CHAPTER XI 



EFFECTS ON THE SPINAL CORD 



The spinal cord, like the brain, appears relatively resistant to the effects of 

 inanition, although the nerve cells show marked degenerative changes in certain 

 types of partial inanition (pellagra, etc.). After a brief summary, the effects of 

 inanition upon the spinal cord will be considered under (A) total inanition, and 

 (B) partial inanition. 



Summary of Effects on the Spinal Cord 



In general, as might be expected, the changes in the spinal cord during inani- 

 tion resemble those in the brain, although differing in some details. In weight 

 the adult spinal cord suffers little or no loss, the decrease usually being less than 

 10 per cent, even at death from either total or partial inanition. In young 

 animals during inanition the spinal cord, like the brain, exhibits a persistent 

 growth with retarded or even declining body weight. This may occur during 

 partial inanition (scurvy, aqueous inanition). Upon ample refeeding after a 

 period of inanition, the spinal cord usually recovers its normal proportionate 

 weight, although after severe or prolonged inanition in young animals the later 

 growth of the spinal cord upon refeeding may be subnormal. 



The structural changes in the spinal cord are also in general comparatively 

 slight, especially in the white substance, although congestion is frequent and 

 variable changes in the gray substance appear, especially in the later stages of 

 inanition. These changes resemble those found in the brain, sometimes being 

 less intensive but often more so. During total inanition (complete or incomplete) 

 the nerve cells, especially in the anterior horn, may undergo atrophic degener- 

 ation with a variable degree of cytoplasmic vacuolation, chromatolysis, 

 neurofibrillar derangement, and nuclear enlargement or pycnosis, rarely kary- 

 olysis or karyorrhexis. In extreme cases, some cells may degenerate and 

 disappear entirely; while others show comparatively slight changes. The 

 medullated fibers may show diffuse degenerative changes, probably secondary 

 to the disturbances in the nerve cells. Proliferation of the neuroglia may occur. 

 The changes during hibernation are comparatively slight. 



In the various forms of partial inanition, the structural changes in the spinal 

 cord in general resemble those during total inanition, with certain special 

 features in addition. In protein deficiency (including pellagra) the congestion 

 is greater and degenerative changes in the nerve cells are usually more intensive, 

 involving pigmentary degeneration and frequently total necrosis and dis- 

 integration, especially in some regions. There are also more extensive 

 degenerative changes in the white substance, especially in the posterior and 



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