ABSTRACT
Recognition of the influence of the sympathetic nervous system on muscle function is quite essential in successful management of reflex sympathetic dystrophy (RSD). Sympathetic block relieves muscle contraction and improves motor function of the extremity involved in RSD. The unpleasant nociceptive impulse results in hypertonicity, flexor muscles stimulation, spasticity, withdrawal, tremor, dystonia, and cold skin. The proprioceptive system exerts an inhibitory effect on the anterior horn cells and anterolateral horn cells. Surgery in the case of temporomandibular joint disease or thoracic outlet syndrome results in vicious circle and aggravation of RSD. The use of sympathetic block, heat, biofeedback, and transcutaneous nerve stimulator on trigger points relieves the pain and movement disorder. The selective therapeutic efficacy of sympathetic proximal nerve block in relief of hyperpathic pain as opposed to nonhyperpathic pain reflects the importance of efferent pathways in the development of RSD and hyperpathia.
