Zhen Gao,1,* Meng-Jie Cui,2,* Hai-Jun Wang,2 Jing Zhang,3 Cheng Xu,4 Lai-Xi Ji2 

1Experimental Management Center, Shanxi University of Traditional Chinese Medicine, Taiyuan, Shanxi, 030024, People’s Republic of China; 2Second Clinical Medical College, Shanxi University of Traditional Chinese Medicine, Taiyuan, Shanxi, 030024, People’s Republic of China; 3Acupuncture and Moxibustion Department II, Affiliated Hospital of Shanxi University of Traditional Chinese Medicine, Taiyuan, Shanxi, 030024, People’s Republic of China; 4Radiology Department, Shanxi Provincial People’s Hospital, Taiyuan, Shanxi, 030012, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Lai-Xi Ji, Second Clinical Medical College, Shanxi University of Traditional Chinese Medicine, Jinci Road Section 1, No. 89, Taiyuan, Shanxi, 030024, People’s Republic of China, Email jlx@sxtcm.edu.cn

Purpose: The objective of this research is to delve into the central pathological mechanisms involved in the transformation from acute to chronic pain.
Patients and Methods: This study enrolled 86 individuals with acute neck pain and 89 with chronic neck pain. Utilizing a 3.0T MR scanner, we obtained three-dimensional T1-weighted imaging (3D-T1WI) images and analyzed structural differences between the two groups with Freesurfer software to evaluate alterations in cortical thickness. Additionally, Blood Oxygen Level-Dependent functional Magnetic Resonance Imaging (BOLD-fMRI) images were acquired to assess intergroup differences in low-frequency amplitude using DPARSF software.
Results: Chronic neck pain patients exhibited increased cortical thickness in the left rostral middle frontal, left isthmus cingulate, left superior frontal, and right precuneus regions compared to those with acute neck pain. Low-frequency amplitude measures revealed decreased activity in the left dorsolateral superior frontal gyrus and left postcentral gyrus, among other areas, and increased activity in the right middle frontal gyrus and the opercular part of the right inferior frontal gyrus.
Conclusion: Our findings indicate that dysfunction and structural changes in the limbic system and prefrontal cortex may play a pivotal role in the progression from acute to chronic neck pain. These insights provide a significant new direction for understanding the central mechanisms underlying pain chronicity.

Keywords: functional magnetic resonance imaging, amplitude of low frequency fluctuation, cortical thickness, neck pain, acute pain, chronic pain