In the chronic stage of Complex Regional Pain Syndrome (CRPS), motor disturbances are common and cause significant disability. The motor dysfunction of CRPS is a poorly understood phenomenon that... Show moreIn the chronic stage of Complex Regional Pain Syndrome (CRPS), motor disturbances are common and cause significant disability. The motor dysfunction of CRPS is a poorly understood phenomenon that is characterized predominantly by a decrease or loss of voluntary muscle control. This thesis aims to obtain a better understanding of the pathophysiology underpinning the motor dysfunction of CRPS by examining the potential roles of decreased inhibition of the motor system, changes in sensory processing and problems in sensory-motor integration. In specific, characteristics of muscle activity recordings are scrutinized in order to determine whether the loss of voluntary motor control and abnormal postures in CRPS exhibit characteristics of dystonia that are associated with reduced inhibition of the motor system (i.e., excessive muscle activation and enhanced mirror activity). The potential role of impaired processing of proprioceptive information related to wrist orientation and force production is examined, as well as the involuntary and voluntary (sensory-)motor interactions between the affected and unaffected arm. Furthermore, a systematic review of the literature on the motor consequences of experimental pain in healthy humans is presented in order to gain insight into the potential role of pain-related processes in the motor and sensory and motor disturbances of CRPS. Show less
Bank, P.J.M.; Peper, C.E.; Marinus, J.; Beek, P.J.; Hilten, J.J. van 2013
Complex Regional Pain Syndrome (CRPS) is a painful disorder affecting one or more extremities. CRPS is characterized by various combinations of sensory, autonomic and motor disturbances. Genetic... Show moreComplex Regional Pain Syndrome (CRPS) is a painful disorder affecting one or more extremities. CRPS is characterized by various combinations of sensory, autonomic and motor disturbances. Genetic factors are suggested to play a role in CRPS, but this has not been extensively studied. Therefore the aims of this thesis were to study the contribution and the size of the contribution of genetic factors in CRPS and to identify possible susceptibility and causative genes for CRPS. In our studies we have shown that CRPS may develop without a noxious event and it has been suggested that such patients have a larger genetic predisposition. Furthermore we have found that CRPS may occur in a familial form, but did not observe a clear inheritance pattern. We calculated a measure of familial aggregation. This study yielded no indications for a large overall increased risk of developing CRPS for siblings of CRPS patients. Significant associations were found with CRPS and dystonia and two HLA-B62 and HLA-DQ8. We also evaluated the presence of causative mutations in known primary dystonia genes and causative mutations in the SCN9A gene. No such mutations were identified, indicating that these genes do not seem to play a major role in CRPS. Show less
