Journal of Pain Research (Oct 2018)
Modulation of prefrontal connectivity in postherpetic neuralgia patients with chronic pain: a resting-state functional magnetic resonance-imaging study
Abstract
Jun Li,1,* Xuehua Huang,2,* Kangning Sang,1 Mark Bodner,3 Ke Ma,2 Xiao-Wei Dong1,4 1Key Laboratory of Brain Functional Genomics (MOE and STCSM), Shanghai Changning ECNU Mental Health Center, Institute of Cognitive Neuroscience, School of Psychology and Cognitive Science, East China Normal University, Shanghai, China; 2Department of Pain Management, Xin Hua Hospital, affiliated with Shanghai Jiao Tong University School of Medicine, Shanghai, China; 3MIND Research Institute, Irvine, CA, USA; 4NYU-ECNU Institute of Brain and Cognitive Science, NYU Shanghai, Shanghai, China *These authors contributed equally to this work Background: Although the interaction between pain and cognition has been recognized for decades, the neural substrates underlying their association remain unclear. The prefrontal cortex (PFC) is known as a critical brain area for higher cognitive functions, as well as for pain perception and modulation. The objective of the present study was to explore the role of the PFC in the interaction between chronic pain and cognitive functions by examining the relationship between spontaneous activity in the frontal lobe and pain intensity reported by postherpetic neuralgia (PHN) patients.Methods: Resting-state functional magnetic resonance imaging data from 16 PHN patients were collected, and regional homogeneity and related functional connectivity were analyzed.Results: The results showed negative correlations between patients’ pain scores and regional homogeneity values in several prefrontal areas, including the left lateral PFC, left medial PFC, and right lateral orbitofrontal cortex (P<0.05, AlphaSim-corrected). Further analysis revealed that the functional connectivity of some of these prefrontal areas with other cortical regions was also modulated by pain intensity. Therefore, functional connections of the left lateral PFC with both the left parietal cortex and the left occipital cortex were correlated with patients’ pain ratings (P<0.05, AlphaSim-corrected). Similarly, functional connectivity between the right lateral orbitofrontal cortex and bilateral postcentral/precentral gyri was also correlated with pain intensity in the patients (P<0.05, AlphaSim-corrected).Conclusion: Our findings indicate that activity in the PFC is modulated by chronic pain in PHN patients. The pain-related modulation of prefrontal activity may serve as the neural basis for interactions between chronic pain and cognitive functions, which may link to cognitive impairments observed in chronic pain patients. Keywords: postherpetic neuralgia, chronic pain, prefrontal cortex, fMRI, regional homogeneity, functional connectivity
