Causalgia - A meta-analysis of the literature

Background: Causalgia is not familiar to most physicians whose training and experience are limited to civilian practice. Hypothesis: Through a thorough review of the literature, we attempted to determine the boundaries of causalgia and separate it from other sympathetically related disorders. Data Sources: Database search for English-language articles in MEDLINE and Index Medicus up to the year 2000 as both keyword and subject under causalgia. Study Selection: References that described any new cases referred to as "causalgia" by their authors were included in a meta-analysis. Data Synthesis: One hundred ten articles contained a total of 1528 cases of causalgia. High-velocity missiles caused at least 77% of the injuries. In 72% and 90% of the cases reported, the time from injury to onset of pain was within 1 week and 1 month, respectively. Median nerve alone or in combination with other nerves (56%) and sciatic trunk injury (60%) were the most common nerves involved. In 92%, the nerve injury was incomplete. The most prominent clinical manifestations included burning pain in 86%, increased sweating in 73%, relief with application of cold in 62%, warmth in 50%, paresthesias in 96%, absence of anesthesia in 81%, and sensitivity to stimuli in 98%. Response to sympathetic blocks was observed in 88%. Finally, a total of 94% of the patients undergoing sympathectomy were cured. Conclusions: Cases of causalgia are easy to recognize and treat, with excellent results. Causalgia always follows a somatic nerve injury, usually partial, and is associated with near-constant, very severe pain distal to the injury in the extremity, varied in nature but characteristically with a predominantly burning quality. An effective anesthetic block of the appropriate part of the sympathetic chain frequently immediately relieves the pain. Most cases are cured by surgical sympathectomy.