title: Changes in functional connectivity of pain modulatory systems in women with primary dysmenorrhea.
abstract: Menstrual pain is the most prevalent gynecological complaint, and is usually without organic cause (termed primary dysmenorrhea, PDM). The high comorbidity in the later life of PDM with many functional pain disorders (associated with central dysfunction of pain inhibition, eg, fibromyalgia) suggests possible maladaptive functionality of pain modulatory systems already occurred in young PDM women, making them vulnerable to functional pain disorders. Periaqueductal gray (PAG) matter functions as a critical hub in the neuraxis of pain modulatory systems; therefore, we investigated the functional connectivity of PAG in PDM. Forty-six PDM subjects and 49 controls received resting-state functional magnetic resonance imaging during menstruation and periovulatory phases. The PAG of PDM subjects exhibited adaptive/reactive hyperconnectivity with the sensorimotor cortex during painful menstruation, whereas it exhibited maladaptive hypoconnectivity with the dorsolateral prefrontal cortex and default mode network (involving the ventromedial prefrontal cortex, posterior cingulate cortex, or posterior parietal cortex) during menstruation or periovulatory phase. We propose that the maladaptive descending pain modulatory systems in PDM may underpin the central susceptibility to subsequent development of various functional disorders later in life. This hypothesis is corroborated by the growing body of evidence that hypoconnectivity between PAG and default mode network is a coterminal to many functional pain disorders.
authors: Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan Department of Obstetrics and Gynecology, School of Medicine, National Yang-Ming University, Taipei, Taiwan Institute of Biomedical Informatics, School of Medicine, National Yang-Ming University, Taipei, Taiwan Integrated Brain Research Unit, Division of Clinical Research, Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan.
authors: Shyh-Yuh
authors: SY
authors: Wei
authors: Hsiang-Tai
authors: HT
authors: Chao
authors: Cheng-Hao
authors: CH
authors: Tu
authors: Wei-Chi
authors: WC
authors: Li
authors: Intan
authors: I
authors: Low
authors: Chih-Ying
authors: CY
authors: Chuang
authors: Li-Fen
authors: LF
authors: Chen
authors: Jen-Chuen
authors: JC
authors: Hsieh
mesh_terms: D000328:Adult; D001931:Brain Mapping; D004412:Dysmenorrhea / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009415:Nerve Net / Q000503:physiopathology*; D010146:Pain / Q000503:physiopathology*; D010147:Pain Measurement; D010487:Periaqueductal Gray / Q000503:physiopathology*; D055815:Young Adult