Evidence for Central Sensitization in Patients With Chronic Whiplash Associated Disorders Based on Self-reported Outcomes of Pain (Beliefs), Disability, Central Sensitization, Quantitative Sensory Testing, and Electro-encephalography.

Chronic whiplash associated disorders (CWAD) are frequently occuring conditions with varying degrees of neck pain and disability. They occur usually as a consequence of a motor vehicle accident. Acute whiplash injury has an annual incidence of 200-300 per 100.000 and affects 83% of persons in a traffic collision. Up to 50% of WAD patients do not fully recover, and up to 25% continue to have moderate to severe pain-related disabilities. The consequent pain and disability give rise to substantial socioeconomic cost. In Europe, the annual cost of WAD was estimated to be 12 billion euro.

Chronic neck pain, as observed in CWAD, is often incompletely responsive to available therapies. Due to the current lack of knowledge concerning the underlying factors responsible for the maintenance of these chronic pain conditions, there is no consensus on dedicated and specific therapy approaches for CWAD, resulting in a treatment gap in this condition. The chronicity and severeness of the disorders has led to paradigm shifts in the reasoning about chronic pain from seeing it as a symptom towards as a disease. Neuroimaging has provided evidence that chronic pain is a multidimensional process affecting sensory and emotional processing based on an altered state of the central nervous system in the form of central sensitization (CS). This sensitization results from an increased responsiveness to a variety of stimuli and expresses itself in the form of hyperalgesia, allodynia, referred pain, and ultimately in chronic widespread pain. Changes in both structural and functional brain activity and connectivity over time contribute to an augmentation of pain perception, by an enhanced pain facilitation and defective inhibition of nociceptive signals. It remains however debated whether CS is present as a pathophysiological feature in CWAD.

In this project we hypothesize that CS is one of the main features of the pathophysiology of CWAD, and that relationships occur between QST and EEG on one hand, and self-reported pain, disability, quality of life, psychological correlates and central sensitization on the other hand.

Therefore, 70 patients with CWAD and 70 (gender and age) matched healthy controls will be invited to fill out questionnaires, perform a QST protocol and EEG measurements.

The questionnaires will be filled out online during the two weeks before the determined testing moment and will consist of the Neck Disability Index, the Short Form Health Survey-36 items, a 0-10 Numeric Rating Scale for pain, the Central Sensitization Inventory, the Dutch version of the Pain Catastrophizing Scale, the Impact of Event Scale revised, the Pain anxiety symptoms scale (PASS-20), the patient specific complaints questionnaire (PSK), the Dolour neuropathic 4 (DN4) and the Leeds Assessment of Neuropathic Symptoms and Signs pain scale (S-LANSS). Dutch versions of all questionnaires will be used.