The Effect of tDCS in the Preoperative Period of Hallux Valgus Surgical Treatment
Condition: Chronic Pain; Hallux Valgus
MeSH terms: Hallux Valgus; Bunion; Chronic Pain
Study type: Interventional

Summary: 
      This is a clinical trial that intend to determine if transcranial direct current stimulation
      (tDCS) is effective in the treatment of postoperative pain and in the anxiety level in the
      preoperative period of hallux valgus surgical treatment
    

Detailed description: 
      Introduction: Forefoot deformities are important cause of feet pain and discomfort and affect
      around 80% of general population, predominantly in female population. Among teenagers and
      adults´ common forefoot deformities is hallux valgus. To achieve the deformity heal, surgical
      treatment is needed. The transcranial direct current stimulation (tDCS) is a non invasive
      technic, that aims for the central nervous system modulation for pain control, which can
      become a therapeutic option for postoperative pain. Experimental studies have shown that tDCS
      has reverted the hyperalgesia induced by chronic stress and articular inflammatory pain, has
      reduced total knee arthroplasty postoperative opioid consumption and a single 20 minutes
      session has shown reduction in endoscopic procedures opioid consumption, safety and minimal
      adverse effects. However, the tDCS effect in preoperative hyperalgesia has not been explored
      yet in sensitized patients, neither in anxiety and postoperative rehabilitation of patients
      submitted to hallux valgus surgical correction. In this study, it was chosen to use tDCS to
      stimulate cerebral cortex due to its efficacy in painful syndromes, for being a non invasive,
      low cost and easy-to-apply technic in comparison to other neurostimulation technics and
      especially, for its potential to counter-regulate the mal adaptive neuroplastic alterations
      associated to chronic pain. Objective: to evaluate the effect of tDCS compared to tDCS-sham
      in the pain control (visual analog scale score, pain threshold and the descendent modulator
      system), perioperative anxiety, postoperative analgesic drug consumption and in the
      rehabilitation of patients with arthralgia of the first metatarsophalangeal articulation
      submitted to hallux valgus surgical correction. Method: it is a randomized, blinded,
      placebo-sham controlled clinical trial which includes 40 female patients, between 18 and 70
      years old, candidates to hallux valgus surgical treatment by combined Chevron + Akin
      osteotomy due to arthralgia of the first metatarsophalangeal articulation. The patients will
      be randomized and divided into two groups that will be treated with two tDCS or tDCS-sham
      sessions of 20 minutes each in preoperative period. Expected results: This study will
      evaluate the effect of tDCS as a treatment option to postoperative pain and perioperative
      anxiety of patients submitted to hallux valgus surgical correction. In case of proven
      efficacy, this technic can become a low cost, easy access, safe and effective treatment
      option for these patients.
    

Intervention name(s): Active tDCS; Sham tDCS
Intervention type(s): Device; Device
Intervention description(s): The stimulation will be administered with a pair of surface electrodes, sponge coated, soaked in saline. A battery-powered constant current stimulator will be used for this purpose (tDCS device). The stimulation is performed by placing the anodal electrode in the primary motor cortex (M1) and the cathodal one in the contralateral supraorbital area and it will use a 2 mA (milliampere) current.; The sham tDCS consists in the same montage of the active tDCS, but the device is turned off 30 seconds after stimulation starts (without letting the patient notice it). The rest of the montage is kept identical to the active one during the 20 minutes session
Other intervention name(s): transcranial direct current stimulation (tDCS); Sham transcranial direct current stimulation (Sham tDCS)
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: Transcranial Direct Current Stimulation; tDCS; Hallux Valgus; Chronic Pain