Transcranial direct current stimulation for provoked vestibulodynia: What roles do psychosexual factors play in treatment response?

There is growing evidence that provoked vestibulodynia (PVD), a frequent and debilitating condition, is characterized by central sensitization. This study aimed to examine predictive factors of transcranial direct current stimulation (tDCS) efficacy in this chronic pain population. Exploratory analysis derived from a randomized controlled trial was performed to assess predictors of pain reduction among 39 women with PVD who received 10 daily sessions of either active or sham tDCS. Clinical characteristics (e.g. pain intensity, duration and pain sensitivity) and psychosexual factors (e.g. pain catastrophizing, pain-related fear, anxiety, depressive symptoms and vaginal penetration cognitions) were assessed at baseline and used to predict tDCS response at 3-month follow-up. Analysis revealed that higher depressive symptoms and lower negative self-image cognitions were significant predictors of pain reduction at follow-up and accounted for 62.3% of the variance in the active tDCS group. Higher genital incompatibility cognitions were related to poorer response, regardless of treatment group. These findings suggest that women with PVD presenting higher depressive symptoms and lower levels of negative self-image cognitions could derive greater benefits from tDCS. These results suggest that tDCS could be effective in a subgroup of women with PVD - a possibility worth exploring with future prospective larger studies.

Are Cognitive Load and Focus of Attention Differentially Involved in Pain Management: An Experimental Study Using a Cold Pressor Test and Virtual Reality.

OBJECTIVE: The aim of this study is to assess whether distraction (lack of attentional focus) and attention (cognitive load) are differentially involved in the analgesic effect of virtual reality (VR) immersions during a cold pressor test (CPT). METHODS: Thirty-one participants were randomly assigned to four experimental conditions (high and low cognitive load, attention with or without a reminder of the pain stimuli) and performed three CPTs. Pain was assessed based on the duration of the CPT (pain tolerance), a visual analog rating scale of perceived pain intensity during the CPT and the subjective pain scale of the Short form McGill Pain Questionnaire (SF-MPQ). RESULTS: The statistical analyses revealed that VR immersions were associated with less pain compared to the baseline (all p <0.001), but for the experimental manipulations, only the conditions where there was an increase in cognitive load (ie, from low cognitive load at Immersion 1 to high cognitive load at Immersion 2) were effective for increasing pain tolerance (significant Time X Conditions interaction). The interactions were not significant for pain intensity assessed with the VAS or the SF-MPQ. CONCLUSION: The results suggest that increases in cognitive load play an important role in the analgesic effect of VR immersion, although the combination of attentional focus and cognitive load may be important. Suggestions are given for designing a replication study.

Efficacy of transcranial direct-current stimulation in women with provoked vestibulodynia.

BACKGROUND: Provoked vestibulodynia is a highly prevalent condition characterized by acute recurrent pain located at the vaginal entrance in response to pressure application or attempted vaginal penetration. Despite a wide variety of treatments offered to women with provoked vestibulodynia, a high proportion of women are refractory to conventional treatment. Transcranial direct-current stimulation is a noninvasive brain stimulation technique that has been shown effective for improving various chronic pain conditions. Growing evidence suggests that the central nervous system could play a key role in provoked vestibulodynia. Targeting the central nervous system could therefore be a promising treatment for women with provoked vestibulodynia. OBJECTIVE: The purpose of this study was to evaluate and compare the efficacy of active and sham transcranial direct-current stimulation in reducing pain intensity during intercourse in patients with provoked vestibulodynia. STUDY DESIGN: We conducted a triple-blind, parallel-group, randomized controlled trial. Women aged 17-45 years diagnosed with provoked vestibulodynia by a gynecologist using a validated protocol were randomized to 10 sessions of either active transcranial direct-current stimulation (intensity = 2 mA) or 10 sessions of sham transcranial direct-current stimulation, over a 2-week period. Both active and sham transcranial direct-current stimulation were applied for 20 minutes, with the anode positioned over the primary motor cortex, and the cathode over the contralateral supraorbital area. Outcome measures were collected at baseline, 2 weeks after treatment, and at 3-month follow-up by an evaluator blinded to group assignment. The primary objective was to assess pain intensity during intercourse, using a numerical rating scale. Secondary outcomes focused on sexual function and distress, vestibular sensitivity, psychological distress, treatment satisfaction, and patient impression of change. Statistical analyses were conducted on the intention-to-treat basis, and treatment effects were evaluated using a mixed linear model for repeated measures. RESULTS: A total of 40 patients were randomly assigned to receive either active (n = 20) or sham (n = 20) transcranial direct-current stimulation treatments from November 2014 through February 2016. Baseline characteristics were similar between the active and sham transcranial direct-current stimulation groups. In full compliance with the study protocol, every participant followed all courses of the study treatment, including assessments at 2-week and 3-month follow-up. Pain during sexual intercourse was not significantly different between active and sham treatment groups 2 weeks after treatment (P = .84) and at follow-up (P = .09). Mean baseline and 2-week assessment pain intensity were, respectively, 6.8 (95% confidence interval, 5.9-7.7) and 5.6 (95% confidence interval, 4.7-6.5) for active transcranial direct-current stimulation (P = .03) vs 7.5 (95% confidence interval, 6.6-8.4) and 5.7 (95% confidence interval, 4.8-6.6) for sham transcranial direct-current stimulation (P = .001). Nonsignificant differences between the 2 groups were also found in their sexual function and distress after treatment (P > .20) and at follow-up (P > .10). Overall, at 2-week assessment 68% assigned to active transcranial direct-current stimulation reported being very much, much, or slightly improved compared to 65% assigned to sham transcranial direct-current stimulation (P = .82), and still comparable at follow-up: 42% vs 65%, respectively (P = .15). CONCLUSION: Findings suggest that active transcranial direct-current stimulation is not more effective than sham transcranial direct-current stimulation for reducing pain in women with provoked vestibulodynia. Likewise, no significant effects were found on sexual function, vestibular sensitivity, or psychological distress.

Efficacy of transcranial direct-current stimulation (tDCS) in women with provoked vestibulodynia: study protocol for a randomized controlled trial.

BACKGROUND: Provoked vestibulodynia is the most common form of vulvodynia. Despite its high prevalence and deleterious sexual, conjugal, and psychological repercussions, effective evidence-based interventions for provoked vestibulodynia remain limited. For a high proportion of women, significant pain persists despite the currently available treatments. Growing evidence suggests that the central nervous system (CNS) could play a key role in provoked vestibulodynia; thus, treatment targeting the CNS, rather than localized dysfunctions, may be beneficial for women suffering from provoked vestibulodynia. In this study, we aim to build on the promising results of a previous case report and evaluate whether transcranial direct-current stimulation, a non-invasive brain stimulation technique targeting the CNS, could be an effective treatment option for women with provoked vestibulodynia. METHODS/DESIGN: This single-center, triple-blind, parallel group, randomized, controlled trial aims to compare the efficacy of transcranial direct-current stimulation with sham transcranial direct-current stimulation in women with provoked vestibulodynia. Forty women diagnosed with provoked vestibulodynia by a gynecologist, following a standardized treatment protocol, are randomized to either active transcranial direct-current stimulation treatment for ten sessions of 20 minutes at an intensity of 2 mA or sham transcranial direct-current stimulation over a 2-week period. Outcome measures are collected at baseline, 2 weeks after treatment and at 3-month follow-up. The primary outcome is pain during intercourse, assessed with a numerical rating scale. Secondary measurements focus on the sexual function, vestibular pain sensitivity, psychological distress, treatment satisfaction, and the patient's global impression of change. DISCUSSION: To our knowledge, this study is the first randomized controlled trial to examine the efficacy of transcranial direct-current stimulation in women with provoked vestibulodynia. Findings from this trial are expected to provide significant information about a promising intervention targeting the centralization of pain in women with provoked vestibulodynia. TRIAL REGISTRATION: Clinicaltrials.gov, NCT02543593 . Registered on September 4, 2015.

Triggering Descending Pain Inhibition by Observing Ourselves or a Loved-One in Pain.

OBJECTIVES: Recent studies demonstrate that empathy-evoked brain responses include the activation of brainstem structures responsible for triggering descending pain inhibition. Unfortunately, direct evidence linking empathy for pain and descending inhibitory controls (conditioned pain modulation) is lacking. This study, therefore, aimed to determine if the observation of ourselves or a loved-one in pain could activate descending pain inhibition without exposure to a noxious stimulation; which is otherwise required. METHODS: Descending pain inhibition was triggered by immersing the right arm of participants (15 heterosexual couples; mean age±SE: 28.89±2.14) in a bath of cold water. The effects of empathy on descending pain inhibition were observed by immersing the right arm of participants in a bath of lukewarm water while having them watch a video of either themselves or their spouse during a previous nociceptive immersion. Immersion of the arm in a bath of lukewarm water without empathic (video) observation was also included as a control condition. RESULTS: A strong inhibitory response activated by the mere observation of the video of themselves or their spouse in pain without a nociceptive conditioning stimulus. Associative statistics also showed that strong pain catastrophizing responses while watching the video resulted in stronger pain inhibition. Moreover, high levels of empathy were associated with stronger pain inhibition, but only for women. DISCUSSION: This study showed that observing someone in pain triggers descending pain inhibition. Results also demonstrate how empathy and gender are affecting pain modulation mechanisms.

Telepresence experienced in videoconference varies according to emotions involved in videoconference sessions.

Previous studies have linked telepresence to the strength of the therapeutic relationship experienced during telepsychotherapy. This finding comes as a surprise for many people who have been involved in a teleconference meeting, where telepresence is often considered weak. The aim of this study is to (re)evaluate the impact of emotional engagement on telepresence. Participants were randomly assigned to one of the two conditions: (a) emotionally charged verbal exchange first (followed by a more neutral verbal exchange), or (b) emotionally neutral verbal exchange first (followed by an emotionally charged verbal exchange). A distraction task was performed between the two verbal exchanges in videoconference. Results showed that verbal exchanges involving stronger emotions increase telepresence. These results may explain why telepresence is so high in telepsychotherapy.