Complex Regional Pain Syndrome Type 1 (CRPS) Clinical Trial
Official title:
Investigation of the Efficacy of Transcranial Direct Current Stimulation (tDCS) Added to the Graded Motor Imagery (GMI) in the Treatment of Complex Regional Pain Syndrome (CRPS) Type 1
The efficacy of the current standard non-pharmacological treatments for complex regional pain syndrome (CRPS), a painful syndrome mostly occurring after musculoskeletal trauma, is suboptimal. It thus appears essential to examine new non-pharmacological therapeutic imagery (GMI) - a non-pharmacological approach with the highest level of evidence (level II). As suggested by the most recent clinical guideline 2, a potential solution would be to add an electrotherapeutic procedure - transcranial direct current stimulation (tDCS) - that may prove effective in modulating cortical excitability and reducing the effect of cortical reorganization on pain. Given the positive results previously obtained in patients with neuropathic pain, it is hypothesized that tDCS will prove to be an innovative add-on treatment method for CRPS patients, and help reduce pain and disability.
Executive summary: The efficacy of the current standard rehabilitation treatments for
complex regional pain syndrome (CRPS), a painful syndrome mostly occurring after
musculoskeletal trauma, is suboptimal. For instance, the first line of treatment in
rehabilitation, progressive motor imagery (GMI), only induces a 50% improvement in symptoms.
Although such improvement is interesting, further solutions should be sought to enhance
clinical outcomes. It is thus essential to explore new options of therapy. A potential
solution to enhance clinical outcomes would be to add an electrotherapeutic procedure, such
as transcranial direct current stimulation (tDCS). Given the positive results previously
obtained in patients with neuropathic pain, we hypothesize that tDCS will induce functional
and structural reorganization in the cortex and lead to better pain relief. The cortical
reorganization frequently observed in CRPS patients mainly involves a shrinkage of cortical
map of the affected limb on primary and secondary somatosensory cortex. Interestingly,
therapies that aim to reverse the cortical reorganization are often associated with a
decrease in pain. Therefore, combining GMI and tDCS could lead to added pain relief compared
to traditional GMI treatments alone. Furthermore, neuroimaging before and after the
procedures could help us explain if and how this is achieved. Objectives: Thus, the primary
objective of this research is to study the therapeutic efficacy of tDCS in the treatment of
CRPS type 1 in addition to the current best evidence-based rehabilitation treatment, GMI.
The second objective is to study, through MRI/fMRI, how brain structures and functions are
changed following tDCS and GMI treatments, and whether these changes correlate to clinical
changes.
Methodology: To achieve the first objective, we will recruit adults diagnosed with CRPS type
1 via established collaborations with different physicians from our university affiliated
hospital. Participants will be randomly allocated into one of the two treatment groups A)
experimental group, which will receive the GMI and tDCS stimulation; B) control group, which
will receive GMI and sham [placebo] tDCS stimulation. GMI treatment is composed of a
three-phase protocol, each lasting two weeks. The GMI treatments will be performed using
software and well-established procedures (www.noigroup.com). For its part, the tDCS will be
applied for 5 consecutive days during the first 2 weeks of phase 1 and once a week during
the 4 other weeks. The anodic (positive) stimulation over the motor cortex (M1)
contralateral of the affected limb is sought to modulate cortical excitability and promote
pain inhibition and cortical reorganization. Sample size estimates (β:80%,α 5%) show that 15
subjects/group will be necessary.
Anticipated results and impact of the proposed project: This project will allow us to
investigate the therapeutic efficacy of an innovative approach to the treatment of CRPS,
primarily for the purpose of enhancing the clinical outcomes of GMI. In the event of
positive results, we will be able to further examine the therapeutic benefits of this
modality in a larger clientele and even in other populations (i.e., patients with chronic
low back pain). In addition, our results may contribute to the creation of a clinical
practice guide, since there currently is insufficient evidence-based data to establish
guidelines regarding the non-pharmacological treatment of CRPS. Finally, MRI/fMRI analysis
will help us to capture the phenomenon of tDCS-driven cortical reorganization.
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Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Outcomes Assessor), Primary Purpose: Treatment