Influence of Variations in Fluid Intake on Intracranial Pressure in "Epileptics"

Cannon¹has called attention to the "coordinated physiological reactions" that maintain the constancy or "homeostasis" of the organism. Much of our knowledge of physiology has come from study of the mechanisms by which "steady states" are maintained. Perhaps equally illuminating are the mechanisms by which homeostasis may be disturbed. Cerebrospinal fluid pressure, i. e., hydrostatic pressure to which the central nervous system is exposed, is one of these "steady states." Weed and McKibben²found this pressure to be nearly constant at 119 mm. of spinal fluid in cats (ether anesthesia and basal conditions). In non-anesthetized healthy adult human beings we have found the pressure to be rarely outside the limits of from 80 to 180 mm. of spinal fluid (recumbent position and basal conditions). In a series of articles³that have been published, one of us has shown that the osmotic and hydrostatic forces of the blood