In 1919, Weed and McKibben,1 experimenting with cats, first called attention to the fact that the cerebrospinal fluid pressure as well as the bulk of the brain could be reduced by the intravenous injection of various hypertonic solutions of electrolytes. The important observation was made that, within certain limits, the amount of fall in pressure of the cerebrospinal fluid is an index to the extent to which the volume of the brain has been reduced. In their experiments, they used sodium chlorid, sodium sulphate and sodium bicarbonate. They likewise noted a fall in pressure but not to such a marked degree after the intravenous injection of hypertonic crystalloids, such as glucose.
It also was observed that the intravenous use of concentrated solutions of sodium chlorid was often followed by severe respiratory and cardiac disturbances. This was sometimes noted after the first few cubic centimeters had been injected, and was
MORRISSEY EJ. THE EFFECT OF MAGNESIUM SULPHATE ON THE CEREBROSPINAL FLUID PRESSURE AND ON THE BRAIN VOLUME. Arch Surg. 1925;11(5):778-789. doi:10.1001/archsurg.1925.01120170133009