CHAPTER X 



EFFECTS ON THE BRAIN 



In general the brain appears relatively resistant to the effects of both total 

 and partial inanition. Usually little or no loss in weight or changes in gross or 

 microscopic structure are apparent. In advanced stages of starvation, however, 

 and especially in types of partial inanition (beriberi, pellagra) involving neural 

 or psychic disturbances, there are well-marked degenerative changes in the 

 nerve cells. After a brief summary, the effects of inanition upon the brain will 

 be considered under (A ) total inanition, and (B) partial inanition. 



Summary of Effects of Inanition on the Brain 



The brain in general is extremely resistant to loss in weight during total inani- 

 tion or on water alone. In adults, both human and infrahuman, even with a 

 loss of 40 or 50 per cent in body weight, the loss in brain weight is below 10 per 

 cent, usually below 5 per cent, and often shows no appreciable change. This 

 is also true in general during the various forms of partial inanition; but in some 

 cases there may be an actual increase in brain weight (with edema in pellagra, 

 etc.) or a definite atrophy, with decreased weight (during protein deficiency, 

 pellagra, etc.). 



In atrophic infants, the brain is capable of continued growth with retarded, 

 or even stationary, body weight. The same is true in young animals, especially 

 in newborn subjected to prolonged underfeeding, although in some cases (acute 

 inanition, various forms of partial inanition, and at later ages) the brain weight 

 may remain unchanged, or even show a slight loss. In human rickets the brain 

 appears enlarged (often hydrocephalic), but in experimental rickets in animals 

 it is usually normal in weight. After severe underfeeding, the brain may fail to 

 grow properly upon subsequent ample refeeding. 



In structure, the brain during total inanition (or on water only) grossly 

 appears normal, excepting a variable degree of congestion, especially in the 

 meninges. Microscopically the white substance (medullated fibers) usually 

 appears normal. Aside from a variable degree of hyperemia, the gray substance 

 usually likewise shows no marked change, except in the nerve cells. Even most 

 of these cells frequently appear normal, but there are often atrophic and 

 degenerative changes which are extremely variable in different individuals, in 

 different cells, and in different regions of the brain. As a rule, the changes 

 appear well marked only in advanced stages of inanition. 



These brain cell changes, which have been extensively studied in various 

 animals, are especially evident in some of the large cells (of Betz and Purkinje, 

 etc.), although frequently more intensive in the smaller cells. The changes 



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