Painful disorders of peripheral nerves.

Introduction The classical description of painful sequelae to peripheral nerve injury is that by Weir-Mitchell in his book Injuries of Nerves and their Consequences. This was published in 1872 and related to experience gained during the American Civil War. Later, in 1900, Sudeck described an acute atrophy of bone, associated with swelling, pain and loss of function. A variety of terms are applied to this condition including reflex sympathetic dystrophy, Sudeck's atrophy and algodystrophy. Over the years many authors have pointed out the remarkable similarity clinically between painful sequelae of peripheral nerve damage, now known as causalgia and Sudeck's atrophy in that both are associated with severe spontaneous pain, swelling of the affected hand or foot, changes in the muscles, joints and skin and marked hypersensitivity over the innervated zone-later spreading to adjacent zones. Until recently it was believed that Sudeck's atrophy was a manifestation of an abnormal response of the sympathetic nervous system to injury, but recent work has shown that the sympathetic nervous system is not at fault but that it is a hypersensitivity of the large diameter afferent nerves to normal circulating noradrenaline that seems to be responsible (Wallin, Torebjork and Hallin, 1976). Characteristically Sudeck's atrophy follows fairly trivial injuries, whereas causalgia is associated with partial division of peripheral nerves.