IN THE recent war, as in other wars, many young men received wounds of the extremities and injuries to the large peripheral nerves. Once more, as a result of such injuries, causalgia has appeared on a large scale. This painful condition of an extremity was known to Denmark1 (1813) and Paget2 (1864), before the classic and detailed description of the condition was given in 1864 by Mitchell, Morehouse and Keen3 during the American Civil War. The term causalgia, meaning burning pain, was introduced by Weir Mitchell4 in 1872. As Livingston5 (1944) has shown, it seems clear that Mitchell used the term to describe the symptom of burning pain rather than an entire clinical syndrome. In the literature causalgia usually refers to a definite clinical entity. However, there is still a wide difference of opinion as to which signs and symptoms constitute the essential part of