RT Journal Article SR Electronic T1 Nonpositional headache caused by spontaneous intracranial hypotension JF Neurology JO Neurology FD Lippincott Williams & Wilkins SP 1768 OP 1769 DO 10.1212/WNL.51.6.1768 VO 51 IS 6 A1 Wouter I. Schievink A1 Kris A. Smith YR 1998 UL http://n.neurology.org/content/51/6/1768.abstract AB