Fuxiang Chen1, Fuyong Chen1, Zhanfang Shang2, Yuan Shui3, Guorong Wu4, Chen Liu5, Zhangya Lin1, Yuanxiang Lin1, Lianghong Yu1, Dezhi Kang6, Wei Tao7, Yongjie Li3. 1. Department of Neurosurgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, China. 2. Department of Neurosurgery, Mindong Hospital Affiliated to Fujian Medical University, Fu' an, Fujian 355000, China. 3. Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China. 4. Faculty of Psychology, Southwest University, Chongqing 400715, China. 5. Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612, United States. 6. Department of Neurosurgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, China. Electronic address: kdz99988@sina.com. 7. Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China. Electronic address: taowmail@163.com.
Abstract
OBJECTIVE: The central mechanisms underlying postherpetic neuralgia (PHN) pain remains unknown. The primary purpose of this study was to identify microstructural white matter changes closely related to the PHN pain by means of diffusion tensor imaging (DTI) and tract-based spatial statistics (TBSS) analysis. METHODS: DTI data of the brains were obtained from 8 PHN patients and 8 healthy controls (HC) that were matched in age, gender, and educational level. DTI metrics, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD), were separately compared between the two groups using TBSS analysis to detect subtle microstructural changes. Partial correlation analyses were also conducted to evaluate the association between the altered DTI measures and clinical features. RESULTS: Average diffusion indices of white matter skeletons in the whole-brain showed no significant difference between the two groups. However, compared to the HC group, patients with PHN pain revealed reductions in localized FA and AD values in white matter underlying insula, occipital lobe, cerebellum, precentral gyrus, and many other regions, but without distinct change in regional MD and RD levels. In addition, decline of FA and AD values in patients represented significant negative correlations with PHN pain duration when the effect of VAS scores were excluded. CONCLUSION: The current study suggest that there exists altered microstructure integrity of white matter in multiple brain regions in patients with PHN, and these changes increase in size as the duration of the pain increases. These findings might provide a new insight into the mechanism of PHN pain in brain.
OBJECTIVE: The central mechanisms underlying postherpetic neuralgia (PHN) pain remains unknown. The primary purpose of this study was to identify microstructural white matter changes closely related to the PHN pain by means of diffusion tensor imaging (DTI) and tract-based spatial statistics (TBSS) analysis. METHODS: DTI data of the brains were obtained from 8 PHNpatients and 8 healthy controls (HC) that were matched in age, gender, and educational level. DTI metrics, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD), were separately compared between the two groups using TBSS analysis to detect subtle microstructural changes. Partial correlation analyses were also conducted to evaluate the association between the altered DTI measures and clinical features. RESULTS: Average diffusion indices of white matter skeletons in the whole-brain showed no significant difference between the two groups. However, compared to the HC group, patients with PHN pain revealed reductions in localized FA and AD values in white matter underlying insula, occipital lobe, cerebellum, precentral gyrus, and many other regions, but without distinct change in regional MD and RD levels. In addition, decline of FA and AD values in patients represented significant negative correlations with PHN pain duration when the effect of VAS scores were excluded. CONCLUSION: The current study suggest that there exists altered microstructure integrity of white matter in multiple brain regions in patients with PHN, and these changes increase in size as the duration of the pain increases. These findings might provide a new insight into the mechanism of PHN pain in brain.