Statistics from Altmetric.com
Correction notice This letter has been amended since it was published Online First. The affiliation for Susanne A Schneider was incorrect and this has now been changed.
Contributors RE: assessing the patients, writing the first draft. SAS, NPQ and KPB: assessing the patients, reviewing the paper.
Competing interests None.
Patient consent Obtained.
Provenance and peer review Not commissioned; externally peer reviewed.
▸ Additional material is published online only. To view please visit the journal online (http://dx.doi.org/10.1136/jnnp-2012-304779).
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.