Magnetic resonance imaging in clinically isolated lesions of the brain stem. - Ormerod,I.E.; Bronstein,A.; Rudge,P.; Johnson,G.; Macmanus,D.; Halliday,A.M.; Barratt,H.; Boulay,E.P Du.; Kendal,B.E.; Moseley,I.F. (J Neurol Neurosurg Psychiatry, 1986)