Department of Psychology, Università Cattolica del Sacro Cuore, Milan, Italy.
Fondazione Policlinico Universitario 'Agostino Gemelli' IRCSS, Rome, Italy.
Acta Neurol Scand. 2022 May;145(5):571-578. doi: 10.1111/ane.13585. Epub 2022 Feb 2.
Functional movement disorders (FMD) refer to a heterogeneous group of manifestations incongruent with known neurological diseases. Functional neuroimaging studies in FMD indicate the overlap between cerebral regions in which abnormal activation occurs and those considered crucial for theory of mind (ToM), the ability to attribute mental states. The aim of this study was to explore whether FMD might be related to ToM disorders to the extent that they reduce the ability to make inferences about the mental states underlying motor behaviour during social interaction.
MATERIALS & METHODS: Eighteen subjects with FMD and 28 matched healthy controls (HC) were given a ToM battery. The severity of FMD was rated by the Simplified-FMD Rating Scale (S-FMDRS). Dissociative symptoms were evaluated by the Dissociative Experiences Scale (DES-II).
FMD scored worse than the HC in most ToM tasks: second-order False Beliefs (p = .005), Faux-Pas Recognition Test (p < .001) and Reading the Mind in the Eyes Test (p = .020); control questions elicited normal scores. The DES-II indicated dissociative-borderline psychopathology and negatively correlated with accuracy on the second-order False Belief (Spearman's rho = -.444; p = .032); the positive correlation between DES-II and severity of motor symptoms (S-FMDRS) approached significance (Spearman's rho test = .392; p = .054). ToM disorders were not correlated with S-FMDRS, due to the typical variability in FMD over time with regard to the severity of symptoms and the district of body involved.
Our results are consistent with the hypothesis that FMD are related to ToM deficits, and future studies are needed to define the specific nature of this relationship.
功能性运动障碍（FMD）是指一组与已知神经疾病不一致的表现异质性群体。FMD 的功能性神经影像学研究表明，异常激活发生的脑区与被认为对心理理论（ToM）至关重要的脑区之间存在重叠，心理理论是归因于心理状态的能力。本研究旨在探讨 FMD 是否与 ToM 障碍有关，以至于它们降低了在社交互动中推断运动行为背后的心理状态的能力。
18 名 FMD 患者和 28 名匹配的健康对照者（HC）接受了 ToM 测试。FMD 的严重程度由简化 FMD 评定量表（S-FMDRS）评定。分离症状由分离体验量表（DES-II）评估。
FMD 在大多数 ToM 任务中的得分均低于 HC：二阶错误信念（p=0.005）、过失识别测试（p<0.001）和眼神阅读心理测试（p=0.020）；控制问题得出了正常分数。DES-II 表明存在分离边缘性精神病理学，与二阶错误信念的准确性呈负相关（Spearman 相关系数为-0.444；p=0.032）；DES-II 与运动症状严重程度（S-FMDRS）之间的正相关接近显著（Spearman 相关系数检验为 0.392；p=0.054）。由于 FMD 随时间推移症状严重程度和涉及的身体部位的变化而变化，因此 ToM 障碍与 S-FMDRS 没有相关性。
我们的结果与 FMD 与 ToM 缺陷有关的假设一致，需要进一步的研究来定义这种关系的具体性质。
