Carryover of previous treatment outcomes to subsequent medical treatment outcomes seems to be pervasive. The influence of a treatment history can generalize across treatments and across symptoms.... Show moreCarryover of previous treatment outcomes to subsequent medical treatment outcomes seems to be pervasive. The influence of a treatment history can generalize across treatments and across symptoms. These generalization effects in clinical practice have been studied experimentally in placebo and nocebo effects, which are beneficial and adverse effects that do not arise from active treatment components, respectively. The aim of this thesis was to answer the question of whether previously learned placebo and nocebo effects can generalize within and across somatosensory sensations. Additionally, the thesis also explored the role of individual characteristics as predictors (e.g., anxiety, stress, attention, catastrophizing) for the generalization of placebo and nocebo effects. The findings of the thesis have showed that placebo and nocebo effects can generalize within pain and itch modalities, but can not generalize from pain to itch and from itch to touch. The generalization effects of placebo and nocebo effects can not be predicted by psychological characteristics (e.g., anxiety- and stress symptoms) in healthy individuals. Moreover, the dissertation addresses the limitations of the work and directions for future research, as well as giving implications for clinic practice. Show less
The prevalence of musculoskeletal complaints in professional musicians is higher compared to the general population (Odds ratio 2.3): point prevalences in the literature range between 9% and 68%;... Show moreThe prevalence of musculoskeletal complaints in professional musicians is higher compared to the general population (Odds ratio 2.3): point prevalences in the literature range between 9% and 68%; year prevalences range between 41% and 93%. Female gender is the most important risk factor. Also among amateur musicians musculoskeletal complaints are frequent, the year prevalence of playing-related is 68%. Female gender, a sudden increase in playing time and playing a string instrument were the main risk factors. Among professional musicians with musculoskeletal complaints, the impact of these complaints on daily functioning is appreciated as more severe, compared non-musicians with musculoskeletal complaints. Also, healthcare usage is higher among musicians with these complaints. Musicians with complaints report worse illness perceptions compared to non-musicians with musculoskeletal complaints. In the last part of this thesis biomechanical aspects of violin playing are evaluated: Violinists with complaints show more activity of the superficial neck and shoulder muscles while playing the instrument, which is hypothesized to be the result of co-contraction. From a biomechanical point of view, playing without a shoulder rest, or with a shoulder rest with minimal height seems favourable, the latter being subjectively most comfortable by the violinists. Show less
Motor disturbances are frequently reported in Complex Regional Pain Syndrome (CRPS) and may involve muscle weakness, problems with initiation and execution of movements and abnormal postures. The... Show moreMotor disturbances are frequently reported in Complex Regional Pain Syndrome (CRPS) and may involve muscle weakness, problems with initiation and execution of movements and abnormal postures. The general aim of this thesis was to investigate the contribution of sensory dysfunction to motor deficits in CRPS patients and to improve quantification of motor dysfunction. Comprehensive quantitative sensory testing techniques showed that a lower pressure pain threshold, measured over muscles, was the most prominent sensory abnormality in affected body parts of CRPS patients with and without dystonia, compared to healthy controls. Moreover, an association was found between sensory and motor dysfunction. A reduced pressure pain threshold was also the most deviant abnormality found in unaffected extremities of CRPS patients, indicating that muscle hyperalgesia is a widespread characteristic of CRPS. Furthermore, there were indications that impaired processing of proprioceptive information related to force production is disturbed in CRPS patients. Reliability and validity of the Range of Motion Scale (ROMS), a new clinical rating scale developed to assess the severity of fixed abnormal postures, was demonstrated. The phenomenology of movement disorders after peripheral trauma was systematically reviewed and potential mechanisms that may explain the underlying pathophysiology were discussed. Show less
Although osteoarthritis is a common disease, there are currently no disease-modifying availible. For a long time osteoarthritis was considered a purely degenerative disease without inflammation of... Show moreAlthough osteoarthritis is a common disease, there are currently no disease-modifying availible. For a long time osteoarthritis was considered a purely degenerative disease without inflammation of the synovium (synovitis). However, recent research has shown that synovitis is of importance in patients with osteoarthritis. Therefore, this thesis aimed to understand the role synovitis in ossteoarthritis. In the first part of this thesis, we investigated the nature of synovitis by examining the synovium of osteoarthritis patients using differnt laboratory techniques. Furthermore, we validated a new synovitis scoring system on MRI with contrast. In the second part of this thesis, we investigated role of synovitis in relation to clinical characteristics such as pain and structural damage. This thesis shows that synovial inflammation in osteoarthritis is not only frequently present, but may also play a role in the pathophysiology of osteoarthritis and development of clinical features. Results presented in this thesis provide insight into different aspects of synovial inflammation aimed at increasing our understanding of the pathophysiology of OA and aiding to the development of disease-modifying drugs in OA. Show less
