RT Journal Article SR Electronic T1 Clarification JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 944 OP 944 DO 10.1136/jnnp.2010.232371cl VO 82 IS 8 YR 2011 UL http://jnnp.bmj.com/content/82/8/944.1.abstract AB