Algodystrophy: recent insight into the pathogenic framework.

Algodystrophy, nowadays called CRPS I, is a painful syndrome characterized by sensory and vasomotor disturbance, edema and functional impairment. Significant progress in knowledge about the pathogenic mechanisms of the disease have been recently achieved, but they are not yet fully understood and some clinical aspects are still lacking of a whole pathogenetic comprehension. The local release of pro-inflammatory neuropeptides and some cytokines may be the event that triggers and maintains the disease, causing hyperalgesia and allodynia. In the following phases, the impaired capillary permeability, the interstitial edema and the consequent hypoxia and local acidosis have been proposed as possible pathophysiological pathways. The local hyperactivity of the sympathetic nervous system supposed in the past has not be confirmed and the hypothesis of an altered nociceptive processing at CNS level has limited evidences in acute phases of the disease. The steady bone involvement could be confirmed by the efficacy of bisphosphonates in the treatment of early disease.