The Use of Accelerated Heavy Particles for 



Production of Radiolesions and Stimulation 



in the Central Nervous System 



Cornelius A. Tobias* 



Medical Physics Division, Donner Laboratory, 

 University of California, Berkeley 



The central nervous system has a more intricate ors;anization than any of 

 the other organ systems of the human body: its functions seem to depend on 

 the spatial configuration of its delicate structural elements, and on spatial 

 and temporal interrelationships of its neuronal discharges. 



Through past centuries up to the present, a tremendous amount of knowl- 

 edge has accumulated with respect to gross, microscopic, and submicroscopic 

 anatomical structures of the central nervous system ; and relatively recently 

 it has become {X)ssible by the use of surgical instrmnents to make lesions in 

 various parts of the brain, then follow^ the abnormal pattern of physiological 

 and electrical activity thus created by a variety of techniques. In surgical 

 interference with brain structure, whether this be done for the purpose of 

 physiological study or with therapeutic aim. serious limitations are encoun- 

 tered: the entire path of the surgeons needle or knife produces injury from 

 surface to depth with interruption of neuronal pathways and blood vessels. 

 The result can be hazard for hemorrhage, subsequent necrosis, and later 

 formation of scar tissue along the pathway of surgical injury. The presence 

 of scarring by itself can lead to disturbances of electrical fimction and to new 

 injury with the production of more extensive lesions. While there are con- 

 stantly new improvements in operative technicjue and while much new 

 knowledge is gained by the current methods, one should maintain an interest 

 in novel approaches to the problems of neurophysiology. The role of ac- 

 celerated heavy particles will be outlined here in historical background. This 

 is done to illustrate that man's curiosity in relatively remote and discon- 

 nected, "useless" aspects of nature can sometimes lead to new tools, new 

 methods, and new knowledge in very practical and useful realms. 



* The author's research is supported by the .\EC. 



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