Department of Psychiatry and Psychotherapy, RWTH Aachen University, 52074 Aachen, Germany.
Neuroimage. 2010 Jul 1;51(3):1184-93. doi: 10.1016/j.neuroimage.2010.02.049. Epub 2010 Feb 24.
Tourette syndrome is a neuropsychiatric disorder with the cardinal symptoms of motor and vocal tics. Often tics are accompanied by comorbidities such as obsessive-compulsive disorder, attention-deficit-hyperactivity disorder or depression. Research has mainly focused on the cortico-striato-thalamo circuit, but clinical symptoms and recent neuroimaging studies reporting altered resting network connectivity have suggested abnormalities in Tourette syndrome beyond the major motor circuits. We acquired diffusion-weighted data at 1.5T in nineteen adult patients fulfilling the DSM-IV-TR criteria for Tourette syndrome and in a healthy control group. Diffusion tensor imaging (DTI) analysis in our adult TS sample shows a decrease of FA and increase in radial diffusivity in the corticospinal tract. There are widespread changes (reduced FA and increased radial diffusivity) in the anterior and posterior limb of the internal capsule. Furthermore, it confirms prior findings of altered interhemispheric connectivity as indicated by a FA-decrease in the corpus callosum. In addition, our results indicate that TS is not restricted to motor pathways alone but affects association fibres such as the inferior fronto-occipitalis fascicle, the superior longitudinal fascicle and fascicle uncinatus as well. Tics are the hallmark of Tourette syndrome, so the involvement of the corticospinal tract fits in well with clinical symptoms. Cortical regions as well as limbic structures take part in the modulation of tics. Our findings of alterations in long association fibre tracts and the corpus callosum are a potential source for hindered interhemispheric and transhemispheric interaction. The change in radial diffusivity points toward a deficit in myelination as one pathophysiological factor in Tourette syndrome.
妥瑞氏症是一种神经精神疾病，其主要症状包括运动性抽搐和发声性抽搐。通常，抽搐会伴有强迫症、注意缺陷多动障碍或抑郁症等共病。研究主要集中在皮质纹状体丘脑回路，但临床症状和最近的神经影像学研究报告称，静息网络连接改变，提示妥瑞氏症除了主要运动回路之外还有异常。我们在 19 名符合 DSM-IV-TR 妥瑞氏症标准的成年患者和健康对照组中，在 1.5T 下获得了扩散加权数据。我们对成年妥瑞氏症患者样本的弥散张量成像（DTI）分析显示，皮质脊髓束的 FA 值降低，径向弥散度增加。内囊前肢和后肢广泛存在变化（FA 值降低，径向弥散度增加）。此外，它证实了先前发现的大脑半球间连接改变，表现为胼胝体 FA 值降低。此外，我们的结果表明，妥瑞氏症不仅局限于运动通路，还影响联合纤维，如下额枕束、上纵束和钩束。抽搐是妥瑞氏症的标志，因此皮质脊髓束的参与与临床症状相符。皮质区域和边缘结构参与抽搐的调节。我们在长联合纤维束和胼胝体中发现的改变是阻碍大脑半球间和半球间相互作用的潜在来源。径向弥散度的变化表明髓鞘形成缺陷是妥瑞氏症的一个病理生理因素。
