Primary Dysmenorrhea (PDM), defined as menstrual pain without discernable organic causes, is inexorably common in adolescent women, about 40-90% of women may suffer from it, and 20% of them can be severe in the context of being refractory to medication, daily function impairment, and having pain of severe degree. Novel therapeutic method is in need for pain alleviation for this particular phenotype. We have previously reported that PDM females may engage motor-cortex based descending pain modulation system in our resting-state functional Magnetic Resonance Imaging (rs-fMRI) and thermal pain-activation fMRI studies. Based on the reported analgesic efficacy of transcranial Direct Current Stimulation (tDCS) on the motor cortex for various experimental painful conditions and clinical pain disorders, we reason that tDCS can be effective for the severe and medication-refractory PDM patients. This study aim to investigate the analgesic efficacy of tDCS in severe PDMs and to elucidate the dynamic brain neuroplasticity in the context of functional connectivity (FC) of pain matrix after tDCS intervention. We will recruit 30 severe PDMs and randomly allocate them to either real or sham group in a triple-blind manner. rs-fMRI for functional connectivity analysis will be performed before and after the tDCS intervention. The imaging data will be correlated with behavioral and psychological measurements. This is the first study in the literature investigating the tDCS efficacy for severe PDM. The result can promise a new possibility for clinical application.
Name: Active tDCS
Name: Sham tDCS
Description: pain scale; from 0 to 10; score 0: no pain, score 10: unbearable pain
Measure: Visual Analog Scale (VAS) Time: change from baseline (1st menstrual phase, before tDCS) at one month (2nd menstrual phase, with tDCS), change from baseline (1st menstrual phase, before tDCS) at two months (3rd menstrual phase)Description: Resting-state functional magnetic resonance imaging (rs-fMRI) is a well established method of functional magnetic resonance imaging (fMRI) that is used to evaluate regional interactions in the brain that occur in a resting (task-negative) state, when a subject is not performing an explicit task. Functional connectivity is the connectivity between brain regions that share functional properties, it can be defined as the correlation between spatially remote neurophysiological events, expressed as the neural networks of brain.
Measure: Functional connectivity of rs-fMRI Imaging Time: change from baseline (before tDCS, before 2nd menstrual phase) at one week (after tDCS completion), change from baseline (before tDCS, before 2nd menstrual phase) at four weeks (before the 3rd menstrual phase)Description: To assess the threshold of thermal sensation (cold, cold-pain, heat, heat-pain; from 0 to 50 centigrade temperature), according to the established protocol of an ascending limit approach for heat pain and a descending limit approach for cold pain.
Measure: Quantitative sensory testing (QST) Time: change from baseline (before tDCS) at one week (after tDCS completion), change from baseline (before tDCS) at four weeks (before the 3rd menstrual phase), change from baseline (before tDCS) at five weeks (after the 3rd menstrual phase)Description: To assess anxious symptoms; from 20 to 80; score 20: not anxious, score 80: extremely anxious
Measure: Spielberger State-Trait Anxiety Inventory (STAI) Time: change from baseline (before tDCS) at one week (after tDCS completion), change from baseline (before tDCS) at four weeks (before the 3rd menstrual phase), change from baseline (before tDCS) at five weeks (after the 3rd menstrual phase)Description: To assess anxious symptoms; from 0 to 63; score 0: not anxious, score 63: extremely anxious
Measure: Beck Anxiety Inventory (BAI) Time: change from baseline (before tDCS) at one week (after tDCS completion), change from baseline (before tDCS) at four weeks (before the 3rd menstrual phase), change from baseline (before tDCS) at five weeks (after the 3rd menstrual phase)Description: To assess depressive symptoms; from 0 to 63; score 0: not depressed, score 63: extremely depressed
Measure: Beck Depression Inventory (BDI) Time: change from baseline (before tDCS) at one week (after tDCS completion), change from baseline (before tDCS) at four weeks (before the 3rd menstrual phase), change from baseline (before tDCS) at five weeks (after the 3rd menstrual phase)Description: To assess pain-maladaptive psychological status; from 0 to 52; score 0: not pain Catastrophizing , score 52: extremely pain Catastrophizing
Measure: Pain Catastrophizing Scale (PCS) Time: change from baseline (before tDCS) at one week (after tDCS completion), change from baseline (before tDCS) at four weeks (before the 3rd menstrual phase), change from baseline (before tDCS) at five weeks (after the 3rd menstrual phase)Description: To assess pain status; from 0 to 78; score 0: not painful, score 78: extremely painful
Measure: Long-form McGill Pain Questionnaire (MPQ) Time: change from baseline (before tDCS) at one week (after tDCS completion), change from baseline (before tDCS) at four weeks (before the 3rd menstrual phase), change from baseline (before tDCS) at five weeks (after the 3rd menstrual phase)Description: To assess quality of life; he SF-36 consists of eight scaled scores, which are the weighted sums of the questions in their section. Each scale is directly transformed into a 0-100 scale on the assumption that each question carries equal weight. From 0 to 100; score 0: equivalent to maximum disability, score 100: no disability.
Measure: Short-Form Health Survey (SF-36) Time: change from baseline (before tDCS) at one week (after tDCS completion), change from baseline (before tDCS) at five weeks (after the 3rd menstrual phase)Description: To assess testosterone, progesterone, estrogen
Measure: Blood Hormones Measurement Time: change from baseline (before tDCS) at one week (after tDCS completion), change from baseline (before tDCS) at four weeks (before the 3rd menstrual phase)Description: To genotype the single nucleotide polymorphism genotyping (i.e., BDNF Val66Met polymorphism (rs6265), COMT Val158Met polymorphism (rs4680), OPRM1 (rs1799971), 5HTR2A (rs6313), SLC6A4 (rs25531)) from blood specimen
Measure: Genotyping Time: baselineDescription: To assure blinding efficacy; Patients do self-assessment about whether they receive real tDCS or sham tDCS. Assessment questionnaire:1 or 0. 1: real tDCS; 0: sham tDCS.
Measure: Efficacy of tDCS blinding Time: At 1 months after tDCS interventionAllocation: Randomized
Parallel Assignment
There are 5 SNPs
To genotype the single nucleotide polymorphism genotyping (i.e., BDNF Val66Met polymorphism (rs6265), COMT Val158Met polymorphism (rs4680), OPRM1 (rs1799971), 5HTR2A (rs6313), SLC6A4 (rs25531)) from blood specimen.
To genotype the single nucleotide polymorphism genotyping (i.e., BDNF Val66Met polymorphism (rs6265), COMT Val158Met polymorphism (rs4680), OPRM1 (rs1799971), 5HTR2A (rs6313), SLC6A4 (rs25531)) from blood specimen.
To genotype the single nucleotide polymorphism genotyping (i.e., BDNF Val66Met polymorphism (rs6265), COMT Val158Met polymorphism (rs4680), OPRM1 (rs1799971), 5HTR2A (rs6313), SLC6A4 (rs25531)) from blood specimen.
To genotype the single nucleotide polymorphism genotyping (i.e., BDNF Val66Met polymorphism (rs6265), COMT Val158Met polymorphism (rs4680), OPRM1 (rs1799971), 5HTR2A (rs6313), SLC6A4 (rs25531)) from blood specimen.
To genotype the single nucleotide polymorphism genotyping (i.e., BDNF Val66Met polymorphism (rs6265), COMT Val158Met polymorphism (rs4680), OPRM1 (rs1799971), 5HTR2A (rs6313), SLC6A4 (rs25531)) from blood specimen.