Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX, USA; University of Guanajuato, Mexico.
Human Motor Control Section, NINDS, National Institutes of Health, Bethesda, MD, USA.
Neurobiol Dis. 2019 Jul;127:32-44. doi: 10.1016/j.nbd.2019.02.013. Epub 2019 Feb 21.
Functional movement disorders (FMDs), known over time as "hysteria", "dissociative", "conversion", "somatoform", "non-organic" and "psychogenic" disorders, are characterized by having a voluntary quality, being modifiable by attention and distraction but perceived by the patient as involuntary. Although a high prevalence of depression and anxiety is observed in these patients, a definitive role of psychiatric disorders in FMDs has not been proven, and many patients do not endorse such manifestations. Stressful events, social influences and minor trauma may precede the onset of FMDs, but their pathogenic mechanisms are unclear. Patients with FMDs have several abnormalities in their neurobiology including strengthened connectivity between the limbic and motor networks. Additionally, there is altered top-down regulation of motor activities and increased activation of areas implicated in self-awareness, self-monitoring, and active motor inhibition such as the cingulate and insular cortex. Decreased activation of the supplementary motor area (SMA) and pre-SMA, implicated in motor control and preparation, is another finding. The sense of agency defined as the feeling of controlling external events through one's own action also seems to be impaired in individuals with FMDs. Correlating with this is a loss of intentional binding, a subjective time compression between intentional action and its sensory consequences. Organic and functional dystonia may be difficult to differentiate since they share diverse neurophysiological features including decreased cortical inhibition, and similar local field potentials in the globus pallidus and thalamus; although increased cortical plasticity is observed only in patients with organic dystonia. Advances in the pathogenesis and pathophysiology of FMDs may be helpful to understand the nature of these disorders and plan further treatment strategies.
功能性运动障碍（FMDs），随着时间的推移被称为“癔症”、“分离性”、“转换性”、“躯体形式”、“非器质性”和“心因性”障碍，其特征是具有自愿性质，可通过注意力和分心来改变，但被患者认为是不由自主的。尽管这些患者中观察到抑郁和焦虑的患病率较高，但精神障碍在 FMDs 中的明确作用尚未得到证明，而且许多患者不认同这种表现。应激事件、社会影响和轻微创伤可能先于 FMDs 的发生，但它们的发病机制尚不清楚。FMDs 患者的神经生物学存在多种异常，包括边缘和运动网络之间的连接增强。此外，运动活动的自上而下调节发生改变，涉及自我意识、自我监控和主动运动抑制的区域（如扣带回和脑岛）的激活增加。辅助运动区（SMA）和前 SMA 的激活减少，这些区域涉及运动控制和准备，这是另一个发现。代理感，即通过自己的行动控制外部事件的感觉，似乎也在 FMDs 患者中受损。与之相关的是意图绑定的丧失，即意图动作与其感觉后果之间的主观时间压缩。功能性和器质性肌张力障碍可能难以区分，因为它们具有不同的神经生理特征，包括皮质抑制减少，以及苍白球和丘脑的局部场电位相似；尽管仅在器质性肌张力障碍患者中观察到皮质可塑性增加。FMDs 的发病机制和病理生理学的进展可能有助于理解这些疾病的性质，并规划进一步的治疗策略。
