RT Journal Article SR Electronic T1 Proceedings of the Association of British Neurologists, Birmingham, April 1991 JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 240 OP 245 DO 10.1136/jnnp.55.3.240 VO 55 IS 3 YR 1992 UL http://jnnp.bmj.com/content/55/3/240.abstract AB