On the pathogenesis of primary dysmenorrhea

Abstract

Primary dysmenorrhea is a relevant medical and social problem. Its prevalence in the population of mostly young women, less than 30 years old, is up to 80%. Given the prevalence, severity of manifestations, significant economic losses, and the lack of a unified strategy for the management of such patients, searching for new ways to correct the disorders associated with primary dysmenorrhea is particularly relevant. The study objective was to elucidate pathogenetic mechanisms of the pain syndrome and accompanying manifestations of primary dysmenorrhea. The review presents a modern view of the pathogenesis of primary dysmenorrhea from the stand-point of successive stages of pain onset and information processing — nociception, transduction, transmission, modulation, and perception. The author also described the effect of hormones regulating the menstrual cycle on pain perception and their role in the development of primary dysmenorrhea. Conclusion: Pain syndrome in primary dysmenorrhea should be considered from the aspect of a multifactorial conceptual model of pain. Local factors directly triggering the cascade of pain reactions in primary dysmenorrhea are prostaglandins and leukotrienes. In the hormonal dysregulation associated with primary dysmenorrhea, the possible key parameter is an inadequate difference between levels of progesterone and estrogen in the luteal phase of the cycle; in result, pro-antinociceptive effects of progesterone are not realized, which leads to a lowered pain threshold. Primary severe dysmenorrhea is characterized by pronounced manifestations of the psycho-autonomic syndrome, which are significant for subjective assessment of pain intensity. Severe cases of primary dysmenorrhea can be a «yellow flag» of patient’s psychosocial distress and require an individualized strategy of treatment.