As reported in the current issue of Pain Practice, researchers at Walter Reed Army Medical Center have tried a Stellate Ganglion nerve block instead of anti-anxiety drugs to treat the disorder. As far as I can tell the sample size was all of two, but the research was based on prior reports of success by a Chicago based anesthesiologist, Dr. Eugene Lipov. The authors of the study concluded:
Selective blockade of the right stellate ganglion at C6 level is a safe and minimally invasive procedure that may provide durable relief from PTSD symptoms, allowing the safe discontinuation of psychiatric medications.
Other experts cautioned that more research is needed - with a sample size of two, I'd hope so. Although the ABCnews.com report states the study was placebo controlled, the abstract of the journal article says both subjects got SGB and reported relief. (maybe there's a different study ABC news if referring to, but I'm not seeing it.)
Abstract of the article HERE