An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Heitzer E, Sandner-Kiesling A, Schippinger W, Stohscheer I, Osprian I, Bitsche S, Eisner F, Verebes J, Hofmann G, Samonigg H.Heitzer E, et al.Pain Physician. 2012 Nov-Dec;15(6):499-510.Pain Physician. 2012.PMID: 23159968Free article.