Normal cerebrospinal fluid pressure.

Abstract

✓ The authors report studies of cerebrospinal fluid (CSF) pressure in 31 young normal volunteers. In half, a 22-gauge needle was used, and in the other half a 26-gauge needle. The opening CSF pressure was monitored for 10 minutes and also in some during the CSF withdrawal period and the 10-minute CSF reformation period. Cardiac CSF pulse amplitudes and Queckenstedt responses following the opening pressure-monitoring period were also recorded before and after the fluid withdrawal. The average opening pressure was 14.5 cm of 0.15 M sodium chloride (S.D., 3.7) with the 22-gauge needle, and 15.7 cm (S.D., 3.6) in subjects receiving the 26-gauge needle. In each subject the opening pressure tended to fluctuate around a characteristic individual level; in five perfectly relaxed normal volunteers an average value of 20 cm was observed, with a maximal value of 24 cm. The amplitude of the cardiac pulse had a direct relationship to the individual CSF pressure. CSF was withdrawn at two different rates; both withdrawal rates generated approximately linear pressure decay curves. When the withdrawal rates were 5 and 1 ml/min, the average decline of pressure at the end of the period was 9.2 and 5.2 cm respectively. The mean CSF pressures increased only slightly during the 10-minute CSF reformation period. The data obtained should help to define whether a young adult patient does indeed have a CSF pressure elevation.