310 DISEASES OF THE SPINAL MARROW AND ITS MEMBRANES. 

 ADDITIONS TO THE REVISED EDITION OF 1880. 



SECTION II. DISEASES OF THE SPINAL MARROW AND ITS MEMBRANES. 



1. P. 302. 



Some diseases may affect the entire cross-section of the spine 

 unequally, while others are limited to certain parts. In the latter 

 only certain physiological functions are affected, so that their symp- 

 toms must differ. Infantile spinal paralysis and progressive mus- 

 cular atrophy are affections of certain parts of the anterior portion 

 of the medulla spinalis, while in locomotor ataxy the posterior .part 

 is affected. 



2. P. 304. 



It is doubtful whether the disease starts from the nerve-fila- 

 ments or from the intervening substance ; the fact of the process 

 being generally limited to the posterior columns favors the former 

 view. The vessels are sometimes unchanged, at others their adven- 

 titia is thickened and fatty, their calibre diminished or closed. 



Some observers think the affection is due to disease of certain 

 limited portions of the posterior roots two lateral, thin, gray striae, 

 corresponding to the intermedullary extensions which Kolliker terms 

 inner root-filaments. According to Char cot, sclerosis of these lat- 

 eral striae is the only constant anatomical change. The sclerosis 

 may spread from the posterior columns to other parts, as the poste- 

 rior nerve-roots, or even to different nerves, as the sciatic, crural, 

 and brachial, but especially to some cerebral nerves, as the optic, 

 oculo-motor, trochlear, and hypoglossal. It may also extend to the 

 posterior horns of the gray substance, and to the lateral columns, 

 or to the gray anterior horns ; in which cases, of course, the symp- 

 toms will be varied. The disease may begin at any point of the 

 spine, but generally spreads in the long axis ; usually it begins in 

 the lumbo-dorsal region, and spreads along the lateral striae of the 

 posterior columns to the cervical region, or even to the cerebral 

 nerves and brain, as is shown by psychical changes and depression. 

 On the other hand, primary cerebral disease may be followed by 

 tabes, and it has been asserted that the progressive paralysis of the 

 insane sometimes chiefly affects the posterior roots. 



3. P. 308. 



In many tabes patients, sometimes as the first symptom, there is 

 impairment of vision, beginning as concentric limitation of the vis- 

 ual field in one eye, or sometimes as achromatopsia, gradually grow- 



