There seem to be no controlled studies demonstrating efficacy of neurolytic sympathetic blocks. Possible side effects, ranging from trivial to devastating, are of even greater importance with these more permanent procedures—painful sequelae may include phenol or alcohol neuritis and postsympathectomy pain (sympathalgia), which can also occur after surgical sympathectomy.
6
BMJ. 1998 March 14; 316(7134): 792–793.