Subacromial Corticosteroid Injections and tDCS in Rotator Cuff Tendinopathy
Condition: Rotator Cuff Tendinosis; Rotator Cuff Impingement Syndrome; Rotator Cuff Impingement; Rotator Cuff Injuries; Rotator Cuff Syndrome of Shoulder and Allied Disorders
MeSH terms: Tendinopathy; Shoulder Impingement Syndrome; Syndrome; Rotator Cuff Injuries
Study type: Interventional

Summary: 
      This study evaluates the effects of corticosteroid injections over time, as well as the
      additional effect provided by subsequent transcranial direct current stimulation (tDCS) of
      the motor cortex on patients with rotator cuff tendinopathy of the shoulder. All patients
      will receive a subacromial corticosteroid injection. Two weeks later, a third will receive a
      treatment of tDCS, a third will receive a placebo a-tDCS treatment, and the last third will
      not receive any additional treatment.
    

Detailed description: 
      Corticosteroid injections (CSI) are often used by physicians in the treatment of rotator cuff
      tendinopathy, a painful chronic degeneration of the tendons in the shoulder. However, the
      effect of CSI in comparison with placebo is disputed in the scientific literature, with most
      studies only showing mild short-term effect (less than six weeks) on pain compared to placebo
      injections.

      Transcranial direct current stimulation (tDCS) is a non-invasive technique allowing to
      stimulate areas of the brain in order to change the excitability of the neurons. When the
      negative electrode is applied on the motor cortex of the brain, it increases the excitability
      of the neurons in that area, which in turns inhibits the activity of the thalamus, an area of
      the brain linked with the perception of pain. Some studies have shown that tDCS can improve
      chronic pain of different origins, such as lower back pain, fibromyalgia, stroke,
      osteoarthritis, and post-operative pain.

      We tested whether applying tDCS following a CSI would have more effect on patient's pain,
      function, and activity, than CSI alone.
    

Intervention name(s): Transcranial direct current stimulation
Intervention type(s): Device
Intervention description(s): The tDCS anode was applied on the primary motor cortex area responsible for the control of the rotator cuff, as determined using transcranial magnetic stimulation and surface electromyography. The cathode was applied on the contralateral forehead, just above the eyebrow. The electrodes were soaked in saline solution to improve conductivity and the montage was secured with rubber bands and adhesive tape.
The tDCS device (Soterix Medical 1x1 tDCS device) was then gradually turned to an intensity of 2mA. This stimulation was continued for a total of 20 minutes, after which it was gradually stopped.
Other intervention name(s): Anodal transcranial direct current stimulation; Non invasive brain stimulation
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: All participants received a subacromial corticosteroid injection.
Two weeks following the injection, participants were randomized into 3 groups:
Anodal transcranial direct current stimulation (treatment group)
Placebo tDCS (placebo group)
No further intervention (control group)
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: transcranial direct current stimulation; non invasive brain stimulation; tDCS; NIBS; subacromial corticosteroid injection