Pain Characteristics, Fear-avoidance Variables, and Pelvic Floor Function as Predictors of Treatment Response to Physical Therapy in Women With Provoked Vestibulodynia.

OBJECTIVE: The aim was to investigate whether pretreatment pain characteristics, psychological variables, and pelvic floor muscle (PFM) function predict the response to physical therapy (PT) in women with provoked vestibulodynia (PVD). MATERIALS AND METHODS: One hundred-five women diagnosed with PVD underwent 10 weekly sessions of individual PT comprising education, PFM exercises with biofeedback, manual therapy, and dilators. Treatment outcomes were evaluated at pretreatment, post-treatment, and 6-month follow-up and included pain intensity (numerical rating scale 0 to 10) and sexual function (Female Sexual Function Scale). Multilevel analyses were used to examine the potential predictors of response over time including pain characteristics (PVD subtype, pain duration), psychological variables (fear of pain, pain catastrophizing), and PFM function assessed with a dynamometric speculum (tone, flexibility, and strength). RESULTS: PVD subtype and PFM tone were significant predictors of greater treatment response for pain intensity reduction. Secondary PVD (ie, pain developed after a period of pain-free intercourse) and lower PFM tone at baseline were both associated with greater reduction in pain intensity after PT and at follow-up. Among the psychological variables, fear of pain was the only significant predictor of better treatment response when assessed through improvement in sexual function, where higher fear of pain at baseline was associated with greater improvement after PT. DISCUSSION: This study identified PVD secondary subtype, lower PFM tone, and higher fear of pain as significant predictors of better treatment response to PT in women with PVD.

Unpredictable pain timings lead to greater pain when people are highly intolerant of uncertainty.

BACKGROUND AND PURPOSE: Many psychological factors are known to influence pain perception. Among them, intolerance of uncertainty (IU) may play a key modulating role in situations where uncertainty prevails, especially uncertainty regarding the timing of painful events. The objective of this study was to explore the impact of individual differences in IU on pain perception during predictable and unpredictable stimulation timings. We hypothesized that people with high IU, as opposed to those with low IU, would perceive more pain when the timing of painful stimulations cannot be predicted, as compared to when they can. METHODS: Twenty (20) healthy adults, aged between 18 and 35 years old, were recruited. Painful sensations were provoked using transcutaneous electrical stimulations of the right sural nerve. By measuring IU (Intolerance of Uncertainty Scale) and subjective pain (verbal numerical rating scale), it was possible to test the relationship between IU and pain perception, by simulating predictable and unpredictable painful experiences. This was done through cued shock interval (CSI) blocks, with either variable timing or fixed timings (long or short time frame). Self-administered questionnaires were also used to measure pain hypervigilance, pain catastrophizing, state anxiety, and trait anxiety. RESULTS: Pearson correlations confirmed the presence of an association (r=0.63) between IU and the change in pain intensity provoked by unpredictable stimulation timings. Importantly, this association was significant only for stimulations provided at long CSIs, indicating that higher IU scores predicted higher pain intensity scores when stimulation timings became unpredictable, and when the cued delay was long. No association was found between pain scores and other psychological variables. CONCLUSIONS: Our results show that IU moderately correlates to the change in pain intensity provoked by unpredictable stimulation timings. High IU scores were associated with a worsening of the subjective pain experience, especially during long delays in an unpredictable situation. These observations suggest that IU could be considered as a psychological variable that is able to influence pain perception in certain situations. IMPLICATIONS: Assessing and addressing IU could be an added value in pain-related therapy, especially in chronic pain.