- Correspondence to Dr Stephen D Silberstein, Jefferson Headache Center, Thomas Jefferson University, 900 Walnut Street, Suite 200, Philadelphia, PA 19107, USA;
- Received August 20, 2014
- Accepted August 22, 2014
- First published October 6, 2014.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.