Pain Exposure Physical Therapy (PEPT) Versus CBO in Patients With Complex Regional Pain Syndrome Type I (CRPS-1)

Hypothesis:

PEPT is expected to be 30% more effective and around three-folds cheaper than usual therapy (CBO)

Objective:

The current Dutch CBO guideline treatment of Complex Regional Pain Syndrome Type I (CRPS-1) is very disappointing with chronification, disability and subsequent high medical costs and personal suffering. A possible better treatment is intensive function-oriented physical therapy or Pain Exposure in Physical Therapy (PEPT). However, there are no adequate studies performed that demonstrate the efficacy of PEPT and therefore PEPT is lacking in the Dutch CBO CRPS-1 guidelines. Despite a lacking scientific argumentation, the PEPT approach or Macedonian therapy, is now being adopted on a large scale among physical therapists in The Netherlands. There are two level C retrospective cohort studies demonstrating a promising and clinical relevant beneficial effect on pain and function after PEPT. In response to the growing demand for scientific argumentation among doctors and physical therapists with respect to the efficacy of PEPT, we conducted a pilot study at the UMC St Radboud Nijmegen. The results of this pilot study were very promising and therefore, we decided to design a large RCT to investigate the treatment effects and costs in CRPS patients treated with PEPT compared to CRPS patients treated with usual therapy according to the Dutch CBO guidelines.

Study design:

Prospective, single-blinded, randomized clinical trial. After base-line measurements (T0), measurements are performed at three (T1) and six months (T2) after inclusion. Follow-up is at nine months (T3).

Study population:

Patients with Complex Regional pain Syndrome (CRPS-1) of either upper or lower extremity according to Bruehl's/IASP criteria (see attachment) between 3 and 24 months after initial injury will be selected for the study. After information about standard and experimental treatments for CRPS and after informed consent, patients will enter the study and randomization for usual (CBO) or experimental (PEPT) treatment will be performed.

Intervention:

Treatment group: In the treatment group medication prescribed for CRPS is tapered to zero. No invasive treatments like sympathetic blocks, and/or operations will be performed. After information about the mechanism of action of PEPT in relation to CRPS, patients receive five sessions of PEPT including homework exercises. The basic of PEPT is a function-oriented exercise therapy. The PEPT physical therapist manipulates restricted joints and intensively trains functional skills irrespective of pain experience during or after the therapy. Patients are stimulated to use an active coping style to achieve a clear functional goal in 5 sessions.

Control group: Usual treatment of CRPS according to the Dutch CBO CRPS guideline 2006 including, analgesics (WHO pain ladder), neuropathic drugs, N-acetylcysteine, calcium channel blocker, ketanserin and DMSO (dimethylsulphoxide). On indication, percutaneous sympathetic blocks or spinal cord stimulation will be performed. In addition, patients receive physical therapy with exercises within pain limits (pain contingent), splints and if necessary, aids for ADL activities.

Outcome measures:

Primary outcome measure is the Impairment level SumScore (ISS), which consists of three measurement parameters (pain, active range of motion and temperature) and four measurement instruments (VAS, McGill Pain Questionnaire, goniometry of mobility of joints and skin thermometer). A cost-effectiveness analysis from a societal perspective comparing PEPT to usual care in patients with CRPS will be performed. This will be done along-side the clinical trial.

Sample size calculation/data analysis:

The sample size calculation is based on the following finding and expectation. The improvement in ISS (primary outcome) over one year for the standard physical therapy group was 50% [Oerlemans, APMR 2000], for the PEPT group it is estimated at minimal 70-80%. Given an alpha of 0,05 and a power of 80% for a one sided Chi-square test 31 patients are needed per group. The Student T- test is used to calculate differences between both groups in mean ISS.

Inclusion criteria

Patients between 18 and 80 years of age with Complex Regional pain Syndrome (CRPS-1) of either upper or lower extremity according to Bruehl's/IASP criteria between 3 and 24 months after initial injury will be selected for the study.

Exclusion criteria

Patients who do not comply with the inclusion criteria especially those who have other causes that may explain a pain syndrome will be excluded (IASP criterium)