Motor System Activation With Transcranial Direct Current Stimulation and Physical Exercise to Reduce Pain in Elderly

Activating Motor System to Relieve Pain in Elderly: What is the Role of Physical Exercise and Transcranial Stimulation

Physical exercises are known to reduce chronic pain in elderly individuals by activating the motor system. However, it seems that exercises are not effective for everyone. The investigators believe that elderly individuals with altered corticospinal tract will be those in whom the exercise alone are not sufficient to relieve pain. For those patients, adding an exogenous stimulation of the motor system such as transcranial direct current stimulation (tDCS) would facilitate the corticospinal tract, and consequently, would help exercises to relieve chronic pain. The investigators hypothesize that combining tDCS with the exercises will be more effective than exercises alone, but only in individuals who initially show low corticospinal projections.

Prevalence and intensity of chronic pain increases substantially with age. According to several studies, physical exercises are effective to reduce chronic pain in elderly. However, it seems that exercises are not effective for everyone. One of the hypotheses raised is that the people in whom the exercises have no effect would be those with an alteration of the corticospinal tract. Transcranial direct current stimulation (tDCS) is a non-invasive neurostimulation technique known to facilitate the corticospinal tract when applied over the motor cortex.

Elderly suffering from chronic pain will be recruited in this double-blind, parallel-group, randomised control trial. Participants will be randomized to receive exercises combined to real tDCS (5 daily sessions, 2 mA, 20 minutes) or to sham tDCS. Intervention will last 8 weeks at a rate of 3 workouts per week.

Inclusion Criteria:

• To have musculoskeletal chronic pain
• Not to change medication and life habits during the study

Exclusion Criteria:

• People physically active before the study (more then 150 min of moderate to vigorous exercise par week)
• To have an uncontrolled cardiovascular disease
• To have orthopedic limitation or contraindication to physical exercise
• To have contraindication to tDCS
• To have contraindication to TMS
• To have contraindication to MRI