Transcranial direct current stimulation is safe and effective in autoimmune myopathies: a randomised, double-blind, sham-controlled trial.

OBJECTIVES: We aimed to assess the safety and efficacy of transcranial direct current stimulation (tDCS) in patients with systemic autoimmune myopathies (SAMs). METHODS: This prospective, randomised, sham-controlled, double-blind, study included 20 patients with SAMs allocated to receive sham or active tDCS (2mA, 20 minutes, 3 days). Electrodes were positioned with the anode over the C1 or C2, whereas the cathode was placed over the Fp2 or Fp1, respectively. The groups were evaluated in four periods with specific questionnaires and functional tests: pre-stimulation and after 30 minutes, three weeks, and eight weeks post-tDCS. RESULTS: Two patients from the sham group withdrew after the three sessions. The demographic data, type of myositis, disease duration, and disease status were comparable between the active and sham tDCS groups. After interventions, in the active tDCS group, the physical aspects of SF-36 in week eight, mean and better timed up-and-go test at each evaluation, peak torque of stimulated inferior limb extension improved significantly (p<0.05). The emotional aspect of SF-36 decreased only in the active tDCS group (p<0.001). The patients' adherence to the protocol was 100% and no serious adverse event was reported, including disease relapses. CONCLUSIONS: This study evidences the safety of tDCS, as well as its potential efficacy in improving muscle strength and function in SAMs patients. More studies with a larger sample and longer tDCS sessions are necessary to corroborate the results of the present study.

Increased Delta and Theta Power Density in Sickle Cell Disease Individuals with Chronic Pain Secondary to Hip Osteonecrosis: A Resting-State Eeg Study.

PURPOSE: Identify the presence of a dysfunctional electroencephalographic (EEG) pattern in individuals with sickle cell disease (SCD) and hip osteonecrosis, and assess its potential associations with depression, anxiety, pain severity, and serum levels of brain-derived neurotrophic factor (BDNF). METHODS: In this cross-sectional investigation, 24 SCD patients with hip osteonecrosis and chronic pain were matched by age and sex with 19 healthy controls. Resting-state EEG data were recorded using 32 electrodes for both groups. Power spectral density (PSD) and peak alpha frequency (PAF) were computed for each electrode across Delta, Theta, Alpha, and Beta frequency bands. Current Source Density (CSD) measures were performed utilizing the built-in Statistical nonparametric Mapping Method of the LORETA-KEY software. RESULTS: Our findings demonstrated that SCD individuals exhibited higher PSD in delta and theta frequency bands when compared to healthy controls. Moreover, SCD individuals displayed increased CSD in delta and theta frequencies, coupled with decreased CSD in the alpha frequency within brain regions linked to pain processing, motor function, emotion, and attention. In comparison to the control group, depression symptoms, and pain intensity during hip abduction were positively correlated with PSD and CSD in the delta frequency within the parietal region. Depression symptoms also exhibited a positive association with PSD and CSD in the theta frequency within the same region, while serum BDNF levels showed a negative correlation with CSD in the alpha frequency within the left insula. CONCLUSION: This study indicates that individuals with SCD experiencing hip osteonecrosis and chronic pain manifest a dysfunctional EEG pattern characterized by the persistence of low-frequency PSD during a resting state. This dysfunctional EEG pattern may be linked to clinical and biochemical outcomes, including depression symptoms, pain severity during movement, and serum BDNF levels.

Transcranial direct current stimulation during a prolonged cognitive task: the effect on cognitive and shooting performances in professional female basketball players.

The negative effect of prolonged cognitive demands on psychomotor skills in athletes has been demonstrated. Transcranial direct current stimulation (tDCS) could be used to mitigate this effect. This study examined the effects of tDCS over the left dorsolateral prefrontal cortex (DLPFC) during a 30-min inhibitory Stroop task on cognitive and shooting performances of professional female basketball players. Following a randomised, double-blinded, sham-controlled, cross-over design, players were assigned to receive anodal tDCS (a-tDCS, 2 mA for 20 min) or sham-tDCS in two different sessions. Data from 8 players were retained for analysis. Response Time decreased significantly over time (p < 0.001; partial η2 = 0.44; no effect of condition, or condition vs. time interaction). No difference in mean accuracy and shooting performance was observed between tDCS conditions. The results suggest that a-tDCS exert no additional benefits in reducing the negative effects of prolonged cognitive demands on technical performance compared to sham (placebo).Practitioner summary: Prolonged cognitive demands can negatively affect the athletes' performance. We tested whether transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) could attenuate these effects on cognitive and shooting performance in professional female basketball players. However, tDCS did not exert any additional benefits compared to sham.Abbreviations: tDCS: transcranial direct current stimulation; a-tDCS: anodal transcranial direct current stimulation; PFC: prefrontal cortex; DLPFC: dorsolateral prefrontal cortex; PCT: prolonged cognitive task; TT: time trial; RT: response time; NASA-TLX: National Aeronautics and Space Administration Task Load Index; RPE: ratings of perceived exertion; CR-10 scale: category rating scale; EEG: electroencephalogram; AU: arbitrary units.

Modulation of Isometric Quadriceps Strength in Soccer Players With Transcranial Direct Current Stimulation: A Crossover Study.

Vargas, VZ, Baptista, AF, Pereira, GOC, Pochini, AC, Ejnisman, B, Santos, MB, João, SMA, and Hazime, FA. Modulation of isometric quadriceps strength in soccer players with transcranial direct current stimulation: a crossover study. J Strength Cond Res 32(5): 1336-1341, 2018-The aim of this study was to evaluate the effect of transcranial direct current stimulation (tDCS) on the maximum isometric muscle contraction (MVIC) of the knee extensors in soccer players at the preprofessional level. Twenty female soccer players aged 15-17 years (mean = 16.1; SD = 0.9) with 5.2 ± 2.6 years of training were randomly divided into 2 groups to receive either active or sham tDCS in a single session (2 mA; 0.057 mA·cm). The MVIC of the knee extensors was evaluated in both lower limbs by manual dynamometry in 5 sets of contractions divided into 4 blocks: (a) prestimulation, (b) during tDCS, (c) 30 minutes after tDCS, and (d) 60 minutes after tDCS. After an interval of 7 days, the groups were evaluated again, and the type of initial stimulation was inverted between participants. The MVIC of the knee extensors increased significantly during active tDCS (dominant limb (DL) = 0.4; IC = 0.1-0.8 N·Kg), 30 minutes after active tDCS (DL = 0.9; IC 0.4-1.4 N·Kg), and 60 minutes after active tDCS (DL = 1.0; IC 0.3-1.6 N·Kg) but not for sham tDCS. Our conclusion was that tDCS temporarily increases isometric quadriceps strength in adolescent female soccer players, which may be useful for both strength training and rehabilitation.

Primary Motor Cortex Organization Is Altered in Persistent Patellofemoral Pain.

OBJECTIVE: Reorganization of the primary motor cortex (M1) may be a feature of persistent patellofemoral pain (PFP), but no studies have investigated M1 organization in this condition. Here we aimed to examine the organization of the M1 representation of the quadriceps muscles in people with PFP and healthy controls. DESIGN: Using a cross-sectional design, the M1 representation of the rectus femoris, vastus lateralis, and vastus medialis was mapped using transcranial magnetic stimulation in 11 individuals with PFP and 11 controls. Measures of pain severity were also made. RESULTS: Individuals with PFP had reduced map volumes (P < 0.001) and an anterior shift in the M1 representation (P = 0.03) across all three quadriceps muscles compared with controls. Greater overlap of the M1 representation (P = 0.02) and a reduction in the number of discrete cortical peaks (P = 0.009) across all three quadriceps muscles were also observed in individuals with PFP compared with controls. There was no relationship between altered M1 organization and pain in PFP. CONCLUSIONS: These findings provide evidence of altered M1 organization in individuals with PFP compared with healthy controls. Notably, no difference in M1 organization was observed for the medial and lateral heads of the quadriceps in PFP. These data have relevance for our understanding of the pathophysiology of PFP and for the design of future treatments that aim to target M1 in this condition.

Spinal Manipulative Therapy and Sports Performance Enhancement: A Systematic Review.

OBJECTIVE: The purpose of this study was to review the literature regarding the relationship between spinal manipulative therapy (SMT) and sports performance. METHODS: PubMed and Embase databases were searched for original studies published up to July 2016. Inclusion criteria were if SMT has been applied to athletes and if any sports performance-related outcome was measured. RESULTS: Of the 581 potential studies, 7 clinical trials were selected. Most studies had adequate quality (≥6/11) when assessed by the PEDro scale. None of those studies assessed performance at an event or competition. Four studies revealed improvement in a sports performance test after SMT. Meta-analysis could not be performed because of the wide differences in methodologies, design, and outcomes measured. Spinal manipulative therapy influences a wide range of neurophysiological parameters that could be associated with sports performance. Of the 3 studies where SMT did not improve test performance, 2 used SMT not for therapeutic correction of a dysfunctional vertebral joint but to an arbitrary previously set joint. CONCLUSIONS: Although 4 of 7 studies showed that SMT improved sports performance tests, the evidence is still weak to support its use. Spinal manipulative therapy may be a promising approach for performance enhancement that should be investigated with more consistent methodologic designs.

Neuropathic pain after brachial plexus avulsion--central and peripheral mechanisms.

REVIEW: The pain that commonly occurs after brachial plexus avulsion poses an additional burden on the quality of life of patients already impaired by motor, sensory and autonomic deficits. Evidence-based treatments for the pain associated with brachial plexus avulsion are scarce, thus frequently leaving the condition refractory to treatment with the standard methods used to manage neuropathic pain. Unfortunately, little is known about the pathophysiology of brachial plexus avulsion. Available evidence indicates that besides primary nerve root injury, central lesions related to the abrupt disconnection of nerve roots from the spinal cord may play an important role in the genesis of neuropathic pain in these patients and may explain in part its refractoriness to treatment. CONCLUSIONS: The understanding of both central and peripheral mechanisms that contribute to the development of pain is of major importance in order to propose more effective treatments for brachial plexus avulsion-related pain. This review focuses on the current understanding about the occurrence of neuropathic pain in these patients and the role played by peripheral and central mechanisms that provides insights into its treatment. Pain after brachial plexus avulsion involves both peripheral and central components; thereby it is characterized as a mixed (central and peripheral) neuropathic pain syndrome.

Altered Dynamic Brain Connectivity in Individuals With Sickle Cell Disease and Chronic Pain Secondary to Hip Osteonecrosis.

Individuals with sickle cell disease (SCD) exhibit changes in static brain connectivity in rest. However, little known as chronic pain associated with hip osteonecrosis affects dynamic brain connectivity during rest and the motor imagery task. The aim of this study was to investigate the characteristics of the dynamic functional brain connectivity of individuals with SCD and chronic pain secondary to hip osteonecrosis. This is a cross-sectional study comparing the dynamic brain connectivity of healthy individuals (n = 18) with the dynamic brain connectivity of individuals with SCD and chronic pain (n = 22). Individuals with SCD and chronic pain were stratified into high- or low-intensity pain groups based on pain intensity at the time of assessment. Dynamic brain connectivity was assessed through electroencephalography in 3 stages, resting state with eyes closed, and during hip (painful for the SCD individuals) and hand (control, nonpainful) motor imagery. Average weight of the edges and full synchronization time (FST)-time required for 95% of the possible edges to appear over time during a given task-were evaluated. Regarding the average weight of the edges, individuals with SCD and high-intensity pain presented higher edge weight during hip motor imagery. The average weight of the edges correlated positively with pain intensity and depression symptoms. Individuals with SCD and chronic pain complete the cerebral network at rest more quickly (lower FST). Individuals with SCD and chronic pain/hip osteonecrosis have impaired dynamic brain network with shorter FST in rest network and more pronounced diffuse connectivity in individuals with high-intensity pain. The dynamic brain network evaluated by time-varying graphs and motif synchronization was able to identify differences between groups.

Immediate Effects of Spinal Manipulative Therapy on the Performance of Elite Brazilian Soccer Players: A Pilot Randomized Controlled Trial With an Internally Validated Sham Treatment.

Objective: The purpose of this study was to assess the feasibility of the procedures' routine, the recruiting rate, the presence of any significant detrimental impact on the players' training routine, and the sham efficacy in achieving blinding. Methods: A parallel randomized controlled clinical trial was performed with 20 elite soccer players who were randomly assigned to 1 of 2 groups: spinal manipulative therapy (SMT) and sham SMT. All players were from the same team, were injury free, and were naive to SMT. Measured outcome tests (30-m sprint run with a 10-m split and change of direction [COD] test) were performed at the same time by all participants immediately before and after interventions. Photocell devices were used for data acquisition. Results: Twenty participants were analyzed (10 in each group). There were no changes to the sprint (10 m and 30 m) and COD test results immediately after either of the interventions. All participants in both groups (SMT and sham SMT) answered "yes" to a question after the intervention asking if they were treated by SMT. No adverse effects or training routine impairment were reported. Conclusion: This pilot study protocol showed it was an appropriate design for a confirmatory clinical trial. The study had minimal effect on the team training routine, and the recruitment rate was excellent. The proposed sham SMT strategy was successful in blinding the players. In this sample, SMT did not have any immediate effect on the performance of these elite soccer players, as measured by 10- and 30-m sprint times and COD sprint times.

Differences in brain activity between fast and slow responses on psychomotor vigilance task: an fNIRS study.

Attention is a basic human function underlying every other cognitive process. It is demonstrated in the functional Magnetic Resonance Imaging literature that frontoparietal networks are involved with attentive performance while default mode networks are involved with inattentive performance. Yet, it is still not clear whether similar results would be found with functional Near-Infrared Spectroscopy. The goal of our study was to investigate differences in hemodynamic activity measured by functional Near-Infrared Spectroscopy between fast and slow responses on a simple sustained attention task both before and after stimulus onset. Thirty healthy adults took part in the study. Our results have shown differences between fast and slow responses only on channels over medial frontal cortex and inferior parietal cortex (p < 0,05). These differences were observed both before and after stimulus presentation. It is discussed that functional Near-Infrared Spectroscopy is a good tool to investigate the frontoparietal network and its relationship with performance in attention tasks; it could be used to further investigate other approaches on attention, such as the dual network model of cognitive control and brain states views based on complex systems analysis; and finally, it could be used to investigate attention in naturalistic settings.

Knee pain prevalence and associated factors in a Brazilian population study.

OBJECTIVES: To estimate the association among knee pain and central obesity. METHODS: A cross-sectional study was carried out in Salvador, Brazil, with a sample of 2,297 individuals ≥20 years of age. A standardized questionnaire was applied at home to collect data about pain, sociodemographic characteristics and abdominal circumference measurement. Unadjusted (bivariate analysis) and adjusted odds ratio (OR) and 95%CI were estimated by using backward stepwise logistic regression. RESULTS: The prevalence of knee pain was found in 11.2% of the studied sample. Unadjusted OR associations (P<0.1) were found for male (OR 2.70, CI [confidence interval] 2.01-3.63), older age (OR 2.98, CI 1.89-4.42), and obesity (OR 1.62, CI 1.22-2.15). Adjusted ORs (P<0.05) were found for obesity-married individuals (OR 4.69, CI 1.09-20.11), separated (OR 11.03, CI 2.09-58.20) or widowed (OR 7.17, CI 1.40-36.61), and male (OR 2.35, CI 1.25-4.41). The OR of nonobese men was 2.66, CI 1.74-4.06, but being married seems to protect them of knee pain (OR 0.66, CI 0.45-0.96). CONCLUSION: In this study, we found a knee pain prevalence of 11.2% and positive association with the male gender, married, separated or widowed, and a protective association for knee pain in nonobese married male. Aging, obesity, and excessive alcohol consumption were independent correlates of knee pain in the studied population sample.

Effect of Transcranial Direct Current Stimulation on Professional Female Soccer Players' Recovery Following Official Matches.

This study investigated the effect of transcranial direct current stimulation (tDCS) combined with a recovery training session on the well-being and self-perceived recovery of professional female soccer players after official matches. Data from 13 world-class players were analyzed after participating in four official soccer matches of the first division of the Brazilian Women's Soccer Championship (7-, 10-, and 13-day intervals). We applied anodal tDCS (a-tDCS) over the left dorsolateral prefrontal cortex with 2 mA for 20 minutes (+F3/-F4 montage) the day after each match. Participants underwent two randomly ordered sessions of a-tDCS or sham. Players completed the Well-Being Questionnaire (WBQ) and the Total Quality Recovery (TQR) scale before each experimental condition and again the following morning. A two-way repeated-measures ANOVA showed a significant time x condition interaction on the WBQ (F(1,11)=5.21; p=0.043; ηp2=0.32), but not on the TQR (F(1,12) = 0.552; p = 0.47; ηp2 = 0.044). There was a large effect size (ES) for a-tDCS for the WBQ score (ES = 1.02; 95%CI = 0.17;1.88), and there was a moderate WBQ score increase (ES = 0.53; 95%CI = -0.29;1.34) for the sham condition. We found similar increases in the TQR score for a-tDCS (ES = 1.50; 95%CI = 0.63-2.37) and the sham condition (ES = 1.36; 95%CI = 0.51-2.22). These results suggest that a-tDCS (+F3/-F4 montage) combined with a recovery training session may slightly improve perceived well-being beyond the level of improvement after only the recovery training session among world-class female soccer players. Prior to widely adopting this recovery approach, further study is needed with larger and more diverse samples, including for female teams of different performance levels.

Acute effect of high-definition and conventional tDCS on exercise performance and psychophysiological responses in endurance athletes: a randomized controlled trial.

Transcranial direct current stimulation (tDCS) has been used aiming to boost exercise performance and inconsistent findings have been reported. One possible explanation is related to the limitations of the so-called "conventional" tDCS, which uses large rectangular electrodes, resulting in a diffuse electric field. A new tDCS technique called high-definition tDCS (HD-tDCS) has been recently developed. HD-tDCS uses small ring electrodes and produces improved focality and greater magnitude of its aftereffects. This study tested whether HD-tDCS would improve exercise performance to a greater extent than conventional tDCS. Twelve endurance athletes (29.4 ± 7.3 years; 60.15 ± 5.09 ml kg-1 min-1) were enrolled in this single-center, randomized, crossover, and sham-controlled trial. To test reliability, participants performed two time to exhaustion (TTE) tests (control conditions) on a cycle simulator with 80% of peak power until volitional exhaustion. Next, they randomly received HD-tDCS (2.4 mA), conventional (2.0 mA), or active sham tDCS (2.0 mA) over the motor cortex for 20-min before performing the TTE test. TTE, heart rate (HR), associative thoughts, peripheral (lower limbs), and whole-body ratings of perceived exertion (RPE) were recorded every minute. Outcome measures were reliable. There was no difference in TTE between HD-tDCS (853.1 ± 288.6 s), simulated conventional (827.8 ± 278.7 s), sham (794.3 ± 271.2 s), or control conditions (TTE1 = 751.1 ± 261.6 s or TTE2 = 770.8 ± 250.6 s) [F(1.95; 21.4) = 1.537; P = 0.24; η2p = 0.123]. There was no effect on peripheral or whole-body RPE and associative thoughts (P > 0.05). No serious adverse effect was reported. A single session of neither HD-tDCS nor conventional tDCS changed exercise performance and psychophysiological responses in athletes, suggesting that a ceiling effect may exist.

Effect of tDCS on well-being and autonomic function in professional male players after official soccer matches.

This study aimed to examine the effect of transcranial direct current stimulation (tDCS) used as a recovery strategy, on heart rate (HR) measures and perceived well-being in 12 male professional soccer players. tDCS was applied in the days after official matches targeting the left dorsolateral prefrontal cortex (DLPFC) with 2 mA for 20 min (F3-F4 montage). Participants were randomly assigned to anodal tDCS (a-tDCS) or sham tDCS sessions. Players completed the Well-Being Questionnaire (WBQ) and performed the Submaximal Running Test (SRT) before and after tDCS. HR during exercise (HRex) was determined during the last 30 s of SRT. HR recovery (HRR) was recorded at 60 s after SRT. The HRR index was calculated from the absolute difference between HRex and HRR. A significant increase was observed for WBQ (effect of time; p<0.001; ηp2=0.417) with no effect for condition or interaction. A decrease in HRR (p = 0.014; ηp2=0.241), and an increase in HRR index were observed (p = 0.045; ηp2=0.168), with no effect for condition or interaction. No change for HRex was evident (p>0.05). These results suggest that a-tDCS over the DLPFC may have a positive effect on enhancing well-being and parasympathetic autonomic markers, which opens up a possibility for testing tDCS as a promising recovery-enhancing strategy targeting the brain in soccer players. The findings suggest that brain areas related to emotional and autonomic control might be involved in these changes with a possible interaction effect of tDCS by placebo-related effects, but more research is needed to verify this effect.

Insular and anterior cingulate cortex deep stimulation for central neuropathic pain: Disassembling the percept of pain.

OBJECTIVE: To compare the analgesic effects of stimulation of the anterior cingulate cortex (ACC) or the posterior superior insula (PSI) against sham deep (d) repetitive (r) transcranial magnetic stimulation (TMS) in patients with central neuropathic pain (CNP) after stroke or spinal cord injury in a randomized, double-blinded, sham-controlled, 3-arm parallel study. METHODS: Participants were randomly allocated into the active PSI-rTMS, ACC-rTMS, sham-PSI-rTMS, or sham-ACC-rTMS arms. Stimulations were performed for 12 weeks, and a comprehensive clinical and pain assessment, psychophysics, and cortical excitability measurements were performed at baseline and during treatment. The main outcome of the study was pain intensity (numeric rating scale [NRS]) after the last stimulation session. RESULTS: Ninety-eight patients (age 55.02 ± 12.13 years) completed the study. NRS score was not significantly different between groups at the end of the study. Active rTMS treatments had no significant effects on pain interference with daily activities, pain dimensions, neuropathic pain symptoms, mood, medication use, cortical excitability measurements, or quality of life. Heat pain threshold was significantly increased after treatment in the PSI-dTMS group from baseline (1.58, 95% confidence interval [CI] 0.09-3.06]) compared to sham-dTMS (-1.02, 95% CI -2.10 to 0.04, p = 0.014), and ACC-dTMS caused a significant decrease in anxiety scores (-2.96, 95% CI -4.1 to -1.7]) compared to sham-dTMS (-0.78, 95% CI -1.9 to 0.3; p = 0.018). CONCLUSIONS: ACC- and PSI-dTMS were not different from sham-dTMS for pain relief in CNP despite a significant antinociceptive effect after insular stimulation and anxiolytic effects of ACC-dTMS. These results showed that the different dimensions of pain can be modulated in humans noninvasively by directly stimulating deeper SNC cortical structures without necessarily affecting clinical pain per se. CLINICALTRIALSGOV IDENTIFIER: NCT01932905.

High- and low-frequency transcutaneous electrical nerve stimulation delay sciatic nerve regeneration after crush lesion in the mouse.

The stimulation of peripheral nerve regeneration has been studied in different ways, including the use of electrical fields. The capacity of this modality to enhance nerve regeneration is influenced by the parameters used, including current type, frequency, intensity, and means of administration. Transcutaneous electrical nerve stimulation (TENS) is a frequently used form of administering electrical current to the body, but its effects on peripheral nerve regeneration are not known. This study assessed the influence of TENS on sciatic nerve regeneration, using a model of crush lesion in the mouse. Mice were stimulated 30 min a day, 5 days a week, for 5 weeks with both high- (100 Hz) and low- (4 Hz) frequency TENS. Control animals had the sciatic nerve crushed but were not stimulated. Assessment was performed weekly by functional analysis using the Static Sciatic Index for the mouse and at the end of the experiment by light and electron microscopy. The results showed that although there were no differences between the groups regarding the Static Sciatic Index values, TENS led to nerves with morphological signs of impaired regeneration. At light microscopy level, TENS nerves presented more axons with dark axoplasm, signs of edema, and a less organized cytoarchitecture. Electronmicrographs showed fewer and thinner thick myelinated fibers and increased number of Schwann cell nuclei. Myelinated axon diameters and density and diameter of nonmyelinated fibers were not affected by TENS, leading to the conclusion that this regimen of electrical stimulation leads to a delayed regeneration after a crush lesion of the sciatic nerve in the mouse. All these effects were more pronounced on high-frequency TENS nerves.

Factors associated with pain in individuals infected by human T-cell lymphotropic virus type 1 (HTLV-1).

INTRODUCTION: Despite the high prevalence of chronic pain in individuals infected with HTLV-1, predictive and protective factors for its development are still unclear. OBJECTIVE: To identify factors associated with chronic pain in individuals with HTLV-1. METHODS: This cross-sectional study was conducted in a reference center for treatment of patients infected with HTLV-1 in Salvador, Bahia, Brazil. The study included individuals infected with HTLV-1, over 18 years, and excluded those with difficulty to respond the pain protocol. Data on sociodemographic, health behavior, and clinical characteristics were collected in a standardized way. The prevalence ratio (PR) of pain is described, as well as the factors independently associated with the presence of pain, which were assessed by multiple logistic regression. RESULTS: A total of 142 individuals were included in the study, mostly female (62.7%), aged 20-64 years (73.2%), married (61.3%), with less than eight years of education (54.2%), and with a steady income (79.6%). Multivariate analysis showed that being symptomatic for HTLV-1 - sensory manifestations, erectile dysfunction, overactive bladder, and/or HAM/TSP (PR=1.21, 95% CI: 1.05 to 1.38), self-medication (PR=1.29, 95% CI: 1.08-1.53), physiotherapy (PR=1.15, 95% CI: 1.02-1.28), and depression (PR=1.14, 95% CI: 1.01-1.29) were associated with an increased likelihood of presenting pain. On the other hand, physical activity (PR=0.79, 95% CI: 0.67-0.93) and religious practice (PR=0.83, 95% CI: 0.72-0.95) were associated with a decreased likelihood of having pain. CONCLUSION: The use of self-medication, physiotherapy and the presence of depression are independently associated with neurological symptoms in HTLV-1 infected patients. Religious practice and physical activity are both protective for the development of pain.

Does Transcranial Direct Current Stimulation Combined with Peripheral Electrical Stimulation Have an Additive Effect in the Control of Hip Joint Osteonecrosis Pain Associated with Sickle Cell Disease? A Protocol for a One-Session Double Blind, Block-Randomized Clinical Trial.

Chronic pain in Sickle Cell Disease (SCD) is probably related to maladaptive plasticity of brain areas involved in nociceptive processing. Transcranial Direct Current Stimulation (tDCS) and Peripheral Electrical Stimulation (PES) can modulate cortical excitability and help to control chronic pain. Studies have shown that combined use of tDCS and PES has additive effects. However, to date, no study investigated additive effects of these neuromodulatory techniques on chronic pain in patients with SCD. This protocol describes a study aiming to assess whether combined use of tDCS and PES more effectively alleviate pain in patients with SCD compared to single use of each technique. The study consists of a one-session double blind, block-randomized clinical trial (NCT02813629) in which 128 participants with SCD and femoral osteonecrosis will be enrolled. Stepwise procedures will occur on two independent days. On day 1, participants will be screened for eligibility criteria. On day 2, data collection will occur in four stages: sample characterization, baseline assessment, intervention, and post-intervention assessment. These procedures will last ~5 h. Participants will be divided into two groups according to homozygous for S allele (HbSS) (n = 64) and heterozygous for S and C alleles (HbSC) (n = 64) genotypes. Participants in each group will be randomly assigned, equally, to one of the following interventions: (1) active tDCS + active PES; (2) active tDCS + sham PES; (3) sham tDCS + active PES; and (4) sham tDCS + sham PES. Active tDCS intervention will consist of 20 min 2 mA anodic stimulation over the primary motor cortex contralateral to the most painful hip. Active PES intervention will consist of 30 min sensory electrical stimulation at 100 Hz over the most painful hip. The main study outcome will be pain intensity, measured by a Visual Analogue Scale. In addition, electroencephalographic power density, cortical maps of the gluteus maximus muscle elicited by Transcranial Magnetic Stimulation (TMS), serum levels of Brain-derived Neurotrophic Factor (BDNF), and Tumor Necrosis Factor (TNF) will be assessed as secondary outcomes. Data will be analyzed using ANOVA of repeated measures, controlling for confounding variables.

Transcranial Direct Current Stimulation Combined with Aerobic Exercise to Optimize Analgesic Responses in Fibromyalgia: A Randomized Placebo-Controlled Clinical Trial.

UNLABELLED: Fibromyalgia is a chronic pain syndrome that is associated with maladaptive plasticity in neural central circuits. One of the neural circuits that are involved in pain in fibromyalgia is the primary motor cortex. We tested a combination intervention that aimed to modulate the motor system: transcranial direct current stimulation (tDCS) of the primary motor cortex (M1) and aerobic exercise (AE). In this phase II, sham-controlled randomized clinical trial, 45 subjects were assigned to 1 of 3 groups: tDCS + AE, AE only, and tDCS only. The following outcomes were assessed: intensity of pain, level of anxiety, quality of life, mood, pressure pain threshold, and cortical plasticity, as indexed by transcranial magnetic stimulation. There was a significant effect for the group-time interaction for intensity of pain, demonstrating that tDCS/AE was superior to AE [F (13, 364) = 2.25, p = 0.007] and tDCS [F (13, 364) = 2.33, p = 0.0056] alone. Post-hoc adjusted analysis showed a difference between tDCS/AE and tDCS group after the first week of stimulation and after 1 month intervention period (p = 0.02 and p = 0.03, respectively). Further, after treatment there was a significant difference between groups in anxiety and mood levels. The combination treatment effected the greatest response. The three groups had no differences regarding responses in motor cortex plasticity, as assessed by TMS. The combination of tDCS with aerobic exercise is superior compared with each individual intervention (cohen's d effect sizes > 0.55). The combination intervention had a significant effect on pain, anxiety and mood. Based on the similar effects on cortical plasticity outcomes, the combination intervention might have affected other neural circuits, such as those that control the affective-emotional aspects of pain. TRIAL REGISTRATION: (www.ClinicalTrials.gov), identifier NTC02358902.