Painful peripheral states and sympathetic blocks.

TLDR

In chronic painful conditions, sympathetic nerve supply is blocked by local anaesthesia or guanethidine, and the sympathetic system’s influence on sensation is discussed. Sympathetic blocks relieve pain only when hyperpathia is present, indicating that peripheral noradrenaline sustains both pain and hyperpathia.

Abstract

In various chronic painful states, the sympathetic nerve supply was blocked either by injecting the sympathetic chain and ganglia with local anaesthesia or by the injection of guanethidine during occlusion of the circulation. There was a striking relation between the presence of hyperpathia and the relief of pain by the blocks. The sympathetic block was unlikely to relieve the pain unless hyperpathia accompanied the pain; when hyperpathia was present, a sympathetic block relieved both the constant pain and the hyperpathia. The effectiveness of the guanethidine blocks shows that the pain and the hyperpathia are maintained by the emission of noradrenaline in the periphery. The facts related to the sympathetic system and sensibility are discussed.