中髓鞘的代偿作用，或者可能代表了异常的额颞叶连接。
