Pathophysiology of Complex Regional Pain Syndrome Type I: Update

A search for published articles, focusing on epidemiology and pathophysiology, was performed using, as electronic bibliographic database, Medline from 1980 until present.For each pathophysiological mechanism, a separate search was conducted in Medline, using the query 'complex regional pain syndrome Type I' combined with one of the following queries: for autonomic nervous system dysfunction was used 'sympathetic nervous system' or 'sympathetically maintained pain'; for inflammation, 'inflammation' or 'neurogenic inflammation' or 'neuropeptide' or 'hypoxia'; for central sensitization, 'hyperalgesia' or 'wind-up' or 'NMDA receptor' or 'glial cells'; for brain plasticity, 'cortical reorganization' or 'referred sensations' or 'hemisensory impairment'; for psychological factors, 'psychology' or 'psychiatric' or 'behavior'.With the purpose of overviewing the known risk factors, the query 'complex regional pain syndrome Type I' was combined with the following terms: 'incidence', 'prevalence', 'genetic factors'.Abstracts were screened manually, and full test papers were considered if the abstract suggested an experimental or observational study focused on the pathogenesis of CRPS I or a review concerning one or more pathogenetic mechanisms or an association between CRPS I and risk factors.Only articles written in English were included.