RT Journal Article SR Electronic T1 Preface JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 561 OP 563 DO 10.1136/jnnp.43.7.561 VO 43 IS 7 A1 C D Marsden YR 1980 UL http://jnnp.bmj.com/content/43/7/561.abstract AB