Effects of Transcranial Direct Current Stimulation for Treatment of Primary Dysmenorrhea: Preliminary Results of a Randomized Sham-Controlled Trial Rodrigo Pegado, PhD,* Luana Karyne Silva, Ugrad Res,* H egila da Silva Dantas, Ugrad Res,* Hialison Andrade C^ amara, Ugrad Res,* Karime, Andrade Mescouto, PT,* Edson Meneses Silva-Filho, PT,* Johnnatas Mikael Lopes, PhD, ‡ Maria Thereza Albuquerque Barbosa Cabral Micussi, PhD, † and Grasi  ela Nascimento Correia, PhD* *Faculty of Health Science of Trairi and ; † Health Science Center, Federal University of Rio Grande do Norte, Rio Grande do Norte, Brazil; ‡ FACEX University Center, Nassau University Center, Rio Grande do Norte, Brazil Correspondence to: Rodrigo Pegado, PhD, Faculty of Health Science of Trairi, Federal University of Rio Grande do Norte, Trair  ı St. 59200-000, Santa Cruz-RN, Brazil. Tel: þ55 (84) 99915-004; E-mail: rodrigo@facisa.ufrn.br. Conflicts of interest: There is no conflict of interest to be declared regarding this trial. Abstract Objective. The aim of this trial was to investigate the effects of five consecutive sessions of anodal transcranial direct current stimulation (tDCS) over the motor cortex (M1) on pain, mood, and physical performance in patients with pri- mary dysmenorrhea (PDM). Design. This is a double-blind randomized controlled trial. Subjects. Twenty-two partici- pants with PDM according to the No. 345-PDM Consensus Guideline were included. Methods. Eleven active treatment and 11 sham stimulation patients received five applications over a one-week period. The primary outcome measures were pain evaluated by numeric rating scale (NRS) and McGill Questionnaire score. Secondary outcomes measures were responses to the Positive and Negative Affect Schedule (PANAS), Hamilton Anxiety Scale (HAM-A), grip strength, and six-minute walk test (6MWT). Baseline data were performed during the first menstrual cycle, and dur- ing the second menstrual cycle, participants were conducted to tDCS treatment, and postintervention data were col- lected. Results. The intervention provided significant improvements on NRS in active tDCS, shown as an interaction between group intervention vs pre/postintervention vs days of menstrual cycle (Wald x 2 ¼ 10.54, P ¼ 0.005), main ef- fect of days of menstrual cycle (Wald x 2 ¼ 25.42, P < 0.001), and pre/postintervention (Wald x 2 ¼ 6.97, P ¼ 0.008). McGill showed an interaction effect between pre/postintervention and group of stimulation (Wald x 2 ¼ 18.45, P ¼ 0.001), with a large reduction in active tDCS (P < 0.001, d ¼ 0.75). Psychological and functional outcomes did not dif- fer between groups or pre/postintervention. Conclusions. tDCS could provide pain relief in subjects with PDM. These results provide some preliminary evidence for the potential role of tDCS as a contributor to the management of symptoms of PDM. Key Words: Transcranial Direct Current Stimulation; Dysmenorrhea; Pain; Rehabilitation Introduction Primary dysmenorrhea (PDM) is one of the most preva- lent and debilitating conditions; it is defined as painful cramps that occur with menstruation [1]. Characteristic symptoms of PDM usually occur at the onset of men- strual flow, lasting from eight to 72 hours, and include lower abdominal or pelvic pain with or without radiation to the back or legs [2]. Secondary associated symptoms include nausea, vomiting, fatigue, back pain, headache, dizziness, and diarrhea [3]. PDM is an important public health problem, with many negative effects on female physical health, mood states, social relationships, and work activities [4]. Cross-sectional studies on 41,140 adolescents and young women reveal that the prevalence of PDM varies from 34% to 94% [4]. PDM has been considered a genuine chronic pain con- dition, and it co-occurs generally with many chronic pain syndromes in the context of suffering for a long lifetime V C The Author(s) 2019. Published by Oxford University Press on behalf of the American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com 3615 Pain Medicine, 21(12), 2020, 3615–3623 doi: 10.1093/pm/pnz202 Advance Access Publication Date: 10 September 2019 Original Research Article Downloaded from https://academic.oup.com/painmedicine/article/21/12/3615/5566353 by guest on 20 June 2022