Modern Pain Neuroscience Applied to Chronic Pain in Patients With Chronic Whiplash Associated Disorders

Modern pain neuroscience has advanced our understanding of chronic whiplash associated disorders (WAD). Previous studies have shown the importance of central sensitization, characterized by hypersensitivity of the somatosensory system, in explaining poor treatment outcome. Therefore, and to address the need for a better treatment of chronic WAD, we recently proposed a modern neuroscience approach to chronic WAD. Such approach includes two specific parts: 3 sessions of therapeutic pain neuroscience education followed by 15 sessions of dynamic and functional cognition-targeted exercise therapy and stress management techniques. The main principles of cognition-targeted are the following: All exercises should be performed in a time-contingent ("Perform this exercise 10 times, regardless of the pain") rather than in a symptom-contingent way ("Stop or adjust the exercise when it hurts"). Goal setting is essentially done together with the patient, focussing on functionality. The treating physical therapist should continuously assess and challenge the patients' cognitions and perceptions about the pain and the anticipated outcome of each exercise, to change maladaptive cognitions and perceptions into positive ones. The primary scientific objective of the study entails examining the effectiveness of a modern pain neuroscience approach versus usual care evidence-based physiotherapy for reducing dysfunctioning in patients with chronic WAD. The secondary scientific objective of the study entails examining the effectiveness of a modern neuroscience approach versus usual care evidence-based physiotherapy for reducing pain, central sensitization, psychological problems, and socio-economic burden in patients with chronic WAD. The trial will randomize 120 patients with chronic WAD, aged between 18 and 65 years, to the experimental (modern pain neuroscience approach (n = 60)) or control treatment (usual care evidence-based physiotherapy: 3 sessions of neck school followed by 15 sessions of graded and active exercise therapy focusing on strength, flexibility, endurance, and ergonomic principles (n= 60)). The primary outcome measure is functional status. Secondary outcome measures include pain, health-related quality of life, psychological correlates, socio-economic factors, and measures of central sensitization, including electrical detection and electrical pain thresholds measured with a constant current electrical stimulator, endogenous pain facilitation (temporal summation of electrical pain), endogenous pain inhibition assessed by the conditioned pain modulation paradigm (electrical stimulation as test stimulus and the cold pressor test (immersion of one hand in cold water of 12°C) as conditioning stimulus). In addition, quantitative scalp Electroencephalography (EEG) to measure various parameters of brain activation will be performed during the conditioned pain modulation paradigm. To comply with these scientific objectives, the 120 chronic WAD patients will be subjected to the baseline assessment of all outcome measures. Follow-up assessments will be performed immediately after 16 weeks of therapy (all tests), and 6 months (all tests) and 12 months (only questionnaires) after finishing the therapeutic intervention. To investigate these objectives, a muli-center triple-blind randomized, controlled trial with 1 year follow up will be performed. Appropriate statistical analyses will be performed to evaluate and compare treatment effects. Statistical, as well as clinical significant differences will be defined and the effect size will be determined. Relations between functional status, pain, psychological correlates and central sensitization will be investigated. Furthermore, prediction of pain and functional status by central sensitization and psychological correlates will be performed in chronic WAD patients. Also, factors associated with clinically important changes in the outcome measures will be unraveled. In addition, factors associated with poor outcome following treatment will be assessed.