 Furthermore, trauma related cytokine release, exaggerated neurogenic inflammation, sympathetic afferent coupling, adrenoreceptor pathology, glial cell activation, cortical reorganisation, and oxidative damage (e.g., by free radicals) are all factors which have been implicated in the pathophysiology of CRPS.The mechanisms leading to reduced bone mineral density (up to overt osteoporosis) are still unknown.Potential explanations include a dysbalance of the activities of sympathetic and parasympathetic autonomic nervous system  and mild secondary hyperparathyroidism.