Abstract
BackgroundAn imbalance in the excitatory/inhibitory systems in the pain networks may explain the persistent chronic pain after hallux valgus surgery. Thus, to contra-regulate this dysfunction, the use of transcranial direct current stimulation (tDCS) becomes attractive.ObjectiveWe tested the hypothesis that two preoperative active(a)-tDCS sessions compared with sham(s)-tDCS could improve the postoperative pain [as indexed by Visual Analogue Scale (VAS) at rest and during walking (primary outcomes)]. To assess their effect on the change in the Numerical Pain Scale (NPS0-10) during Conditioned Pain Modulation (CPM-task), disability related to pain (DRP) and analgesic consumption (secondary outcomes). Also, we assessed if the brain derived neurotrophic factor (BDNF) in the cerebral spinal fluid (CSF) after tDCS could predict the intervention’s effect on the DRP.MethodsIt is a prospective, double blind, sham-controlled, randomized single center, 40 women (18–70 years-old) who had undergone hallux valgus surgery were randomized to receive two sessions (20 minutes each) of anodal a-tDCS or s-tDCS on the primary motor cortex at night and in the morning before the surgery. To assess the DRP was used the Brazilian Profile of Chronic Pain: Screen (B-PCP:S).ResultsA-tDCS group showed lower scores on VAS at rest and during walking (P<0.001). At rest, the difference between groups was 2.13cm (95%CI = 1.59 to 2.68) while during walking was 1.67cm (95%CI = 1.05 to 2.28). A-tDCS, when compared to s-tDCS reduced analgesic doses in 73.25% (P<0.001), produced a greater reduction in B-PCP:S (mean difference of 9.41 points, 95%CI = 0.63 to 18.21) and higher function of descending pain modulatory system (DPMS) during CPM-task.ConclusionA-tDCS improves postoperative pain, the DRP and the function of DPMS. Also, the CSF BDNF after a-tDCS predicted the improvement in the DRP. In overall, these findings suggest that a-tDCS effects may be mediated by top-down regulatory mechanisms associated with the inhibitory cortical control.Trial registrationClinicalTrials.gov NCT02360462
Highlights
Foot pain affects 17 to 42% of the adult population [1] while hallux valgus is responsible for 28% of all causes [1,2]
A-transcranial direct current stimulation (tDCS), when compared to s-tDCS reduced analgesic doses in 73.25% (P
The cerebral spinal fluid (CSF) brain-derived neurotrophic factor (BDNF) after a-tDCS predicted the improvement in the disability related to pain (DRP)
Summary
Foot pain affects 17 to 42% of the adult population [1] while hallux valgus is responsible for 28% of all causes [1,2]. One year after hallux valgus surgery, moderate-to-severe chronic pain persists in 21% at rest and 43% during walking [4]. Consistent evidence has shown that chronic pain is associated with a disinhibited state of cortical neural circuits [5,10] that are reverted after anodal tDCS of primary motor cortex [11]. This neural disinhibited state may be related to the level of brain-derived neurotrophic factor (BDNF), which. An imbalance in the excitatory/inhibitory systems in the pain networks may explain the persistent chronic pain after hallux valgus surgery. To contra-regulate this dysfunction, the use of transcranial direct current stimulation (tDCS) becomes attractive
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
