Functional connectivity of brain areas related to social cognition and anxiety in cervical dystonia

Introduction Recent studies highlighted the importance of non-motor symptoms, including emotional processing dysfunction, in individuals with cervical dystonia (CD). The resting state functional connectivity of areas involved in emotional processing, and the modulatory role of social anxiety on this connectivity, remain unexplored in CD. We hypothesized that CD patients would have altered functional connectivity between limbic areas involved in emotional processing as compared to healthy subjects and examined how variations in social anxiety affect connectivity. Methods 14 CD patients and 26 age- and sex-matched healthy controls completed a series of questionnaires and underwent functional magnetic resonance imaging (fMRI). Resting state functional connectivity was investigated between seeds (amygdala and insula) and whole brain ROIs, and in conventional functional networks. The modulatory role of social anxiety was investigated. Results CD patients showed reduced intra-regional connectivity in the insula, reduced connectivity between the right insula, left parietal operculum and left central opercular cortex. CD patients also showed clear reductions in connectivity in the salience, dorsal attention and sensorimotor resting state networks, as well as modest inter-network connections between language and fronto-parietal networks. In CD patients, higher anxiety scores and performance on affect naming tasks were associated with lower connectivity between right and left insula and between right insula and left central opercular cortex. Conclusion This study demonstrates that the previously observed deficits in emotional processing in CD patients may be underpinned by reduction in resting state functional connectivity in limbic areas and salience network with anxiety and social perception as a modulating factor.