- Correspondence to Dr M J Smith, Department of Neurosurgery, Hospital of the University of Pennsylvania, 3400 Spruce St, 3rd Floor Silverstein, Philadelphia, PA 19104, USA;
- Received September 13, 2013
- Accepted December 2, 2013
- First published January 3, 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.