Impaired Ability to Relax Pelvic Floor Muscles in Men With Chronic Prostatitis/Chronic Pelvic Pain Syndrome

Objective: Excessive pelvic floor muscle activity has been suggested as a source of pain in chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). Our objective was to determine whether men with CP/CPPS have changes in neural drive that impair their ability to relax pelvic floor muscles. Methods: We recruited 90 men (42 with CP/CPPS and 48 in the control group [without a history of pelvic pain]). All completed the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI). We quantified the ability to relax by comparing resting pelvic floor muscle activity under 2 conditions: a "rest-only"condition, in which participants were instructed to simply relax, and a "rest-between-contraction"condition, in which participants were instructed to rest for several seconds between voluntary pelvic floor muscle contractions. We used multivariate mixed-effects models to examine differences between the groups (men with CP/CPPS and men in the control group) as well as the effect of 6 symptoms captured by the NIH-CPSI: pain related to location (perineum, testicles, penis, suprapubic region) and activity (urination, ejaculation). Results: Men with CP/CPPS were significantly different from men in the control group; men with CP/CPPS had higher resting activity in the rest-between-contraction condition than in the rest-only condition, whereas men in the control group had similar resting activities in both conditions. This effect was strongest in men who reported ejaculation-related pain, which was 70% of the CP/CPPS group. Conclusion: Men without a history of pelvic pain were able to relax their pelvic floor muscles back to baseline after performing voluntary pelvic floor muscle contractions. In contrast, men with CP/CPPS, particularly those with ejaculation-related pain, had an impaired ability to relax their pelvic floor muscles. Impact: This study may support the investigation of more personalized physical therapist approaches for CP/CPPS that enhance the ability to relax pelvic floor muscles as a mechanism for pain reduction.