1 88 INANITION AND MALNUTRITION 



The brain is always markedly sclerosed in all parts, sometimes edemic. There 

 is proliferation of the neuroglia, and the corpora amylacea probably represent 

 altered glia cells. The nerve cells of the brain all show a variable degree of 

 change. Pigmentation is the commonest (also found in the sympathetic 

 ganglia). The tigroid (Nissl) substance undergoes granular disintegration, 

 first in the circumnuclear zone; later the whole cell becomes homogeneous, 

 sometimes greatly vacuolated; the nucleus may be displaced and finally dis- 

 appears; ultimately the whole cell may disintegrate into several small masses. 

 The degree of cell change is proportional to the length of the period of insanity. 



Mott ('13) also found degenerative changes with a variable degree of chroma- 

 tolysis and lesions of the neurofibrillae in the Betz and Purkinje cells in a case of 

 pellagra. The changes are less intensive than those found in the spinal cord (to 

 be mentioned later). 



Fat Deficiency. — In several rats which had been fed by McCollum on lipoid- 

 free rations, with retarded growth of the body, Hatai ('15) found the brain and 

 spinal cord each apparently reduced about 2 per cent in weight, the gray sub- 

 stance being affected more than the white. In 45 human autopsies in cases of 

 edema apparently due to insufficient food, especially poor in fat and protein, 

 Prince ('21) observed no macroscopic lesions in the nervous system. 



Salt Deficiency. Rachitis. — In human rickets, the occurrence of hydro- 

 cephalus was noted by Whistler (1645) ar >d Glisson (1650). Seibold (1827) 

 noted an increase in the fluid of the brain ventricles (also subdural), and an 

 enlargement of the Pacchionian bodies. Comby ('oi ) found a variable tendency 

 to hydrocephalus in rachitic infants, and Stoeltzner ('03) mentioned mild hydro- 

 cephalus as a possibly significant condition. Cheadle and Poynton ('07) 

 likewise believed that the brain may be involved in rickets. Pfaundler ('22) 

 states that in human rickets the brain is enlarged, as though swollen; vascular 

 congestion causes ventricular dropsy, and the softened cranium permits hydro- 

 cephalic enlargement. Karger ('20) claims that the enlargement of the rachitic 

 brain is not due to hydrocephalus. "In den bekannten grossen rachitischen 

 Schadeln findet sich in der Regel kein Hydrozephalus, sondern ein abnorm 

 grosses Gehirn; in diesem sind bisher mikroskopisch keine wesentlichen Abweich- 

 ungen von normalen nachgewiesen worden und die Versuche, diese Frage auf 

 chemischen zu beantworten, haben bis jetzt zu eindeutigen Ergebnissen nicht 

 gefiihrt." 



Neurath ('24) reviews the neurologic changes in rickets, especially the 

 cerebral changes, which are associated with mental retardation in infants. 



In dogs and pigeons on low salt diets, Forster ('73) observed weakness, 

 trembling and paralysis, but no macroscopic lesions of the central nervous 

 system at autopsy. In puppies on calcium-poor meat and lard diet, producing 

 a rachitic (or pseudorachitic) condition, Voit ('80) found the brain weight nearly 

 normal or possibly (as he thought) above normal. Quest (,'06) demonstrated 

 that the brain in such rachitic puppies shows an increased water content, but 

 normal calcium content. Jackson and Carleton ('23) found the brain weight 

 nearly normal in a large series of albino rats in various stages of experimental 

 rickets. 



