Pain catastrophization, fatigue, and sleep-related impairment in women with PFMP

Objectives: Myofascial pain is a chronic musculoskeletal disorder that has been identified throughout the body, including in the pelvis, and is characterized by trigger points within the muscle leading to local and referred pain. Pelvic floor myofascial pain (PFMP) has been associated with the presence and severity of pelvic floor disorder symptoms in women. Central sensitization, the amplification of central nervous system signaling resulting in pain amplification, is one mechanism proposed to explain the association between PFMP and pelvic floor disorder symptoms. Pain catastrophization, the negative cognitive and emotional response to real or anticipated pain, is characterized by helplessness, rumination, and magnification and is often associated with increased pain severity and worse pain outcomes in patients with central sensitization. The objective of this pilot study is to investigate the presence of pain catastrophization in patients with PFMP and the effect of PFMP on physical, mental, and social health compared to controls using validated questionnaires.

Methods: This is a cross-sectional pilot study of new patients presenting for evaluation of pelvic floor disorders. All new adult patients were eligible, regardless of presenting complaint. Patients were consented and completed electronic questionnaires including the American College of Rheumatology (ACR) Fibromyalgia Survey, Female Genitourinary Pain Index, Pain Catastrophizing Scale, and several PROMIS measures in advance of their appointment. Data, including demographics, medical and surgical history, and pelvic floor myofascial examination scores, were abstracted from the medical record after the visit. Patients were categorized as having PFMP (pain ³4/10 at ³2 sites) or controls. Demographic and clinical variables and questionnaire scores were compared between cases and controls using t-tests, chi-square, and Wilcoxon-Mann-Whitney tests as appropriate.

Results: 112 patients were enrolled and completed all questionnaires: 47 with PFMP and 65 controls. Demographics were similar between cases and controls (Table 1). Patients with PFMP on examination had statistically higher scores on the Female Genitourinary Pain Index (summary and subscale scores) and Pain Catastrophizing Scale (total, and rumination and helplessness subscales, Table 2). Patients with PFMP demonstrated significantly higher rates of fatigue and sleep-related impairment as well as worse physical function on PROMIS Measures (Table 2) and were more likely to meet criteria for fibromyalgia based on the ACR diagnostic criteria, although this did not meet significance.

Conclusions: Patients with PFMP on examination demonstrate greater pain catastrophization, fatigue, and sleep related impairment as well as worse physical functioning compared to controls. As pain catastrophization is associated with central sensitization, these findings may support a role for central sensitization in the link between PFMP and pelvic floor disorder symptoms. Future studies should explore and quantify the extent of central sensitization in women with PFMP.