Additive effect of tDCS combined with Peripheral Electrical Stimulation to an exercise program in pain control in knee osteoarthritis: study protocol for a randomized controlled trial.

BACKGROUND: Knee osteoarthritis (OA) has been linked to maladaptive plasticity in the brain, which may contribute to chronic pain. Neuromodulatory approaches, such as Transcranial Direct Current Stimulation (tDCS) and Peripheral Electrical Stimulation (PES), have been used therapeutically to counteract brain maladaptive plasticity. However, it is currently unclear whether these neuromodulatory techniques enhance the benefits of exercise when administered together. Therefore, this protocol aims to investigate whether the addition of tDCS combined or not with PES enhances the effects of a land-based strengthening exercise program in patients with knee OA. METHODS: Patients with knee OA (n = 80) will undertake a structured exercise program for five consecutive days. In addition, they will be randomized into four subgroups receiving either active anodal tDCS and sham PES (group 1; n = 20), sham tDCS and active PES (group 2, n = 20), sham tDCS and PES (group 3, n = 20), or active tDCS and PES (group 4, n = 20) for 20 min/day for five consecutive days just prior to commencement of the exercise program. The primary outcomes will be subjective pain intensity (VAS) and related function (WOMAC). Secondary outcomes will include quality of life (SF-36), anxiety and depression symptoms (HAD), self-perception of improvement, pressure pain thresholds over the knee, quadriceps strength, and quadriceps electromyographic activity during maximum knee extension voluntary contraction. We will also investigate cortical excitability using transcranial magnetic stimulation. Outcome measures will be assessed at baseline, 1 month after, before any intervention, after 5 days of intervention, and at 1 month post exercise intervention. DISCUSSION: The motor cortex becomes less responsive in knee OA because of poorly adapted plastic changes, which can impede exercise therapy benefits. Adding tDCS and/or PES may help to counteract those maladaptive plastic changes and improve the benefits of exercises, and the combination of both neuromodulatory techniques must have a higher magnitude of effect. TRIAL REGISTRATION: Brazilian Registry on Clinical Trials (ReBEC) - Effects of electrical stimulation over the skull and tight together with exercises for knee OA; protocol number RBR-9D7C7B. TRIAL REGISTRATION: ID: RBR-9D7C7B . Registered on 29 February 2016.

Active Hip Flexion is a predictor of mobility in Amyotrophic Lateral Sclerosis.

BACKGROUND: Muscle Force (MF) and amplitude of active movement (AAM) are progressively affected in amyotrophic lateral sclerosis (ALS). These measurements are correlated with mobility but influence it in a distinct manner. OBJECTIVE: To determine the influence of MF and AAM on the mobility of the subjects with ALS. METHODS: The formula for identifying the covariables and scale of mobility of the Amyotrophic Lateral Sclerosis Assessment Questionnaire were applied to 23 subjects with ALS. The MF data of the knee and ankle flexors and extensors were collected in the most affected limb. In conjunction, the AAM of hip and knee flexion were captured. Multiple linear regressions were used, considering alpha ≤0.05. RESULTS: MF and AAM interfered in mobility and are responsible for 63.6% of the variation in mobility. The variable that explained this variation was the AAM of hip flexion. The stage of disease was considered a covariable. CONCLUSION: AAM of hip flexion is a safe predictor of mobility in ALS. Retarding loss of this AAM may maintain these subjects functional for a longer time. It was not possible to use MF of the muscles evaluated to predict mobility.

The parameters of transcutaneous electrical nerve stimulation are critical to its regenerative effects when applied just after a sciatic crush lesion in mice.

We investigated the effect of two frequencies of transcutaneous electrical nerve stimulation (TENS) applied immediately after lesion on peripheral nerve regeneration after a mouse sciatic crush injury. The animals were anesthetized and subjected to crushing of the right sciatic nerve and then separated into three groups: nontreated, Low-TENS (4 Hz), and High-TENS (100 Hz). The animals of Low- and High-TENS groups were stimulated for 2 h immediately after the surgical procedure, while the nontreated group was only positioned for the same period. After five weeks the animals were euthanized, and the nerves dissected bilaterally for histological and histomorphometric analysis. Histological assessment by light and electron microscopy showed that High-TENS and nontreated nerves had a similar profile, with extensive signs of degeneration. Conversely, Low-TENS led to increased regeneration, displaying histological aspects similar to control nerves. High-TENS also led to decreased density of fibers in the range of 6-12 µm diameter and decreased fiber diameter and myelin area in the range of 0-2 µm diameter. These findings suggest that High-TENS applied just after a peripheral nerve crush may be deleterious for regeneration, whereas Low-TENS may increase nerve regeneration capacity.