Nonpharmacologic pain management, in particular heat, acupuncture, or transcutaneous electrical nerve stimulation (TENS), may be useful (41–43). Acupuncture is thought to excite receptors or nerve fibers, blocking pain impulses through interactions with mediators like serotonin and endorphins. The perception of pain signals is altered with TENS. It does not directly affect uterine contractions. Abdominal electrical or chemical heating pads are effective in treating primary dysmenorrhea. A Cochrane review evaluated seven randomized controlled trials that used herbal and dietary therapies such as vitamins, minerals proteins, herbs, and fatty acids for relief of dysmenorrhea. There are insufficient data to support any herbal or vitamin regimen (42).
Methods used only rarely to treat primary dysmenorrhea include surgical laparoscopic uterine nerve ablation and presacral neurectomy and hysterectomy (44).
Secondary dysmenorrhea is cyclic menstrual pain that occurs in association with underlying pelvic pathology. The pain of secondary dysmenorrhea often begins 1 to 2 weeks before menstrual ﬂow and persists until a few days after the cessation of bleeding. Underlying causes include endometriosis, adenomyosis, subacute endometritis and pelvic inﬂammatory disease, copper intrauterine devices (IUDs), ovarian cysts, congenital pelvic malformations, and cervical stenosis. Whereas the diagnosis of primary dysmenorrhea is based on history and presence of a normal pelvic examination and ultrasound, the diagnosis of secondary dysmenorrhea may require review of a pain diary to confirm cyclicity and, in addition to a transvaginal ultrasound examination, laparoscopy and/or hysteroscopy may be indicated.
The most common cause of secondary dysmenorrhea is endometriosis, followed by adenomyosis and nonhormonal intrauterine devices. NSAIDs and hormonal contraceptives are less likely to provide pain relief in women with secondary dysmenorrhea than in those with primary dysmenorrhea. The differential diagnosis of secondary dysmenorrhea is outlined in Table 16.3. The management of secondary dysmenorrhea is treatment of the underlying disorder.
Adenomyosis Adenomyosis is defined as presence of endometrial stroma and glands within the myometrium, at least one low-power field from the basis of the endometrium, whereas endometriosis is characterized by ectopic endometrium appearing within the peritoneal cavity. Adenomyosis, endometriosis, and uterine leiomyomas frequently coexist. Although occasionally noted in women in their younger reproductive years, the average age of symptomatic women is usually older than 40 years. Increasing parity, early menarche, and shorter menstrual cycles may all be risk factors according to one study (45–47).
Symptoms typically associated with adenomyosis include excessively heavy or prolonged menstrual bleeding, dyspareunia, and dysmenorrhea. Symptoms often begin up to 2 weeks before the onset of a menstrual ﬂow and may not resolve until after the cessation of menses.
The uterus is typically diffusely enlarged, although usually less than 14 cm in size, and is often soft and tender, particularly at the time of menses. Mobility of the uterus is not restricted, and there is no associated adnexal pathology (48).
Adenomyosis is a clinical diagnosis. Imaging studies including pelvic ultrasound or MRI, although helpful, are not definitive. Because of the cost of MRI and negligible improvement in diagnostic accuracy, this study is not recommended routinely. In women with diffuse uterine enlargement and negative pregnancy test results, secondary dysmenorrhea may be attributed to adenomyosis; however, the pathologic confirmation of suspected adenomyosis can be made only at the time of hysterectomy.