Date	Event	Description
14 January 2011	New search has been performed	New searches run January 2011. Eight references retrieved. We identified no new studies.
22 October 2008	Amended	Converted to new review format.
22 October 2008	New search has been performed	The literature search was repeated on 22 October 2008. We identified 11 articles, which included five review articles, two case reports and two case series. None of these articles were included in the update of our review as none of these studies were randomised controlled trials that abided with our inclusion criteria.
18 August 2006	New search has been performed	New searches run June 2006. No new studies identified.