Alterations of Intracranial Tension. 217 



120 (1580) 



Alterations of intracranial tension by salt solutions in the alimen- 

 tary canal. 



By Harvey Cushing and Frederick E. B. Foley. 



[From the Laboratory of Surgical Research, Harvard Medical 

 School, and the Surgical Clinic, Peter Bent Brigham Hospital}. 



In two interesting and suggestive papers 1 Weed and McKibben 

 demonstrated the significant physiological fact that it is possible 

 to reduce the cerebrospinal fluid pressure and diminish the bulk of 

 the brain by injecting a hypertonic solution into the blood stream. 

 Conversely they found that hypotonic solutions had the opposite 

 effect: a rise of cerebrospinal fluid pressure and an increase of 

 brain bulk. In the course of our studies their work has been 

 repeated and their general conclusions confirmed. 



The clinical bearing of these facts is obvious. Particularly 

 they concern the states commonly referred to as "pressure symp- 

 toms." By similar methods it has been found possible to secure 

 these same results in patients with increased degrees of intracranial 

 tension. It was felt that the undesirable effects on pulse, respir- 

 ation and blood pressure of such intravenous injections might 

 contraindicate their use. For this reason the effects of gastroin- 

 testinal doses of hypertonic solutions were studied. 



In a large series of animal experiments it has been found that 

 practically the same effects may be obtained by the gastrointest 'nal 

 route of administration. By this method the intracranial changes 

 are not attended by disturbances of pulse, respiration or blood 

 pressure, also the possible alterations of the cellular elements of 

 the blood are avoided. 



Twenty to thirty cubic centimeters of a saturated sodium 

 chloride solution introduced into the duodenum or rectum of an 

 average-sized cat produced a maximal fall of cerebrospinal fluid 

 pressure precisely comparable to that which occurred when the 

 solution was given intravenously. Following such doses the 



1 "Experimental Alterations of Brain Bulk," Am. Journ. Physiol., 1919, XLVIII, 

 p. 531; "Pressure Changes in the Cerebrospinal Fluid following Intravenous Injection 

 of Solutions of Various Concentrations," Ibid., p. 512. 



