Myofascial Pain Myofascial syndrome is documented in about 15% of patients with chronic pelvic pain (120). These patients are noted to have numerous trigger points, hyperirritable areas within a tight band of skeletal muscle or within its fascia (123,124). Trigger points are possibly initiated by pathogenic autonomic reﬂex of visceral or muscular origin and are painful on compression (124–126). The referred pain of the trigger point occurs in a dermatomal distribution and may be caused by nerves from the muscle or deeper structures sharing a common second-order neuron in the spinal cord. The patient can experience weakness and restriction in range of motion of the affected muscle. Physical therapy is a mainstay (127). Painful trigger points characteristically can be abolished with the injection of local anesthetic into the painful area, and topical lidocaine patches or creams can be useful (123). Trigger points can be present in women with chronic pelvic pain irrespective of presence or type of underlying pathology. In one study, 89% of women with chronic pelvic pain had abdominal, vaginal, or lumbosacral trigger points (123). In the absence of the initial or ongoing organic pathology, various factors are theorized to predispose to the chronicity of the myofascial syndrome, including psychological, hormonal, and biomechanical factors (124). A multidisciplinary approach to myofascial pain must include cognitive behavioral and relaxation approaches.
Abdominal wall and pelvic ﬂoor myofascial pain is often exacerbated during the premenstrual period or by stimuli to the dermatome of trigger points (e.g., full bladder, bowel, or any stimulation to organs that share the dermatome of the involved nerve) (125).
On examination, fingertip pressure on the trigger points evokes local and referred pain.
Tensing of the muscles by either straight leg lifting or raising the head off the table or palpation increases the pain. A specific jump sign can be elicited by palpation with fingertip or a cotton swab. An electric (tingling) sensation confirms correct needle placement (123).
Massage therapy can help relieve the pain in some cases. “Myofascial release” is a special vigorous message that can be effective (124). Depending on the location of the myofascial trigger points, pelvic ﬂoor physical therapy is indicated (128). Sustained pressure with adequate force to a trigger point for a specified period can inactivate the irritable nerve (129). NSAIDs, gabapentin, pregabalin, low-dose TCAs, and benzodiazepines may be useful in patients requiring pharmacologic interventions. Injection of the trigger point with 3 mL of 0.25% bupivacaine provides relief that usually outlasts the duration of the anesthetic action. After four to five biweekly injections, the procedure should be abandoned if long-lasting relief is not obtained. A 60-patient randomized controlled trial compared lidocaine patch and placebo patch versus anesthetic injection for the treatment of myofascial pain syndrome. The study revealed similar efficacy of anesthetic patch to the gold standard treatment with trigger point injection and was associated with less discomfort than injection therapy (126). Acupuncture can be effective (130). Concomitant with injection at trigger points; relaxation, stress reduction, and cognitive-behavioral pain management should be undertaken, especially if anxiety, depression, history of emotional trauma, physical or sexual abuse, sexual dysfunction, or social or occupational disruption are present.