Altered Structural and Functional Connectivity of Salience Network in Patients with Classic Trigeminal Neuralgia

Classic trigeminal neuralgia (CTN) is a neuropathic pain disorder displaying spontane-ously stabbing or electric shock-like paroxysms in the face. Previous research suggests structural and functional abnormalities in brain regions related to sensory and cognitive-affective dimensions of pain contribute to the pathophysiology of CTN. However, few studies to date have investigated how changes in whole-brain functional networks and white matter connectivity are related to CTN. We performed an independent component analysis to examine abnormalities in resting state functional connectivity of large-scale networks in 48 patients with CTN compared to 46 matched healthy partici-pants. Then, diffusion tensor tractography was performed to test whether these alterations of func-tional connectivity in intrinsic networks were associated with impairment of the white matter tracts connecting them. Distinct patterns of functional connectivity were detected within default mode net-work, somatosensory network, and salience network (SN) in the CTN group when compared with healthy controls. Furthermore, abnormality of SN was negatively correlated with pain severity. In support of aberrant functional connectivity within SN, structural disintegration was observed in the white matter tract from left anterior insula (aIns) to left anterior cingulate cortex (ACC) in CTN. These results suggest that altered structural and functional connectivity between aIns and ACC may under-pin the aberrant SN in patients with CTN and provide an alternative target for clinical interventions. Perspective: This article presents distinctive abnormalities of functional and structural connectiv-ity from aIns to ACC in the patients with CTN, which is associated with pain ratings. This measure could potentially provide an alternative target for clinicians to alleviate this type of intermittent and refractory pain.(c) 2022 by United States Association for the Study of Pain, Inc.

Automated summary

This study identified abnormalities in resting state functional connectivity of large-scale networks and white matter connectivity in CTN patients. Abnormalities in the salience network were negatively correlated with pain severity, and structural disintegration was observed in the white matter tract between aIns and ACC. These findings suggest a potential alternative target for clinical interventions to alleviate CTN pain.