Sorbonne University, 75005 Paris; Inserm U1127, CNRS UMR7225, UM75, ICM, F-75013, Paris, France.
Movement Investigation and Therapeutics Team, ICM, Paris, France.
Mol Psychiatry. 2021 Jul;26(7):3548-3557. doi: 10.1038/s41380-020-00890-5. Epub 2020 Sep 29.
Tourette disorder (TD), which is characterized by motor and vocal tics, is not in general considered as a product of impulsivity, despite a frequent association with attention deficit hyperactivity disorder and impulse control disorders. It is unclear which type of impulsivity, if any, is intrinsically related to TD and specifically to the severity of tics. The waiting type of motor impulsivity, defined as the difficulty to withhold a specific action, shares some common features with tics. In a large group of adult TD patients compared to healthy controls, we assessed waiting motor impulsivity using a behavioral task, as well as structural and functional underpinnings of waiting impulsivity and tics using multi-modal neuroimaging protocol. We found that unmedicated TD patients showed increased waiting impulsivity compared to controls, which was independent of comorbid conditions, but correlated with the severity of tics. Tic severity did not account directly for waiting impulsivity, but this effect was mediated by connectivity between the right orbito-frontal cortex with caudate nucleus bilaterally. Waiting impulsivity in unmedicated patients with TD also correlated with a higher gray matter signal in deep limbic structures, as well as connectivity with cortical and with cerebellar regions on a functional level. Neither behavioral performance nor structural or functional correlates were related to a psychometric measure of impulsivity or impulsive behaviors in general. Overall, the results suggest that waiting impulsivity in TD was related to tic severity, to functional connectivity of orbito-frontal cortex with caudate nucleus and to structural changes within limbic areas.
妥瑞氏症（TD）的特征为运动性抽搐和发声性抽搐，尽管常与注意力缺陷多动障碍和冲动控制障碍有关，但一般不认为其为冲动的产物。尚不清楚哪种类型的冲动（如果有的话）与 TD 以及具体的抽搐严重程度有内在关联。等待型运动冲动性，定义为难以抑制特定动作，与抽搐有一些共同特征。在一组与健康对照组相比的成年 TD 患者中，我们使用行为任务评估了等待运动冲动性，以及使用多模态神经影像学方案评估了等待冲动性和抽搐的结构和功能基础。我们发现，未经治疗的 TD 患者与对照组相比，等待冲动性增加，这与共病情况无关，但与抽搐的严重程度有关。抽搐的严重程度并不能直接解释等待冲动性，而是通过右侧眶额皮质与双侧尾状核之间的连接来介导这种影响。未经治疗的 TD 患者的等待冲动性也与深部边缘结构的更高灰质信号以及功能水平上与皮质和小脑区域的连接有关。无论是行为表现还是结构或功能相关性，都与冲动或一般冲动行为的心理计量测量无关。总的来说，结果表明，TD 中的等待冲动性与抽搐严重程度、眶额皮质与尾状核的功能连接以及边缘区域的结构变化有关。
