RT Journal Article SR Electronic T1 CLINICAL NEUROSURGERY JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 310 OP 311 DO 10.1136/jnnp.38.3.310-b VO 38 IS 3 A1 R. D. Illingworth YR 1975 UL http://jnnp.bmj.com/content/38/3/310.3.abstract AB