Reflex sympathetic dystrophies and algodystrophies: historical and pathogenic considerations

This paper reviews the historical development of the concepts of 'sympathy' of organs and of the sympathetic nervous system. In particular, the afferent function of the sympathetic system is discussed. The attention is focussed on sympathetic reflex dystrophies, known in some European schools as 'algodystrophies'. The pathogenic mechanisms of these affections, especially of causalgia, are discussed, considering the importance of peripheral damage to nerves, lateralisation of pain, 'mirror phenomena', and the relationship between peripheral and central mechanisms of pain.