The Role of Central Nervous System and Hypothalamic-Pituitary-Gonadal (HPG) Axis Changes in the Occurrence of Polycystic Ovary Syndrome: A Narrative Review Article

Background and Objectives Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disorder, affecting at least 10% of women in reproductive age. It is associated with hyperandrogenism, obesity, menstrual iregularity and infertility. There are several hypotheses regarding the metabolic, genetic, epigenetic, and environmental causes of the disease. Although the main cause of the disease is not well known, it seems that the disorder in the central nervous system (CNS) and as a result, the disruption in the production of gonadal hormones is one of the main causes of this syndrome.The relationship between CNS and gonadal steroid hormones is bilateral. As dysfunction of this system plays a role in the development of the disease, alterations in the levels of steroid hormones also affect the activity and flexibility of neuronal connections in the brain. Androgens also send critical feedback to the hypothalamus and pituitary glands and regulate the secretion of GnRH (gonadotropin-releasing hormone).Androgens can disrupt the neuroendocrine reproductive axis by altering the central circuits of the brain. Prescribing drugs against neuronal phenotypes that potentially stimulate excessive GnRH / LH (Luteinizing hormone) secretion could be a new and selective approach to reducing LH frequency in women with PCOS.