Neuropathic Pain, Nociplastic Pain
Conditions
Keywords
Sensitization, 8% capsaicin patch, Quantitative Sensory Testing, Temporal Summation
Brief summary
The primary objective of this study will be to demonstrate a change in pain sensitization parameters before and after the application of the high-concentration capsaicin patch.
Detailed description
Category 2 Study (Interventional Research with Minimal Risks and Constraints), monocentric, uncontrolled, non-randomized, open-label and prospective. This study involves conducting tests and questionnaires before and 1 month after the application of a patch administered as part of standard clinical practice.
Interventions
OTHERQuantitative Sensory Testing and questionnaires
Quantitative Sensory Testing and questionnaires
Sponsors
Nantes University Hospital
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Men or women ≥ 18 years old. * Patients suffering from chronic pelvi-perineal neuralgia (\>3 months) with a DN4 score ≥4 at the inclusion visit, with or without symptoms of central sensitization, and with an indication for topical treatment with high-concentration capsaicin patch (PCHC). * Patients who have signed the informed consent form for the study at the inclusion visit. * Women must meet one of the following criteria at the time of inclusion: * Use adequate contraceptive measures; * or Be postmenopausal (aged over 50 years with amenorrhea for at least 12 months after discontinuation of all exogenous hormonal treatments); * or (If aged under 50 years) have been amenorrheic for at least 12 months after discontinuation of exogenous hormonal treatments, with luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels consistent with postmenopausal levels; * or Have undergone irreversible surgical sterilization (hysterectomy, bilateral oophorectomy, or bilateral salpingectomy), with documentation of the procedure.
Exclusion criteria
* Patients under guardianship, curatorship, or legal protection. * Pregnant or breastfeeding women. * Patients with contraindications to the use of the high-concentration capsaicin patch (PCHC): application on damaged skin, hypersensitivity to any of its components. * Patients simultaneously starting a treatment that may influence central sensitization (e.g., antidepressants, antiepileptics, psychotherapy, physical activity, transcutaneous electrical nerve stimulation). * Patients not affiliated with the French Social Security system. * Patients with insufficient cooperation and/or understanding to strictly comply with the protocol requirements. * Patients who have taken analgesics within the 12 hours prior to measurements.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Composite criterion | Difference between Day 0 and Day 30 | Composite criterion constructed from a Principal Component Analysis including the differences between Day 0 (before patch application) and Day 30 in pain perception thresholds (to cold, heat, pressure, and mechanical stimulation) in both the area treated with the high-concentration capsaicin patch and the corresponding dermatome, as well as the change in the pain receptive field area in the treated zone and the area under the curve of temporal summation measurements. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Measure the effect of the high-concentration capsaicin patch on peripheral sensitization (1) | Between before and 30 days after patch application | Difference in pressure pain thresholds in the treated area |
| Measure the effect of the high-concentration capsaicin patch on peripheral sensitization (2) | Between before and 30 days after patch application | Difference in mechanical stimulation pain thresholds |
| Measure the effect of the high-concentration capsaicin patch on peripheral sensitization (3) | Between before and 30 days after patch application | Difference in cold pain thresholds in the treated area |
| Measure the effect of the high-concentration capsaicin patch on peripheral sensitization (4) | Between before and 30 days after patch application | Difference in heat pain thresholds in the treated area |
| Measure the effect of the high-concentration capsaicin patch on peripheral sensitization (5) | Between before and 30 days after patch application | Difference in pain receptive field area |
| Measure the effect of the high-concentration capsaicin patch (PCHC) on spinal sensitization (1) | Between before and 1 month after patch application. | Difference in pressure pain thresholds in an area of the dermatome not directly treated by the patch: * Ipsilateral retro-malleolar groove (S2 root) for inferior cluneal nerve neuralgia treatment, * Posterior iliac crest relief, 7 cm from the midline (L1) for ilio-inguinal or ilio-hypogastric neuralgia treatment, * Perineal body (S4) for sacrococcygeal plexus neuralgia treatment. |
| Measure the effect of the high-concentration capsaicin patch (PCHC) on spinal sensitization (2) | Between before and 1 month after patch application. | Difference in mechanical stimulation pain thresholds in an area of the dermatome not directly treated by the patch |
| Measure the effect of the high-concentration capsaicin patch (PCHC) on spinal sensitization (3) | Between before and 1 month after patch application. | Difference in cold pain thresholds in an area of the dermatome not directly treated by the patch. |
| Measure the effect of the high-concentration capsaicin patch (PCHC) on spinal sensitization (4) | Between before and 1 month after patch application. | Difference in heat pain thresholds in an area of the dermatome not directly treated by the patch. |
| Measure the effect of the high-concentration capsaicin patch (PCHC) on spinal sensitization (5) | Between before and 1 month after patch application. | Difference in the area under the curve of temporal summation measurements in the treated area |
| Measure the effect of the high-concentration capsaicin patch (PCHC) on spinal sensitization (6) | Between before and 1 month after patch application. | Difference in the duration of pain persistence after the end of temporal summation (in seconds). |
| Measure the patient's therapeutic response to the treatment | Day 30 | Patient Global Impression of Change (PGI-C). The therapeutic response is defined as a patient who scores 1 to 3 on the PGI-C. |
| Evaluate the predictive value of temporal summation with regard to the therapeutic response to the high-concentration capsaicin patch | Between before and 1 month after patch application. | Investigation of a relevant threshold for temporal summation to predict the therapeutic response. Quantification of the positive predictive value. |
| Measure the correlation between Convergences PP scores, CSI, and semi-objective sensitization data | Between before and 1 month after patch application | Measure the correlation between Convergences PP scores, CSI, and semi-objective sensitization data. The Convergences PP score is a clinical questionnaire used to diagnose sensitization in the pelvic region. A score is considered positive from 5/10 (sensitivity = 95%, specificity = 87%). The Central Sensitization Inventory (CSI) is a self-administered questionnaire used to diagnose central sensitization. A score is considered positive from 40/100. Correlations between the Convergences PP score, CSI, and semi-objective sensitization data (pain thresholds and temporal summation) will be measured using Spearman's correlation coefficient to explore the relationships between these variables. |
Countries
France
Contacts
CONTACTAmélie LEVESQUE, MD
Outcome results
None listed