To the Editor.
— Post—lumbar puncture headache is generally ascribed to cerebrospinal fluid leakage from the puncture site. It may be prevented by keeping dural trauma to a minimum by appropriate positioning of the lumbar puncture needle bevel during the procedure. Confusion among medical students regarding the plane along which the needle bevel should be directed to pierce the dura prompted us to review recommendations in this regard in major textbooks of internal medicine and pediatrics.Cecil's Textbook of Medicine1 states that in a patient who is lying in a lateral decubitus position, "the bevel should always be directed cephalad in order to pierce the dura in a vertical fashion." In contrast, the Principles and Practice of Medicine2 recommends that the needle "should be kept parallel to the bed, with the bevel turned to pass through the longitudinally running fibers of the dura." No comments regarding the plane