824 



THE NEBVOUS SYSTEM. 



mentation, and atrophy of the ganglion cells of the anterior horns, an 

 increase in the connective tissue of the corima and of the adjacent white 

 matter, often with destruction of considerable portions of the horns, 

 atrophy of the anterior roots, and distortion of the cord. 



Instead of this shrinkage and atrophy of the horns there is sometimes 

 found, especially if the case come to autopsy not too long after the onset, 

 a gelatinous condition of the horns, the place of the horns being occupied 

 by young neuroglia tissue with many branching cells and fine delicate 

 fibrils resembling glioma (Fig. 538). This gliomatous tissue may break 

 down, forming a cavity surrounded by young neuroglia tissue. More re- 

 cently autopsies made early in the course of the disease show that the 

 changes described above represent only later stages of what originated 



FIG. 537. POLIOMYELITIS AXTKIUOK. 



A, Normal ganglion cells surrounded by nerve fibres: B, degenerated ganglion cells; C, granular masses 

 at place of ganglion cells ; D, small cavity containing fluid. 



as an acute inflammatory process. Examination of the cords from such 

 early cases shows congestion, exudation of leucocytes into the perivas- 



FIG. 538. ACUTE ANTERIOR POLIOMYELITIS. 



Death seven weeks after onset. Showing gliomatous tissue in both horns, with cavity formation in one of 



them. 



