In addition, sympathectomy can cause postsympathectomy pain called sympathalgia in up to 44% of patients undergoing this procedure....
The sympathalgia secondary to sympathectomy usually starts around the first 2 weeks of the surgical procedure. It is a dull and cramping pain and occasionally can be a sharp pain. Although it is temporary in some patients, in others it can persist for several months or years.
H. Hooshmand, M.D.
Chronic Pain, page 156