MYELITIS. 297 



cavity, filled with serum and traversed by delicate connective tissue, 

 may be formed in the spinal medulla. In other cases there is in- 

 duration from connective-tissue proliferation. These sclerosed spots, 

 which are usually somewhat retracted and colored yellow by pigment, 

 form analogues to the yellow plates, which we found as remains of 

 peripheral encephalitis. 



In the second (central) form of myelitis we find the medulla but 

 little swollen at first. On section, the contours of the gray substance 

 appear lost ; it is somewhat darker in color, reddened, and less con- 

 sistent. In oldes and typical cases the spinal medulla is decidedly 

 swollen, and in its centre we find a thin reddish, rusty, or yellow pulp. 

 In this form, also, the tissue-elements, which have broken down to a 

 fine detritus, are sometimes reabsorbed, and fluid exuded in their place, 

 so that, at last, in the axis of the spinal medulla, there is a cavity filled 

 with serum, and surrounded by delicate connective tissue, or traversed 

 by a framework of the same. 



SYMPTOMS AND COURSE. Since acute myelitis is always accom- 

 panied by meningitis, it is also accompanied by the symptoms of spinal 

 meningitis described in the last chapter, and we can only decide, from 

 certain modifications of the symptoms there described, that the me- 

 dulla itself, as well as the meninges, is inflamed. In the commence- 

 ment of the disease there is usually severe fever and more or less ex- 

 tensive pain in the back and extremities, tetanic rigidity of the mus- 

 cles of the back and nape of the neck, contractions of the extremities, 

 alternating with convulsive attacks, and where the respiratory muscles 

 participate in the tetanic tension there is great dyspnoea. The more 

 circumscribed the pain in the back, the more distinctly the peripheral 

 pains and spasms are limited to the parts supplied by nerves from a 

 certain portion of the medulla ; but especially the earlier and more 

 completely paraplegia follows these symptoms of irritation, the more 

 probable it becomes that the spinal medulla itself is inflamed. In very 

 malignant cases these symptoms may get the upper hand very quick- 

 ly, and, even in the first days of the disease, the patient may die from 

 disturbance of the respiration. In other cases the storm passes over, 

 but a paraplegia remains, which hardly ever recovers. Cases running 

 the above course are rare, and are almost always of traumatic origin, 

 or result from perforation of an abscess into the vertebral canal. 



Chronic myelitis, also, is generally preceded by symptoms of irrita- 

 tion ; but, as the participation of the meninges in the tedious inflam- 

 mation of the spinal medulla is slighter and less extensive, they are 

 jsually limited to vague pains, formication, momentary twitching, or 

 painful contractions of the extremities. At the same time many pa- 

 tients complain of a dull pain in the part of the spine corresponding 



