Bridging structural and functional biomarkers in functional movement disorder using network mapping

Background There are gaps in our neurobiological understanding of functional movement disorder (FMD). Objectives We investigated gray matter volumetric profiles in FMD, and related findings to resting-state functional connectivity (rsFC) profiles using Human Connectome Project data. Methods Volumetric differences between 53 FMD patients and 50 controls were examined, as well as relationships between individual differences in FMD symptom severity and volumetric profiles. Atrophy network mapping was also used to probe whether FMD-related structural alterations preferentially impacted brain areas with dense rsFC. Results Compared to controls without neurological comorbidities (albeit with mild depression and anxiety as a group), the FMD cohort did not show any volumetric differences. Across patients with FMD, individual differences in symptom severity negatively correlated with right supramarginal and bilateral superior temporal gyri volumes. These findings remained significant adjusting for FMD subtype or antidepressant use, but did not remain statistically significant adjusting for depression and anxiety scores. Symptom severity-related structural alterations mapped onto regions with dense rsFC-identifying several disease epicenters in default mode, ventral attention, and salience networks. Conclusions This study supports that FMD is a multinetwork disorder with an important role for the temporoparietal junction and its related connectivity in the pathophysiology of this condition. More research is needed to explore the intersection of functional neurological symptoms and mood.

Automated summary

This study investigates the gray matter volumetric profiles in functional movement disorder (FMD) and their relationship with resting-state functional connectivity (rsFC) profiles. The study finds that FMD is a multinetwork disorder and symptom severity-related structural alterations are mapped onto multiple brain regions, with an important role for the temporoparietal junction and its related connectivity.