SYMPATHETIC CONTRIBUTION TO PAIN - NEED FOR CLARIFICATION

Certain patients with a possible contribution of the sympathetic syste m to pain may not fit the definition of complex regional pain syndrome s (CRPS), which raises the question of terminology for those patients. To further clarify the relationship between the sympathetic system an d pain, apart from the need for placebo studies, there remains an urge nt need for a satisfactory definition of the criteria for a complete s ympathetic block. It also remains uncertain whether a change in the di scharge pattern of sympathetic fibres underlies the changes in sympath etic organ function, often found in patients with CRPS.