Adaptive neuroplasticity in the default mode network contributing to absence of central sensitization in primary dysmenorrhea

Lin-Chien Lee; Ya-Yun Chen; Wei-Chi Li; Ching-Ju Yang; Ching-Hsiung Liu; Intan Low; Hsiang-Tai Chao; Li-Fen Chen; Jen-Chuen Hsieh

doi:10.3389/fnins.2023.1094988

Adaptive neuroplasticity in the default mode network contributing to absence of central sensitization in primary dysmenorrhea

Front Neurosci. 2023 Feb 9:17:1094988. doi: 10.3389/fnins.2023.1094988. eCollection 2023.

Authors

Lin-Chien Lee^{1

2

3}, Ya-Yun Chen^{1

2}, Wei-Chi Li^{1

2

4}, Ching-Ju Yang^{1

2}, Ching-Hsiung Liu^{2

5

6}, Intan Low^{1

2}, Hsiang-Tai Chao⁷, Li-Fen Chen^{1

2

8

9}, Jen-Chuen Hsieh^{2

4

9

10}

Affiliations

¹ Institute of Brain Science, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.
² Integrated Brain Research Unit, Division of Clinical Research, Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan.
³ Department of Physical Medicine and Rehabilitation, Cheng Hsin General Hospital, Taipei, Taiwan.
⁴ Department of Biological Science and Technology, College of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan.
⁵ Institute of Traditional Medicine, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.
⁶ Department of Neurology, Lotung Poh-Ai Hospital, Yilan, Taiwan.
⁷ Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan.
⁸ Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, Taipei, Taiwan.
⁹ Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan.
¹⁰ Center for Intelligent Drug Systems and Smart Bio-Devices, National Yang Ming Chiao Tung University, Hsinchu, Taiwan.

Abstract

Introduction: Primary dysmenorrhea (PDM), the most prevalent gynecological problem among women of reproductive age, presents as a regular pattern of cyclic menstrual pain. The presence or absence of central sensitization (i.e., pain hypersensitivity) in cases of PDM is a contentious issue. Among Caucasians, the presence of dysmenorrhea is associated with pain hypersensitivity throughout the menstrual cycle, indicating pain amplification mediated by the central nervous system. We previously reported on the absence of central sensitization to thermal pain among Asian PDM females. In this study, functional magnetic resonance imaging was used to reveal mechanisms underlying pain processing with the aim of explaining the absence of central sensitization in this population.

Methods: Brain responses to noxious heat applied to the left inner forearm of 31 Asian PDM females and 32 controls during their menstrual and periovulatory phases were analyzed.

Results and discussion: Among PDM females experiencing acute menstrual pain, we observed a blunted evoked response and de-coupling of the default mode network from the noxious heat stimulus. The fact that a similar response was not observed in the non-painful periovulatory phase indicates an adaptive mechanism aimed at reducing the impact of menstrual pain on the brain with an inhibitory effect on central sensitization. Here we propose that adaptive pain responses in the default mode network may contribute to the absence of central sensitization among Asian PDM females. Variations in clinical manifestations among different PDM populations can be attributed to differences in central pain processing.

Keywords: central sensitization; default mode network; functional magnetic resonance imaging; menstrual pain; neuroplasticity; noxious heat; pain hypersensitivity; primary dysmenorrhea.

Grants and funding

This work was supported by the Taipei Veterans General Hospital (V100D-001, V100D-001-1, V100D-001-2, and V101C-152), the Ministry of Science and Technology (NSC 100-2314-B-010-006-MY3, NSC 100-2629-B-010-001, NSC 101-2629-B-010-001, NSC 102-2629-B-010-001, and MOST 103-2321-B-010-020), the TVGH-NTUH Joint Research Program (VN103-05, VN104-03, and VN105-03), and the Aim for the Top University Plan of the Ministry of Education for National Yang-Ming University. The funders had no role in the study design, data collection, data analysis, decision to publish, or preparation of the manuscript.