How to understand the complexity of endometriosis-related pain

Abstract

Pain is the most important symptom in patients with endometriosis, and its management is truly challenging. Due to the different localization of the endometriotic lesions in the pelvis, patients suffer from visceral and somatic pain or both at the same time. There are specific and unspecific symptoms characterized by endometriosis. Specific symptoms include dysmenorrhea, cyclic and acyclic pelvic pain, dyschezia, dysuria and dyspareunia. There is also a wide range of unspecific symptoms, such as unspecific bowel and bladder complaints, the emission of pain in the legs, vegetative concomitants like vomiting, emesis, gastric disorders, headaches, dizziness, painful ovulation, irregular pelvic pain, lower back pain, chronic fatigue. These symptoms can be both cyclic and acyclic, and in most cases, they are permanent. Visceral and somatic pain are completely different pain subtypes and can therefore be an explanation for the wide variety of symptoms. The close interaction between visceral sensory nerve fibers and the autonomic ganglia explain the high rate of concomitant vegetative reactions, such as vomiting and orthostatic dysregulation. In general, pain generation is a complex interplay of peripheral and central sensitization mechanisms. Accordingly, the pain produced in endometriotic lesions is the result of mediating substances, nerve fibers, cytokine-releasing immune cells and macrophages synthesis. These interactions seem to stimulate the neurogenic inflammatory process and sensitization of the peripheral nerves. Furthermore, the disruption of the input on the level of the spinal cord and the recognition of the pain in the brain may lead to exaggerated responses known as central hyperalgesia. Hormones and psychological factors influence the pain sensation and make the status of each patient very individual. Consequently, the involvement of professional pain management along with an implementation of pain-coping strategies in the patient’s everyday life are obligatory in chronic pain situations. An additional osteopathic treatment with a manual resolve of muscle blockades to avoid secondary “pain intensifying” changes of the pelvic floor (tension) or malposition through relieving posture, is also recommended. Pain management in patients with endometriosis is very complex and requires an individual treatment strategy for each patient to avoid unnecessary surgical procedures. This information proves that it is hard to break the cycle of pain when chronic pain syndrome is already apparent.