Walsh & Hoyt: Measurements of Intracranial Pressure

Normal cerebrospinal fluid (CSF) pressure in adults, measured by lumbar puncture with the patient in the lateral decubitus position, varies between 80 and 200 mm of water. Contrary to popular belief, CSF pressure is not dependent on weight or height, although pressure readings may be spuriously elevated when the patient coughs, strains, or holds his or her breath during the procedure. Measurements between 201 and 249mm water are not diagnostic and those greater than 250 mm water are elevated. Normal values have not been well established in children but are generally accepted to be 200 mm water or less.