Clinical Trial: The Effect of tDCS in the Preoperative Period of Hallux Valgus Surgical Treatment

Study Status: Active, not recruiting
Recruit Status: Active, not recruiting
Study Type: Interventional

Official Title: The Effect of tDCS in the Preoperative Period of Hallux Valgus Surgical Treatment

Brief 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 Summary: 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
Sponsor: Hospital de Clinicas de Porto Alegre

Current Primary Outcome: Change in pain scores assessed with the visual analogue scale [ Time Frame: Once Daily. It starts in the day before surgical treatment (Day 0), and it is assessed every day until one week after the surgical procedure (total = 10 days) ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

• Preoperative Anxiety level [ Time Frame: Initial contact (before any tDCS session - Day 0) and the moment before the surgical procedure (Day 1) ]
  Anxiety level will be assessed by State-Trait Anxiety Inventory (STAI), adapted to Brazilian Portuguese Language. It will be assessed before the first session of tDCS (on initial contact with the patient - Day 0), and in the moment right before going to the surgical room in the next day (Day 1). Total = 2 evaluations
• Change in the temperature pain threshold [ Time Frame: Day before the surgical treatment (Day 0), and in the moment after the spinal anesthesia recovery in immediate postoperative period (Day 1). ]
  It will be assessed by the Quantitative Sensory Test (QST) in the dominant (right) forearm and in the leg ipsilateral to the foot that will be treated. The heat pain tolerance, the pain threshold to the heat and the temperature defined as pain 6/10 by the participant will be determined. The temperature starts at 32°C, and it heats at a 1.0 °C/sec rate and cools down after a button is pressed or whenever it reaches the max temperature of 52°C. The participant will be asked to press down the button at the first sensation of pain to determine the pain threshold; to press down the button whenever she can not stand the heat anymore for the pain tolerance determination and, for last, to press down the button at the temperature she fells pain equivalent to 6/10 in the numeric scale of pain. The pain threshold and the temperature of pain 6/10 will be determined by the arithmetic mean of 3 evaluations each.
• Change in effect of the descendent modulator system of pain [ Time Frame: Day before the surgical treatment (Day 0), and in the moment after the spinal anesthesia recovery in immediate postoperative period (Day 1). ]
  It will be assessed by the Conditioned Pain Modulation test (CPM). A nociceptive tonic conditioning stimulus - immersion of the non-dominant hand in cold water (0°C for 1 minute) - will be applied concomitant to the progressive thermal stimulus in the dominant forearm as applied in the QST pattern until it reaches the 6/10 pain temperature previously determined by the participant. It will be tested in the day before the surgical treatment (before the first session of tDCS), and after the spinal anesthesia recovery in immediate postoperative period. Total of 2 test days.
• Change in serum biomarkers level: The brain derived neurotrophic factor (BDNF), S100B, nerve growth factor (NGF) and enolase [ Time Frame: The day before the surgical treatment (Day 0), in the moment before the spinal anestesia (Day 1) and a week after the surgical procedure (Day 9) ]
  A blood sample will be collected to measure each plasma biomarker in the day before the surgical treatment (Day 0), in the moment before the spinal anesthesia (Day 1) and a week after the surgical procedure (Day 9). Total = 3 evaluations

Original Secondary Outcome: Same as current

Information By: Hospital de Clinicas de Porto Alegre

Dates:
Date Received: January 22, 2015
Date Started: December 2014
Date Completion: June 2016
Last Updated: February 22, 2016
Last Verified: February 2016