Abnormal cerebral metabolism during menstrual pain in primary dysmenorrhea.
Primary dysmenorrhea (PDM, menstrual pain without pelvic abnormality) is the most common gynecological disorder for women in the reproductive age. It is characterized by cramping pain and enhanced pain sensitivity during the menstruation period. PDM has been associated with peripheral and central sensitization. Abnormal brain mechanisms may further contribute to development and maintenance of the state. Using fluoro-deoxyglucose positron emission tomography, increased activity was observed in prefrontal/orbitofrontal regions and left ventral posterior thalamus while decreased activity mainly was observed in sensorimotor regions of the left hemisphere at onset compared to offset of PDM. These results were specific to menstrual pain and were not found in menstrual matched controls. Orbitofrontal activities were positively related to while somatosensory activities where negatively related to subjective pain ratings. These results show that ongoing menstrual pain in PDM is accompanied by abnormal brain metabolism. Disinhibition of thalamo-orbitofrontal-prefrontal networks may contribute to the generation of pain and hyperalgesia in PDM possibly by maintaining spinal and thalamic sensitization while increasing negative affect. Excessive excitatory input during menstrual pain may induce compensatory inhibitory mechanism in several somatic sensorimotor regions.
Tu
Cheng-Hao
CH
Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.
Niddam
David M
DM
Chao
Hsiang-Tai
HT
Liu
Ren-Shyan
RS
Hwang
Ren-Jen
RJ
Yeh
Tzu-Chen
TC
Hsieh
Jen-Chuen
JC
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001931:Brain Mapping; D004412:Dysmenorrhea / Q000503:physiopathology*; D004958:Estradiol / Q000097:blood; D005260:Female; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008597:Menstrual Cycle / Q000502:physiology; D008598:Menstruation / Q000502:physiology; D015999:Multivariate Analysis; D009483:Neuropsychological Tests; D010146:Pain / Q000209:etiology / Q000503:physiopathology; D010147:Pain Measurement; D049268:Positron-Emission Tomography; D055815:Young Adult
D004958:Estradiol; D005947:Glucose