187 



S>jm2Jtoms.—DroY7smcs5, vertigo, or attacks of giddiness, increased 

 timidity, or fear of familiar objects, paralysis of one limb, hemiplegia, 

 imperfect control of the limbs, and usually a weak, intermittent pulse. 

 In some cases tlie symptoms are analagous to those of apoplexy. The 

 character of the symptoms depends upon the seat of the softening or 

 abscess within the brain. 



CEREBRAL SCLEROSIS. 



This is a result of an inflammation in the structure of the brain af- 

 fecting the connective tissues, which eventually become hypertrophied 

 and press upon nerve cells and fibers, causing their ultimate disappear- 

 ance, leaving the parts hard and indurated. 



Symptoms.— This condition gives rise to a progressive paralysis, and 

 may extend aloug a certain bundle of fibers into the spinal cord. Com- 

 plete paralysis almost invariably supervenes and causes death. 



PATHOLOGY OF ACUTE BRAIN AFFECTIONS. 



On making j?osf ?>Jorfem examinations of horses which have died in 

 the first stages of either of those diseases, we will find an excessive en- 

 gorgement of the capillaries and small blood-vessels, with correspond- 

 ingly increased redness and molecular changes in both contents and 

 the walls of the vessels. If the death has occurred at a later period of 

 the disease, in addition to the redness and engorgement we will find 

 that an exudation of the contents of the blood-vessels into the tissues 

 and upon the surfaces of the inflamed parts has supervened. If the 

 case has been one of encephalitis we will usually find more or less wa- 

 tery fluid in the ventricles (natural cavities in the brain), in the sub- 

 arachnoid space, and a serous exudation between the convolutions and 

 interstitial spaces of the gray matter under the membranes of the brain. 

 The amount of fluid varies in different cases. In some where the ani- 

 mal's blood was very plastic, exudations of a membranous character 

 may be present and are found attached to the surface of the pia mater. 



In meningitis , especially in chronic cases, in addition to the serous 

 effusion, we find changes which may be regarded as characteristic in the 

 formation of a delicate and highly vascular layer or layers of membrane 

 or organized structure on the surface of the dura mater, and also indi- 

 cations of hemorrhages in connection with the membranous formations. 

 Hsematoma or blood tumors may be found embedded in this membrane. 

 In some cases the hemorrhages are copious, causing paralysis or 

 apoplexy, followed by speedy death. 



In cerebritis, or inflammation of the interior of the brain, there is a 

 tendency to softening and suppuration and the formation of abscesses. 

 In some cases the abscesses are small and numerous, surrounded vvith 

 a softened condition of the brain matter, and sometimes we may find 

 one large abscess. In cases of recent development the walls of the ab- 

 scesses are fringed and ragged and have no lining membrane. In older 



