RT Journal Article SR Electronic T1 Correction JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 826 OP 826 DO 10.1136/jnnp.57.8.897corr1 VO 82 IS 7 YR 2011 UL http://jnnp.bmj.com/content/82/7/826.2.abstract AB