SECTION II. 



DISEASES OF THE SPINAL MARROW AND ITS 

 MEMBRANES. 



OHAPTEE I. 



HYP^EKEMIA OF THE SPINAL MARROW A1ST> ITS MEMBKANES. 



THEKE is hardly any doubt that the amount of blood contained in 

 the spinal marrow is subject to variation, and that hyperaemia and 

 anaemia modify its functions just as they do those of the brain. Never- 

 Iheless, the symptoms which we are in the habit of referring to an 

 abnormal amount of blood in the spine are not directly deduced from 

 comparison of the symptoms observed during life with the results of 

 autopsy, but from a priori reasoning. Moreover, in most autopsies no 

 attention is paid to the amount of blood in the spinal marrow, and its 

 estimation offers even more difficulty than is the case in the brain. 



Remarkable vascularity of the spinal medulla and its membranes 

 is most frequently found on autopsy of new-born children and of per- 

 sons who have died of spasmodic affections or of acute febrile diseases. 

 We also find varicose dilatations of the venous plexus in the lower 

 part of the spinal canal, as one of the symptoms of abdominal plethora 

 accompanying cirrhosis of the liver and other diseases that impair the 

 circulation in the abdomen. 



Hyperaemia of the spinal medulla itself leads to swelling and relax- 

 ation of its substance, and to the formation of small ecchymoses ; iu 

 higher grades there is softening of the medullary substance. Accord- 

 ing to Hasse, hyperaemia of the membranes induces increased transu- 

 dation, as a result of which there may be overfilling of the subarach- 

 noid space, extending from below upward as far as the skull. 



As symptoms of hyperaemia of the spinal medulla and its mem- 

 branes, the above author mentions a dull pain, mostly limited to the 

 sacral and lumbar regions, a feeling of numbness and formication in thp 



