RT Journal Article SR Electronic T1 Correction JF Practical Neurology JO Pract Neurol FD BMJ Publishing Group Ltd SP 1 OP 1 DO 10.1136/jnnp.2008.154799corr1 VO 9 IS 1 YR 2009 UL http://pn.bmj.com/content/9/1/1.2.abstract AB