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
The clinical characteristics of Complex Regional Pain Syndrome (CRPS) are defined by pain and various combinations of sensory disturbances, autonomic features, and sudomotor and trophic changes.... Show moreThe clinical characteristics of Complex Regional Pain Syndrome (CRPS) are defined by pain and various combinations of sensory disturbances, autonomic features, and sudomotor and trophic changes. Furthermore, patients with CRPS may suffer from movement disorders, of which dystonia is the most prevalent. Dystonia of CRPS can affect multiple extremities, is often resistant to treatment and seems to have a poor prognosis. Reliable information on the nature, chronology and clinical determinants of dystonia in CRPS patients is lacking but could provide better insight in the underlying pathophysiological mechanism. The results of our studies on clinical and neurophysiologic aspects of patients with multiple CRPS and MDs in CRPS provided data that suggest disturbances at multiple levels of the CNS. Maladaptive neural plasticity likely is an important mechanism underpinning the MDs that may occur in CRPS. The presence of disturbances at multiple levels of the central nervous system parallels recent hypotheses on the underlying mechanisms suggested for other types of dystonia. Finally, the study on intrathecal baclofen administration in patients with CRPS and dystonia showed marked improvement of dystonia and pain scores after one year. Show less
