Structural imaging features of head MRI in patients with functional motor disorder

Objective To explore changes of brain structure in patients with functional movement disorder (FMD) and their correlation with disease severity. Methods Nine patients with FMD (FMD group) as well as 10 gender⁃ and age⁃matched healthy volunteers (control group) were recruited in Ruijin Hospital, Shanghai Jiaotong University School of Medicine, from May to October 2023, and then they underwent MRI. Simplified Functional Movement Disorder Rating Scale (S ⁃FMDRS) was used to assess movement disorder symptoms and severity. Clinical Global Impression ⁃ Severity (CGI ⁃ S) was used to evaluate disease severity. Somatoform Dissociation Questionnaire ⁃ 20 (SDQ ⁃20) was used to assess body dissociation. Chinese version of Maltreatment and Abuse Chronology of Exposure (MACE) was used to assess childhood abuse situation. 36⁃Item Short Form of Health Survey (SF⁃36) was used to assess health status. Hamilton Anxiety Rating Scale (HAMA) and Hamilton Depression Rating Scale 17 (HAMD⁃17) were used to evaluate anxiety and depression. Results Compared with the control group, the FMD group exhibited higher scores on SDQ⁃20 (Z = 2.259, P = 0.028) and Chinese version of MACE (t = ⁃ 3.570, P = 0.002) as well as HAMA (t = ⁃ 3.999, P = 0.001), while SF⁃36 scores for vitality (t = 3.091, P = 0.009) and social functioning (t = 2.275, P = 0.046) were lower in the FMD group. Cortical thickness was greater in the FMD group in the right inferior occipital gyrus and sulcus cortex (t = ⁃ 2.924, P = 0.009), right anterior cingulate gyrus and sulcus cortex (t = ⁃ 3.286, P = 0.004), right orbitofrontal cortex (t = ⁃ 2.381, P = 0.029), while thickness in the left subcallosal area (t = 2.492, P = 0.023) and left paracentral lobule gyrus and sulcus (t = 2.139, P = 0.047), as well as volume of the right cerebellar white matter (t = 2.685, P = 0.016), left cerebellar white matter (t = 2.121, P = 0.049), and the middle posterior region of the corpus callosum (t = 2.550, P = 0.021) were smaller than those of the control group. Correlation analysis revealed left cerebellar white matter were positively correlated with disease duration (r = 0.837, P = 0.038), while cortical thickness in the left subcallosal area were negatively correlated with disease duration (r = ⁃ 0.831, P = 0.040). Conclusions There are structural changes in the limbic system, sensorimotor area, visual cortex, and certain white matter regions in the brains of FMD patients, and several regions were correlated with the disease duration.