Central sensitization in patients with deep endometriosis

Dear Editor, The association between endometriosis and pelvic pain is widely known, but the specific mechanisms by which endometriosis causes pain are still poorly understood [1]. Central sensitization (CS) is a phenomenon in which alterations in the central nervous system cause changes in the perception of pain [2], and these changes have the potential to exacerbate pain symptoms and predispose women with endometriosis to the development of other chronic conditions. Previous research suggested that endometriosis-associated chronic pelvic pain is often related to the presence of CS [3] and could lead to worse response to treatments or lower health-related quality of life (HRQoL) and a higher risk of depression and anxiety. The Central Sensitization Inventory (CSI) was designed to apply the concept of CS to the clinical management of patients with chronic pain [4]. The CSI questionnaire has been validated to differentiate between centrally sensitized and non-sensitized patients in the chronic pain literature, having strong psychometric properties, good internal consistency, and good test–retest validity [4]. A recently published study has shown that CSI could serve as a tool to help identify patients with endometriosis who have pain contributors related to central nervous system sensitization [5]. On the other hand, previous studies evaluating patients with endometriosis did not take into account the severity and type of disease. Moreover, to our knowledge, no previous study has evaluated the presence of CS-related symptoms in patients with deep endometriosis (DE), the type of endometriosis associated with higher levels of pain [1].