Gninenko Nicolas, Müller Eliane, Aybek Selma
Faculty of Science and Medicine, Department of Neurology, University of Fribourg, Fribourg, Switzerland; Department of Neurology, Psychosomatic Medicine Unit, Inselspital Bern University Hospital, University of Bern, Bern, Switzerland.
Faculty of Science and Medicine, Department of Neurology, University of Fribourg, Fribourg, Switzerland; Department of Neurology, Psychosomatic Medicine Unit, Inselspital Bern University Hospital, University of Bern, Bern, Switzerland; Graduate School of Cellular and Biomedical Sciences (GCB), University of Bern, Bern, Switzerland.
Neuroimage Clin. 2025 Apr 27;46:103791. doi: 10.1016/j.nicl.2025.103791.
Functional neurological disorder (FND) is linked to functional changes in brain networks without an underlying brain lesion. However, the dichotomy between functional and structural changes has been challenged by research suggesting that not only functional but also anatomical alterations in the gray and white matter may underlie a subset of symptoms. This study aimed to characterize white matter microstructural integrity and its association with patient-reported and clinician-rated physical symptoms' severity in a large sample of FND patients.
Diffusion-weighted imaging data were collected from 85 FND patients with mixed symptoms and 75 healthy controls (HCs), together with illness duration, clinician-rated (S-FMDRS & CGI), and patient-reported (SF-36) symptom severity. Microstructural integrity was computed based on probabilistic tractography using the Desikan-Killiany parcellation.
Compared to HCs, patients with FND presented widespread reduced microstructural integrity stemming from regions such as the right lateral orbitofrontal cortex, insula, putamen, and superior temporal regions. After adjusting for depression and anxiety, these differences were no longer significant. Within-group analysis revealed that reduced microstructural integrity, particularly in the left precuneus and left superior parietal cortex, was strongly correlated with both patient-reported and clinician-evaluated severity of physical symptoms in FND patients.
Patients with FND present widespread reduced microstructural integrity in the brain, predominantly originating from temporoparietal, paralimbic and associated regions involved in emotion regulation and body awareness. These changes seem to be partly explained by comorbid mood disorders and the severity of physical symptoms, suggesting a plasticity phenomenon rather than trait biomarkers, which warrants further investigation in longitudinal study designs.
功能性神经障碍（FND）与脑网络的功能变化有关，且不存在潜在的脑损伤。然而，功能和结构变化之间的二分法受到了研究的挑战，研究表明，不仅功能变化，而且灰质和白质的解剖学改变可能是一部分症状的基础。本研究旨在对大量FND患者样本中的白质微观结构完整性及其与患者报告和临床医生评定的身体症状严重程度之间的关联进行特征描述。
收集了85名有混合症状的FND患者和75名健康对照者（HCs）的扩散加权成像数据，以及病程、临床医生评定的（S-FMDRS和CGI）和患者报告的（SF-36）症状严重程度。基于使用Desikan-Killiany分割的概率性纤维束成像计算微观结构完整性。
与HCs相比，FND患者的微观结构完整性普遍降低，源于右侧眶额外侧皮质、岛叶、壳核和颞上区等区域。在调整抑郁和焦虑因素后，这些差异不再显著。组内分析显示，微观结构完整性降低，特别是在左侧楔前叶和左侧顶上小叶皮质，与FND患者报告的和临床医生评估的身体症状严重程度密切相关。
FND患者大脑中的微观结构完整性普遍降低，主要源于参与情绪调节和身体感知的颞顶叶、边缘旁和相关区域。这些变化似乎部分由共病的情绪障碍和身体症状的严重程度所解释，提示这是一种可塑性现象而非特质生物标志物，这值得在纵向研究设计中进一步研究。
