Transcranial Direct Current Stimulation to Enhance Rehabilitation in Individuals With Rotator Cuff Tendinopathy
Condition: Rotator Cuff Tendinopathy
MeSH terms: Tendinopathy
Study type: Interventional

Summary: 
      Transcranial direct current stimulation (tDCS), an electrostimulation technique known to
      modulate the motor cortex excitability, has been shown to enhance the effects of
      rehabilitation in populations with neurological injuries. tDCS could similarly be effective
      in individuals with rotator cuff (RC) tendinopathy, as this pathology is also associated with
      pain and motor control deficits. For the treatment of RC tendinopathy, sensorimotor training
      is effective to reduce pain, increase function and enhance motor control of the shoulder. The
      addition of tDCS during sensorimotor training could enhance motor learning associated with
      sensorimotor training and thus improve treatment outcome. PURPOSE: To compare, in terms of
      symptoms, functional limitations and shoulder control, a group receiving a rehabilitation
      program centered on sensorimotor training combined with tDCS to a group receiving the same
      rehabilitation program combined with sham tDCS in individuals with RC tendinopathy. METHODS:
      Forty adults with RC tendinopathy will take part in the 4 evaluation sessions (0, 3, 6, 12
      weeks) and a 6-week rehabilitation program. Outcome measures will be symptoms and functional
      limitations (Disability of the Arm, Shoulder and Hand and the Western Ontario Rotator Cuff
      index), as well as acromiohumeral distance ([AHD] ultrasonographic measurement at 0° and 60°
      of elevation arm). The rehabilitation program will include sensorimotor training,
      strengthening and education. tDCS will be apply during sensorimotor training on the motor
      cortex contralateral to the side of pain. A 2-way ANOVA will be used to analyse the effects
      of tDCS on the outcomes.
    

Detailed description: 
      BACKGROUND: tDCS is a safe and easy to use technique that has emerged as a promising tool to
      induce plasticity and to facilitate sensorimotor rehabilitation with potential application in
      various clinical populations. tDCS has been shown to induce changes that outlast the duration
      of the stimulation, by modulating neuronal membrane potential of the targeted brain region.
      Depending on the flow of current, tDCS can increase or decrease neuronal excitability; anodal
      tDCS induces membrane depolarization and enhanced excitability of cortical neurons, whereas
      cathodal tDCS induces membrane hyperpolarization and reduced excitability of cortical
      neurons. As such, tDCS has the potential to prime the plastic potential of a given brain
      region, making it more responsive to another intervention. For example, it has been shown
      that five days of anodal tDCS combined with training promotes motor skill acquisition still
      detectable three months later; an effect significantly superior to sham tDCS. These effects
      most likely are due to the augmentation of synaptic plasticity that requires the presence of
      brain-derived neurotrophic factor.

      Coupled with sensorimotor training, tDCS can lead to subsequent sustained clinical gains.The
      beneficial effects of tDCS combined with sensorimotor training to normalize motor cortical
      activity and to enhance rehabilitation have been shown in populations with neurological
      injuries, such a stroke. In musculoskeletal populations, anodal tDCS over M1 has also been
      shown to lead to significant pain level reduction. Evidence suggests that tDCS over M1 may
      relieve pain through inhibition of thalamic sensory neurons and disinhibition of neurons
      located in the periaqueductal gray matter. In these latter studies, tDCS was specifically
      aimed at reducing pain and was not coupled with sensorimotor training. In fact, evidence on
      the effect of tDCS coupled with sensorimotor training in musculoskeletal populations is
      scarce, and the effect of such intervention has never been evaluated in individuals with RC
      tendinopathy. Considering that RC tendinopathy is associated with impaired motor control and
      that pain can decrease the excitability of the motor cortex and impair motor learning, the
      investigators believe that it is relevant to determine whether tDCS can enhance sensorimotor
      training, and improve outcome.

      PURPOSE - The primary objective of this randomized control trial is to compare, in terms of
      symptoms and functional limitations, a group receiving a rehabilitation program centered on
      sensorimotor training combined with anodal tDCS to a group receiving the same rehabilitation
      program combined with sham tDCS in individuals with RC tendinopathy. A secondary objective is
      to explore the effects of these interventions on shoulder control and corticospinal
      excitability.

      METHODS - Study Design: This triple-blind (patients, therapist & evaluator), parallel-group
      randomized control trial will include four evaluation sessions over 6 months (baseline, week
      3, week 6, 3-month) and a 6-week rehabilitation program.

      Interventions: Each participant will take part in the same 8-week rehabilitation program
      supervised by an independent physiotherapist. This program, previously shown effective,
      targets the deficits described in individuals with RC tendinopathy. It includes sensorimotor
      training, strengthening, and patient education. Each session lasts 40 minutes, with at least
      75% for sensorimotor training. The rest of the session is used to teach and revise home
      exercises. tDCS will be applied during sensorimotor training (30 min),but only during the
      first five sessions, as these sessions will be during the first phase of motor learning,
      characterized by considerable improvement in performance.

      Statistical Analyses - Descriptive statistics will be used for all outcome measures at each
      measurement time to summarise results. Baseline demographic data will be compared
      (independent t-test and Chi-squared tests) to establish the comparability of groups. All data
      will be tested to check the distributional assumptions for the inferential statistical
      analyses. An intention-to-treat analysis will be used in which all participants will be
      analysed in the group to which they were originally assigned. All dropouts and the reason for
      dropping out of the study will be reported. Any harm or unintended effects during the
      programs will be recorded. A 2-way ANOVA (2 tDCS [Real or Sham] x 4 Time [week 0, 3, 6, 12])
      will be used to analyse the effects of tDCS on primary outcome and secondary outcomes.
    

Intervention name(s): tDCS group; Placebo group
Intervention type(s): Other; Other
Intervention description(s): Interventions: movement training, strengthening, patient education. tDCS will be delivered using a direct current stimulator (constant current of 1.5 mA) via two 35cm2 (5 x 7 cm) saline-soaked surface sponge electrodes (parameters shown effective to enhance training).40 The center of the active electrode will be positioned over C3/C4 (international 10-20 EEG system; corresponding to the cortical representation of upper limb muscles)57, contralateral to the side of pain and the reference electrode over the contralateral supraorbital region. Current intensity will be ramped up (0-1.5 mA) and down (1.5-0 mA) over 15 seconds at the beginning and end of the 30 minutes stimulation period.; Interventions: movement training, strengthening, patient education. The sham tDCS involves electrodes placed in an identical position to that used for active stimulation; however the stimulation will be turned on for 15 seconds and then off to provide participants with the initial "itching" sensation but without current for the remainder of the period. This procedure has been shown to effectively blind participants to the stimulation condition.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: This triple-blind (patients, therapist & evaluator), parallel-group RCT will include four evaluation sessions over 3 months (baseline, week 3, week 6, 3-month) and 8 supervised physiotherapy treatments during a 6-week rehabilitation program (3 sessions the 1st week, 2 sessions the 2nd weeks, 3 session in the last 4 weeks). Thereafter, participants will be randomly assigned to one of two intervention groups, and then take part in their assigned 6-week intervention. At week 3, 6, and 12, the self-administered questionnaires will be re-administered, while US measurements will only be re-evaluated at week 6.
Masking: Triple (Participant, Care Provider, Outcomes Assessor)
Primary purpose: Treatment